May 5, 2015

Small Fruit Report: Central Michigan

Small fruit crops in West Central Michigan are developing rapidly after a long period of low temperatures that maintained the crop dormant for at least two more weeks than the previous year.

Current temperatures are back to the normal temperatures typical of the early spring. During the past 10 days daily temperatures started climbing into the upper 60s promoting better conditions for plant development. During this period, maximum daily temperatures have been on average 64 degrees with an average minimum of 38 degrees. So far, only short periods of freezing temperatures were observed in the area on April 26 and 28. This did not cause a problem for blueberries or strawberries, the two crops that are in active development at this time.

Regarding crop development, blueberries are developing fast thanks to high temperatures from the past week.

Despite the prevailing good weather, the impact of the harsh winter conditions that occurred in January and February is showing in most blueberry varieties. Fields are with few flower buds and in varieties like Elliott and in some Bluecrop fields flower buds that are opening are empty.

The least affected variety is Jersey that shows more viable flower buds than any other variety. These conditions may have a substantial impact on the size of the blueberry crops for this season.

In most cases, winter damage affected entire shoots that, in some fields, reached more than half of the plant’s structure. Growers may need to do extensive pruning of damaged canes to promote new growth.

In regard to early insect pests, degree day (base 50 degrees) accumulation since March 1st is around 135 and the weather forecast for the next five days predicts a degree-day accumulation of 230 by May 11. Therefore, we are expecting the beginning of the emergence of the overwinter generation of the Cherry Fruit Worm within the next few days, especially in southern counties. At this time we recommend placing the pheromone traps to initiate the monitoring of this pest.

— Carlos Garca, Michigan State University