Southeast Michigan fruit regional report – July 2, 2013

Strawberry harvest wrapped up, sweet cherry harvest continues and tart and summer raspberry harvest is beginning.

Weather

This weather last week saw wide swings in rainfall and temperatures. While our Enviro-weather stations in east Michigan recorded between 0.1 to 2.7 inches of rainfall, I have heard numerous reports of 3- to 5-inch rainfall totals in the past week. Our season is running back to normal again in terms of growth stages, growing degree day (GDD) totals and the start of harvest of our fruit crops. Strong winds with some of these fast moving thunderstorms also caused some tree fruits to either snap at the graft union or to lean.

East Michigan growing degree day totals for March 1 to July 1

Location

GDD42

GDD45

GDD50

Commerce (Oakland)

1452

1231

896

Emmett (St Clair)

1437

1218

888

Flint (Genesee)

1608

1378

1031

Lapeer (Lapeer)

1411

1199

877

Petersburg (Monroe)

1624

1389

1030

Pigeon (Huron)

1383

1171

854

Romeo (Macomb)

1485

1264

924

Tree fruits

Apples are approaching 1.75 inches in the south and 1.5 inches around Flint, Mich. June drop continues in a few apple varieties. Hand-thinning continues in apples.

Potato leafhopper adults are being seen in most apple blocks, especially on younger trees. Green apple aphid populations continue to build in many apple blocks, with many blocks also seeing aphids on the fruit. San Jose scale crawlers continue to be seen and are starting to settle into their shell, so the control window is nearing an end. Apple rust mite bronzing has been seen at a few farms. Rosy apple aphid leaf curling remains, however the pest has been controlled well this season by predators in most apple blocks. Wooly apple aphids continue to move from the tree trunks to the terminal branches. Codling moth and oriental fruit moth trap catches remain low. There continues to be high numbers of predators this season. Apple maggot traps need to be set.

I saw new fire blight strikes at three farms yesterday (July 1). I can find just a touch of leaf and fruit scab in most apple blocks. I continue to see twig infections of powdery mildew, mainly on susceptible varieties.

Pears are 1.25 inches at most farms where growers have a crop. All stages of pear psylla are present.

Peaches are 1.5 inches in size. This season’s peach crop falls into two groups. Most have an abundant crop and others have no crop at all. X disease is starting to be seen. Bacterial spot infection on the leaves continues to be found at many farms.

Sweet cherry harvest continues. Fruit size is a problem at most farms. Birds are continuing to feed in most sweet cherry blocks. Cherry leaf spot disease symptoms are being seen in many blocks.

Tart cherry harvest is just starting at a few farms. Tart cherry fruit size continues to be a problem. I have heard the term “pits and stems” more than once in the last week. Cherry leaf spot disease symptoms are being seen in most tart cherry blocks, with yellowing leaves dropping to the orchard floor.

Plums are 1 inch in size for both European and Japanese types.

Small fruits

Strawberry harvest has wrapped up at most farms. It was a very short season at most farms and a very challenging season as well. A combination of temperatures that were either too cold or too hot and excessive rainfall in the last week has resulted in poor berry quality.

Strawberry sap beetle larvae and adults were found at one farm yesterday (July 1). Michigan State University Extension suggests growers start thinking about renovation. Potato leafhopper feeding and leaf curling is being seen in most new plantings. Newly planted berries are runnering well.

Raspberry harvest for early varieties of summer red raspberries is just getting underway at most farms. Canes of fall-bearing types are about 36 inches tall. Leaf curling from potato leafhopper is being seen in both new and established raspberry plantings.

Blueberries are starting to color with harvest expected to begin in a week to 10 days for early maturing varieties.

Grape cane growth continues at a rapid pace. Concord types are almost at berry touch and French hybrid types are at buckshot. Grape berry moths have been caught in traps in commercial plantings in the last week.

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