May 22, 2006 Volume 15 No. 10 Update on Pest Management and Crop Development
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Upcoming Pest Events | Phenologies | Trap Catches | Pest Focus | Insects | Diseases | General Info
Upcoming Pest Events | Phenologies | Trap Catches | Pest Focus | Insects | Diseases | General Info
Upcoming Pest
Events | Phenologies | Trap
Catches | Pest Focus | Insects | Diseases | General
Info
Upcoming Pest Events | Phenologies | Trap Catches | Pest Focus | Insects | Diseases | General Info Highland: Plum Curculio, Tarnished Plant Bug, European
Apple Sawfly, and
Upcoming Pest Events | Phenologies | Trap Catches | Pest Focus | Insects | Diseases | General Info
Geneva Predictions: Codling Moth Lesser Appleworm Mullein Plant Bug Obliquebanded Leafroller Oriental Fruit Moth San Jose Scale Spotted Tentiform Leafminer
Upcoming Pest Events | Phenologies | Trap Catches | Pest Focus | Insects | Diseases | General Info
What started out as an "easy" scab season in our Station orchards here in Geneva turned around to be a serious problem. Following a heavy 3-day infection period at tight cluster, 90% of clusters had scab lesions at petal fall, and the performance of fungicides in our orchard trials confirmed previous experiences. Starting the scab program at half-inch green rather than at green tip and responding to the infection at tight cluster with a post-infection spray provided no or poor control of cluster leaf scab. Dithane at its low mixture rate, but also when mixed with Captan, failed to control cluster leaf scab. As expected for an orchard with resistance to the SI fungicides, Nova, even in combination with Dithane, performed poorly. The performance of the strobilurin Flint was also poor, showing one more time that the strobilurins Flint and Sovran are starting to lose their post-infection edge. Both Scala and Vangard provided adequate post-infection activity, but we will have to wait until harvest to find out whether and how this post-infection advantage can be carried over to good control of fruit scab at harvest. We have continued our sensitivity testing of the apple scab fungus during the 2005 season, and the not so "pretty" picture we found a year earlier has been confirmed. Resistance to the SIs Nova, Procure and Rubigan is by now quite common rather than a rare occasion here and there. Resistance to Syllit is unpredictable. We found that, once an orchard had developed resistance to dodine, this resistance was stable for more than 30 years, even after orchards had been replanted. We have not yet discovered an orchard totally immune to the strobilurins Flint and Sovran. But, sensitivity shifts toward resistance are obvious. These sensitivity shifts have eroded the post-infection power of the strobilurins. They remain very effective in a protective mode. The APs Scala and Vangard remain a "hard nut to crack". We found that in SI-resistant orchards their potency was diminished before they ever were used. We also found that their post-infection advantage in the early scab season provided little advantage in the control of fruit scab at harvest. Where do we go from here? With financial aid provided by the Northeast IPM Center, we will be able to test the resistance level of scab lesions found on leaves of commercial orchards "for free". How many orchards can we test? About 25, on a "first come, first served" basis. We also will not accept samples after 15 July. How to submit leaves with scab lesions to be tested? Easy. Contact Diana Parker, Cornell University, Department of Plant Pathology, 630 West North Street, Barton Laboratory, New York State Agricultural Experiment Station, Geneva, NY 14456. (Telephone 315-787-2400; dmp2@nysaes.cornell.edu). The procedure for collecting and shipping the leaves can be found on our Geneva web site (http://www.nysaes.cornell.edu/pp/extension/tfabp/index.html) or from your regional Cornell Cooperative Extension agents. Each shipment of leaves must be accompanied by the name, the address and the telephone/e-mail number of the submitter, and a summary of the orchard's fungicide history. Please contact Diana Parker prior to a shipment (Telephone 315-787-2400; dmp2@cornell.edu).
Upcoming Pest Events | Phenologies | Trap Catches | Pest Focus | Insects | Diseases | General Info
I'd like to note once again that we did not receive all of the revisions to the "2006 Pest Management Guidelines for Commercial Tree-Fruit Production" in time to include them in the printed version of the "Recommends". These revisions (which pertain to the thinning and growth regulator recommendations) are correct in the online versions, and can be printed out easily enough by going to the website pdf version and printing off the following pages: and page 235 This material is based upon work supported by Smith Lever funds from the Cooperative State Research, Education, and Extension Service, U.S. Department of Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to: Scaffolds
Fruit Journal Online at <http://www.nysaes.cornell.edu/ent/scaffolds/> Return to top
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