Soybean harvest started in the past 7 days in central Nebraska. Mid to later group II’s have pods and seeds that dried rapidly from the hot, windy 90’s degree temperatures. Irrigated yields look very good so far in the mid 70’s bu/ac. Non-irrigated are going to be less than 20 bu/ac in many areas. Some varieties have leaves staying on the plants longer and stems staying greener than normal. This results in a slower harvest.
Adequate and proper timing of irrigation water is going to be the main yield determinate. According to water meter readings, many wells pumped 3 to 4 times the water as last year on both soybeans and corn. Meeting soybean water use during pod elongation and pod filling is critical for high yields.
I have seldom, if ever, treated spider mites in soybeans. But this year, many fields were treated locally during early to mid pod fill. The treatments also controlled stink bugs. On untreated fields, stink bugs caused minor injury to developing seeds.
Early irrigated corn harvest looks very encouraging. Clear, sunny skies throughout the summer and some cooler nights later in August made an excellent grain fill environment. There will be some irrigated fields averaging 250+ bu/ac.
Problems with irrigation systems are now showing up dramatically. Nozzles that were plugged or that didn’t rotate properly left circular patterns in the field resulting in reduced yields. Swing-arm spans on center pivots that weren’t properly calibrated had noticeable yield effects.
Many corn fields received a post tassel fungicide again this year. But if spider mites and oat bird cherry aphids weren’t controlled at that time or later into August, significant damage may have occurred. Combines will find areas in the fields with plants that died prematurely from mites or that have black residue as a result of aphid buildup in spots. These two insects, if left uncontrolled, stressed plants and will affect over all yields.