West central Michigan tree fruit update – Aug. 10, 2021
Peach harvest is underway. The MSU AgBioResearch Earl and Linda Peterson West Central Michigan Research and Extension Center was dedicated on Aug. 5, 2021.
The weather continues to throw everyone for a loop. In most situations, we have drier weather during July and the first of August, but this year seems to be wetter than most years. We had a dry spell from July 30 through Aug. 6, but over the weekend we had rain on Saturday, Sunday and into Monday (Aug. 7-9). The Michigan State University Enviroweather station in Hart recorded 0.13 inches on Aug. 7, 0.85 inches on Aug. 8 and 1.12 inches on Aug. 9. The Enviroweather station in Hart has recorded 2,559 growing degree days (GDD) base 42 and 1,658 GDD base 50.
Peach harvest is underway in the west central region. Fruit is looking good and has good size. The rain may have impacted the intensity of flavor of some varieties.
Apples are sizing well with the recent moisture, and the fruit is beginning to color. We anticipate harvest to be earlier than in past years.
As many growers have finished harvest, we recommend trees keep their leaves into September to minimize chance of cherry leaf spot damage if we have a hard winter. Chlorothalonil or captan are good choices for a post-harvest application. If growers have been clean of leaf spot until now, these orchards may not need a post-harvest application.
We rated our leaf spot efficacy trials, and even the UTC is surprisingly clean this season compared to past seasons, particularly those with wet springs that really jump start leaf spot infection early. This dry spring minimized early infections, and the weather reduced the amount of leaf spot we are seeing in orchards later into the season.
Kenna Schwass is scouting in the west central region for insect pests in peaches and apples for the remainder of the season.
We caught only one peach tree borer in the past week at one peach orchard in Elbridge, Michigan. The trap was set at the Earl and Linda Peterson West Central Michigan Research and Extension Center last week, and we caught 31 peach tree borers this past week. We have caught an average of two greater peach tree borer moths this week in three traps in peaches.
We observed variability in oriental fruit moth in our three traps, but all were low numbers: zero in New Era, seven in Elbridge and three at the West Central Michigan Research and Extension Center.
We caught no oriental fruit moth this week in apples in a block in Elbridge and none at the orchard in New Era. Codling moth numbers were zero at our trap in Elbridge and two moths was found in the codling moth trap in New Era.
We found 70 San Jose scale males in Elbridge and 30 in New Era. Growers should be proactive in apples as this is the stage of this insect that can injure fruit.
We did not detect obliquebanded leaf roller in our traps in any apple traps this week. We found no black stem borers in our traps this week.