Southeast Michigan fruit regional report – September 8, 2015

Gala and McIntosh apple harvest is underway, as are other tree fruits and fall red raspberries.

Weather

With the heat of the past week, our growing degree day (GDD) totals for the region have mostly pushed back to being a few days ahead of normal. However, they have continued to bounce around several times this season from being ahead of normal, to normal, to a few days behind normal. In terms of the beginning of harvest of our fruit crops this season, we have been running a few days ahead of normal, and that continued this week with the harvest of Gala and McIntosh apples.

Most of the region received an average of just over an inch of rain in the last two weeks, but total precipitation was widely scattered, ranging from 0.9 to 2.2 inches. Some growers did not receive any precipitation at all in the last two weeks. As a result, most of our soils have adequate to normal amounts of soil moisture.

I have had a few reports of just a touch of widely scattered hail over the past two weeks that came with thunderstorms.

East Michigan GDD totals for March 1 to Sept. 7, 2015

Location

GDD42

GDD45

GDD50

Commerce (Oakland)

3,334

2,887

2,188

Emmett (St. Clair)

3,325

2,884

2,195

Flint (Genesee)

3,639

3,182

2,462

Lapeer (Lapeer)

3,339

2,897

2,203

Petersburg (Monroe)

3,515

3,058

2,341

Pigeon (Huron)

3,085

2,659

1,996

Romeo (Macomb)

3,522

3,074

2,365

Tree fruits

Apple harvest is underway for most Gala strains and McIntosh. Some growers are going slowly on harvest of these two varieties waiting for them to eat a bit better, especially for fresh or immediate sales. Mac’s are picking easy, so growers need to watch harvest closely. Some fruit has dropped off the tree to the orchard floor, but most was pushed off due to fruit growing too large against the limb. Growers are finding that apples are bruising easily during harvest operations this season for these first of the long list of fall apples. It is mainly showing up the day after harvest after fruit has set in storage for a day. This bruising is most likely the result of the abundant rains most growers have had over the past few months. Some growers are looking ahead to Honeycrisp harvest, but they are at least four to six days away from being mature for the first light picking. Many Honeycrisp blocks are just starting to see bitter pit develop, especially on the largest fruit growing on the bottom tier of scaffold branches.

I began to harvest and analyze apples for the Michigan State University Extension Apple Maturity Reports early last week and took my second set of samples yesterday, Sept. 7. Look for the second Apple Maturity Report of the season to be published late tomorrow afternoon with more details on apple maturity. The apple harvest reports for this region and around the state can be found at the MSU Apples website.

Apple size continues to be very good this season at most farms; for most growers, fruit are around 3 to 3.25 inches in diameter. Summer pruning has wrapped up. In the last week, I started to see new short shots break bud and begin to grow in some apple blocks where summer pruning was first started back in late July. This regrowth is unusual. Retain applications continue to be made.

Pest pressure is winding down for the season, with the exception of late-season worm activity in a few apple blocks, including codling moth, obliquebanded leafroller and third generation oriental fruit moth flight. Growers need to do a thorough job of scouting for this late-season worm or larva activity that I am finding in just a few apple blocks. Woolly apple aphids are a problem in some blocks as well. No brown marmorated stink bugs have been caught in traps this season in east Michigan at fruit or vegetable farms. Beneficial insects continue to actively feed in some apple blocks, but their numbers are declining due to lack of food.

I am seeing more black rot-infected apples than in most years. I am mostly finding it in fruit that was damaged by insect feeding earlier in the season or fruit that was opened up due to hail or bird feeding. Necrotic leaf blotch disease is being seen in many Golden Delicious blocks, causing leaves to yellow and drop to the orchard floor. I continue seeing a few apple trees with the silver leaf fungal disease.

Pear harvest is underway for Bartlett’s and related varieties. Pear size and finish was very good this season.

Peach harvest is quickly winding down for growers with a crop this season. Brown rot is being found in later peach varieties.

Sweet and tart cherry leaf yellowing from cherry leaf spot disease continues at most farms. The yellowing of sweet cherry leaves has only been seen the past two weeks. Some trees are completely defoliated and will be prone to winter damage if we have another cold winter.

Plum harvest of Stanley and related varieties is underway. Brown rot is a problem in some plum blocks. Some blocks have a lot of bacterial spot, mostly on leaves.

Small fruits

Grape clusters are well colored in Concord types and clusters continue filling out for the few European varieties with a crop on them this season. Spotted wing Drosophila (SWD) trap catch is continuing to climb in grapes. Downy mildew and powdery mildew continues being found.

Strawberry fields continue to rebound from renovation, and rows of newly planted fields are now well filled with healthy daughter or runner plants. Where additional nitrogen applications have been made, new leaves are more of a normal, large size and darker green color. Most fields have had good suppression of weeds from herbicide applications made at renovation time. Growers need to keep a close eye for weed seed germination that typically occurs around or just after Labor Day. Another herbicide application may be in order soon in these fields where weed growth is starting to be seen. Growers need to keep an eye on both newly planted and renovated fields for potato leafhopper infestations.

Raspberry harvest of fall red raspberries is in full swing. Trap catch of SWD continues to climb in raspberries. I continue getting calls from raspberry growers finding wormy fruit infested with SWD worms or larvae. Most growers who have been making weekly applications of insecticides are free of SWD. Growers with SWD mostly had longer gaps in control programs or where control measures were started too late in the season. Many growers are finding Botrytis or gray mold in berries picked for a day or so. Some growers are also finding late leaf rust symptoms on leaves.

Blueberry harvest is complete or quickly winding down at most farms. SWD trap catch is continuing to climb in blueberries; growers need to continue control programs through the end of harvest. As is the case in fall red raspberries, I found SWD-infested fruit at several farms where control measures were either started too late in the season or where growers had longer gaps in control programs. Many farms stopped harvesting berries early due to infested berries. 

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