Southeast Michigan fruit regional report – July 15, 2014

Blueberry harvest is underway at some farms and others are close to first harvest. Harvest continues for summer red and black raspberries and even a few fall red raspberries. Green apple aphids and European red mites make an appearance in apples.

Posted on July 15, 2014 by Bob Tritten, Michigan State University Extension

Weather

Good rains have continued for most of the region, resulting in good fruit growth and development for our fruit crops. We have generally seen a month with above normal rainfall. 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 supplies remain well ahead of normal for most fruit growers.

Southeast Michigan GDD totals for March 1 to July 14, 2014

Tree fruits

Apples have continued to size very well this season; near Flint, Michigan most apple varieties are 1.875-2 inches. Hand-thinning operations are still in full swing across the region. Orchard mowing has been a constant job this season as a result of all the rain at most fruit farms. Summer pruning is just getting underway for a few apple varieties that have set their terminal buds for the season. We are just entering the time or window to collect leaf tissue samples for nutrient analysis.

Green apple aphids have made a late appearance in the last week on apple varieties that are still actively growing. As mentioned above, some apple varieties have set their terminal bud for the season; on these varieties, aphids are not being seen. Michigan State University Extension is advising growers to not control them at this time as predators are hungry and should control them well.

European red mite hotspots are just starting to be seen in a few apple blocks. Growers will need to keep an eye for these hotspots to enlarge. I had a report in the last day of 29 apple maggots being caught on red sphere traps at one orchard, which is a very high number and the first catch on red sphere traps for the season. Otherwise, most other apple insect pest numbers have been low in the past week and even for the season. Japanese beetle numbers are slowly increasing in all fruit crops. As apple growers have been hand-thinning the last few weeks, they are finding much higher amounts of damage from plum curculio than they see in other seasons. Good predator numbers continue to be seen in most apple blocks.

Powdery mildew symptoms were first reported in mid-June, however in the last week I have seen much higher numbers of infected terminal branches. I have not seen any symptoms of sooty blotch and flyspeck disease. Last week, I reported that we have received sufficient hours of wetting this season for spores to be available, thus control programs for these diseases should be incorporated into summer cover sprays.

Pears are 1.5-1.75 inches in diameter.

Peach growers are continuing to prune less severally winter-damaged trees and removing dead trees.           

Sweet cherry harvest has ended with many growers not harvesting any crop this season because it was so light. Cherry fruit fly trap catch continues.

Tart cherry harvest has wrapped up for the season. Cherry fruit fly trap catch continues. Leaf drop from cherry leaf spot is just starting to be seen. It is early for this to begin. Growers need to apply a post-harvest fungicide to control this disease.

Plum size has remained about the same for the last few weeks, with European plums mostly 1 inch  and Japanese varieties close to 1.5 inches.

Small fruits

Grapes are at berry touch for Concord and Niagara varieties, with a wide range of fruit development stages this season. Wine grapes continue to have extensive cane death in most varieties with new shoots continuing to emerge from latent buds on the trunk. It is still too early to prune these back. Grape berry moths are continuing to be caught in traps and a few Japanese beetles are being found in grapes.

Strawberry harvest has wrapped up for the season and renovation is now underway. Read “Weed control at strawberry renovation” to review those options at renovation time.

Raspberry harvest continues for summer red and black fruiting varieties. Fall bearing varieties are 40-55 inches in length, with harvest on a few shorter interior canes being seen. First trap catch of spotted wing Drosophila (SWD) has now been reported at a number of farms, all in traps in adjacent fence rows to summer red raspberries. Fruit will need to be protected as harvest nears. Consult recommendations in the “Spotted Wing Drosophila Management Recommendations for Michigan Raspberry and Blackberry Growers” guide at the MSU Spotted Wing Drosophila website for details.

Japanese beetles continue to be found in both summer and fall raspberries. Gray mold has been reported at a few farms on these early berries.

Blueberry harvest began this week on early maturing varieties at a few farms. Other farms will be opening for harvest in the next week. No blueberry maggots have been caught in traps, but are expected soon. Japanese beetles continue to be found in blueberries. SWD infestations are a threat to blueberries as well as raspberries. Consult recommendations in the “Spotted Wing Drosophila Management Recommendations for Michigan Blueberry Growers” guide at the MSU Spotted Wing Drosophila website for details. 

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).