Northwest Michigan fruit report – April 23, 2019
Welcomed warm weather came to the region over the weekend, but cooler temperatures are in the forecast and will likely keep development steady for the remainder of the week.
The last two days have finally started to feel like spring! We hit a daytime high of 78 degrees Fahrenheit on Monday, April 22—Earth Day! Easter Sunday was also a perfect day for an egg hunt. However, those warm temperatures came to an abrupt halt this morning, April 23, when a cold front came through, and the predicted daytime high for today is only 48 F.
With the recent warm days, our growing degree day (GDD) accumulations jumped up to 92 GDD base 42 and 36 GDD base 50. We are about 50 GDD base 42 and 30 GDD base 50 behind our 30-year average. Those warm conditions really moved things along, and the grass almost seemed to green overnight.
Temperatures for the remainder of the week and into the weekend will stay cool, and there is more rain in the forecast for Thursday and potentially another shower on Saturday evening. We suspect the cool down will keep development fairly steady for the next week.
At the Northwest Michigan Horticulture Research Center, Gala buds have started to push the tips of new leaves, but most of our Honeycrisp buds still remain silvery and tight. With green tissue starting to show on earlier varieties in the area, growers have started early season apple scab management programs. The Michigan State University Extension fruit team will be using RIMPro to assist with determining apple scab spore discharge during the primary stage of this disease. For the northwest region, we have three stations with RIMPro access this season: Benzonia, East Leland and Williamsburg Tower.
The recent warm up also pushed the tips of leaves on early variety sweet cherries. These new leaves are sensitive to some chemistries like chlorpyrifos and copper that are sometimes used in dormant season sprays for San Jose scale and bacterial canker. Most of the station’s tart cherries are at side green at this time.
The station’s traps were put in place yesterday. With a slower start to spring, oriental fruit moth are the only traps baited with lures. We will deploy additional lure for other early season pests, like american plum borer and San Jose scale, in the coming weeks. Last season, we had a healthy population of San Jose scale in our sweet cherry variety trial block, but that block was removed last fall. Fortunately, we found another healthy San Jose scale population in our pears that we will monitor this season; thus far, there is no obvious development of the overwintering scales in the pears.