INCOMING
(Art Agnello, Entomology, Geneva)
I’ve hardly ever composed the first newsletter of the year without
there being some snow falling outside my window; in this case (last Thursday),
it was more like freezing rain on its way to becoming snow, but the general
idea is the same. It’s getting so that we don’t measure the
progress towards spring in NY by how many warm days we get anymore, but
by how many warm days we get followed by how many inches of snow (sort
of a degree-snow-day accumulation). At any rate, judging from the long-range
weather predictions, half-inch green should fall anywhere between next
week and early May. I’m only glad I don’t work with crocuses,
since all those growing in our area are mostly wiped out and lying flat
on the ground. El niño, La niña; frankly, I blame the parents.
Post Office Protocol
As befits the usual perfunctory chores that need to be gone through
before actually getting down to business each season, we should first
address the matter of subscriptions. You are reading this issue in the
form that you want to receive it, according to our notoriously low-maintenance
records. If the hard copy has been mailed to you even though you’ve
failed to return the re-subscription card, as usual, you get one or two
more weeks to decide whether you’re going to let us in on your intentions
before we make the decision for you. Rules from higher up require us to
solicit an annual request from each person to maintain their subscription.
Failing the receipt of some kind of notification that you wish to continue
receiving the paper version, we will eventually drop the names of former
(even beloved) subscribers from the list. If you got the e-mail ASCII-text
version last year, it’s being sent to the address you last specified;
if you’re not receiving it (in which case don’t ask me how you’re
supposed to see this message), you forgot to notify us that you switched
to another cyber-identity. Let us know of any preferred changes you wish
to make in this general arrangement (to/from one form or another, address
changes, start-up or stopping of subscriptions, etc.), and we will do
our best to accomodate you.
As before, there is a web version available from the NYSAES server on
the World Wide Web. It is normally up by Tuesday or Wednesday each week,
at:
http://www.nysaes.cornell.edu/ent/scaffolds/
I also post it to the CENET Tree Fruit Discussion Group BB, which I believe
is a list-serve, at:
CCE-TREE-FRUIT-L@CCE.CORNELL.EDU
As usual, we are always happy to consider contributions (particularly
from N.Y. sources) in the form of articles on topics in any of the fruit
crop protection or crop production areas, as well as N.Y. field observations,
trap data, etc. We generally do not send the mailed version of this newsletter
to growers, homeowners, or other private individuals not having some fruit
extension, commercial, university or governmental affiliation, as extension
administrator types consider that audience to be obtaining this information
from their local Cornell Cooperative Extension programs. There are a few
exceptions, mostly for people who were "grandfathered in" before
this policy was instituted, and we prefer to keep this number low. Unless
things get too out of hand, the e-mail version will be sent to anyone
who requests it.
PREPARING THE AIRBLAST SPRAYER FOR WORK
(Andrew Landers, Agricultural
and Biological Engineering, Ithaca)
Checking the sprayer
Surveys have shown that many farmers are using inaccurate sprayers;
faulty sprayers contribute to increased drift levels and waste money through
inefficiency and overuse of chemicals. Sprayers must be regularly checked
over to ensure that proper maintenance has been carried out and that no
outstanding repairs need to be done. Before attempting any work on a machine
make sure that it is fully supported on stands and that all necessary
protective clothing is on hand.
The cost of replacing a faulty pressure gauge that has been indicating
at 15% below the actual pressure is recouped in around two hours’
operation. Maintenance measures such as fitting a new set of nozzles at
the beginning of each season also save money. Even when there is overdosing
by as little as 5%, the cost of a new set of nozzles would be recovered
in less than a day’s work.
CAUTION
• Take great care when adjusting a sprayer while the tractor
engine is running.
• Always ensure that the fan is stationary before approaching
the rear of the sprayer.
• Engage the handbrake when leaving tractor seat.
Fitting the sprayer to the tractor
The selected tractor must always be powerful enough to operate the
sprayer efficiently under the working conditions that will be encountered.
All its external services – hydraulic, electrical and pneumatic –
must be clean and in working order. Tractors fitted with cabs must have
efficient air filtration systems. All protective guards must be in place.
Trailed sprayers are often close-coupled to the tractor, so it is essential
that the drawbar and the PTO shaft are correctly adjusted for turning.
PTO shafts must be disengaged when making very tight turns.
Checking the operation of the sprayer
Part fill the tank with clean water and move the sprayer to uncropped
waste ground. Remove the nozzles. Although not using any chemical at this
point, get into the habit of wearing a coverall, gloves and a face visor
when working with the sprayer. Engage the PTO and gently turn the shaft,
increasing speed slowly to operating revs. Test the on/off and pressure
relief valves, and check the agitation system. Flush through the spray
lines, then switch off the tractor. Refit the nozzles and check the liquid
system again for leaks.
It is a valuable exercise to assess the spray deposits at various
points in the canopy and on upper and lower leaf surfaces of the trees
to be sprayed. This is particularly important if the foliage is dense
or if the trees are grown in beds of three or more rows. Water-sensitive
papers, food colouring or fluorescent tracers are available for this purpose.
An increase in spray volume or adjustment of the nozzles and their locations
may be necessary in order to achieve the correct deposits.
Pre-season maintenance
Follow the checklists before you begin spraying
Hoses
Have you checked…
- for splits and cracks
- connections to ensure they are water-tight
- for hose chafe, particularly in routing clips
Action:
Replace damaged hoses.
Filters
Have you checked…
- for missing filter elements and seals
- for leakage
- for blocked or damaged filters
Action:
Replace any damaged or blocked filters.
Tank
Have you checked…
- for fractures and any other damage
- the tank sits firmly in its mount
- the securing straps are correctly adjusted
- the agitation is working
- the tank is clean
Action:
See the supplier/manufacturer now about fractures and any other repairs.
Controls
Have you checked…
- the control circuitry (electrical, hydraulic or air) for correct operation
- valves for both internal and external leaks
Action:
Replace leaky valves, which waste money and are potentially dangerous
to operators and the environment.
Pump
Have you checked…
- lubrication levels
- for leaks
- the air pressure in the pulsation chamber (if fitted) is at the recommended
level
- the pump rotates freely without friction or noise. Do so by rotating
manually or starting at low speed (corrosion may cause seizing up)
Pressure Gauge
The pressure gauge is vital for indicating whether the nozzles are
delivering the correct amount of chemical per unit time while spraying.
If you have any doubts about the pressure gauge, replace it or refer the
problem to the manufacturer or supplier.
Nozzles
Have you checked…
- all nozzles are the same
- all nozzles are in good condition, with no leaks around the body
- all nozzles are clean and free from obstruction (note: clean with
a soft brush or airline – don’t damage nozzles by using wires
or pins)
- all nozzles deliver to within + or - 5% of the manufacturer’s
chart value
Action:
Always ensure the correct nozzles and operating pressure are selected
before use. Have two or three sets of nozzles in stock to meet different
spray qualities at different volume rates. Inspect nozzles throughout
the season to avoid faults which could prove both costly and damaging
to the environment if they develop unchecked.
Using water only, set to ‘spray’ at the specified pressure
and collect the output from each nozzle in turn for a period of 60 seconds.
Record each output and replace those outside the 5% tolerance around the
manufacturer’s chart value.
Calibration
Where your sprayer has automatic controllers to monitor the speed of
the sprayer and the flow, pressure and area sprayed, have you checked…
- they are in good condition and properly maintained
- they are frequently calibrated for accuracy, with calibration being
checked after every 250 acres’ use
- for leaks, blockages, variations in pressure or any minor damage during
spraying
A recommended calibration technique is summarised as:
• Read the label
• Measure the forward travel speed of the tractor with
the booms out and over the field to be sprayed
• Calculate the nozzle output required
• Select the appropriate nozzle set
• Set the appropriate pressure
• Measure the nozzle output against time
The following checks should be carried out routinely:
• All hoses are tightly connected and free from sharp bends;
cracked or damaged hoses must be replaced.
• All controls move freely and are fully adjustable.
• Pressure gauge reads zero.
• Pump can be turned over by hand.
• Fan turns freely and is not obstructed; bearings are
sound and lubricated.
• Air pressure in pump accumulator (if fitted) is correctly
adjusted.
• Drain plugs and clean filters are in position.
• Tyres on trailed machines are sound and correctly inflated;
wheel nuts are tight.
HEAVY WORDS
Last year, we held an Apple IPM In-Depth School at Geneva, and each
participant of the school received a syllabus containing the proceedings
plus supplementary references on some 50 presentations given by 30 different
speakers. The topics ran sequentially from the dormant season until post-harvest,
and covered management considerations for nearly every pest we could squeeze
into a very full 2-day program. We still have extra copies for sale to
anyone who might want a good reference; it should be useful to the expert
as well as the beginner who needs a good place to start: 280 pages, including
misc. articles (from the NY Fruit Quarterly, J. Econ. Entomol., Mass.
Fruit Notes), plus several bulletins and manuals published by Cornell
Coop. Ext. (Integrated Weed and Soil Management in Fruit Plantings; Wildlife
Damage Management in Fruit Orchards), NRAES (Orchard Spraying: Getting
Results; Hydraulic nozzles for boom sprayers; On-Farm Agrichemical Handling
Facilities), USDA (Fire blight - Its nature, prevention, and control),
and NYS-IPM (Apple IPM: A Guide for Sampling and Managing Major Apple
Pests in New York State, 1999 Revision).
Cost is $30 (or $25 if you pick it up in person so I don’t have
to ship it); send me a check payable to "Cornell University"
or contact me if you need instructions on using a Purchase Order. Approximate
weight, 6 lb; also doubles as a doorstop.
|
