East Michigan fruit update - July 3, 2018

Sweet and tart cherry, summer red raspberry and saskatoon harvest continues. Black raspberry harvest is starting. All crops seem to be holding up well through the heat of the last few days. Cherry growers need to be on the lookout for cherry fruit fly.

July 3, 2018 - Author:


With the heat of the last few weeks, degree day totals have continued to quickly build. With the exception of the Pigeon MSU Enviroweather station, all of our degree day totals are now in the thousands. Our season is still running ahead of normal. It is between seven and 14 days ahead in degree day totals and about five days ahead of normal in terms of the start of harvest of our fruit crops.

Most of the region has seen around an inch of precipitation over the last two weeks, however rainfall totals have been extremely variable over short differences.  Our soils generally remain on the dry side, with most of the thumb area and our sandy sites being very dry. Growers need to keep a close eye on soil moisture supplies for signs of drought stress, especially on newly planted and young fruit plantings. Most growers have been irrigating on a regular basis over the last two weeks.

East Michigan Growing Degree Day Totals for March 1st to July 2nd, 2018





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 have continued to size well, despite dry soils at many farms. They are mostly in the range 1½ to nearly 2 inches in diameter. Some varieties of apples are requiring hand thinning, but the list of which varieties needing hand thinning is quite variable from farm to farm. Most growers are needing to thin Honeycrisp. Leaf yellowing or mottling continues to be seen in Honeycrisp.

There are no new pests to report in apples this week.  Apple maggot trap catch on red sticky traps continues at a low rate. Green apple aphid populations continue to be very high in many blocks. Woolly apple aphids are quickly moving to terminal branches. Japanese beetle  populations continue to build in most apple blocks.  San Jose scale crawler activity has slowed at most farms. Two spotted spider mite numbers have continued to build, several blocks are now above threshold levels. Growers need to do a good job of scouting for them.  Brown marmorated stinkbugs are being found in low numbers in traps at several farms this week. Apple rust mite numbers continue to build but are generally lower than threshold numbers. Obliquebanded leafroller feeding injury on fruit continues to be found. White apple leafhopper and potato leafhopper adults are being seen for the fourth week on apple leaves in just a few apple blocks..  Codling moth crawlers are being found in a few blocks. Rosy apple aphids continue to be found in a few blocks, causing leaf curling.  European red mite adults are more common this week, but still well below threshold levels. On the beneficial side, good numbers of green lace wing adults and eggs are being found this week.

More and more apple scab lesions are showing up on leaves and fruit. Just a touch of fire blight continues to be found in most orchards. At this time these strikes are limited in numbers and can easily be broken out well below the canker and disposed of. Pruners can also be used to remove the strikes but remember that if tools are used that they must be sterilized between cuts. I saw some fruit yesterday that are infected with cedar apple rust. Nectria twig blight continues to be found in light amounts.  More powdery mildew terminal branch strikes continue to be found this week.

Pears have not sized much in the past week, with most being at 1 ¼ to 1 ½ inches in diameter. Pear psylla populations have continued to build in blocks where control measures have not taken place and where suckers have good growth.  

Peaches have not sized much in the past week, they are mostly at 1 3/8 inches in diameter, pit hardening continues. More growers have reported finding brown marmorated stinkbug (BMSB) nymphs feeding on young peach fruit. Growers need to be on the lookout for BMSB in peaches.

Sweet cherry harvest continues, most fruit are between 20 and 25 mm in diameter. We had first trap catch of cherry fruit fly late last week. Spotted wing Drosophila (SWD) trap continues in just a few blocks. However, the flight has started, even though it is limited, others need to be checking traps every few days to determine when SWD start their flight at your farm. When they start being caught in traps, control measures need to start shortly thereafter. There does not seem to be much cracking in sweet sherries this year.  

Tart cherry harvest continues, most fruit are between 18 to 22 mm in diameter. As was covered in the sweet cherry section, growers will need to watch closely for the first spotted wing drosophila trap catch and to begin to control it soon thereafter that catch.   

Plums are about the same size as last week, with European varieties being at 7/8 inches in diameter and 1 ¼ inches for Japanese varieties.  Some European and Japanese varieties have a very light crop on them, most likely due to poor pollination.  

Small fruits

Strawberry renovation continues at most farms. Some growers are considering delaying the beginning of the renovation process until this round of hot weather is over. Make sure berries are watered well following renovation. Many new plantings need some attention to weed control. Where flower buds have been removed I am seeing a good amount of runnering take place in new plantings. Potato leafhopper feeding damage continues to be seen in a few newly planted berry fields.

Raspberry harvest continues in summer red raspberries and is just getting started in black raspberries. Berry size is on the small size this season. Growth has slowed on fall bearing raspberries, flower clusters are starting to form on many of the canes. They will most likely be ready to harvest early this season.

Growers will need to watch closely for the first spotted wing drosophila trap catch and to begin to control it soon thereafter that catch. I am stating to see some potato leafhopper feeding damage to new canes or primocanes in summer raspberries. A few bramble plantings have been hit hard with raspberry sawfly feeding damage.   

Blueberries are starting to color this week and have continued to size, most are between 12 to 18 mm in diameter. Berries have put on enough size to a point where canes are starting to tip over into the aisle way.

Saskatoon harvest continues for the main season varieties. Most fruit in the range of 11 to 13 mm in diameter. Growers report about one more week of harvest.

Grapes continue to put on a good growth, with concord types nearly reaching berry touch and vinifera types at buckshot sized fruit. Powdery mildew continues to be seen on leaves and twospotted spider mite populations continue to build slowly.

Tags: east michigan berries, east michigan fruit update, msu extension

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