MSU Extension

Weather

Rain over several days in the last week has finally come to eastern Michigan, although the total amount of perception at most farms was enough for only temporary relief from drought stress. Precipitation totals for the last week range from a low of 0.5 inches to a high of 3 inches. Signs of drought stress are becoming more evident in established tree and small fruits, with older leaves yellowing and dropping to the ground and even some wilting of leaves on the driest of sites. Drought stress has also resulted in reduced fruit size in blueberries and peaches, and collapse of fruiting terminals in fall red raspberries at many farms.

Our early, warm season is still running more than two weeks ahead of normal in terms of growth stages, and with all of the heat of last three weeks we are back to being three weeks ahead of normal in terms of degree day totals.

Tree fruits

Apples are approaching 2.75 inches in diameter where growers have a crop, with summer apples approaching 3 inches in diameter. Many summer apple varieties have been harvested; Ginger Golds are two weeks away from harvest and Paula Red harvest just a few days behind them. Growers have applied Retain to some Gala apple blocks.

Apple maggot trap catch continues in high numbers, all on yellow sticky traps. With the rainfall of last week I saw a good amount of trap catch in the last few days. Potato leafhopper populations have increased in the last week, with leaf curling continuing to be very common in unsprayed blocks. I recommend that this pest be controlled in young apple blocks and in valuable varieties, like Honeycrisp.

Codling moth trap catch has remained low and steady the last four weeks. Overall, we had very high numbers of codling moths caught on traps from the first generation flight this season, but no catch from the second generation flight since then. Japanese beetles are being found in a few varieties, but their numbers have generally been lower this season than in the last few seasons. A few strikes offire blight continue to be seen.

Pear leaves are starting to yellow from drought stress and drop to the orchard floor.

Peach harvest of Red Haven is underway at farms with a crop this season. Fruit size is being reduced from drought stress at most farms. I am getting a number of reports in the last few days of a high percentage of Red Haven fruit with split pit. Leaves are starting to yellow from drought stress and drop to the orchard floor

Sweet cherry and tart cherry leaf drop from cherry leaf spot disease continues, although the pace of leaf drop has slowed as most farms have applied a fungicide in the last few weeks. Japanese beetle leaf feeding continues at a few farms.

Plums look tough this season as a result of no crop at most farms and the lack of pest controls, and lately from drought stress.

Small fruits

Strawberry fields that have not had irrigation applied since renovation continue to look tough over the last three weeks, mainly due to drought stress. Irrigation pipe needs to be reset and begin watering as soon as possible. Even where irrigation has been applied, fields are not rebounding as they typically do from the stress of renovation this season.

Potato leafhopper leaf cupping and leaf margin burning is common in many new and renovated plantings. Where potato leafhopper controls have been applied in new berries this year, plantings look much better with a great deal of runnering taking place in the last two weeks.

Raspberry harvest on fall bearing types from fruiting lateral canes or bud berries started in the last week at several farms. This harvest is rather limited. Tips of some canes of fall raspberries have dried up due to drought stress. Leaf drop of the lower leaves from drought stress is extensive in fall bearing varieties at most farms.

Spotted wing Drosophila trap catches started to be seen three weeks ago at farms that had trap catches last year. We are finding that trap catches decline a bit in hot weather, however it will increase again when cooler temperatures resume. Potato leafhopper feeding injury has caused extensive leaf cupping in many fall raspberry plantings over the last four weeks. Low numbers of Japanese beetles are being found, mostly in fall raspberry plantings.

Blueberry harvest continues, although small berry size from drought stress is starting to be a problem at many farms. Many growers report that they will finish blueberry harvest in the next seven to 14 days; this is about three to four weeks earlier than most years. Many varieties are being picked at the same time this season.

Japanese beetles are being found, mostly in low to moderate numbers. Remember to check spotted wing Drosophila traps. Bird feeding is extensive at most farms.

Grape berry size is extremely variable this season due to freeze damage that killed most of the primary flower buds. Japanese beetles are being found, mostly in low to moderate numbers. Grapes have put on a great deal of new growth over the last few weeks.