Weather

降水总量从周五晚上下雨,June 26, and Saturday morning of last week varied widely across the region. Rainfall totals ranged from 0.0 to 1.44 inches. Overall, soils over much of the region have continued to dry out. Signs of drought stress are being seen more commonly this week than last week, especially in newly planted tree and small fruit crops, in shallow rooted fruit crops, and this week in younger plantings that are a few years old. Sod in most orchards has turned brown, and lanes and driveways are very dusty.

As a result of another week of warm temperatures, we saw another good increase in growing degree day (GDD) accumulations. Most of ourMichigan State University Enviroweather stationshave seen a rise of 130 GDD base 50 accumulations in the last week.

Our season is still hovering a few days ahead to a few days behind normal for both growth stages and GDD.

East Michigan growing degree day (GDD) totals for March 1 to June 29, 2020
Location	GDD42	GDD45	GDD50
Commerce (Oakland County)	1424	1196	865
Deerfield (Monroe County)	1580	1333	980
Emmett (St Clair County)	1390	1163	841
Flint (Genesee County)	1545	1306	957
Freeland (Saginaw County)	1383	1156	832
Lapeer (Lapeer County)	1414	1185	854
Pigeon (Huron County)	1319	1104	803
Romeo (Macomb County)	1444	1212	877

Tree Fruits

Appleshave continued to size well over the last week, despite dry soils. Most apple fruit are now 1.375 to 1.5 inches in diameter. Most apple varieties have between 22 and 24 inches of new terminal growth. The lingering, long and steady June drop has just about ended, but I am still finding a few small freshly dropped fruitlets on the orchard floor in many varieties. Hand thinning has not started yet in apples but will be needed in many apple varieties.

I have two new insect pests to report in apples this week.Apple maggottrap catch started in the region yesterday, June 29. Low numbers of adults have been caught on both yellow sticky boards and red ball traps.Apple rust mitesare the second new pest to report this week. While numbers are still low, they will bear watching in this hot weather.Potato leafhoppersnumbers have risen dramatically at some farms in the last week, with a good amount of leaf curling. Two weeks ago week I reportedSan Jose scaleadult male trap catch and last week found some crawlers. This week I am just starting to see a few crawlers waxing over, meaning that the crawler control window is beginning to close.

Trap catch ofobliquebanded leafrolleradults is dropping off.European red miteandtwospotted spider mitescontinue to be found in higher numbers, but neither are at threshold levels yet. A fewwhite apple leafhopperadults continue to be found feeding on leaves, as well as a fewwoolly apple aphidsaround pruning scares. I continue to see a fewcodling mothlarvae in apples. Trap counts of adults are generally low at this time. Beneficial or predator numbers continue to build. This week I am finding minute pirate bugs,red velvet mites,lady beetlesandlacewingadults.

I am seeing entire limbs that are wilting and browning fromblack rotinfections in the wood tissue. I have no new reports of growers findingfire blightstrikes. A number of growers are findingcedar apple rustsymptoms on fruit, more than they have seen in years.Apple scabfruit lesions continue to be found. Some apple blocks continue to have high numbers ofpowdery mildewinfected terminals on mildew prone varieties. Protection programs need to be ongoing on mildew prone varieties.

Leaf mottling has started to be found on Honeycrisp leaves. The mottling is caused by the accumulation of large starch granules in the leaves that reduce photosynthesis.

Pearsare mostly 1.25 to 1.5 inches in diameter.Pear psyllaadult numbers continue to slowly rise as suckers continue to elongate. Sucker removal is beginning in pear blocks.

Peachesare between 1.25 and 1.375 inches in diameter. Pit hardening is just beginning. Thinning continues in some blocks; others will not require thinning due to frost damage.Green peach aphidscontinue to be found in many peach blocks. I have not seen any flagging fromoriental fruit mothin peaches but expect to find some soon. Peach leaf curl symptoms are common across the region, but as new leaves develop, the symptoms appear to be diminished.

Sweet cherryharvest started at a few farms in the last few days, others will begin harvest later this week. Unfortunately, harvest has quickly wrapped up at most farms due to the short crop.Leaf spotsymptoms are a new pest to report in sweet cherries this week; control programs need to be maintained. A good amount of bird damage is being found in the remaining fruit, mostly from cedar waxwings and robins.

Due to the short crop, most growers do not need to be concerned about spotted wing Drosophila (SWD) control in sweet cherries. SWD trap catch started to be seen in all traps across the region two weeks, it rose by just a few last week, and this week the number found in traps have only slightly climbed.

Tart cherrieshave colored well in the past week. They are mostly 16 to 18 millimeters in diameter. As is the case in sweet cherries, I have seen a good amount fruit drop in tarts over the last six weeks. Most blocks only have 5 to 10% of a crop remaining, but a few may have 30 to 40% of a crop. Many growers report they don’t have enough of a tart crop to even pick.Leaf spotcontrol programs need to be maintained as cherry leaf spot symptoms are starting to be seen.

For growers with a crop of tart cherries to harvest, you need to be concerned with spotted wing Drosophila (SWD) control. SWD trap catch started in all traps across the region two weeks ago, but their numbers have been fairly low since then. With the start of harvest for some blocks of tart cherries approaching, protection programs will need to start soon to control it.

Plumsare approaching an inch in diameter for European varieties, with Japanese varieties at 1.375 inches. As is the case for both sweet and tart cherries, most plum blocks have a poor crop due to freeze/frost damage.

Small fruits

Strawberry收获已经结束了在过去的几天里ms to the south of Flint, Michigan, with others to follow later this week. Demand for both ready picked and pick your own strawberries was very strong this year. Leaves on newly planted strawberries continue to emerge from the crown, along with flower trusses and runners. Deflowering is taking place. Renovation is beginning at many farms this week. Growers with dry soils may need to get their irrigation systems back into strawberry fields fairly quickly to begin irrigation as renovation is wrapped up.

Raspberryharvest is underway for early maturing summer red raspberries. Later maturing varieties are coloring well and will begin harvest soon. Berry size is small where soils have been dry over the last month. Growth has continued to be good on fall bearing raspberries that have been irrigated, the tallest canes are 30 inches in length. Flower buds are starting to be seen on the bud berry canes or shorter fall red raspberry canes.

Some light amounts of raspberry cane borer and raspberry sawfly larvae feeding damage is being found at just a few farms. Spotted wing Drosophila (SWD) trap catch started to be seen in all traps across the region two weeks ago and continued to be seen in low numbers through this week. With the start of harvest for summer red raspberries, protection programs need to be underway.

Blueberriesare continuing to color well; berry size is mostly between 8 to 12 millimeters in diameter. Blueberry maggot trap catch has been seen in southwest Michigan, but none over here on this side of the state yet. I expect to see trap catch soon.

Grapegrowth has moved quickly again this week, with concords at BB sized fruit. Vinifera varieties at petal fall. Many new canes are 48 inches in length. Japanese beetle adults were found in grape late last week. Their number are low but they are on their way. Grape berry moth populations are very high in southwest Michigan, but I have not seen feeding damage or webbing.

Saskatoonharvest began over the weekend. Remaining fruit are continuing to size and color well. Most fruit are between 11 and 13 millimeters in diameter. Heavy bird feeding continues in saskatoons, mostly from cedar waxwings and robins.

Haskapharvest is underway. Unfortunately, most of the fruit has been consumed by bird feeding over the last few weeks.