Northwest Michigan fruit update – April 16, 2019
A slow start to spring and mild, wet weather ahead.
Despite a few warmer days over the last two weeks, we have had a slower than normal start to spring. The Michigan State University Traverse City (NWMHRC) Enviroweather station has accumulated 39.4 growing degree-days (GDD) base 42 and 11.3 GDD base 50 since Jan. 1, 2019 which is slightly ahead of last season’s accumulations at this time. However, these accumulations are behind our 29-year average of 113.2 GDD base 42 and 43.5 GDD base 50. This slow GDD accumulation is predicted to continue until the later part of this week, which is forecasted to warm up and reach into the low 60s by Easter Sunday. The mid to long range forecast is suggesting temperatures will continue to increase as we move into the growing season, which will result in an overall warmer than normal spring with normal to above normal precipitation and little chance for frost.
A few storm systems are also predicted to pass through the area bringing a chance for rain tonight through Friday. The first, a smaller system, will arrive today/tonight followed by a second larger system. The second system should arrive early tomorrow, bringing rainfall that is predicted through tomorrow afternoon and potentially drying up by Friday.
Additional details on Michigan’s forecast can be found on MSU Extension’s Fruit & Nuts website under the Weather tab). As part of this year’s fruit regional reports, our team will provide recorded weather forecasts presented by MSU’s agricultural climatologist Jeff Andresen, and the latest reports should be posted by the end of the day on Tuesdays.
Pest and disease
Some growers took advantage of warmer, drier weather last week to make copper applications targeting bacterial pathogens like canker and fire blight. However, cold temperatures, wet orchards and snow have prevented most pest/disease management activity in orchard. We have observed swollen buds with side green visible on sweet and tart cherries at the Northwest Michigan Horticulture Research Center. Apple buds are still relatively tight, and there is still time to put on dormant sprays if the weather and orchards are favorable. Although Andresen is predicting few frost events in the near future, watch for overnight freezing temperatures with oil applications.
Last season, San Jose scale was a significant challenge for growers in the area. This pest has been problematic in sweet cherries causing substantial losses of fruiting wood; it has also become increasingly prevalent in apples across the state. Dormant to pre-bloom timing is the first opportunity of the season to take action against this pest when weather conditions are safe for the use of oil. An oil application would provide activity against overwintering European red mite eggs which were also in high populations in some apple orchards last season. Please review the article, “Early season sprays for managing San Jose scale,” for more management information for this pest in apples and sweet cherries.
Lastly, we encourage growers to review the annual pesticide registration and label updates that were recently published by John Wise, MSU Department of Entomology.