Southeast Michigan fruit regional report – July 8, 2014

First trap catch of Spotted wing Drosophila and cherry fruit flies have been seen, and second generation codling moth and oriental fruit moth trap catch is on the rise. Strawberry and sweet cherry harvest has wrapped up and tart cherry harvest continues.

Posted on July 8, 2014 by Bob Tritten, Michigan State University Extension

Weather

Cooler temperatures and good rains have been the norm for the region over the last week, with another series of strong storms moving over the region early Monday morning, July 7. This marks the third significant rain and thunderstorm event in the past three weeks for many fruit growers, all occurring early in the week. Fruit crops have continued to push rapid growth the past three weeks. No hail was reported in this latest round of storms.

Our season remains close to normal for growing degree day (GDD) totals and ahead of normal in terms of beginning of harvest of our fruit crops. Soil moisture is well ahead of normal for most fruit growers. Keeping up with orchard mowing has been a challenge for most growers over the past two weeks as a result of these steady rain events.

East Michigan GDD totals for March 1 to July 8, 2014

Tree fruits

Apples have continued to size very well where soils have been wet; near Flint, Michigan most apples are 1.75 to 2 inches. Hand-thinning operations are in full swing across the region. Sudden wilting of large lower scaffold branches of apples continues to be seen. This winter injury and tree collapse is from extreme cold temperatures early last winter.

Codling moth and oriental fruit moth second generation adult flight is just getting started in the last few days as trap catch is starting to rise. San Jose scale crawler activity is slowing down as crawlers are starting to wax over. The window for controlling crawlers is beginning to close. Apple maggot trap catch on yellow sticky traps started to be found a week ago Monday, June 30; trap catch on yellow cards continues at a slow pace. Once they emerge, apple maggots usually take 10 days before they begin to lay eggs in fruit. Japanese beetle numbers are slowly increasing in all fruit crops. Good predator numbers continue to be seen in most apple blocks with good numbers of lacewing eggs being seen in the last week.

The GDD model for sooty blotch and fly speck diseases indicates that we have received sufficient hours of wetting this season for spores to be available; control programs for these diseases should be incorporated into summer cover sprays.

Pears are 1.25 to 1.5 inches in diameter.

Peach terminal branches are starting to die from first generation oriental fruit moth infestation. Growers are continuing to prune less severely winter-damaged trees and removing dead trees.

Sweet cherry harvest began early last week and quickly ended at most farms due to lack of a crop. Cherry fruit fly trap catch began early last week. Larger scaffold limbs on stressed sweet cherry trees continue to collapse from winter injury.

Tart cherry harvest is underway, but will be wrapping up quickly due to the short crop. Cherry fruit fly trap catch began early last week, but will not be much of an issue for cherry growers as harvest will be ending soon. Bird feeding is a problem as it was in sweet cherries.

Small fruits

Grapes are close to berry touch for Concord and Niagara varieties with a wide range of development stages this season. Wine grapes continue to have extensive cane death in most varieties, but new shots continue to emerge from latent buds on the trunk. It is still too early to prune these back as I hope to see more buds break in the next few weeks. Grape berry moths are continuing to be caught in traps. A few Japanese beetles are being found in grapes.

Strawberry harvest has wrapped up for all but a few farms and renovation is now underway. Read “Weed control at strawberry renovation” from Michigan State University Extension to review those options at renovation time.

Raspberry harvest continues for early maturing summer fruiting varieties, with other varieties having red fruit. Black raspberry harvest is expected to begin in the next week. First trap catch of spotted wing Drosophila (SWD) was reported by a grower near Ann Arbor, Michigan last evening, July 7. The trap catch was in an adjacent fence row to summer red raspberries. I expect to see first catch at other farms in the next few days. Fruit will need to be protected as it is nearing harvest. Consult “SWD Management Recommendations for Michigan Raspberry and Blackberry Growers” at the MSU Spotted Wing Drosophila website for details.

A few Japanese beetles are being found in both summer and fall raspberries. Fall-bearing varieties are 36 to 44 inches in length. A few flower clusters on shorter interior canes are being seen on fall-bearing raspberries.

Blueberries are mostly 14 to 18 millimeters with a good amount of berries coloring in the last week. Harvest is very close for a few early maturing blueberry varieties. No blueberry maggots have been caught in traps, but are expected soon. 

This article was published by Michigan State University Extension. For more information, visit http://www.cnchemicals.com/. To contact an expert in your area, visit http://www.cnchemicals.com/, or call 888-MSUE4MI (888-678-3464).