East Michigan fruit report – June 20, 2017

Strawberry harvest continues across the region, summer red raspberry and saskatoon harvest is just getting underway and sweet cherry harvest will begin in a few days.


Continued warm, summer-like temperatures pushed rapid growth in all of our fruit crops in the past week. Our season remains ahead of normal, now six to nine days ahead in terms of growing degree-day (GDD) totals and the beginning of harvest of our early summer fruit crops.

Precipitation for the past week has been extremely variable over short distances, ranging from a trace to 3-4 inches. Most of our Michigan State University Enviroweather stations recorded rain in four to five of the last seven days. If you averaged rainfall totals for all of our Enviroweather stations in the region, we received an average of 1.08 inches of rain in the last week. However, many of them received just a trace.

Soils remain dry across the region for most farms. For most growers, it has been four weeks since the last significant rain event. Growers are devoting a fair amount of time this past week irrigating fruit crops, especially newly planted tree and small fruit crops.

East Michigan GDD totals for March 1 to June 19, 2017





Commerce (Oakland County)




Deerfield (Monroe County)




Emmett (St Clair County)




Flint (Genesee County)




Freeland (Saginaw County)




Lapeer (Lapeer County)




Pigeon (Huron County)




Romeo (Macomb County)




Tree fruits

Apples are mostly 1.375 to 1.5 inches in size, and have sized well despite dry soils. Wilting of newly planted apples is apparent due to dry soils. June drop continues in many McIntosh blocks and is just starting in other varieties. Hand-thinning continues in blocks on good sites and in blocks close to wind machines.

As I shared last week, most farms have a spotty apple crop, with hand-thinning being required in some blocks and others with just a few apples. With that being said, most growers are finding more apples than they had anticipated just a few weeks ago. There are a few growers that have a full apple crop. More and more apples with frost rings are apparent.

The first sighting of the season of potato leafhopper adults is the only new apple pest to report this week. Their numbers are very low and I have not seen any leaf yellowing or cupping from this pest. White apple leafhoppers numbers are low to modest. As reported last week, green apple aphid populations have exploded in many apple blocks. Good numbers of predators are commonly being found feeding on green apple aphids.

San Jose scale male adult trap catch continues, but their numbers are declining this week. I am seeing a few San Jose scale crawlers. I have not seen any codling moth egg hatch, with adult trap catch on the decline this week. Good numbers of beneficials are being seen this week, especially lady beetle adults.

Cedar apple rust is the only new disease to report in apples this week, although I am seeing very little in well-maintained blocks. There is a great deal of it in wild apple trees and other related species.

Apple scab spore discharge was not found in the last rain event, so primary apple scab season has now officially ended. With the lack of rainfall over the last four weeks, it has been hard to determine when apple scab spore discharge ended. Apple scab lesions are apparent on leaves, although not in great amounts.

Powdery mildew symptoms are visible. I have not seen any fire blight shoot strikes yet this season, but have been told by a few growers in the last week they had a few strikes all from trauma blight, none with flower infections. All of the suspected fire blight strikes I have seen this season were either nectria twig blight or wind-damaged twigs.

Pears are mostly 21 to 23 millimeters in size; it is hard to find any pears in most blocks due to loss from frost. The little fruit that remains is scarred with frost marks and rings. All stages of pear psylla are being apparent.

Peaches are mostly 1.375 to 1.625 inches in size, with most growers having a good crop. A few green peach aphids were found, as well as some light amounts of peach leaf curl symptoms. Oriental fruit moth trap catch has gone down in the past week; I have not found any shoot flagging.

Sweet cherries are very close to the beginning of harvest, most likely in the next few days for early varieties. Fruit continues to color well. Most are at 19 to 22 millimeters in size.

Black cherry aphids continue being active, mostly on suckers on the insides of trees. A few flower thrips continue being seen. Birds, mostly robins and starlings, continue to feed heavily in early maturing varieties that are close to harvest. I have seen brown rot in unsprayed trees in the past few days, but none on commercial blocks that are being sprayed.

Tart cherries are mostly 14 to 18 millimeters in size. Fruit is coloring at a rapid pace. Cherry leaf spot is apparent in just a few trees in most tart cherry blocks, causing leaf yellowing and premature leaf drop. Most growers report they have a good tart cherry crop this season.

Plums are 22 to 24 millimeters in size for European types and Japanese types are 1.25 inches in size. Some Japanese varieties have little to no crop on them this season.

Small fruits

Strawberry harvest continues for most farms, with farms at the peak of harvest for the last few days. The cooler temperatures will help to slow berry ripening and lengthen harvest window. There are a good number of farms that have stopped harvest due to poor fruit quality. See last week’s regional report for more details on farms closing early.

For farms that closed early, renovation can start anytime now. The only caveat to add is where soils are dry; I would wait for soil moisture to return to normal levels before beginning renovation. I would also put irrigation pipes back in renovated fields to irrigate shortly after renovation to help these berries rebound quickly.

New plantings are runnering well. Some new plantings need the runners pulled in to aid in filling rows completely. Some cultivation and hoeing needs to be done as well to help with weed control. Watch that new berries are well-watered, as most fields are dry. It is this time during harvest that I see many newly planted fields being neglected.

Sap beetle is a new pest to report in strawberries this week. Their numbers are generally low. Slug damage was found in more strawberry fields this week. MSU Extension advises to carefully scout now.

Raspberry harvest is just starting for early maturing summer varieties. The fruitlets of most other summer red raspberry varieties are enlarging and starting to color. Fall raspberry varieties have better growth, with the longest canes 28 inches in length.

Blueberry fruit is still mostly 10 to 12 inches size. Early varieties are starting to color. Most varieties have finally started to produce more leaf growth. Overall, we have a very nice blueberry crop this season at most farms.

Saskatoon harvest is just getting underway. Growers have a nice crop, with no winter injury or frost damage.

Grapes are at late bloom to buckshot-sized fruit for concord types with 30 inches of new growth. Vinifera grapes are at full bloom.

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