Is it time to switch seeds?

May 09, 2022

Cool wet weather has delayed planting throughout our trade territory. A few growers have been fortunate enough to get a few acres in, while others have not had the opportunity to plant a kernel of corn or put a bean in the ground. I have many customers that are concerned about the date on the calendar and questioning whether they should plant a shorter season seed or stick to their original plan.

Soybeans are an easier answer than corn, as we are not behind on planting them, and I would not recommend shortening a soybean variety until mid-June or after, as the longer varieties offer more time to fill pods and give us a larger potential to raise more bushel. That is because soybeans are daylength determinant, which means that they will mature as days start to shorten in the fall. The longer we can keep a soybean in the productive state the more pods they should develop.

Corn however matures by Growing Degree Days (GDD). This means that the weather after a corn plant is in the ground makes a significant impact on the maturity date. A 113 day variety needs at least 2702 GDD to reach physiological maturity and a 111 day variety needs 2680 GDD to reach the same maturity. Fall weather has a large impact on moisture of a harvested crop as well. If we have several weeks of warm dry weather after black layer the chance of harvesting a dry crop is substantially higher than when we are dealt a cool wet period of time in the fall. 

Weather after planting is a much larger impact on the maturity of a corn plant than a soybean plant. I would recommend staying with your planned planting recommendations until the third week of May and then reassess your hybrid selections.