Hot, dry weather prevailed over most of Minnesota this past week. According to the USDA NASS Minnesota Field Office, statewide temperatures averaged 4 degrees above normal. Limited rain fell in localized areas with the greatest weekly precipitation of 0.74 inches recorded in Pipestone.
Topsoil moisture supplies were rated 78% adequate to surplus, down from 94% just one week earlier. Corn throughout southern and South Central Minnesota is starting to tassel. As of the end of June, southern Minnesota was at 991 degree days (DD) accumulated since May 1. This is 121 DD above the historical average of 870 DD!
Soybean fields in the state are now flowering and beans planted around May 1 are at V6 and R2. The heat stress from July 1-5 may have caused some flower abortion on the earlier planted soybeans.
We’re already finding some aphids in earlier planted soybeans, so be scouting earlier this year than in the past.
Some early planted soybean fields are also showing signs of Soybean Cyst Nematode. The Lamberton Experiment station reports seeing female nematodes on soybean roots for more than one week now. Identify these problem fields and note whether you need to plant your soybeans a couple weeks later in the future. With later planting dates last year, there were hardly any yellow soybean fields. With earlier planting dates this year, almost every field has some yellowing pockets.