July 30 Conference Call

John’s Updates
1. Many growers with early apple harvests are putting on what they hope will be their last spray for codling moth. John is concerned about the dangers of not controlling late flights of codling moth, and recommends maintaining trap counts beyond your last spray. One option for late season codling moth control is the CM virus, as it has a pre-harvest interval of 1 day.
2. A number of orchards received two inches of rain last week. The protection provided by pesticides applied prior to the rain may have been greatly reduced on those orchards.
3. The last flight of oblique banded leaf roller starts soon.
4. John witnessed very effective parasitism of wooly apple aphid this week.
5. John warns that once you have seen mite damage, it is usually too late to apply a miticide; the populations will crash on their own shortly.
6. Apple maggot populations continue to increase. They are easy to control with low rates of Imidan, or for those who are harvesting soon, Sevin.
Conversation Topics
1. Second generation codling moth: deciding whether or not to spray when trap counts are at threshold, materials that control codling moth as well as other pests, using combination lures to determine the presence of female CM in an orchard.
2. Scouting for wooly apple aphid.
3. Phytophthora: factors that facilitate infection, measures to prevent infection.
4. Leucostoma: factors that facilitate infection, measures to prevent infection.
To hear the recording of this week’s call, dial (641)715-3436. Access code: 516817.