Chapter 24 Potatoes


Link to New York Potato Crop Profile

See New York Potato IPM Elements

Link to Resource Guide for Organic Insect and Disease Management

24.1 Recommended Varieties

Golden
Nematode5
Nitrogen required7
Variety1
Skin color2
Maturity3
Use4
Scab6
Mineral
Muck
Allegany
W
L
T
R
MR
120-150
75
Andover
W
ME
C, T
R
MR
150-175
125
Atlantic
Bu
M
C
R
MR
120-150
100
Chieftain
R
M
T
S
MR
120-150
100
Eva
W
M
T,C
R
MR
150-175
125
Genesee
W
L
T
R
MR
120-150
100
Kanona
Bu
ML
C
R
VS
150-175
100
Keuka Gold9
Y
ML
T
R
R
120-150
100
Marcy
Bu
L
C
R
MR
100-125
75
Monona
W
M
C, T
S
MR
150-1758
1258
Norland
R
E
T
S
R
150-1758
1258
Norwis
W
ML
C, T
S
VS
120-150
100
Pike9
W
ML
C
R
R
120-150
100
Reba
W
M
C, T
R
MR
120-150
100
Redsen
R
E
T
S
MR
150-1758
1258
Salem
W
M
T
R
R
120-150
100
Snowden
Bu
VL
C
S
MS
120-150
75
Superior
Bu
ME
T
S
R
150-1758
1258
Yukon Gold
Y
M
T
S
VS
120-150
100

1: All potato varieties should be considered susceptible to late blight.
2: W = white; Bu = buff white; R = red; RUS = russet; Y = yellow
3: E = early; ME = medium to early; M = medium; ML = medium to late; L = late; VL = very late
4: T = tablestock; C = chipstock
5: R = resistant or S = susceptible to golden nematodes (Race Ro1)
6: R = resistant; MR = moderately resistant; MS = moderately susceptible; S = susceptible to scab; or VS = very susceptible
7: Nitrogen recommended in lb/acre
8: Apply no more than 100 lb of N/acre if an early harvest is desired.
9. May have internal necrosis in susceptible production areas.

 

New York Certified Seed Potatoes - 2008 Crop Directory


24.2 Planting Methods

Only certified seed (2008 Crop Directory) should be used. Diseased seed not only affects the plants that grow from it but puts the rest of the field and the whole farming operation at risk because many diseases can be spread by cutters, planters, and other equipment. In addition, diseased plants from affected seed tubers serve as the primary inoculum source from which other plants in the field can be infected as the inoculum is spread by wind, rain, and insect activity. This is the same risk posed by leaving cull piles exposed in the vicinity of production fields. A grower often cannot tell by looking at tubers whether they will be good for seed. Fortunately, the New York State Foundation Seed Certification Program can survey for these problems. Seed growers can obtain meristem-produced, disease-free plantlets or high quality seed from the Uihlein Foundation Seed Potato Farm at Lake Placid, which is administered by Cornell University. Seed producers are required to use a "flush-out" system, obtaining new seed from the state seed farm each year and producing a limited number of generations. Seed more than four or five generations old often poses a higher production risk for commercial use because repeated field exposure increases the probability of disease introduction and spread within a seed lot which may reduce yields significantly and pose a serious risk of other problems.

When handling seed, growers should maintain lot identity and prevent contamination. Trucks, storage, and handling equipment must be clean and disinfected between each lot of certified seed. Placing seed in storages that have been treated with chlorpropham (CIPC) may result in delayed or irregular sprouting, poor stand, and low yield.

Seed tubers should be stored at 40°F to prevent premature sprouting and dehydration. Tubers should be warmed to 50° to 60°F before being handled and cut. Curing cut seed is best accomplished by placing seed in half-full pallet boxes or spread out in piles only a few feet deep with adequate air circulation, temperature between 55° and 60°F, and about 90 percent relative humidity. After cut seed has been held at optimal curing conditions for one week, the storage temperature should be lowered to between 40° and 45°F to maintain vigor and avoid excessive sprout growth.

For most varieties grown in New York State, seed weight of 1 1/2 to two ounces is optimal. Cut seed should be blocky in shape to reduce the cross-sectional area and facilitate uniform planting by equipment. Mechanical seed cutters should be adjusted to seed size and shape, and seed should be graded to a uniform size before cutting. See Table 24.2.1.


Table 24.2.1 Potato seed (cwt) required to plant one acre.

Distance between
seed in row

34" between rows
Weight of seed pieces (oz)

36" between rows
Weight of seed pieces (oz)
1
1.5
1.75
2
1
1.5
1.75
2
inches
cwt
6
19
29
34
38
18
27
32
37
8
14
22
25
29
14
20
24
27
10
11
17
20
23
11
16
19
22
12
10
14
17
19
9
14
16
18
15
8
11
14
16
7
11
13
14

Chemical treatment is not a substitute for disease-free seed or good sanitation and handling, but it can reduce losses from disease when cut seed is held before planting or is planted into cold, wet soil. It can also prevent the introduction into noninfested soils of surface-borne organisms that cause diseases such as scab, Rhizoctonia, Verticillium wilt, and blackleg.

See Cornell report comparing farm ecosystem and management factors on organic and conventional farms


24.3 Fertility

Soils should be tested frequently for nutrient levels and pH. Many fields with a long history of potato production have accumulated large amounts of phosphorus and potassium (potash). Excessive levels of potash can depress specific gravity. Low soil pH reduces the availability of phosphorus and increases the availability of toxic elements such as iron and aluminum. To control common scab, soil pH should be kept within a relatively narrow range (5.0 to 5.2). If scab-resistant varieties are used, soil pH levels near 6.0 increase availability of phosphorus and other soil nutrients.

All lime and fertilizer recommendations should be based on soil test history. Mineral soils should have pH determined in calcium chloride and should have measurements made of iron, aluminum, and manganese in addition to the traditional measurements of phosphorus (P), potassium (K), and magnesium (Mg). See Table 24.3.1 for the recommended application rates of nitrogen, phosphorus, and potassium. If soil magnesium is below 100, apply 50 pounds of MgO per acre (30 lb magnesium per acre).

Cornell cover crop decision tool

Cornell article: "Closing the phosphorus cycle on vegetable farms: releasing soil-bound phosphorus to support springtime seedling growth."

Go to Cornell Nutrient Analysis Lab website to find out how to get soil samples tested.

Cornell Soil Health website and manual

SARE Publication: "Building Soils for Better Crops"

SARE publication: "Managing Cover Crops Profitably"


Table 24.3.1 Recommended application rate of nutrients based on soil tests.

N pounds/acre
P2O5 pounds/acre
K2O pounds/acre
Comments
Soil Phosphorus Level
Soil Potassium Level
low
med.
high
low
med.
high
very high
120-175
240
180
120
240
120
75
50
Broadcast and disk-in. Sidedress at first cultivation.
75-125
100
75
50
100
75
50
50
 
1: Apply 75-100 lb N/A in bands at planting, then apply remainder when plants are 4-8 inches tall. Reduce N rate by 75 lb/A if a good stand of clover or alfalfa is plowed down.
2: If pH levels are below 5.2 or iron plus aluminum levels are above 200, apply 240 lb phosphate/A regardless of soil phosphate level. Banded phosphate is more available than broadcast applications.

24.4 Harvesting

24.4.1 Enhancing Color of Red SkinnedVarieties

To enhance skin color of red skinned varieties, apply 2.3 oz of Riverdale 2,4-D L.V.4 Ester at bud stage. An additional application ten days later is allowable.The color of smooth skinned varieties such as chieftan is intensified by one or two applications. Color enhancement does not occur when 2,4-D is applied to clones with slightly netted skin.

24.4.2 Vine Killing

Chemical vine killing is used to aid in the harvest operation by desiccating potato vines and weeds and conditioning tubers to reduce bruising and skinning during harvest and handling. It also controls tuber size, minimizes incidence of hollow heart, and helps control diseases such as late blight and leafroll. Ideally, chemical vine kill should simulate natural plant death. Rapid plant death can cause vascular discoloration, and in severe cases, the tissue at the stem of the tuber can become sunken and discolored. This affects the outward appearance of the tuber and provides an entry for decay causing organisms. High rates of chemicals, dry soils, and warm temperatures encourage rapid vine kill. Use low rates of chemicals on hot, dry days and higher rates in cool weather. Do not allow vine killers to drift onto neighboring foliage or crops. Under good conditions, the time between vine killing and harvest is ten to 14 days. For specific chemicals and application rates, see Table 24.4.1.


Table 24.4.1 Vine killing compounds

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 

Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments

diquat dibromide

1-2 pt

24
12-24
Do not apply to drought stressed potatoes.  Make a second application if necessary to obtain dessication of dense vine growth.  A 5 day interval is recommended between applications.  Do not exceed a total of 4 pts. per acre.  Use a nonionic surfactant.
glufosinate-ammonium
Rely
3 pts 9 12 15.4 Not for use in Nassau and Suffolk Counties. Do not split application nor apply more than one application.  Do not apply to potatoes grown for seed.  Plant-back restrictions of 30 to 120 days for various crops.

†Not for use in Nassau and Suffolk Counties

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.4.3 Facility Sanitation
Facilities and handling equipment such as bin pilers should be cleaned and disinfected properly before potatoes are placed in storage. See Table 24.4.2. Bins or equipment treated with quaternary ammonium compounds must be rinsed with drinkable water before coming into contact with potatoes intended for human consumption. Structural, mechanical, and electrical problems should be identified and repaired before the storage area is filled. Check for breaks in moisture barriers and insulation to avoid cold spots during the winter.


Table 24.4.2 Disinfectants.


Common name
Trade name
Rate
Comments

sodium hypochlorite

5.25% chlorine bleach
(Clorox, Lysol, etc.)

1 gal/10 gal water

For use on machinery and floors.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.4.4 Curing and Storage
Cuts and bruises heal most rapidly under conditions described previously for precutting seed. High relative humidity at 50° to 60°F should be provided for two to three weeks at the beginning of the storage period. After this, the temperature should be gradually lowered to 40°F for tablestock or seed or maintained at 50°F for chipstock varieties such as Atlantic or Norchip or at 45°F for Kanona, Monona, or Snowden. When a condition such as field frost, late blight, or ring rot that favors decay is present, the curing period should be eliminated and the temperature dropped as soon as possible.

Desired storage temperature is best achieved with forced-air ventilation controlled thermostatically by an air proportioning system. Air flow should be uniform throughout the storage facility to maintain consistent temperature and oxygen levels. Air flow rates early in the storage season may range from a continuous flow of 1/2 to 1 cu. ft./cwt/min. with high relative humidity to enhance the curing process. Later a maintenance program should use an air flow of 1/2 to 4/5 cu. ft./cwt/min. as needed (five to ten percent of the time). If severe rot potential exists, continuous air flow rates as high as two cu. ft./cwt/min. may be required to cool and dry the tubers. Excessive air flow rates, however, particularly at low relative humidity, will dehydrate tubers and interfere with the wound healing process. Relative humidity in storage should be as high as possible without causing condensation on the tubers and the storage structure. Good insulation properly protected with a vapor barrier reduces the danger of condensation.

24.4.5 Sprout Inhibitors
Sprout inhibitors should be used in conjunction with good storage management. Although most potato varieties are dormant for two to three months after harvest, they will eventually sprout even in long-term cold storage. Two chemical sprout inhibitors are available to lengthen the storage period. Maleic hydrazide is applied as a field spray on green foliage two to three weeks after the full bloom stage. This material is translocated to the tubers and helps prevent sprouting. Chlorpropham (CIPC) is applied as an aerosol through the air ventilation system of the storage facility or as a spray on tubers on the packing line. For specific application rates, see Table 24.4.3. Because the normal warning signal of sprouting will have been suppressed, it is important to examine tubers in the center and at the base of the pile at frequent intervals during the storage season to make sure that storage rots, internal sprouting, or other disorders are not developing. Seed potatoes should not be treated with either material or stored in buildings where CIPC has been applied.


Table 24.4.3 Sprout inhibitors

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments

maleic hydrazide

Drexel Sprout Stop

1-1.33 gal/ 30-150 gal water

12
47
Apply to growing plants when the smallest tubers are 1.5" in diameter, except for Norchip, which must be at least 2" in diameter. Vines must remain green at least several weeks after application. Allow at least a 2 week interval before use of a vine killer. Do not use on seed potatoes.

2 gal/ 30gal water

12
47
chlorpropham (CIPC)

Sprout Nip

EC label

aerosol label

-

-
-
-
Apply directly to tubers. Use as a commercially applied aerosol treatment in storage or as an emulsifiable concentrate applied as a spray after washing tubers. Apply after cuts and bruises have healed (2-3 weeks after harvest). Under dosage may increase internal sprouting. Seed potatoes may show delayed sprouting if placed in treated storage, even if all treated potatoes are removed first. Federal law requires that shipping containers are labeled with the chemical name of this inhibitor.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)



Table 24.4.4 Nonpathogenic disorders.
Cornell fact sheet on detection of tuber diseases in potato


Disorder
Management Option
Recommendation

Variety selection

Andover and Norland are particularly sensitive varieties.

Hollow heart
(Florida fact sheet)
(Nebraska info)

Variety selection
Maintain uniform growing conditions.

Varieties differ in severity. Avoid growing oversized tubers. Utilize appropriate plant spacing. Irrigate and fertilizefor specific variety requirements.
Internal necrosis
(Florida fact sheet)

Variety selection
Minimize heat stress

Varieties differ in susceptibility. Irrigation reduces soil temperatures and increases calcium uptake.

Blackspot
(Idaho paper)
(Nebraska paper)

Avoid bruising tubers
Maintain tuber turgor
Minimize impact events during harvesting, transporting, grading, and handling. Store in high humidity and warm before handling operations.
Secondary tubers
Avoid old seed
Purchase good quality seed and keep in cold storage.

See non-infectious disease fact sheet from Alberta, Canada

See Cornell GAPsNET

See UC Davis post harvest guide for potatoes

See Cornell "Smart Marketing" series

See USDA grade standards for fresh potatoes, seed potatoes, processing potatoes, and chipping potatoes

See USDA Agricultural Marketing Service site

See current wholesale prices from US markets

See Cornell article on a New York Potato Promotion project

SARE Publication: "Marketing Strategies for Farmers and Ranchers"

SARE Publication: "Direct Marketing Resource Guide"


24.5 Disease Management

| Seed piece decay | Seedborne pathogens | Bacterial soft rot | Fusarium dry rot | Early blight | Late blight |
| Verticillium wilt | Fusarium wilt | Root rot | Canker & Black scurf | Botrytis vine rot |
| White mold | Nematodes | Golden nematode | Potato scab | Bacterial ring rot |
| Pink rot | Powdery scab | Leak | Silver scurf |

SARE Publication: "A Whole-Farm Approach to Managing Pests"

See Cornell article on assessing virus resistance in NY potatoes

24.5.1 Seed piece decay and seedborne pathogens
primarily caused by Fusarium dry rot, Rhizoctonia black scurf, Helmnthosporium silver scurf, common scab, and bacterial soft rot pathogens

See Cornell fact sheet on detection of tuber diseases in potato

See Cornell fact sheet on Fusarium dry rot

See Cornell fact sheet on Rhizoctonia disease of potato

Time for concern: Plant emergence
Key characteristics:

Management Option Recommendation
Resistant varieties No resistant varieties are available.
Site selection Seed planted into warm, well-drained soil will emerge faster.
Seed selection/treatment Seed quality is the most important factor in minimizing losses due to this disease. Plant only certified seed. Carefully inspect seed at the time of receipt. If possible, evaluate the seed before it is shipped. For a guide to potato seed evaluation see Reference 1. Seed treatment is the second most important consideration to optimize stand establishment and early-season growth. Seed should be warmed to 50ÉF before handling, cutting, or planting. New York Certified Seed Potatoes - 2008 Crop Directory
Planting Shallow planting and light cultivation to break up compact soil will increase soil temperature, improve oxygen levels around the seed piece, and speed plant growth.
Note(s) Physiological disorders due to lack of oxygen and cold temperatures during storage or transit contribute to seed piece problems and poor stand establishment.
Scouting/thresholds,
Crop rotation,
Postharvest, and
Sanitation
These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
Seed piece treatments
fludioxonil + mancozeb

0.5 lb /cwt

-
24
1-2/cwt
Use Maxim MZ (Groups 12 + M3) against Rhizoctonia black scurf, silver scurf,  black dot, Fusarium and seed piece late blight.  Also labeled for use for seed potato production.
flutolanil + mancozeb
Moncoat MZ

0.75-1 lb/cwt

-
24
<1/cwt
Use Moncoat MZ (Groups 7 + M3) against Rhizoctonia, Fusarium dry rot and seed piece late blight.
mancozeb

Potato Seed Treater PS

1-1.33 lb/cwt
-
24
0.9-1.2/cwt
 
1.25 lb/50gal
-
24
13.7/50 gal
Use mancozeb (Group M3) for Fusarium seed piece decay, for seed piece LB movement.
1 lb/cwt
-
24
0.9-1.2/cwt
To control Fusarium seed piece decay.  Plant as soon as possible after treatment.
imidacloprid + mancozeb
Gaucho-MZ 0.75 lb/cwt - 24 1/cwt Suppression of Fusarium dry rot, Rhizoctonia, and seed piece late blight. Aids in control of aphids, Colorado potato beetle and other insects.
imidacloprid + thiophanate-methyl + mancozeb
Tops-MZ-Gaucho 0.75 lb/cwt - 24 1.4/cwt Tops-MZ-Gaucho (fungicide Groups 1 + M3) has activity towards Rhizoctonia, silver scurf, Fusarium dry rot and seed piece late blight.  Aids in control of aphids, Colorado potato beetle, and other insects.
thiophanate-methyl + mancozeb + cymoxanil
Evolve 0.75 lb/cw - 24 2.1/cwt Evolve (Fungicide Groups 1 + M3 + 27)  has activity towards Rhizoctonia, silver scurf, Fusarium dry rot and better activity towards seed piece late blight.
thiophanate-methyl + mancozeb

Tops MZ

0.75 lb/cwt

-
24
2-2.7/cwt
Tops MZ (Fungicide Groups 1 + M3) has activity towards Rhizoctonia, silver scurf, Fusarium dry rot and seed piece late blight.
Trichoderma harzianum
T-22 HC 0.5-2 oz/cwt - 0 - For suppression of Rhizoctonia black scurf and stem canker.  Not effective in cool and wet soils.
In furrow treatments
azoxystrobin

In-furrow
0.4- 0.8 fl oz
1000 row
feet

-
4
<1
Quadris and Amistar (Group 11) are effective for control of Rhizoctonia, silver scurf and black dot. Use higher rate if field location is conductive for disease development or if potatoes are grown on muck soils.
Amistar 80 WDG

0.125-0.25 oz/1000 row feet

-
4
<1
flutolanil

**Moncut 70DF

0.71-1.1 lb/A

-
12
12-19
Not for use in Nassau/Suffolk Counties.  May leak into ground water.  Moncut (Group 7) is used for control of Rhizoctonia stem canker and black scurf.
pyraclostrobin

0.4-0.8 fl oz/1000 row feet

12
2.7-5.4/A
Use as an aid in the control of soilborne Rhizoctonia. If field has a history of Rhizoctonia, use at the higher rate and tank-mix with a fungicide with a different mode of action.
pentachloronitrobenzene (PCNB)

5-10 pts
(5.2-10.4 fl. oz/1000 row feet)

-
12

146-291/A

 

For Rhizoctonia control, apply in 10-20 gallons of water per acre based on a 34-inch row spacing. Spray an 8.5 inch band into seed furrow at time of planting.

OLF= Other labeled formulations.
** = Not for use in Nassau/Suffolk counties.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.2 Bacterial soft rot, Erwinia spp.

See Cornell fact sheet on detection of tuber diseases in potato

Time for concern: Between harvesting and marketing
Key characteristics: Bacteria may be present in lenticels, which appear as tan or water-soaked areas on the tuber surface. Advanced infections will be seen as soft rot of the tuber flesh. The amount of damage depends on the population of the bacteria on and in the seed, seed storage and handling practices, and variety susceptibility. See Reference 1.

Management Option Recommendation
Resistant varieties No resistant varieties are available.
Site selection Infection of the lenticels is common in saturated soils.
Seed selection/treatment Plant disease-free seed. New York Certified Seed Potatoes - 2008 Crop Directory
Harvest Avoid injuries to the tuber during harvest.
Note(s) Soft rot bacteria infects through the stolons or through lesions created by other disease organisms or wounds.
Postharvest The use of chlorine wash treatments can prevent the spread of decaying bacteria by killing the organism on contact. See Section 10.1 in the Postharvest Handling chapter. Provide good conditions for wound healing (55É to 60ÉF and 95 percent relative humidity, with good ventilation) for two to three weeks. Following the curing period, temperatures should be kept as low as possible. Do not move potatoes unnecessarily during the storage period because new wounds will be created. Severely affected tuber lots should not be stored.
Scouting/thresholds,
Crop rotation, and
Sanitation
These are not currently viable management options.

Compound(s)

Common name
Trade name     

Rate/A
    Product    
Comments
chlorine
AgClor 310

65-125 ppm

Add to wash water. The temperature of the water and the potato should be close. Follow the label. Water pH should be between 6 and 7.5.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.3 Fusarium dry rot primarily Fusarium sambucinum and Fusarium solani

See Cornell fact sheet on Fusarium dry rot

See Cornell fact sheet on detection of tuber diseases in potato

Time for concern: Planting, harvest, and postharvest
Key characteristics: Symptoms include sunken and shriveled areas on the surface of the tubers. The rot may extend to the center of the tuber and contain a fungal growth that is pink, white, or yellow. Affected tissue often becomes colonized by soft rot bacteria. See References 1 and 2.

Management Option Recommendation
Scouting/thresholds Inspect for Fusarium dry rot before pruchasing. If necessary, grade out affected tubers before cutting seed.
Note(s) The Fusarium dry rot pathogens have developed resistence to thiophanate-methyl.
Resistant varieties No resistant varieties are available.
Site selection Plant seed with a Fusarium problem in warm ground and cover with as little soil as practical.
Seed selection/treatment Purchase seed with as little dry rot as possible. Seed becomes more susceptible as the storage season progresses. Warm seed to at least 50ÉF before handling and cutting to minimize injury and promote growth. Bruising the seed during handling spreads the disease. Treat seed with a fungicide. Protect seed from wind and sunlight during planting because dehydration weakens seed. Cut only as much seed as can be planted within 24 hours. Cut with sharp knives and disinfect seed cutting and handling equipment often. Always disinfect between seed lots. Do not mix seed lots. New York Certified Seed Potatoes - 2008 Crop Directory
Harvest Harvest tubers after skins are set and when pulp temperature is greater than 50ÉF.
Postharvest The fungus infects through wounds at harvest. Avoid injuries to the tuber and provide conditions for wound healing in storage (55É to 60ÉF and 95 percent relative humidity with good ventilation) for two to three weeks. Following the curing period, temperatures should be kept as low as possible. Do not move potatoes unnecessarily during storage because new wounds will spread the disease.
Crop rotation and Sanitation These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
thiabendazole
Mertect 340-F
3.8 lb/gal

0.42 fl oz/2000 pounds

-
12
<1
Apply Mertect (Group 1) uniformly in a fine mist with water to each ton of potatoes as tubers pass over a bin loader.  Do not apply to cut tubers.  Note:  Fusarium resistance makes disease control unpredictable.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.4 Early blight, Alternaria solani, ,- minor for A. tomatophila

See Cornell fact sheet on early potato early blight

See Cornell fact sheet on detection of tuber diseases in potato

Organic management of early blight on solanaceous crops

Time for concern: Early to mid-July through harvest
Key characteristics: Leaf lesions are dark brown and appear leathery with faint, concentric rings giving a "target-spot" effect. Spots grow to 1/2 inch. Tuber infections appear as small, irregular, brownish black spots which are usually sunken. The rotted tuber tissue is firm, hard, and somewhat corky. Tuber infection is much less common than foliar infection. See References 1, 3, and 4.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of early blight. No thresholds have been established. NEWA makes daily calculations of P-days.
Resistant varieties Potato varieties differ in their susceptibility to early blight. Onaway is particularly susceptible.
Note(s) Environmental stress such as drought increases plant susceptibility.
Crop rotation

Minimum two year rotation without potatoes, tomatoes, or eggplants if severe outbreaks have occurred. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Seed selection/treatment Plant disease-free, certified seed. New York Certified Seed Potatoes - 2008 Crop Directory
Vine killing Infection to tubers can be reduced by allowing tubers to mature in the ground for at least two weeks after the vines die. Dig when the vines are dry.
Harvest Avoid wounding during harvest.
Sanitation Plow under all plant debris and volunteer potatoes immediately after harvest.
Site selection and
Postharvest
These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 

Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
azoxystrobin+chlorothalonil
Quadris Opti
1.6 pt

14

12
30.6
Resistance to QoI fungicides (which includes azoxystrobin) in A. solani isolates from potatoes has been identified in NYS. Although this resistance is not know to be widespread, the use of azoxystrobin as Quadris Opti would be a prudent method for early blight control while still retaining the benefits of this mixture for the control of late blight and black dot. Do not apply more than 1 sequential foliar application of this product or other strobilurin (Group 11) before alternating with a fungicide that has a different mode of action. Do not spray this product where spray drift may reach apple trees or use same sprayer to apply sprays to apple trees.
boscalid
Endura 70WDG
2.5-4.5 oz
30
12
5-7
Do not make more than two sequential applications Boscalid (Group 7) before alternating to a labeled fungicide with a different mode of action.
chlorothalonil

Bravo WS, Equus
or OLF
6 lb/gal

0.75-1.5 pt
7
12
16-33
Note eye wash requirement and reduced seasonal amounts for shortened reentry interval on label.
famoxadone + cymoxanil

Tanos 50 DF

6 oz
14
12
3.8
See comments below
Resistance to QoI fungicides (which includes famoxadone) in A. solani isolates from potatoes has been identified in NYS.  Although this resistance is not known to be widespread, the use of Tanos in a tank-mix with a protectant will retain the value of this product for early blight control. Tanos must be tank-mixed with an appropriate contact fungicide that has a different mode of action (eg. chlorothalonil [M5] or mancozeb, maneb or metiram [M3]), using at least the minimum labeled rate of each fungicide. Do not make more than one application of Tanos (Groups 11 + 27) before alternating to an effective fungicide with a different mode of action (other than Group 11). Also labeled for the control of Brown Spot (Alternaria alternata). For best results in controlling Brown Spot, tank-mix Tanos with a mancozeb or maneb fungicide.
fenamidone

(†) Reason 500 SC

5.5-8.2 fl oz
14
12
3-5
(†) Not for use or sale in Nassau or Suffolk Counties. See comments below.
For optimum results, begin applications of Reason (Group 11) when environmental conditions become favorable for disease development.  Do not make more than 1 application before alternating with a fungicide with good efficacy for control of Early Blight and the other diseases on the label.  Alternating fungicide should have a different mode of action (other than Group 11).
iprodione
Rovral 50WP
0.5 lb/lb

1-2 lb

14
24
6-11
Rovral belong to fungicide Group 2.
mancozeb
Dithane DF
or **OLF

0.75 lb/lb

1-2 lb

3
24
11-22
Apply up to 4 applications. For alternation and as tank-mix protectant.
maneb
Maneb 75DF
0.75 lb/lb
1.5-2 lb
3
24
24-32
For alternation and as tank-mix protectant.
Manex
4 lb/gal

1.2-1.6 qt

3
24
26-35
For alternation and as tank-mix protectant.
metiram
Polyram  80DF
0.8 lb/lb

1.5 - 2 lb

3
24
48-64
For alternation and as tank-mix protectant.
pyraclostrobin
Headline EC

6-9 fl oz

3
12
2.8-4.2
No aerial application in NYS.Resistance to QoI fungicides (which includes pyraclostrobin) in A. solani isolates from potatoes has been identified in NYS.  Although this resistance is not know to be widespread, the use of Headline tank-mixed with a protectant  fungicide like chlorothalonil, mancozeb, maneb or metiram would be a prudent method for early blight control while still retaining the benefits of pyraclostrobin for the control of late blight and black dot.  Do not apply more than 1 sequential foliar application of this product or other strobilurin (Group 11) before alternating with a fungicide that has a different mode of action.
pyrimethanil
Scala SC + protectant

7 fl oz

7
12
3.4 + protectant
Use Scala (Group 9) only in a tank mix with the recommended dose rate of another effective early blight fungicide.
trifloxystrobin
Gem 500 SC

2.9-3.8 fl oz

7
12
2.4-3.1
Not for aerial application in NYS. Resistance to QoI fungicides (which includes trifloxystrobin) in A. solani isolates from potatoes has been identified in NYS.  Although this resistance is not know to be widespread, the use of Gem tank-mixed with a protectant  fungicide like chlorothalonil, mancozeb, maneb or metiram would be a prudent method for early blight control while still retaining the benefits of trifloxystrobin for the control of late blight. Do not make more than one foliar application of this group 11 fungicide before switching to a fungicide with a different mode of action.
triphenyltin hydroxide + maneb

*Super Tin 80 WP or OLF+
Maneb 75DF
or **OLF

1.87 oz

8-16 oz

7
48

6.6 +

8-16

In addition to controlling blight, use of Super Tin or OLF (Group 30) may suppress Colorado potato beetle feeding and reduce egg laying and larval survival.  Note new maximum allowable amounts per season.  Higher rates of Super Tin or OLF (2.5-3.75 oz) are used when not combined with another fungicide registered for potato disease control.
zoxamide + mancozeb
*Gavel 75DF

1.5-2 lb

3
48
33-44
Begin application of Gavel (Groups 22 + M3) at first sign of disease.

* Restricted use only
** Other labeled formulations.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.5 Late blight, Phytophthora infestans

See Cornell fact sheet on potato late blight

See Cornell fact sheet on late blight of potato and tomato

See Cornell fact sheet on detection of tuber diseases in potato

Organic management of late blight on solanaceous crops

Late Blight Research at Cornell

Time for concern: Throughout the growing season and in storage
Key characteristics: The spores are commonly carried by wind, rain, and equipment. Lesions on leaves and stems become visible as small flecks within three to five days after infection. The infected tissue is initially water-soaked but becomes brown or black in a few days. Lesions are often surrounded by a halo of light green tissue. Under high humidity, sporulation is visible as a delicate, white mold surrounding the lesion. See References 1, 3, and 5.

Management Option Recommendation
Scouting/thresholds

Watch fields for the development of late blight. Start applications of fungicides when plants are six to eight inches high. Continue applications throughout the season and until vines are no longer green. Use disease severity values to monitor disease favorable conditions throughout the growing season via late blight network E-mail group. Contact extension office or IPM specialist for information about access.NEWA collects weather data on a daily basis and calculates late blight severity units for many potao gowing areas. See Reference 6.

Note(s) Late blight fungus has developed a resistance to metalaxyl (mefenoxam).
Resistant varieties Potato varieties differ slightly in their susceptibility, but commercial varieties do not have useful levels of resistance. The most susceptible varieties are: FL-1533, Monona, Atlantic, Superior, Norchip, and Shepody.
Site selection Avoid fields that cannot be effectively sprayed.
Hilling Proper hilling practices reduce the exposure of tubers to spores.
Vine-killing Proper vine-killing practices reduce the exposure of tubers to spores.
Seed selection/treatment Plant disease-free seed. New York Certified Seed Potatoes - 2008 Crop Directory
Postharvest Monitor storage potatoes for infection.
Sanitation Eliminate cull piles before plants emerge in the spring.
Crop rotation This is not a currently viable management option.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
azoxystrobin

Quadris F

6.2-15.4 fl oz

14
4
1-3
Do not apply more than 1 sequential foliar application of these products or other strobilurin (Group 11fungicides) before alternating with a fungicide that has a different mode of action.  If late blight symptoms favor disease increase, use higher rates on 5 day schedule.  Do not spray these three products where spray drift may reach apple trees or use same sprayer to apply sprays to apple trees.
Amistar
2-5 oz
14
4
2-4
azoxystrobin+chlorothalonil
Quadris Opti
1.6 pt

14

12
30.6
Do not apply more than 1 sequential foliar application of these products or other strobilurin (Group 11fungicides) before alternating with a fungicide that has a different mode of action.  If late blight symptoms favor disease increase, use higher rates on 5 day schedule.  Do not spray these three products where spray drift may reach apple trees or use same sprayer to apply sprays to apple trees.
chlorothalonil

Bravo WS, Equus
or OLF
6 lb/gal

0.75 -1.5 pt
7
12
16-33
Note eye wash requirement and reduced seasonal amounts for shortened reentry interval on label. For alternation and as tank mix protectant.
cyazofamid

Ranman 400 SC

1.4-2.75 fl oz

7
12
<1
See comments below
Note that Ranman (Group 21) is specific for late blight and requires a mixing partner for control of early blight (ie. tank mix with chlorothalonil [M5] or mancozeb[M3]).  Do not make more than three consecutive applications of Ranman before alternating to an effective fungicide with a different mode of action. For tuber blight control, make the last 2-3 applications prior to desiccation on a weekly schedule, using the 2.75 fl oz rate.
cymoxanil

Curzate 60 DF + protectant fungicide

3 1/3 oz

14
12
1
Curzate (Fungicide Group 27) provides locally systemic control but must be mixed with one of the protectant fungicides listed.   Works best early and mid-season when potatoes are actively growing.
dimethomorph
Forum SC + protectant fungicide
4.0-6.4 oz
4
12
3-4
Tank mix Forum (Group 15 fungicides) with a protectant fungicide but not with mefenoxam or metalaxyl products.  Rotate with other products labeled for LB control.  May be applied after vine-killing and at high rate offers suppression of tuber blight.
famoxadone + cymoxanil

Tanos 50 DF

6-8 oz
14
12
3.8-5.1
See comments below
Do not make more than one application of Tanos (Groups 11 + 27) before alternating to an effective fungicide with a different mode of action (other than  Group 11).  Tanos must be tank-mixed with an appropriate contact fungicide that has a different mode of action (eg. chlorothalonil [M5]or mancozeb, maneb or metiram [M3]), using at least the minimal labeled rate of each fungicide.  When weather conditions favor late blight or late blight is present in the area, use the 8 oz rate of Tanos and make fungicide applications on a 5-7 day schedule.
fenamidone

(†) Reason 500 SC

5.5-8.2 fl oz
14
12
3-5
(†) Not for use or sale in Nassau or Suffolk Counties. See comments below.
†Not for use or sale in Nassau or Suffolk Cos. For optimum results, begin applications of Reason (Group 11) when environmental conditions become favorable for disease development.  Do not make more than 1 application before alternating with a fungicide with good efficacy for control of Late Blight and the other diseases on the labeled.  Alternating fungicide should have a different mode of action (other than Group 11). Tuber blight control will result as a consequence of good foliar blight control, complete killing of vines before harvest, and proper tuber storage conditions.
mancozeb

Dithane DF 
or **OLF

0.75 lb/lb

1-2 lb

3
24
11-22
For alternation and as tank-mix protectant
mandipropamid + difenoconazole

Revus Top
2.08 lb/gal

5.5-7 fl oz/A

14
12
The addition of a non-ionic surfactant is recommended; do not make more than 2 consecutive applications before switching to an effective fungicide with a different MOA
maneb
Maneb 75DF
0.75 lb/lb

1.5-2 lb

3
24
24-32
For alternation and as tank-mix protectant
Manex
4 lb/gal

1.2-1.6 qt

3
24
19-25
For alternation and as tank-mix protectant
metiram
Polyram  80DF
0.8 lb/lb

2 lb

3
24
64
For alternation and as tank-mix protectant
phosphorous acid
Phostrol, ProPhyt or OLF, mixed with a protectant fungicide

2.5-10 pt in min. of 20-50 gal water

0
4
10-42
Also for suppression of storage rots like pink rot.
propamocarb hydrochloride
Previcur Flex SC + protectant fungicide

0.7-1.2 pt

14
12
10-17
Previcur Flex (Group 28) must be tank- mixed with protectant fungicide in order to control both late blight and early blight
pyraclostrobin
Headline EC

6-12 fl oz

3
12
2.8-5.6
No aerial application in NYS. Use a combination of pyraclostrobin with a protectant (chlorothalonil, mancozeb, maneb or metiram) for control of late blight while still maintaining control of early blight and black dot. Do not make more than one application of Headline before alternating to a labeled non-Group 11 with a different mode of action.
trifloxystrobin
Gem 500 SC

3.8 fl oz and tank mixed with a protectant

7
12
3.1 + protectant
Not for aerial application in NYS.Gem should always be applied in a tank-mix with chlorothalonil, mancozeb, maneb or metiram using at least 75% of the protectant labeled rate for late blight control, while retaining the control of early blight. Do not make more than 1 application of Gem (Group 11) before alternating with a fungicide with a different mode of action.
triphenyltin hydroxide + mancozeb

*Super Tin 80 WP or OLF +
Maneb 75DF or OLF

1.87 oz

8-16 oz

7
48

6.6 +

8-16

In addition to controlling blight, use of Super Tin fungicide (Group 30) may suppress Colorado potato beetle feeding and reduce egg laying and larval survival.  Note new maximum allowable amounts per season.
zoxamide + mancozeb
*Gavel 75DF

1.5-2 lb

3
48
33-44
Begin the application of Gavel (Fungicide Groups 22 + M3) at first report of disease or when late blight is reported in the area.  Usage can contribute to tuber blight protection.
Post Harvest Treatment
Phosphorous acid
Phostrol or OLF

13 fl oz in 1/2 gal of water

0
4
6.7/half gal
Use Phostrol or OLF (Group 33) for suppression of late blight and pink rot.  Ensure complete and even coverage.  Will not cure already infected tubers, but rather it will control further spread while in storage. Not recommended for fresh market tubers especially if enlarged lenticels are a problem.

* Restricted use only ** Other labeled formulations.
Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

Late Blight Research at Cornell

24.5.6 Verticillium wilt, Verticillium albo-atrum and V. dahliae

See Cornell fact sheet on detection of tuber diseases in potato

Ohio State fact sheet on Fusarium and Verticillium wilts on potato

Organic management of VW on solanaceous crops

Time for concern: Mid-season to harvest
Key characteristics: Wilt symptoms result from the growth of the fungus in the water-conducting tissues of the root and stem. Yellowing, wilting, and defoliation are the first symptoms. These typically occur on one side of a leaf or one side of the plant. When the affected stems are cut diagonally at the base, brown streaks are observed. See Reference 1.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of Verticillium wilt. No thresholds have been established.
Resistant varieties For tuber symptoms, late-maturing varieties are more resistant than early-maturing varieties. See Section 24.1 Recommended varieties. Superior is particularly susceptible.
Crop rotation

Rotation with grains reduces soil populations. The pathogen survives for several years without a host crop and will infect and reproduce on certain weeds. Rotate away from potatoes as frequently as possible. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Site selection,
Seed selection/treatment,
Postharvest, and
Sanitation
These are not currently viable management options.

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
metam sodium
Vapam HL
4.26 lb/gal

37.5-75 gal

Rate varies with application method and soil type. Fumigate in the fall or summer if land is fallow.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/) 

24.5.7 Fusarium wilt, Fusarium spp.

See Cornell fact sheet on detection of tuber diseases in potato

Ohio State fact sheet on Fusarium and Verticillium wilts on potato

Time for concern: Mid-season to harvest
Key characteristics:
Symptoms include tuber lesions and vascular discoloration. Wilting and chlorosis of the foliage is similar to Verticillium wilt. Laboratory isolation of the fungus is necessary for positive identification. See Reference 1.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of Fusarium wilt. No thresholds have been established.
Resistant varieties No resistant varieties are available.
Crop rotation Crop rotation is not useful because the fungi survive in the soil for long periods without host plants.
Site selection Avoid fields which have had severe outbreaks in the past.
Seed selection/treatment,
Postharvest, and
Sanitation
These are not currently viable management options.

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
metam sodium
Vapam HL
4.26 lb/gal

37.5-75 gal

Rate varies with application method and soil type. Fumigate in the fall or summer if land is fallow.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.8 Black Dot root rot, Colletotrichum coccodes

Cornell fact sheet on black dot

Time for concern: Growing season and into storage
Key characteristics:
This disease is also referred to as "black dot" because of the numerous black, fungal structures that appear on tubers, stolons, roots, and stems both above- and below ground. Root growth is reduced and appears brown to black in color. Tuber infection appears as brown to gray discoloration over a large part of the tuber surface or as round spots larger than 1/4 inch in diameter. See Reference 7.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of root rot. No thresholds have been established.
Note(s) Avoid plant stress, optimize soil moisture, and maintain adequate fertility. Tuber symptoms can be confused with and occur in conjunction with silver scurf.
Resistant varieties No resistant varieties are available, but late-maturing varieties are more vulnerable to yield reduction. Varieties that appear to be moderately resistant include Genesee, Keuka Gold, Lehigh, NorDonna, Norland, and Norwis, Varieties that are moderately susceptible to susceptible include Andover, Banana, Chieftain, Eva, Monona, Pike, Reba, Superior, and Yukon Gold.
Crop rotation

Minimum two year rotation to a grain crop. Try to manage solanaceous weeds during this period. Do not rotate with tomatoes. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Seed selection/treatment Plant disease-free seed. New York Certified Seed Potatoes - 2008 Crop Directory
Postharvest Deep plowing will bury infected debris and promote decomposition.
Site selection and Sanitation These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 

Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
azoxystrobin

Quadris F

6.2-15.4 fl oz

14
4
1-3
Do not apply more than 1 application of these products or other strobilurins (Group 11) before alternating with a fungicide that has a different mode of action such as chlorothalonil. Do not spray these products where spray drift may reach apple trees or use same sprayer to apply sprays to apple trees.
Amistar 80WDG
2-5 oz
14
4
2-4
azoxystrobin+chlorothalonil
Quadris Opti SC
1.6 pt

14

12
31
Do not apply more than 1 application of these products or other strobilurins (Group 11) before alternating with a fungicide that has a different mode of action such as chlorothalonil. Do not spray these products where spray drift may reach apple trees or use same sprayer to apply sprays to apple trees.
fenamidone

(†) Reason 500 SC

5.5-8.2 fl oz
14
12
3-5
(†) Not for use or sale in Nassau or Suffolk Counties. See comments below.
*Not for use or sale in Nassau or Suffolk Cos. For optimum results, begin applications of Reason (Group 11) when environmental conditions become favorable for disease development.  Do not make more than 1 application before alternating with a fungicide with good efficacy for control of Black Dot and the other diseases on the label.  Alternating fungicide should have a different mode of action (other than Group 11).
mancozeb
##Manzate 75DF

1-2 lb

3
24
11-22
##2(ee) Applications can begin when plants are 4-6 inches high using the lowest rate.  As vines increase in size, apply the higher rates.  Vine-kill should occur 14 days before harvest.
pyraclostrobin
Headline EC

6-9 fl oz

3
12
2.8-4.1
No aerial applicationin NYS. Do not make more than 1 application before alternating to a labeled fungicide with a different mode of action.

*Restricted use only (†) Not for use in Nassau/Suffolk Counties

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

23.5.9 Canker and Black scurf, Rhizoctonia solani

See Cornell fact sheet on Rhizoctonia disease of potato

See Cornell fact sheet on detection of tuber diseases in potato

Ohio State fact sheet on Rhizoctonia on potato

Organic management of black scurf on solanaceous crops

Time for concern: Growing season
Key characteristics: This fungus causes a variety of symptoms on tubers including cracking, malformation, and russeting. The black scurf symptom is common. The sclerotia may be flat and superficial or large, irregular, and lumpy. See References 1 and 8.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of canker. No thresholds have been established.
Note(s) If conditions are cold and wet, potatoes should be planted shallowly or planted deeply and covered shallowly. This encourages rapid emergence and reduces the chance of sprout burn.
Resistant varieties No resistant varieties are available.
Crop rotation

Minimum three year rotation to corn or grain crops. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Site selection Heavy, poorly-drained soils should be avoided.
Seed selection/treatment Plant disease-free, certified seed. Seed should be treated with a fungicide before planting or an in furrow treatment at planting. See seed piece decay section. New York Certified Seed Potatoes - 2008 Crop Directory
Vine-killing Minimize the time tubers stay in the soil after vine death.
Postharvest and
Sanitation
These are not currently viable management options.

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
metam sodium
Vapam HL
4.26 lb/gal

37.5-75 gal

-
-
-
Rate varies with application method and soil type. Fumigate in the fall or summer if land is fallow.

See Seed piece and in-furrow treatments in Section 23.5.1 for more treatments.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.10 Botrytis vine rot, Botrytis cinerea

Cornell Botrytis fact sheet

Oregon State gray mold ID fact sheet

Time for concern:
Key characteristics: This fungus infects dead tissue and can be seen as a fuzzy, gray growth on dead blossoms or senescent leaves. It is sometimes mistaken for late blight. Under wet conditions and when vine growth is lush, the fungus may move into the stem tissue. The stem rot is initially wet and slimy. The fungus sporulates on infected tissue and produces a dense, gray to off-white growth.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of Botrytis vine rot. No thresholds have been established.
Resistant varieties No resistant varieties are available.
Note(s) Nitrogen rates that result in excess vine growth aggravate this disease.
Site selection

Avoid planting in fields with soils that drain poorly.

SARE Publication: "Building Soils for Better Crops"

SARE publication: "Managing Cover Crops Profitably"

Crop rotation,
Seed selection/treatment,
Postharvest, and
Sanitation
These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 

Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
chlorothalonil

Bravo WS, Equus
or OLF
6 lb/gal

0.75-1.5 pt
7
12
16-33
Note eye wash requirement and reduced seasonal amounts for shortened reentry interval on label.
mancozeb
##Manzate 75DF

1-2 lb

3
24
11-22
##2(ee) For suppression of Botrytis

* Other labeled formulations.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

23.5.11 White mold, Sclerotinia sclerotiorum

See Cornell fact sheet on bean white mold (same organism)

UMAINE fact sheet on potato white mold

Organic management of white mold on solanaceous crops

Time for concern:
Key characteristics: The fungus is soilborne and generally infects stems at the soil line, but the infection may occur on any part of the plant. Symptoms include dense, cottony, white growth and the production of hard, black, irregularly-shaped sclerotia on infected tissue. This disease is not common on potatoes in New York.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of white mold. No thresholds have been established.
Note(s) Avoid excessive irrigation and high nitrogen rates.
Resistant varieties No resistant varieties are available.
Crop rotation

Rotation with grains reduces soil populations. Avoid rotations with beans. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Site selection,
Seed selection/treatment,
Postharvest, and
Sanitation
These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
boscalid
Endura 70WDG
5.5-10 oz
30
12
12-20
Do not make more than 2 sequential applications of Endura (Group 7) before switching to a  fungicide with a different mode of action.  Ground application is the preferred method to ensure thorough coverage.
Coniothyrium minitans

2-4 lbs/50-100 gals water

0
4
0.7-1.4
Apply biofungicide at least 3 months prior to anticipated white mold outbreak. Read label for details of soil application and incorporation which is critical for performance.
iprodione
Rovral
0.5 lb/lb

2 lb

14
12
11
Complete coverage is essential for control. Apply at first sign of disease or prior to row closure and repeat on a 14-21 day interval if the weather has been wet.
pyraclostrobin

6-12 fl oz

3
12
2.8-5.6
No aerial application in NYS.  Provides suppression only for white mold. Do not make more than 1 application of Headline (Group 11) before alternating with a fungicide with a different mode of action. 
thiophanate-methyl

1-1.5 lb

21
12
16-24
Make first application of Topsin M (Group 1) just prior to row closure, and repeat if conditions warrant.  Tank mix with other fungicides for early and late blight control.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

23.5.12 Potato scab, Streptomyces spp.

See Cornell fact sheet on potato scab

See Cornell fact sheet on detection of tuber diseases in potato

Cornell PDC fact sheet on potato scab

Organic management of scab on solanaceous crops

Time for concern: Flower to end of season
Key characteristics:
The symptoms run from superficial russeting to deep pitting. See References 1 and 9.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of potato scab. No thresholds are available.
Resistant varieties Planting resistant varieties in fields where scab has been a problem is useful, but not sufficient to prevent scab under high, disease pressure. Superior is the standard for resistance in the Northeast. Other resistant cultivars include Belchip, Centennial Russet, Norchip, Norgold Russet, Norland, and Onaway.
Crop rotation

Rotate away from potatoes and alternate hosts such as radishes, beets, and carrots. Plant grains, corn, or alfalfa. Avoid red clover. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Site selection Light-textured soils favor scab infection. Maintain pH levels below 5.2. Although severe scab occurs at high soil pH, there is an acid-scab which can occur in soils with a pH below 5.2.
Irrigation Maintain moisture during the six weeks following tuberization.
Sanitation Applying manure to potato fields can increase scab severity.
Seed selection/treatment and Postharvest These are not currently viable management options.
Compounds No pesticides are available to manage potato scab.

23.5.13 Bacterial ring rot, Clavibacter michiganensis subsp. sepedonicum

See Cornell fact sheet on detection of tuber diseases in potato

Ohio State fact sheet on bacterial ring rot

Time for concern: Seed purchase, planting, throughtout season, and at harvest
Key characteristics:
When infected tubers are cut crosswise, a creamy yellow to brown breakdown of the vascular ring is observed. Squeezing the infected tuber causes a cream-colored, cheesy exudate to ooze from the vascular ring. Secondary organisms attack infected tubers in storage and may cause skin cracks and a reddish brown discoloration. See Reference 1.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of bacterial ring rot. No thresholds have been established.
Resistant varieties No resistant varieties are available.
Seed selection/treatment Plant disease-free, certified seed. Serious crop losses can result if infected seed is used because the pathogen is readily spread during seed cutting and planting operations. New York Certified Seed Potatoes - 2008 Crop Directory
Planting Disinfect equipment and containers between seed lots. See Table 24.4 Disinfectants.
Sanitation All tuber handling equipment and storage areas must be disinfected if this disease occurs.
Crop rotation,
Site selection, and
Postharvest
These are not currently viable management options.
Compound(s) No pesticides are available to manage bacterial ring rot.

 

25.5.14 Pink rot, Phytophthora erythroseptica

See Cornell fact sheet on detection of tuber diseases in potato

Ohio State fact sheet on pink rot and leak

Time for concern: Growing season through marketing
Key characteristics: External symptoms appear around the stem end or eyes and lenticels. The infected area turns purple to dark brown with a black band. Tubers become rubbery or spongy and exude a liquid when squeezed. When cut, the infected tissue turns pink in a matter of minutes, then darkens to brown and finally to black. See Reference 1.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of pink rot. No thresholds have been established.
Resistant varieties No resistant varieties are available. Varieties that appear to be moderately resistant include Andover, Atlantic, Keuka Gold, Marcy, Norwis, Pike, Snowden, and Superior. Varieties that are moderately susceptible or susceptible include Allegany, Chieftain, Eva, Lehigh, NorDonna, Norland, Reba, Red LaSoda, and Yukon Gold.
Site selection This disease is favored by cool weather and wet soils. Avoid planting in poorly drained areas.
Seed selection/treatment Plant disease-free seed.New York Certified Seed Potatoes - 2008 Crop Directory
Postharvest This pathogen will spread in storage if tubers are not kept dry.
Crop rotation and
Sanitation
These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
cyazofamid

In-furrow 0.42 floz/1,000 linear ft in min 5 gal water

Hilling or Foliar 2.75 fl oz

7
12
A side dressing of Ranman in combination with a PO3 material applied at hilling may be necessary for additional control. Where no mefenoxam-resistant strains of pink rot are present, the  full foliar  rate of Ranman (2.75 fl oz) can be tank-mixed with mefenoxam-containing fungicides for additional control.
mefenoxam Apply Ridomil Gold EC or OLF (Group 4) as a 6-8 inch band at planting in a minimum of 3 gals. of water.  See label for details.  Only for use at-plant-stage to prevent resistance development.  Resistance  to  mefenoxam is present in some strains of the pink rot fungus in New York.  Supplement this treatment with foliar application of Ridomil Gold Bravo or OLF (Groups 4 + M5) at flowering and again 2 weeks later if conditions are warranted as noted on the label.

Ridomil Gold EC
or OLF

In-furrow 0.42 oz/1000 linear feet

48
mefenoxam + copper hydroxide

Foliar
2 lb

14
48
43
mefenoxam + mancozeb

2.5 lb

3
48
58.8
mefenoxam + chlorothalonil

2 lb

14
48
60.4
phosphorous acid

In-furrow 3.75-10 pts in min 3 gal water

Foliar
2.5-10 pt in min 20 gal water

 

0
4

15-41

 

 

10-41

For suppression of storage pink rot, combine the in-furrow treatment of Phostrol or OLF (Group 33) with a mefenoxam fungicide (if no resistance occurs) or consider Ranman. Additional in-season foliar applications of Phostrol or OLF tank mixed with a mefenoxam (if no resistance occurs) or with Ranman may be necessary.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.15 Powdery scab, Spongospora subterranea

See Cornell fact sheet on detection of tuber diseases in potato

Time for concern: Cold, wet seasons, growing season through marketing
Key characteristics: Lesions are similar to common scab lesions, but have a powdery texture due to the olive green to brown spore mass produced by the fungus at harvest. Lesions are first visible as purple spots on the tuber surface then as cankers without spore masses. This fungus (protozoan) is the vector for potato Mop Top virus. See Reference 1.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of powdery scab. No thresholds have been established.
Resistant varieties In a study conducted in Pennsylvania, Norchip showed some resistance.
Site selection Avoid planting in low spots with poor drainage.
Seed selection/treatment Plant disease-free seed.New York Certified Seed Potatoes - 2008 Crop Directory
Crop rotation,
Postharvest, and
Sanitation
These are not currently viable management options.
Compound(s) No pesticides are available to manage powdery scab.

24.5.16 Leak, Pythium spp.

See Cornell fact sheet on detection of tuber diseases in potato

Ohio State fact sheet on pink rot and leak

Time for concern: Harvest
Key characteristics: External symptoms consist of gray to brown lesions with water soaked appearance around wounds or near the stem. A freshly cut affected tuber turns reddish tan, then brown, and finaly black. See Reference 1.

Management Option Recommendation
Scouting/thresholds If fields have been flooded, scout for infection. No thresholds have been established.
Resistant varieties No resistant varieties are available.
Seed selection/treatment Plant disease-free seed.New York Certified Seed Potatoes - 2008 Crop Directory
Harvest Avoid harvesting immature tubers during hot or wet weather.
Postharvest Keep storage temperature low (40 to 45 F) if the disease is detected..
Crop rotation, Site selection, and
Sanitation
These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
mefenoxam Apply Ridomil Gold EC or OLF (Group 4) as a 6-8 inch band at planting in a minimum of 3 gals. of water. Can be supplemented with a phosphorous acid product. See label for details. Only for use at-plant-stage to prevent resistance development. Supplement this treatment with foliar application of Ridomil Gold Bravo or OLF (Groups 4 + M5) at flowering and again 2 weeks later if conditions are warranted, as noted on the label.

Ridomil Gold EC
or OLF

In-furrow 0.42 oz/1000 linear feet

48
mefenoxam + copper hydroxide

Foliar
2 lb

14
48
43
mefenoxam + mancozeb

2.5 lb

3
48
58.8
mefenoxam + chlorothalonil

Ridomil Gold Bravo or OLF

2 lb

14
48
60.4
phosphorous acid

Phostrol, ProPhyt or OLF mixed with mefanoxam

In-furrow 3.75-10 pts in min 3 gal water

Foliar
2.5-10 pt in min 20 gal water

 

0
4

15-41

 

 

10-41

For suppression of leak, combine the in-furrow treatment of Phostrol or OLF (Group 33) with a mefenoxam fungicide (Group 4). Additional in-season foliar applications of Phostrol or OLF tank mixed with a mefenoxam containing fungicide may be necessary.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.17 Silver scurf, Helminthosporium solani

See Cornell fact sheet on silver scurf

See Cornell fact sheet on detection of tuber diseases in potato

Time for concern: At planting and through growing season
Key characteristics: Silver scurf infects only the skin of the potato. Symptoms appear at the stolon end as small, pale, brown spots. Severe browning of the surface layers of tubers may occur, followed by sloughing-off of the outer layers of the periderm. Lesions are circular. The silvery appearance of older lesions is most obvious when the tubers are wet. See References 1 and 10.

Management Option Recommendation
Scouting/thresholds Lesions may be difficult to detect at harvest. Tubers often develop symptoms in storage.
Resistant varieties No resistant varieties are available.
Seed selection/treatment Plant disease-free seed. Fludioxonil + mancozeb (Maxim MZ) and thiophanate-methyl + mancozeb (Tops MZ) are registered as seed treatments and Quadris as an in-furrow treatment. See seed piece decay section. New York Certified Seed Potatoes - 2008 Crop Directory
Harvest Harvest tubers early. Vine killing 2-3 weeks before harvest showed less silver scurf than when tubers were harvested green.
Postharvest High relative humidity (90-95%) and warm temperatures (47-56°F) favor the development and spread of silver scurf in storage. Lowering the temperature to 39-45°F and the relative humnidity to 85-90% as quickly as possible in the first month of storage can delay sporulation. Disinfect storages to kill spores that remain from the previous year's crop.
Crop rotation

Soil-borne inoculum has been implicated in the seasonal occurence of silver scurf. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Site selection, and
Sanitation
These are not currently viable management options.
Compound(s) See seed piece treatment to manage silver scurf.

Compound(s)
Common name

Trade Name  Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
See seed piece and in furrow treatments in Section 23.5.1


23.5.18 Nematodes, primarily northern root-knot (Meloidogyne hapla) and the lesion (principally, Pratylenchus penetrans)

Time for concern: Before and during planting
Key characteristics: Both the root-knot nematode and the lesion nematode are widespread in New York soils and at high populations can cause significant yield losses for potatoes. Damage from these nematodes is especially high on sandy and organic soils as well as in poor health soils. The populations and damage of lesion nematodes has steadily increased in recent years, probably due to the increase use of grains as cover and rotational crops to improve soil quality and health. In addition, lesion nematode even at low soil population interacts with Verticillium dahliae in causing the early dying disease. Potato serves as a good host for both nematodes and is thus not a desirable host to have in a rotational crop program. The diagnostic symptoms are found on the fine fibrous roots as galls or root thickenings of various sizes. Similarly, above-ground symptoms of potatoes infected with lesion nematodes are of general stunting and infected roots may or may not show brown to black lesions. The presence of nematodes in roots or in soil around roots is the only definitive evidence of their involvement.

Management Option Recommendation
Scouting/thresholds Record symptoms of damage and assay roots and soil for the presence and density of nematodes. Threshold level of root-knot nematode on potatoes in organic soil is between 4-8 eggs/cc soil. A density as low as 1 lesion nematode/cc soil has caused damage to potatoes.

"How to" instructions for soil sampling for nematode bioassays

"How to" instructions for farmers to conduct a field test for root knot nematode using lettuce

"How to" instructions for farmers to conduct a field test for root lesion nematode using soybean

See article about on-farm method of assessing nematode population

Resistant varieties No resistant varieties are available.
Crop rotation Both nematodes have a wide host range, thus it is difficult to design a practical, economic, and effective crop rotation. Grain crops such as wheat, rye, oats, barley, corn, and sudangrass are not hosts for the root-knot nematode. However, onion, carrot, lettuce, celery, soybeans, clover, alfalfa, and beans are good hosts to the root-knot nematode. All grain crops are good hosts to lesion nematode, except a number of cultivars of ryegrass and forge pearl millet. In addition, most cultivars of clovers, soybean, alfalfa, vetch and beans are also good hosts to lesion nematode.

Crop rotation and disease management article

Cornell article: "Cropping sequences and root health"

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Cover Crops

All the grain crops listed above are suitable for use as cover crops against the root-knot nematode. Sudangrass is a non-host to root-knot nematode, but is a host to lesion nematode. However, the soil incorporation of green manure of sudangrass before the first frost will reduce the population of both nematodes and their damage to potatoes. Certain white clover and flax lines have given similar results. Also, cruciferous crops including rapeseed, mustard, oil seed radish and others are effective in reducing populations of these nematodes when incorporated as green manures in warm soils.

See Cornell reports on the impact of using green maure crops on nematode populations 2002, 2003,

Sanitation Wash equipment after use in infested fields.
Seed selection/treatment Select vigorous, disease free and properly treated seeds. .New York Certified Seed Potatoes - 2008 Crop Directory
Soil Treatment Where economical and possible, the use of pre-plant soil fumigants (Telone, Vapam) is highly effective in controlling root-knot and lesion nematodes. Of the nonfumigant-type nematicides, only *†Vydate has been registered for use on potatoes under a special Local Need (24C) labeling for in-furrow use as well as foliar applications. See below for details.
Site selection and Postharvest
These are not currently viable management options.

Compound(s)

Cornell article: "General guidelines for managing fungicide resistance"

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
oxamyl

†*Vydate C-LV
2 lb/gal

2.1-4.2 pts/A, in-furrow

7 days before digging
48
20-40
Not for use in Nassau/Suffolk Counties.  24cfor in-furrow application: Apply †*Vydate C-LV as a concentrated band spray in the seed row with the spray nozzle positioned behind the planter tube. Adjust nozzles so that a spray pattern is 6-8 inches wide to cover the bottom and sides of the furrow.

Check NYS PIMS (Product, Ingredient, and Manufacturer System) to see if the label is current for New York. SPECIAL NEW YORK RESTRICTIONS MAY APPLY. (http://magritte.psur.cornell.edu/pims/)

24.5.19 Golden nematode, Globodera rostochiensis

USDA/APHIS Golden nematode information

Time for concern: Throughout the growing season
Key characteristics: This is a regulated pest.

Management Option Recommendation
Scouting/thresholds Record the occurrence and severity of a golden nematode infestation. No thresholds have been established.
Resistant varieties Plant resistant varieties. See Section 24.1 Recommended Varieties.
Crop rotation

Rotate away from solanaceous crops. Be sure to minimize the number of solanaceous weeds in the field. Crop rotation and disease management article

Cornell cover crop decision tool

Cornell Forage Species Selection Tool

Seed selection/treatment Plant disease-free, certified seed. New York Certified Seed Potatoes - 2008 Crop Directory
Site selection, Postharvest, and Sanitation These are not currently viable management options.
Compound(s) No pesticides are available to manage golden nematodes.

24.6 Insect Management

| Insecticide Resistance Management | Aphids | Colorado potato beetle | Variegated cutworms |
| Subterranean & surface cutworms |European corn borer | Flea beetle | Potato leafhopper |
| Symphylan | Wireworms | Spider mites | Slugs &Snails

SARE Publication: "Manage Insects on Your Farm: A Guide to Ecological Strategies"

SARE Publication: "A Whole-Farm Approach to Managing Pests"

Table 23.6.1 Insecticide Resistance Management

Genetic resistance to insecticides is an inherited change in the sensitivity of a pest population that is reflected in the failure of a product to achieve the expected level of control.  The objective of insecticide resistance management (IRM) is to prevent or delay the onset of resistance or to help regain susceptibility in insect pest populations. In practice, alternations, sequences or rotations of insecticides from different IRM classes (modes of action) reduce selection for resistance in any one class and prolong the effective life of compounds having that mode of action.

Mode of Action

IRM Class

Chemical Class

Chemical Name

Trade Name

Acetyl Cholineesterase Inhibitors

1

Carbamates 

carbaryl

Sevin XLR Plus

carbofuran

†*Furadan 4F

methomyl

*Lannate LV

oxamyl

†*Vydate L

Organophosphates

dimethoate

Dimethoate 400

ethoprop

†*Mocap

methamidophos

*Monitor 4

methyl parathion

*Penncap M

phorate

†*Thimet 20G

phosmet

Imidan 70WP

Gaba-Gated Chloride Channel Antagonists

2

Cyclodienes

endosulfan

*Thionex 3EC

Sodium Channel Modulators

3

Pyrethroids

bifenthrin

*Brigade 2EC, *Capture 2EC

cyfluthrin (beta)

*Baythroid XL, *Renounce 20WP

cyhalothrin (lambda)   *Warrior II

esfenvalerate

*Asana XL

permethrin

*Ambush 25W, *Pounce 25WP

Nicotinic Acetylcholine Receptor Agonists

4

Chloronicotinyl

acetamiprid

Assail

*imidacloprid

*Admire Pro, *Provado 1.6F, Generic imidacloprid

Nicotinic Acetylcholine Receptor Allosteric Activators

5

Spinosyns

spinosad

Entrust, SpinTor

Spinetoram Radiant SC

Chloride Channel Activators

6

Abamectin

abamectin

*Agri-Mek, *Abba

Selective Homopteran Feeding Blocker
9B
Pymetrozine pymetrozine Fulfill
9C
Flonicamid flonicamid Beleaf 50 SG

Microbial Disruptors of Insect Midgut Membranes

11

Bacillus thuringiensis

Bt

Novodor

Moulting Disruptor (Dipteran)
17
Cyromazine cyromazine Trigard

Voltage Dependent Sodium Channel Blockers

22

Oxadiazines

indoxacarb

Avaunt

Multiple Modes of Action (Mixture of several active ingredients)

Chloronicotinyl and Pyrethroid

imidacloprid
cyfluthrin

*Leverage 2.7

Unknown Mode of Action

 

 

Azadirachtin

azadirachtin

Ecozin, 3EC, Neemix 4.5

Bifenazate bifenazate Acramite 4SC

Cryolite

sodium aluminofluoride

Kryocide, Prokil Cryolite 96

 

24.6.1 Colorado potato beetle (CPB), Leptinotarsa decemlineata

See pictures of CPB damage
See pictures of CPB life cycle

Organic management of CPB on solanaceous crops

Time for concern: Late April through vine-kill
Key characteristics: The adults have alternate black and yellowish orange stripes that run lengthwise on the wing covers, five of each color on each wing. The beetles are 3/8 inch long by 1/4 inch wide and convex in shape. The eggs are yellowish orange and deposited in clusters on the underside of leaves. Egg masses contain between 20 and 40 eggs. Larvae are small, humpbacked, and red with two rows of black spots on each side of their body. See Reference 11 and http://www.nysaes.cornell.edu/ent/factsheets/.

Management Option Recommendation
Scouting/thresholds Take a representative sample of the field weekly. Sample five vines at five sites. Count the number of adults, small larvae (less than 1/4 inch), and egg masses. Count egg masses with less than ten eggs as half an egg mass. If the number of CPB in a particular life stage falls within the range given below or if the field is >30 acres, sample 25 more vines. The basic sample unit should be a plant "hill" until plants are 12 inches in height and a single mainstem the remainder of the season.
Life stage Number of CPB counted on 25 vines
  LOW INTERMEDIATE HIGH
  Stop   Stop
  Compute Mean Sample 25 more Vines Compute Mean
Small larvae <52 53-199 >200
Large larvae <22 23-67 >68
Adults <7 8-22 >23

If scouting only 25 samples (5 sites) walk through the other 5 sites to verify pest densities. If any counts are in the intermediate range, sample 25 more plants and compute the means. Don't sample more than 50 vines per field. Report numbers of adults and larvae per 50 vines. If hot spots are found, flag them and apply insecticide.

  Thresholds/50 Vines:
Egg masses Avaunt, Bt, Cryolite, Neem, Trigard insecticides: 4 with at least 25% of the earliest deposited egg masses hatched or in the process of hatching
Small larvae 200 (76 if using Avaunt, Bt, Cryolite, Neem or Trigard)
Large larvae 75 (31 if using Avaunt, Bt, Cryolite, Neem or Trigard)
Adults 25
Resistance management

Given the phenomenal ability of the CPB to develop resistance to insecticides, a major goal in managing this pest is to delay the onset of resistance. In areas where levels of resistance are low and most labeled insecticides provide effective management, we suggest rotation of insecticides from different chemical classes and modes of action. See Table 3.2.1 Registered insecticides by crop. The goal is to differentially target specific generations. This can be done in the following manner:

Before July 15

Overwintered Adults (pyrethroids + PBO)

1st Larval Generation (neem, Bacillus thuringiensis, cryolite, pyrethroids + PBO, spinosyns, Trigard)
After July 15 Summer adults (carbamates, organophosphates, endosulfan) 2nd larval generation (Bacillus thuringiensis, carbamates, imidacloprid, abamectin, organophosphates, endosulfan)

To minimize selection for resistance, only use insecticides when needed; make foliar applications; use the minimum dosage necessary to provide control; rotate insecticides of different chemical classes and modes of action; create refuges untreated by insecticides where susceptible populations can survive to mate with resistant individuals and dilute the frequency of resistant genes in pest populations.

A classification of insecticides based on their mode of action is available in pdf format. This guide can be used to help avoid or delay the development of insecticide resistance, as well as manage populations that have developed resistance to a particular insecticide. It is a large file - 97 page, 780k pdf file 

Shelton, A.M., W.T. Wilsey, and D. M. Soderlund. 2001. Classification of insecticides and acaracides for resistance management

Bt and other relatively slow-acting larvicides If use of a Bt insecticide or another relatively slow-acting larvicide (e.g. Avaunt, cryolite, neem, Trigard) is anticipated, the field should be sampled at two to four day intervals during the period of initial egg hatching when the daily high temperature is above 70°F for two or more days. An application should be made within one or two days if the threshold conditions for egg masses or small larvae have been reached. Satisfactory management of the first larval generation can usually be achieved with several applications of these products at five to seven day intervals during the period of egg hatching.  Note:  Bt products will not control other pests.
Neonicotinoid insecticides (*Admire,* Advise, *Alias, Assail,* Couraze, * Impulse, *Macho, *Montana, *Nuprid, *Pasada, *Prey, *Provado, *Widow) The primary use of these insecticides should be in management of CPB. Growers may sometimes achieve practical season-long control of CPB with one soil application of a neonicotinoid product at planting or one to three foliar applications of these products. To minimize selection for resistance, use the following guidelines: never rely exclusively on neonicotinoid insecticides; use these products with other management tools; do not use Assail or imidacloprid products on a field that was treated with a neonicotinoid at planting; for nonrotated fields, do not use neonicotinoids more than once every two years; avoid using Assail or imidacloprid products just prior to or during dispersal of summer adults to winter hibernation sites and never use Assail or imidacloprid products strictly for control of leafhoppers or aphids.
Imidacloprid insecticides This class of insecticide that has no known cross resistance. Its primary use should be the management of CPB. Growers can expect to achieve practical season-long control of CPB with one soil application of Admire at planting or one to three foliar applications of Provado. To minimize selection for resistance, use the following guidelines: never rely exclusively on Admire and/or Provado; use these products with other management tools; do not use Provado on a field that was treated with Admire at planting; for nonrotated fields, do not use Admire or Provado more than once every two years; do not use Provado just prior to or during dispersal of summer adults to winter hibernation sites; and never use Admire or Provado strictly for control of leafhoppers or aphids.
Cryolite insecticides These insecticides are insoluble in water and applied as suspensions. They should be added to the spray tank slowly with constant agitation and recirculation. They are abrasive and damaging to roller-type pumps and nozzles. Ceramic or stainless steel nozzles are preferred. They provide excellent control of larvae less than 1/4 of an inch, but are subject to wash-off by irrigation or rain. For maximum effectiveness, residues should not be subject to irrigation or rain for at least 24 hours following application. These insecticides will not provide control of other pests. Natural enemies Naturally-occurring predators, parasitoids, and pathogens help suppress infestations. Use Reference 12 for identification of natural enemies.
Resistant varieties Elba, Prince Hairy and King Hairy are resistant to CPB's.
Crop rotation One year rotation to small grains or corn can result in greater than 90 percent reduction of early-season adult infestation. Rotation is most effective when large blocks are rotated on a farm or coordinated among adjacent farms. Avoid rotation to tomatoes, eggplants, and other species belonging to the solanaceae family. Minimize the presence of volunteer potatoes in rotational crops by avoiding fall plowing and through the use of sprout inhibitors. Plant slow-emerging or late-season cultivars to fields that did not have potatoes the previous year.
Site selection Avoid planting potatoes in fields where late-season cultivars with high CPB populations were grown the previous year. If these fields must be planted, grow a rapid-emerging, early-maturing cultivar.
Flaming Adult CPB's overwinter in hedgerows and wooded areas adjacent to potato fields. Flaming is most effective when used around the borders (the outside eight to 16 rows) of the field. However, in the case of widespread colonization by adults, flaming is more successful when used throughout the field. The most effective time to use a propane flamer is from plant emergence until the plants reach six inches in height. Best control is achieved on warm, sunny days with little wind when adults are actively feeding in the upper foliage. Flaming is ineffective when done in the early morning, late evening, or on cool, cloudy days. Burners should be operated eight to ten inches above the soil at four to six miles per hour. Plant injury from flaming is minimal and does not reduce yields. Video tapes detailing flaming are available. See Reference 13.
Trap crop Plant trap strips along the edges of the field as early as weather and soil conditions will allow. Cover seed shallowly to promote rapid emergence. Flame and vacuum control methods are recommended for treatment of the trap crop.
Natural Enemies

Naturally-occurring predators, parasitoids, and pathogens help suppress infestations. Use Reference 12 for identification of natural enemies. Coleomegilla maculata lengi, Lebia grandis, Podisus maculiventris, Perillus bioculatus, Chrysoperla, Edovum puttleri, Myiopharus aberrans, Myiopharus doryphorae, Bacillus thuringiensis var. tenebrionis, Beauvaria bassiana, Steinernema carpocapsae, Heterorhaditis bacteriophora, Phalangium spp.

Michigan State site "Enhancing Beneficial Insects with Native Plants"

ATTRA publication: "Farmscaping to enhance biological control"

Trench trap Install plastic-lined trench traps next to hibernation sites or between adjacent fields at least one week before adults emerge. Trenches should be one to two feet deep and six to 24 inches wide at the top. They can be U or V shaped with side walls sloping at angles between 65 and 90 degrees. Level the crown at the top of the trench and line the trench with mulching plastic. For a more detailed description, see Reference 13.
Seed selection,
Postharvest, and
Sanitation
These are not currently viable management options.

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
Seed Piece Treatment

imidacloprid

*Admire Pro
4.6 lb/gal
0.17-0.35 fl oz/100 lb of seed-pieces
-
12
0.2-0.4/ 100 lb seed

Apply as diluted spray onto seed pieces using a shielded spray system.  Do not make a subsequent application of  imidacloprid (in-furrow or foliar) following an imidacloprid seed-piece treatment.

*Advise 2FL, *Alias 2F
*Macho 2.0 FL,
*Montana2F,
*Widow
2lb/gal
0.4-0.8 fl oz/100 lb of seed-pieces
-
12
0.2-0.4/ 100 lb seed

Apply as diluted spray onto seed pieces using a shielded spray system.  Do not make a subsequent application of  imidacloprid (in-furrow or foliar) following an imidacloprid seed-piece treatment.

 

imidacloprid + thiophanate-methyl + mancozeb

Tops-MZ-Gaucho Potato Seed-Piece Treatment
0.75 lb /100 lb of seed-pieces
-
24
1.4/ 100 lb seed

Do not exceed 0.25 lb (ai) of imidacloprid per acre per year.  Also aids in control of some diseases.

Foliar and Soil Applied Treatments

abamectin

0.15 lb/gal

8-16 fl oz

14
12
<1
Do not make more than 2 applications per crop. Make first application when approximately 50% of the egg masses have hatched and larvae are present. Provides better control of larvae than of adults.
*Agri-Mek .15EC
0.15 lb/gal

8-16 fl oz

14
12
<1
Do not make more than 2 applications per crop. Make first application when approximately 50% of the egg masses have hatched and larvae are present. Provides better control of larvae than of adults.

acetamiprid

Assail 30SG
 0.3 lb/lb

1.5-4.0 oz

7
12
<1-2
Do not exceed 4 applications per season or a total of 16 oz per acre per season. Systemic translaminar activity.
azadirachtin (neem)

Neemix 4.5

2-16 oz

0
<1
Larvicide. Initiate applications and maintain frequency in a manner similar to that of Bt's. Best control is achieved at the upper end of the use range. Slower acting than Bt or cryolite products. Will not control aphids or leafhoppers.

Ecozin 3EC

8 oz

0
<1
Bacillus thuringiensis, var. tenebrionis

Novodor

1-4 qt

0
12
2-7
For use against 1st and 2nd instar larvae. Ineffective against large larvae and adults. Nontoxic to predators and parasites.
carbofuran

** *Furadan 4F
4 lb/gal

1 qt

14
48
45
NOT FOR USE ON LONG ISLAND. Variable performance. May leach into groundwater.
cryolite

Kryocide
0.96 lb/lb

10-12 lb

0
12
205-247
For use against small- to medium-size larvae. Ineffective against adults. Nontoxic to predators and parasites. Do not apply at less than 7 day intervals. Application to exposed tubers may result in excess residues.

Prokil Cryolite 96
0.96 lb/lb

10-12 lb

0
12
205-247
cyhalothrin (lambda)

*WarriorII
2.08 lb/gal

1.3-1.9 fl oz

7
24
1-2
Avoid use on pyrethroid-resistant populations.
 
cyfluthrin
*Baythroid XL
1 lb/gal
1.6-2.8 fl oz
0
12
1-2
Avoid use on pyrethroid-resistant populations.Avoid use on pyrethroid-resistant populations.
*Renounce 20WP
0.2 lb/lb
2-3.5 oz
0
12
1-2
†*cyromazine

Trigard
0.75 lb/lb

2.7-5.3 oz

7
12
3.1-6.0
For use against 1st and 2nd instar larvae. Ineffective against adults.  Refer to label for rotational crop restrictions.  Not for use in Nassau or Suffolk Counties.
 
endosulfan

*Thionex 3EC
3 lb/gal

1.3-2.6 pt

1
48
18-37
May improve control when tank mixed with pyrethroids, oxamyl, or azinphos-methyl. Less toxic to predators than all other insecticides except Bt and cryolite. Thionex 3 EC: Also labelled for control of CPB in rotational succulent peas.
imidacloprid
*Admire Pro
4.6 lb/gal
5.7-8.7 fl oz
-
12
5.3-8.1

For soil application only; apply according to one of 4 methods specified on label.  Systemic activity within plant. Do not exceed 0.31 lb AI/A/season. Observe the plant-back interval for any crop not listed on the label. Will not provide control of ECB, climbing cutworm, or potato stemborer.

*Advise 2FL,
*Alias 2F,
*Macho 2.0 FL, *Widow
2lb/gal

0.9-1.3 fl oz/1000 ft
-
12
0.4-0.6/ 1000 feet

For soil application only; apply according to one of 4 methods specified on label.  Systemic activity within plant. Do not exceed 0.31 lb AI/A/season. Observe the plant-back interval for any crop not listed on the label. Will not provide control of ECB, climbing cutworm, or potato stemborer.

*Couraze 1.6F, *Impulse 1.6FL,
*Nuprid 1.6F,
*Pasada 1.6F,
*Prey 1.6,
*Provado 1.6F
1.6 lb/gal

3.75 fl oz

7
12
1.4
For foliar application only. Do not exceed 15 fl oz/A/season.  Systemic activity within plant. Observe the plant-back interval for any crop not listed on the label. Will not provide control of ECB, climbing cutworm, or potato stemborer.

*Montana2F
2lb/gal

3 fl oz (foliar)

0.9-1.3 fl oz/1000 ft (soil)

7

12

12

1.4

0.4-0.6/ 1000 ft

For foliar application. Do not exceed 12 fl oz/A/season.

For soil application; apply according to one of 4 methods specified on label. Systemic activity within plant. Do not exceed 0.31 lb AI/A/season. Observe the plant-back interval for any crop not listed on the label. Will not provide control of ECB, climbing cutworm, or potato stemborer.

 
imidacloprid + cyfluthrin

*Leverage 2.7

3.0-3.75 fl oz
7
12
2-2.5
Do not exceed 15 fl oz/acre per season. Systemic and contact activity. Excellant broad spectrum insect control.
indoxacarb

**Avaunt 0.3 lb/lb

3.5-6.0 oz

7
12
3-5
Not recommended for use on Long Island. The inclusion of piperonyl butoxide (PBO) at the rate of 0.25 lb a.i. is recommended for best results. May be slow-acting in controlling larvae; weak against adult CPB. Will not provide control of leafhoppers or aphids.
oxamyl

** *Vydate L
2 lb/gal

1-2 qt

7
48
11-22
Not for use in Nassau/Suffolk Counties. Effective in combination with endosulfan against pyrethroid resistant adults. May leach into groundwater. Relatively less toxic to predators than other insecticides except Bt, cryolite, and endosulfanNote: In-furrow application at planting of Vydate C-LV made under special local need labeling for nematode management may provide early season suppression of foliar arthropod pests.
phosmet

*Imidan 70-WSB
0.70 lb/lb

1.3 lb

7
24
22
Variable performance. Not recommended on Long Island. Has provided excellent control of adults and larvae in some locations of upstate New York when used in combination with carbaryl and PBO. For use only on potatoes harvested by machine.
spinosad

Entrust 80%

1-2 oz

7
4
<1-2
For larvae only.  Do not apply more than 6.5 oz per acre per crop season. Recommended for certified organic production if approved by sanctioning body.

Spin Tor 2SC
2 lb/gal

3-6 fl oz

7
4
<1-2
For larvae only. Do not apply more than 21 fl oz per acre per crop season.
 
spinetoram

Radiant SC
1 lb/gal

6-8 oz
7
4
<1-2
Best against larvae.  Do not exceed two consecutive applications of Group 5 insecticides (spinetoram, spinosad).


24.6.2 Aphids (For greenhouse whitefly management, see flonicamid)
primarily the green peach aphid, Myzus persicae;
potato aphid, Macrosiphum euphorbiae; melon aphid, Aphis gossypii;
buckthorn aphid, Aphidula rhamni; and foxglove aphid, Aulacorthum solani


See pictures of GPA life cycle

Potato aphid damage
Potato aphid life cycle

Melon aphid life cycle

Organic management of GPA and PA on solanaceous crops

Time for concern: June through vine-kill
Key characteristics: Adults of the potato infesting aphid species are approximately 1/25 to 2/25 inch in length and vary in color from yellow to black. They may be winged or wingless. In the fall, winged aphids are produced and mate. The eggs are black and less than 1/50 inch in length. See http://www.nysaes.cornell.edu/ent/factsheets/.

Management Option Recommendation
Scouting/thresholds

Plant damage from feeding by aphids is often subtle and seldom reflected, at least in the early stages, by obvious changes in plant growth, growth form, or foliage color. Large populations may be detected by the appearance of cast skins, sooty mold, or shiny honeydew accumulations on lower foliage and the soil. Put up either yellow sticky traps or water-pan traps. Traps should be examined twice a week and the number of winged aphids recorded and removed. A total catch of ten aphids per trap over a seven day period is an alert to the possible need for application of an insecticide. When the number of aphids per trap increases, examine one fully expanded leaf from each of five different plants in different rows at each of ten sites per field. Count all of the aphids. Apply insecticide when the following acton threshold is reached.

PLANT GROWTH STAGE ACTION THRESHOLD

Before tuber intiation 100 aphids/50 leaves
Tuber initiation - 2 weeks before vine kill 200 aphids/50 leaves
Within 2 weeks of vine kill 500 aphis/50 leaves

Yellow sticky traps Traps should be located away from tree lines and tall weeds where they might be obscured and should be at least 12 inches above the plant canopy. Mount traps vertically along the edges of the field by stapling to a wooden stake.
Water-pan traps Traps should be located away from tree lines and tall weeds where they might be obscured and should be at least 12 inches above the plant canopy. Any water-tight container holding a minimum of one gallon of water with a minimum diameter of twelve inches can be used. If metal containers are used, they must be painted a deep yellow. The trap must be equipped with an overflow for rainwater by cutting a circular hole one inch in diameter in the side of the pan about two inches below the rim. A small piece of window screen should be cemented over the hole to retain aphids when rainwater raises the level of water in the pan. Fill the pan with several inches of water, several drops of liquid dishwashing detergent, and one teaspoon of quaternary ammonium disinfectant. See Table 24.4.
Natural enemies

Naturally-occurring predators, parasitoids, and pathogens help suppress infestations. Use Reference 12 for identification of natural enemies. Green Peach aphid: Coleomegilla maculata lengi, Hippodamia convergens, Coccinella septempunctata, Cocinella tranversogutatta, Cycloneda munda, Hippodamia variegata, Aphidoletes aphiimyza, Aphidius matricariae, Diaeretiella rapae, Praon aguti, Praon occidentale, Ephedrus incompletus, Lysephlebus testaceipes, Aphelinus semiflavus, Pandora neoaphidis. Melon aphid: Coleomegilla maculata lengi, Hippodamia convergens, Coccinella septempunctata, Cycloneda munda, Praon aguti, Praon occidentale, Lysephlebus testaceipes. Potato aphid: Coleomegilla maculata lengi, Hippodamia convergens, Coccinella septempunctata, Geocoris spp., Orius insidiosus, Orius tristacolor, Nabis americoferus, Chrysoperla, Zoophthora radicans, Phalangium spp., Aphidius nigripes, Praon aguti, Praon occidentale, Ephedrus incompletus, Beauveria bassiana, Nabis spp.

Michigan State site "Enhancing Beneficial Insects with Native Plants"

ATTRA publication: "Farmscaping to enhance biological control"

Note(s) Aphid populations may decline rapidly during periods of heavy rainfall. Insecticides applied for leafhoppers may also suppress aphids.
Resistant varieties Although all currently available potato cultivars are susceptible to infection by the potato leaf roll virus (PLRV), many cultivars are resistant to the manifestation of virus infection in tubers. The following cultivars are particularly likely to express the phloem (net) necrosis indicative of PLVR infection: Russet Burbank and BakeKing.
Site selection Avoid planting fields immediately downwind of any barrier. Hedgerows, wood lots, or hilly terrain reduce wind velocity and increase the number of dispersing aphids falling into fields.
Seed selection/treatment Plant disease-free, certified seed. New York Certified Seed Potatoes - 2008 Crop Directory
Mulches Use reflective mulches or mineral sprays to limit virus transmission by migrant aphids.
Harvest Harvest the crop as early as possible to minimize vulnerability to late-season aphid colonization and virus infection.
Sanitation Maintain effective management of weeds in and on the margins of fields. Eliminate volunteer plants and rogue diseased plants.
Insecticide Resistance Management

A classification of insecticides based on their mode of action is available in pdf format. This guide can be used to help avoid or delay the development of insecticide resistance, as well as manage populations that have developed resistance to a particular insecticide. It is a large file - 97 page, 780k pdf file 

Shelton, A.M., W.T. Wilsey, and D. M. Soderlund. 2001. Classification of insecticides and acaracides for resistance management

Crop rotation and Postharvest These are not currently viable management options.

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
 Trade name
Rate/A
    Product
PHI
    (days)
REI
    (hours)
Field
    Use EIQ
Comments
acetamiprid
Assail 30SG
 0.3 lb/lb
2.5-4.0 oz 7 12 1-2
Do not exceed 4 applications per season or a total of 16 oz per acre per season. Systemic translaminar activity.

dimethoate

Dimethoate 400 or OLF
4 lb/gal

1 pt

0 (if mech. harvested)
48
32
Systemic activity. Variable performance. Selects strongly for resistance in aphids
esfenvalerate
*Asana XL
0.66 lb/lb
5.8-9.6 fl oz 7 12 1-2
May not be compatible with TPTH fungicides on some cultivars. Do not apply more than 0.35 lb AI/A/season
flonicamid

Beleaf 50 SG
0.5 lb/lb

2-2.8 fl oz 7 12  
Also provides control of plant bugs and greenhouse whitefly.  Use highest rate for management of whiteflies.
imidacloprid
*Couraze 1.6F,
*Impulse 1.6FL,
*Nuprid 1.6F,
*Pasada 1.6F,
*Prey 1.6,
*Provado 1.6F
1.6 lb/gal
3.75 fl oz 7 12

1.4

Among the best materials available for management of melon aphids. Systemic activity within plant. Foliar application only. Do not exceed 15 fl oz/A/season. Observe plant-back interval for crops not listed on the label.
*Montana2F
2lb/gal
3 fl oz 7 7 1.4 Do not exceed 12 fl oz/A/season.
imidacloprid + cyfluthrin
*Leverage 2.7 3.75 fl oz 7 12 2.5 Do not exceed 15 fl oz/acre per season. Systemic and contact activity. Excellent broad spectrum insect control. .
methamidophos
*Monitor 4
4 lb/gal
1.5-2 pt 14 96 22-29 Best material for management of green peach and potato aphids. Poor performance against melon aphid. Systemic activity within plant. Does not appear to select strongly for resistance in aphids.
methomyl
*Lannate LV
2.4 lb/gal
1.5-3 pt 6 48 13-27 Effective against melon aphids. May not be compatible with TPTH fungicides on some cultivars.
oxamyl
** *Vydate L
2 lb/gal
1-2 qt 7 48 11-22 NOT FOR USE ON LONG ISLAND. May leach into groundwater. Systemic activity within plant. .  Note: In-furrow application at planting of Vydate C-LV made under special local need labeling for nematode management may provide early season suppression of foliar arthropod pests
pymetrozine
Fulfill
0.5 lb/lb
2.75-5.5 oz 14 12 2 Translaminar systemic activity. Feedling ceases soon after exposure and aphids die of starvation usually within 4 days. Allow 7 days between applications. Surfactant recommended with all applications. Will not control leafhoppers.



24.6.3 Potato leafhopper, Empoasca fabae

See pictures of PLH damage
See pictures of PLH life cycle

Organic management of PLH on solanaceous crop

Time for concern: Early June through August
Key characteristics: Adult is wedge-shaped, iridescent green in color, and 1/8 inch long. The body is widest at the head. Eggs, are laid singly on the underside of leaves. Both adults and nymphs are very active, running forward, backward, or sideways. The symptoms produced by feeding have been termed "hopperburn." The first sign of hopperburn is whitening of the veins. These areas become flaccid and yellow in color, then desiccate, turn brown, and die. Leaf curling may occur. The entire process takes four to five days. See Reference 14.

Management Option Recommendation
Scouting/thresholds Check for the presence of adult PLH's by using a sweep net or by placing yellow sticky traps near the field edges. Nymphs are best sampled by visual examination of the undersides of leaves on the lower half of the plant. Threshold: treat when more than one adult is found per sweep or more than 15 nymphs are found on 50 leaves.
Natural enemies

Although a variety of natural enemies of potato leafhopper have been reported, their impact on infestations is not well known. Use Reference 12 for identification of natural enemies. Geocoris spp., Orius insidiosus, Orius tristacolor, Nabis americoferus, Chrysoperla, Zoophthora radicans, Phalangium spp.

Michigan State site "Enhancing Beneficial Insects with Native Plants"

ATTRA publication: "Farmscaping to enhance biological control"

Resistant varieties

Elba, Prince Hairy and King Hairy are resistant to the potato leafhopper.

See Cornell report on mixing PLH resistant and susceptible varieties in fields

See Cornell report on PLH susceptibility of potato varieties grown on organic farms

Insecticide Resistance Management

A classification of insecticides based on their mode of action is available in pdf format. This guide can be used to help avoid or delay the development of insecticide resistance, as well as manage populations that have developed resistance to a particular insecticide. It is a large file - 97 page, 780k pdf file 

Shelton, A.M., W.T. Wilsey, and D. M. Soderlund. 2001. Classification of insecticides and acaracides for resistance management

Crop rotation,
Site selection,
Seed selection/treatment,
Postharvest, and
Sanitation

These are not currently viable management options.

See Cornell report on floating row covers and PLH

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments

acetamiprid

Assail 30SG
 0.3 lb/lb
1.5-4.0 oz 7 12 1-2
Do not exceed 4 applications per season or a total of 16 oz per acre per season. Systemic translaminar activity.
carbaryl
Sevin XLR Plus
4 lb/gal

1 qt

7
12
18
Repeated use after mid-July is sometimes associated with late-season outbreaks of aphids.
carbofuran

** *Furadan 4F
4 lb/gal

1-2 pt

14
48
22-45
NOT FOR USE ON LONG ISLAND. May leach into groundwater. Systemic activity within plant.
cyfluthrin (beta)
*Baythroid XL
1 lb/gal
0.8-1.6 fl oz
0
12
<1-2
 
*Renounce 20WP
0.2 lb/lb
1 - 2 oz
0
12
<1-2
 
cyhalothrin (lambda)

*WarriorII
2.08 lb/gal

0.96-1.6 fl oz

7
24
0.6-1.0
 
dimethoate
Dimethoate 400
4 lb/gal

1 pt

7
48
32
Systemic activity
endosulfan

*Thionex 3EC
3 lb/gal

1.3-2.6 pt

1
48
18-37
Among insecticides recommended, this is the least toxic to ladybird beetles, which are important predators of aphids.
esfenvalerate

*Asana XL
0.66 lb/gal

5.8-9.6 fl oz

7
12
1-2
May not be compatible with TPTH fungicides on some cultivars. Do not apply more than 0.35 lb AI/A/season.
imidacloprid + cyfluthrin

**Leverage 2.7

3.0-3.75 fl oz
7
12
2-2.5
Do not exceed 15 fl oz/acre per season. Systemic and contact activity. Excellant broad spectrum insect control.
methamidophos

*Monitor 4
4 lb/gal

1-2 pt

14
96
15-29
Section 2(ee) recommendation based on efficacy data. The user must possess a copy of this recommendation at the time of application. Systemic activity within plant. Excellant residual control of leafhoppers. Effective against leafhoppers and most aphids but does not select strongly for resistance in either aphids or the Colorado potato beetle.
methomyl

*Lannate LV
2.4 lb/gal

1.5-3 pt

6
48
13-27
May not be compatible with TPTH fungicides on some cultivars.
methyl parathion

*Cheminova Methyl 4EC 4 lb/gal

1.5 pt

6
96
71.3
Repeated use after mid-July is sometimes associated with late-season outbreaks of aphids.
oxamyl

** *Vydate L
2 lb/gal

1-2 qt

7
48
11-22
NOT FOR USE ON LONG ISLAND.
May leach into groundwater. Systemic activity within plant. .  Note: In-furrow application at planting of Vydate C-LV made under special local need labeling for nematode management may provide early season suppression of foliar arthropod pests
permethrin

*Ambush
0.25 lb/lb

6.4 oz

14
12
9
May not be compatible with TPTH fungicides on some cultivars.

*Pounce 3.2 EC
3.2 lb/gal

4 fl oz

7
12
9
phorate

** *Thimet 20-G
0.20 lb/lb
Locknload
Smartbox

15 lb

90
48
204
Apply at planting in the seed furrow or drill granules in bands 2-4" on each side of the seed row, 1-2" below the seed piece. Less effective on muck than mineral soils
phosmet
*Imidan 70-WSB
0.70 lb/lb

1.3 lb

7
24
22
Variable performance.

See a report of 2001 efficacy trials for OMRI approved (organically approved) materials for potato leafhopper

24.6.4 Flea beetles, Epitrix cucumeris, Systena frontalis & other species

Potato flea beetle life cycle

Potato flea beetle damage

Organic management of FB on solanaceous crops

Time for concern: May through August
Key characteristics: Shiny, black beetle, about 1/16 inch long, that jumps when disturbed and chews tiny holes in foliage. Larvae are slender white worms which usually feed on roots; second generation larvae sometimes feed on tubers producing pits and roughness.  See http://www.nysaes.cornell.edu/ent/factsheets/.

Management Option Recommendation
Scouting/thresholds Check for the presence of adult flea beetles by using a sweep net or by examining foliage. Begin treatment at threshold of 2 adults per sweep and/or 15 feeding holes per terminal leaf.
Natural enemies

Naturally-occurring predators, parasitoids, and pathogens help suppress infestations. Use Reference 12 for identification of natural enemies. Collops vittatus, Microctonus vittatae

Michigan State site "Enhancing Beneficial Insects with Native Plants"

ATTRA publication: "Farmscaping to enhance biological control"

Resistant varieties Prince Hairy and King Hairy are resistant to flea beetles.
Insecticide Resistance Management

A classification of insecticides based on their mode of action is available in pdf format. This guide can be used to help avoid or delay the development of insecticide resistance, as well as manage populations that have developed resistance to a particular insecticide. It is a large file - 97 page, 780k pdf file 

Shelton, A.M., W.T. Wilsey, and D. M. Soderlund. 2001. Classification of insecticides and acaracides for resistance management

Crop rotation,
Site selection,
Postharvest  and
Sanitation
These are not currently viable management options.

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments

acetamiprid

Assail 30SG
 0.3 lb/lb
1.5-2.5 oz 7 12 1-2
Do not exceed 4 applications per season or a total of 16 oz per acre per season. Systemic translaminar activity.
bifenthrin

*Brigade 2EC
*Sniper
2 lb/gal

2.1-6.4 fl oz 21 12 2.9-8.8
Do not exceed 0.5 lb ai per acre per season, including soil application.
carbaryl

Sevin XLR Plus
4 lb/gal

1 qt

7
12
18
Repeated use after mid-July is sometimes associated with late-season outbreaks of aphids.
carbofuran

** *Furadan 4F
4 lb/gal

1-2 pt

14
48
22-45
NOT FOR USE ON LONG ISLAND.
May leach into groundwater. Systemic activity within plant.
cyfluthrin (beta)
*Baythroid XL
1 lb/gal
1.6-2.8 fl oz
0
12
1-2
 
*Renounce 20WP
0.2 lb/lb
2 - 3.5oz
0
0
1-2
 
cyhalothrin (lambda)

*WarriorII
2.08 lb/gal

1.3-1.9 fl oz

7
24
0.8-1.2
 
endosulfan

*Thionex 3EC
3 lb/gal

1.3-2.6 pt

1
48
18-37
Among insecticides recommended, this is the least toxic to ladybird beetles, which are important predators of aphids.
esfenvalerate
*Asana XL
0.66 lb/gal
5.8-9.6 fl oz
7
12
1-2
May not be compatible with TPTH on some cultivars. Do not apply more than 0.35 lb AI/A/season.
imidacloprid + cyfluthrin

**Leverage 2.7

3.0-3.75 fl oz
7
12
2-2.5
Do not exceed 15 fl oz/acre per season. Systemic and contact activity. Excellant broad spectrum insect control.
methamidophos

*Monitor 4
4 lb/gal

1-2 pt

14
96
15-29
Section 2(ee) recommendation based on efficacy data. The user must possess a copy of this recommendation at the time of application. Systemic activity within plant. Effective against leafhoppers and most aphids but does not select strongly for resistance in either aphids or the Colorado potato beetle.
methomyl

*Lannate LV
2.4 lb/gal

1.5

6
48
13
May not be compatible with TPTH fungicides on some cultivars.
methyl parathion

*Cheminova Methyl 4EC 4 lb/gal

1.5 pt

6
96
71.3
Repeated use after mid-July is sometimes associated with late-season outbreaks of aphids.
oxamyl

** *Vydate L
2 lb/gal

1-2 qt

7
48
11-22
NOT FOR USE ON LONG ISLAND.
May leach into groundwater. Systemic activity within plant. . Note: In-furrow application at planting of Vydate C-LV made under special local need labeling for nematode management may provide early season suppression of foliar arthropod pests.
permethrin

*Ambush
0.25 lb/lb

6.4 oz

14
12
9
May not be compatible with TPTH fungicides on some cultivars.

*Pounce 3.2 EC
3.2 lb/gal

4 fl oz

7
12
9
May not be compatible with TPTH fungicides on some cultivars.
phorate

** *Thimet 20-G
0.20 lb/lb
Locknload
Smartbox

15 lb

90
48
204
Apply at planting in the seed fur­row or drill granules in bands 2-4” on each side of the seed row, 1-2” below the seed piece. Less effective on muck than mineral soils.
phosmet

*Imidan 70-WSB
0.70 lb/lb

1.3 lb

7
24
22
Variable performance. Not recommended on Long Island.  Only use on potatoes harvested by machine.

 

24.6.5 Subterranean and Surface cutworms

Ontario, Canada cutworm fact sheet

Time for concern: May through harvest
Key characteristics: Many species of cutworms attack potatoes. The larvae are brown or gray and grow to about 1/5 inch in length. Some species cut the stems at the soil level, while others feed underground. See http://www.nysaes.cornell.edu/ent/factsheets/pests.html

Management Option Recommendation
Scouting/thresholds Apply insecticide baits (if available) by broadcast as late in the evening as possible when damage is first observed. Control will be improved if applications are made during periods of high humidity and when the soil surface is moist.
Resistant varieties No resistant varieties are available.
Insecticide Resistance Management

A classification of insecticides based on their mode of action is available in pdf format. This guide can be used to help avoid or delay the development of insecticide resistance, as well as manage populations that have developed resistance to a particular insecticide. It is a large file - 97 page, 780k pdf file 

Shelton, A.M., W.T. Wilsey, and D. M. Soderlund. 2001. Classification of insecticides and acaracides for resistance management

Crop rotation,
Site selection,
Seed selection/treatment,
Postharvest, and
Sanitation
These are not currently viable management options.


24.6.6 Variegated cutworm, Peridroma margaritosa

Ontario, Canada cutworm fact sheet

Time for concern: June through August
Key characteristics: The adult is a brown moth. Eggs are laid in masses of 60 or more. Mature larvae, 1 1/4 to 1 3/4 inches in length, may appear "greasy." Larvae curl into a C when disturbed. The larvae remove foliage on the lower half of plants. Yields can be reduced if substantial defoliation occurs during tuber initiation and bulking. See Reference 15.

Management Option Recommendation
Scouting/thresholds Examine the foliage in the evening for the presence of larvae and signs of feeding. Also examine wet, low lying areas of the field for the presence of larvae. Examine 25 randomly chosen plants. Threshold: when the population reaches an average of three larvae per stem or if post-bloom defoliation exceeds 15 percent of the vine.
Insectide use Larvae are present on the foliage only during the evening, and insecticides will be most effective if applied during this period or near dusk. Thorough coverage of the foliage and soil surface is essential for good management. This may require the use of application equipment delivering at least 50 gallons per acre at pressures of 60 psi or more.
Natural enemies

Naturally-occurring predators, parasitoids, and pathogens help suppress infestations. Use Reference 12 for identification of natural enemies.

Michigan State site "Enhancing Beneficial Insects with Native Plants"

ATTRA publication: "Farmscaping to enhance biological control"

Resistant varieties No resistant varieties are available.
Insecticide Resistance Management

A classification of insecticides based on their mode of action is available in pdf format. This guide can be used to help avoid or delay the development of insecticide resistance, as well as manage populations that have developed resistance to a particular insecticide. It is a large file - 97 page, 780k pdf file 

Shelton, A.M., W.T. Wilsey, and D. M. Soderlund. 2001. Classification of insecticides and acaracides for resistance management

Crop rotation,
Site selection,
Postharvest, and
Sanitation
These are not currently viable management options.

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product 
PHI
(days)
REI
(hours)
Field
Use EIQ 
Comments
cyfluthrin (beta)
*Baythroid XL
1 lb/gal
0.8-1.6 fl oz 0 12 <1-1  
*Renounce 20WP
0.2 lb/lb
1 - 2 oz 0 12 <1-1  
cyhalothrin (lambda)

*WarriorII
2.08 lb/gal

0.96-1.6 fl oz

7
24
0.6-1
 
esfenvalerate
*Asana XL
0.66 lb/gal
5.8-9.6 fl oz 7 12 1-2
May not be compatible with TPTH fungicides on some cultivars. Do not apply more than 0.35 lb AI/A/season.
methamidophos
*Monitor 4
4 lb/gal
1 qt 14 96 15
methomyl
*Lannate LV
2.4 lb/gal
1.5 pt 6 48 13
May not be compatible with TPTH fungicides on some cultivars.
permethrin
*Pounce 25 WP
0.25 lb/lb
6.4-12.8 oz 7 12 14-27
May not be compatible with TPTH fungicides on some cultivars.

 

24.6.7 European corn borer (ECB), Ostrinia nubilalis

See pictures of ECB life cycle

Ontario, Canada fact sheet on ECB

Organic management of ECB on solanaceous crops

Time for concern: mid-July through early August
Key characteristics: Eggs are laid in scale-like masses on the undersides of leaves and fruit. The larvae are gray with rows of brown spots. The head capsule is dark brown. Larvae are 3/4 inch long when fully developed. The adult is a yellowish/reddish brown moth, about one inch in length.See References 16 and 17. See http://www.nysaes.cornell.edu/ent/factsheets/pests.html

Management Option Recommendation
Scouting/thresholds

The optimum time for application of an insecticide coincides with hatching of egg masses and is best determined by the detection of peak flight periods. Use blacklight and pheromone traps to monitor ECB's or cage infested corn stalks from a nearby field in a screened enclosure and monitor moth emergence. It is also advisable to sample the grassy areas bordering fields since the adult frequent these areas during daylight hours and may be more readily found in these areas than within cropped areas.

Threshold: greater than 15 percent of the stems are infested.

NEWA makes daily degree day forecasts for ECB emergence. The most recent trap catches of the WNY Sweet Corn Pheromone Trap Network are posted and updated each Tuesday during the growing season.

Natural enemies

Naturally occurring predators, parasitoids, and pathogens help suppress infestations. UseReference 12 for identification of natural enemies. Eriborus terebrans, Podisus maculiventris, nuclear polyhedrosis virus, Orius insidiosus, Orius tristicolor, Vairimorpha necatrix, Coleomagilla maculata lengi, Chrysoperla, Trichogramma minutum, Trichogramma ostriniae, Trichogramma evanescens, Trichogramma nubilale, Bacillus thuringiensis var. kurstaki, Propylea quatuordecimpunctata, Macrocentrus grandii Goidandich, Lydella thompsoni, Beauveria bassiana, Aplomya caesar, Nosema

See Cornell article on farmers using the biological control organism Trichogramma ostriniae to control european corn borer on potatoes

Michigan State site "Enhancing Beneficial Insects with Native Plants"

ATTRA publication: "Farmscaping to enhance biological control"

Note(s) Volunteer corn should be removed from potato fields since it is the preferred host and may attract moths to the field.
Resistant varieties Survival and establishment of larvae vary depending on potato cultivar and field conditions. Larval survival on four popular cultivars follows: Sebago > Monona > Superior > Katahdin. Under field conditions Sebago, Monona, and Norchip are more susceptible to attack by ECB's and to infection by aerial blackleg than other cultivars.
Plowing Up to 60 percent of overwintering larvae may be killed by moldboard or chisel plowing prior to moth emergence.
Site selection Avoid planting potatoes in fields that have been rotated to corn. If this is not feasible, cut corn stubble as short as possible and shred stalk material over a wide area to destroy the majority of overwintering larvae .
Sanitation Mowing grasses around fields forces female moths, which nromally reside in these areas, to move away from fields.
Crop rotation,
Rotations with ECB-resistant (Bt) field corn varieties may reduce corn borer problems in potatoes.
Insecticide Resistance Management

A classification of insecticides based on their mode of action is available in pdf format. This guide can be used to help avoid or delay the development of insecticide resistance, as well as manage populations that have developed resistance to a particular insecticide. It is a large file - 97 page, 780k pdf file 

Shelton, A.M., W.T. Wilsey, and D. M. Soderlund. 2001. Classification of insecticides and acaracides for resistance management

Seed selection/treatment, and Postharvest These are not currently viable management options.

 

Compound(s)

Comparing Environmental Risks of Pesticides
In the "Field Use EIQ" column is the range of EIQ (Environmental Impact Quotient) values for the rate range recommended for each pesticide (lower EIQ = lower environmental impact). Other pesticide risk models are useful for specific purposes. WIN-PST is required for some USDA NRCS conservation plans.

Common name
Trade Name 
Rate/A
Product