There has been a lot of interest in SC over the past few years in double-cropping soybeans behind corn. The main question that I hear is, “What is the last day I can plant soybeans and make a crop?”
Since 2022, we have been researching this system with the hope of helping answer some of these questions. Based on our planting date data, by the end of this weekend, we need to consider parking the planter. While we can extend our planting window beyond this August 10th date the yield penalty with these soybeans really just starts dragging down the average yield.
Our data suggest that we are losing around 0.5 bushels per day in this system, so between the time this post is published and Monday, soybean yield potential will have lost around 1.5 bushels per acre. One and a half bushels may not sound like much, but when the yield potential is only 25 to 35 bushels per acre, we are talking almost 6% in 3 days!
Other news, our earliest planted soybeans and early maturity group varieties are rapidly approaching R6.5, the growth stage in which we trigger desiccation applications. No soybean rust has been found in SC to-date. A few reports of frogeye leaf spot in susceptible varieties are showing up, given the frequent rains/showers and cloudy days, we do have some favorable climate for disease to build up.
If you have any questions about desiccation timing in soybeans or fungicide use/applications, let us know!
