East Michigan fruit update – July 23, 2019
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EmailSpotted wing Drosophila trap catch numbers have taken a big jump this week. Tart cherries, summer red and fall raspberries and blueberries need to be protected.
Weather
Much needed rain from thunderstorms moved over the region last Friday, July 19, and over the weekend. High winds were also a part of many of these storms. There was some damage to trellis systems and limb breakage in tree fruits. A few growers reported short quick bursts of pea-sized hail from these same storms.
The precipitation totals from these events at our Michigan State University Enviroweather stations in the table below ranged from 0.31 to 1.3 inches. However, I had many reports from fruit growers that they received far more precipitation, some over 3 inches. With these recent rains, drought stress of fruit crops has had some relief. Newly planted tree fruit seemed to have responded well to these recent rains.
With the heat of the last week, our season has again moved forward from being normal to now being three to seven days ahead of normal when looking at growing degree day (GDD) totals for region. However, when I look at the start of harvest of our fruit crops currently being harvested, we are at least a week ahead of normal for the typical start of harvest dates.
Be sure to check out the new animated weather forecasts from Jeff Andresen, our agricultural meteorologist, at the Weather tab on the Michigan State University Extension Fruit & Nuts Page.
|
East Michigan GDD totals for March 1 to July 22, 2019 | |||
|---|---|---|---|
|
Location |
GDD42 |
GDD45 |
GDD50 |
|
Commerce (Oakland County) |
2,055 |
1,756 |
1,308 |
|
Deerfield (Monroe County) |
2,269 |
1,950 |
1,474 |
|
Emmett (St Clair County) |
1,730 |
1,453 |
1,043 |
|
Flint (Genesee County) |
2,139 |
1,834 |
1,375 |
|
Freeland (Saginaw County) |
1,996 |
1,707 |
1,267 |
|
Lapeer (Lapeer County) |
1,965 |
1,671 |
1,234 |
|
Pigeon (Huron County) |
1,775 |
1,498 |
1,085 |
|
Romeo (Macomb County) |
2,108 |
1,807 |
1,355 |
Tree fruits
Apple growth has slowed for most growers; they are mostly 2 to 2.5 inches in diameter. Hand thinning continues. I have no new apple pests to report this week.
Green apple aphid numbers are building quickly in some apple blocks. Last week I reported the first few Japanese beetle adults, this week I am finding good numbers in a number of fruit crops, including feeding mainly in younger apple trees. Apple maggot trap catch continues on both yellow sticky traps and red ball traps this week; however, their numbers are generally low. More woolly apple aphids are being found in hot spots in apple blocks, a few are moving out toward the terminals. A few European red mite adults continue to be found, as well as a few blocks with apple rust mite adults. I have not found any leaf reddening or bronzing yet. A few orchards are finding obliquebanded leafroller and redbanded leafroller larvae. Codling moth larvae feeding injury was seen for the first time this week. Potato leafhopper adults are being found in many apple blocks.
There are no new beneficials to report this week. Lady beetles, six spotted thrips and green lacewing adults continue to be found.
Apple scab fruit lesions continue to be found in more blocks this week. Powdery mildew-infected terminals continue in many apple blocks.
Pears are mostly 1.5 to 1.75 inches in diameter. Pear psylla continues to be present in all stages.
Peaches have taken a good swell in the past week; they are mostly 1.75 to 2.25 inches in diameter for the largest sized fruit. Some early varieties are starting to color. A few green peach aphids continue being found.
Sweet cherry harvest is winding down this week at a few farms and has ended for most farms over the weekend. Some farms had larvae in fruit late last week from either cherry fruit fly or spotted wing Drosophila, mostly in fruit in the top middle of larger trees. This infestation was mostly a spray coverage issue. Bird feeding pressure is high in both sweet and tart cherries.
Tart cherry harvest continues across the region. Cherry fruit fly trap catch started to be seen around July 4, and trap catch continues. Some farms had larvae in fruit late last week from either cherry fruit fly or spotted wing Drosophila, mostly in fruit in the top middle of larger trees. This infestation was mostly a spray coverage issue. There are blocks with heavy leaf drop from cherry leaf spot disease. Bird feeding pressure is high in both tart and sweet cherries.
Plums are mostly 1 inch in diameter for European varieties, with some starting to color. There has been a good amount of fruit drop again this week in European plums. Japanese varieties are mostly 1.25 to 1.75 inches in diameter. Methley plums are close to being ready to harvest. Many Japanese varieties have a light crop this season.
Small fruits
Strawberry renovation continues at most farms. Newly planted strawberries are runnering well. I have seen several new plantings late last week and this week with severe leaf curling from potato leafhopper adult feeding.
Raspberry harvest continues for summer red raspberries. Black raspberry harvest is winding down. Berries have been ripening quickly with the heat. Last week, many growers started picking the bud berries or berries on the shorter interior growing canes of fall red raspberries. Spotted wing Drosophila adult trap catches took a sharp upward turn late last week and this week trap catch numbers have climbed again. Control measures should have started over the weekend. Some traps are catching very high numbers of other look-alike fruit flies this season.
Blueberry harvest is underway at almost all farms this week. The largest fruit is 14 to 18 millimeters in diameter. Some varieties have put on a good amount of branch and leaf growth in the last month. Spotted wing Drosophila adult trap catches took a sharp upward turn late last week and this week trap catch numbers have climbed again. Control measures should have started over the weekend. Some traps are catching very high numbers of other look-alike fruit flies this season. A am starting to see a few canes begin to die from Phomopsis canker.
Saskatoon harvest wrapped up two weeks ago.
Grapes are nearing berry touch this week. Grape berry moth larvae were reported being found feeding in grape clusters late last week. Japanese beetles continue to be found in greater numbers this week. A few growers are seeing higher numbers of twospotted spider mites. Powdery mildew symptoms are starting to be seen on leaves. A second round of removing suckers from the base of canes is taking place in many varieties. Lastly, there is some berry drop taking place this week when fruit clusters are touched
