Spring 2014 has been quite challenging with wet soil and cold temperatures. We’ve received several calls and e-mails regarding soybean seedling damage (from those who have actually been able to plant). It appears that some soybean fields were hit with a “trifecta” of stress issues. What should we be looking for in terms of frost, PPO herbicide injury, and disease?
Frost can occur at air temperatures between 32 to 36 degrees F while a freeze requires temperatures less than 32 degrees. From the weather records I have looked over, air temperature dropped as low as 34 degrees F in northern Ohio on May 16. Soybean plants should be assessed for frost damage at least five days after suspected injury to inspect for regrowth. If damage occurs above the cotyledons, the plant will likely recover. If damage occurs below the cotyledons, the plant will not recover. Look for a discolored hypocotyl (the “crook” of the soybean that first emerges from the ground) which indicates that damage occurred below the cotyledons. … Continue readingRead More »