AppleTalk Conference Call Summary
Tuesday, July 29th, 2014, 8:00 – 9:00 a.m.
Presenter: John Aue, Threshold IPM.
Moderator: Peter Werts, IPM Institute of North America; questions or comments,
July 29th Call download: Click Here
Post-harvest sanitation and disease control
Sanitation for postharvest disease management. Dave Rosenberger. Scaffolds Fruit Journal. July 28, 2014. http://www.scaffolds.entomology.cornell.edu/2014/SCAFFOLDS%207-28-14%20.pdf.
Weather outlook
August’s predicted temperatures range from 60 to 80°F, with a low chance for hot and humid weather. Milder temperatures this coming month will promote fruit development and reduce the probability of fruit rot development. With the reduced risk of rot infections fungicide treatments can begin to seize, unless rot or scab legions are present. Note: scab legions will continue to develop once temperatures decrease in the fall. To reduce inoculum maintain protectant layer of fungicide.
Scouting for fruit rots minute 11:15
Inoculum levels of fruit rots, e.g., black, white and bitter rot, can be estimated by examining mummified Cortland fruit. Uniformly brown mummies with no signs of fruiting bodies or concentric rings are not an indication of a fruit rot, rather a result of other nonpathogenic organisms.
Apple curculio 14:20
The difference between AC and TPB damage is that AC leaves a hole at the bottom of the funnel; inspect with 10x or greater magnification. TPB does not create a hole. Scaring may also be present near AC injury; will not be crescent shaped. Scaring and hole are damage indicative of AC.
Depth of funnel can indicate when AC was active in orchard; deeper tunnel suggests earlier in the season.
Early season oviposition damage has not been a major concern since it is superficial surface damage. Heavier feeding damage occurs when AC emerge midseason and feed on the fruit.
Apple curculio (AC) emerge from same over wintering sites as plum curculio, but immigrate into the orchard at a later time when there is a potential gap in insecticide coverage. Scout areas where plum curculio damage has been observed. Monitor fruit while hand thinning. If damage has not been observed while hand thinning it is a good indicator that AC is not in orchard. Look inside hole and peel off flesh to differentiate between codling moth, leafroller and European corn borer. AC feeding damage looks like hollowed out bowl.
An option for control may to apply an insecticide to the perimeter before populations leave the block. Typical codling moth materials will not have control. Assail (acetamiprid), Avaunt (indoxacarb), Calypso (thiacloprid) or Imidan (phosmet) may provide utility. These material do not need be applied to the whole orchard unless damage is widespread.
Additional images below.
Note: We are not sure if this heavy feeding damage is from apple curculio. Evidence from AC activity earlier in the season suggests that it is.
Second generation codling moth 42:10
With cooler weather it is recommended to use degree day calculations when timing applications for control of second generation codling moth. If trap counts are mild for the first biofix (second generation), then counts increase rapidly, an additional biofix can be set for the larger flight. A couple of management options exist for this scenario: 1, apply granulosis virus for the smaller biofix and Altacor (chlorantraniliprole) or Delegate (spinetoram) for second biofix; 2, apply low rate of Altacor or Delegate for first biofix and apply high rate in locations with high trap captures for second biofix.
Trap counts can also be used to determine efficacy of first generation control or a weakness in spray program. If trap counts are uniform from trap to trap during second generation, it is likely there is an in house population. If using organophosphates, Imidan (phosmet), put new trap liners in traps before an application to check effectiveness of material. Trap counts should be very low or zero following an application. If traps continue to capture moths there is most likely resistance issues. Discontinue use of this material.
Additional articles and resources
Photo courtesy of Dennis Norton.
Photo courtesy of Dennis Norton.
Photo courtesy of Dennis Norton.
Photo courtesy of Dennis Norton.
