By Nicolle Ritchie and Angie Gradiz
Weather
Except for a couple of light pop-up showers, the past week was dry and warm with cool nights. Temperatures will increase a little for the upcoming week, although precipitation is expected to remain low. With potato harvest ongoing and seed corn harvest set to start soon, dry weather is good news.
Crops and pests
Full-season soybeans are finishing R5 (seed fill) and entering R6 (full seed). Continue to watch out for red crown rot, which is a disease not yet confirmed in Michigan that looks similar to sudden death syndrome and brown stem rot. If you suspect red crown rot, submit a sample to the Michigan State University Plant and Pest Diagnostics Lab. Michigan Soybean Committee and the United Soybean Board will cover the diagnostic fees. You can also request a soybean sampling kit.
Corn kernel development continued, with fields mostly ranging from R4 (dough) to R5 (dent). Seed corn continues to dry down, and harvest will begin soon. Tar spot was confirmed in St. Joseph and Van Buren counties this week. Unless the tar spot pressure is considerable, there is little benefit to going after tar spot with a fungicide at this point in the season.
Late blight was found in St. Joseph County potatoes two weeks ago, and there have been no further detections. Last week, the farm with the late blight detection generously hosted an in-person identification and management meeting, organized by crop consulting company Mid-Michigan Agronomy, who detected and genotyped the late blight.
Source : msu.edu