Did your IPM program work?

This fall, taking some time for harvest assessments will not only help you to assess this year's IPM program, but will also help to prepare you for next season. Before harvest, look at 200-400 apples, randomly picked from the top, sides and bottoms of trees, and evaluate for pest damage. Anything causing 2-5% damage is of concern.

Good pictures and descriptions of damage that you might encounter can be found online at www.ontario.ca/cropipm (or on your Ontario AppleIPM CD) and in your Pub. 310, Apple IPM manual. The "Often-Confused-With" pictures can help sort out what the damage might be. The Apple IPM manual has a harvest assessment page to copy for recording your results. Look for Appendix H on page 215.

Which block to do? To get the best idea of what's happening in your orchard, assess all blocks. However, giving yourself an hour or so per block, you can instead select representative areas of the orchard, if time is limited. If you assess the same block every year, you can compare your results and notice trends over time.

How to do it? Choose at least 10 (large trees) to 20 (dwarf trees) healthy trees randomly throughout the block. Select 200-400 apples, turning each to see all sides of the fruit without removing it. Choose fruit from different positions on the trees: upper, inner and outer. The key is to choose randomly, and write it down!

Also make notes of damage to leaves such as scab, tentiform leaf mines, powdery mildew, apple leaf curling midges and other feeding. This information will be important when planning your IPM program next year.

Early harvest assessments done already this year have indicated an overall successful year for pest management. There were some orchards that struggled with aphids, codling moth and OBLR, causing both foliar and fruit damage. In the east, damage from European Apple sawfly was relatively low. As well, some blocks experienced higher pressures of leafcurling midge or mites, resulting in leaf curl or bronzing, respectively. Evidence of dogwood borer in graft unions of various M9 plantings have some growers considering DWB Isomate mating disruption next year. In a few orchards where fungicide programs failed or rains caused havoc on proper timing, powdery mildew and scab was observed, as well as flyspeck/blister spot, frog-eye leaf spot, black rot and bitter rot. If you do find some fruit with rots, set them aside and let us know. We would be interested in what pathogen caused the rot.

For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca