Southeast Michigan fruit regional report – July 28, 2015

Lodi apple harvest is underway, with early peach and blueberry harvest continuing and summer red raspberry harvest wrapping up.

Weather

With the exception of a few areas in the region that received scattered rain showers this past Saturday, July 25, most of the region has been dry over the past week. Our soils remain on the dry to average side of normal for soil moisture levels, but there are a few isolated farms where soils remain very dry. I am surprised to see that fruit size for our tree fruit crops has continued to do well despite how dry some of our soils are. However, the same cannot be said for strawberries that are rebounding from the renovation process and are in great need for moisture.

Our season is generally running about normal for growing degree day (GDD) totals for most of eastern Michigan. In terms of the beginning of harvest of our fruit crops, they have generally been running a few days ahead of normal for most fruit farms.

East Michigan GDD totals for March 1 to July 27, 2015

Location

GDD42

GDD45

GDD50

Commerce (Oakland)

2,205

1,884

1,394

Emmett (St Clair)

2,172

1,857

1,378

Flint (Genesee)

2,422

2,090

1,580

Lapeer (Lapeer)

2,236

1,920

1,434

Petersburg (Monroe)

2,361

2,030

1,522

Pigeon (Huron)

2,024

1,724

1,270

Romeo (Macomb)

2,316

1,993

1,494

Tree fruits

Apples at most farms continue to size very well this season. Lodi harvest started over the weekend at most farms. Apples for most growers are 2.125 inches to the largest at 2.75 inches in diameter. A few growers have begun summer pruning in varieties where most of the terminal buds have set for the season. Leaf modeling in Honeycrisp continues to get more intense.

Pest pressure is generally low in apples at this time. The exception being San Jose scale second generation adult male flight trap catch being very high this week. Look for crawler activity in a few weeks. Many growers have been surprised to find fruit marked up from the first generation crawler activity. Trap catch of apple maggots mostly on yellow sticky traps and lesser amounts on red sphere traps continues, but their numbers remain low. The small obliquebanded leafroller larvae I was seeing the past two weeks have been controlled at most farms. There are a few more fall webworm nests this week compared to last. Codling moth and oriental fruit moth trap catch is slowly on the rise for second generation flight. A few more potato leafhopper adults and nymphs are being seen feeding on and curling leaves. Japanese beetle adults continue being seen clustered together, but overall their population levels have been down the past few years.

European red mite adult and egg numbers continue to build in a few hotspots on leaves and a few eggs are being laid in the calyx end of fruit in a few apple blocks, mostly on trees alongside dusty lanes or roads and in these spots on the inside middles of larger trees. Apple rust mites are being found on leaves in increasing numbers in many apple blocks. They are good prey for predator mites to feed on. No brown marmorated stink bugs have been caught in traps this season in eastern Michigan at fruit or vegetable farms. However, reports of homeowners finding them inside homes and outbuildings continue. Excellent numbers of beneficial insects continue to actively feed in most apple blocks, this week many Amblyseius fallacis and stigmaeid or yellow mites are present.

I have not seen any new fire blight strikes in the past week, so I think it has run its course for the season. More apple scab lesions continue to show up on leaves and fruit. Leaf drop from apple scab continues in unsprayed and wild apple trees.

Pears took on a nice swell in fruit size this past week, most are 2 to 2.375 inches in diameter. Some light amounts of pear sheet scab are starting to be visible. All stages of pear psylla continue being seen.

Peaches are mostly 2.5 inches in diameter; harvest of early varieties continues. I expect to see Redhaven harvest start in about a week. Brown rot started to show up in the past week, even in blocks where control measures were tightened up during all of the rains in June. Bacterial leaf spot-infected leaves and fruit continue being seen in many peach blocks, especially in blocks with no crop this season where pest control has been reduced.

Sweet cherry scaffold limbs continue to collapse and die from injury these past two winters. No cherry fruit flies have been caught in the past week.

Tart cherry leaf yellowing and drop from cherry leaf spot disease continues at many farms, with entire limb defoliation in some trees. Cherry leaf spot needs to be controlled at this time and for the rest of the summer.

Plum harvest is underway for Methley, and the Shiro variety fruit has taken on a nice swell and are starting to color. European plums are mostly 1.125 inches in diameter. Some blocks have a lot of bacterial spot, mostly on leaves. Black knot continues to be seen on wild and unsprayed plum trees.

Small fruits

Grape clusters continue to fill out for Concord types and European varieties are at berry touch for the few varieties with a crop on them this season. Japanese beetle adults continue being seen and are clustering together in groups of four to six adults, but their numbers have generally been lower for the past few seasons. Downy mildew and powdery mildew continue being found.

Strawberry renovation is complete at most farms and new leaves are starting to emerge from the crown. Growers with dry soils need to irrigate soon.

Raspberry harvest of summer fruiting types continues, but will be wrapping up quickly at most farms. New canes or primocanes have put on an exceptional amount of new growth this season, mainly due to abundant moisture supplies in June. Fall red raspberry canes have also put on good new growth this season and continue to set flower buds. I am finding numerous flower buds or “bud berries” this season being formed on the shorter lateral canes of fall raspberries and are being harvested at this time. These early berries are not part of the main crop.

Spotted wing Drosophila (SWD) adults continue being caught in traps in raspberries. Michigan State University Extension advises growers to continue control programs. Japanese beetle adults continue being seen and are clustering together, but their numbers have generally been lower for the past few seasons.

Blueberry harvest continues with excellent berry size at most farms. Blueberries continue to ripen quickly. No blueberry maggots have been caught in traps. SWD trap catch is continuing in blueberries; growers need to continue control programs. Japanese beetle adults continue to be seen and are starting to cluster together, but their numbers have generally been lower for the past few seasons. Phomopsis canker and twig blight-infected canes continue being found as wilted leaves and twigs, with leaves turning light brown.

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