Grain Sorghum Response to Planting Date

Determining an optimal planting date for grain sorghum [ Sorghum bicolor (L.) Moench] is critical to maximize yield and economics of production. Therefore, research was conducted to quantify the response of grain sorghum yield to planting date and hybrid maturity and to develop an optimal planting date window for Missouri growers. Six grain sorghum hybrids were planted on five dates in 1992 and 1994 and four dates in 1993. Two hybrids were selected from each of three maturity classes (early, medium, and late) based on production conditions in central Missouri. The experimental design was a randomized complete block in a split‐plot arrangement with four replications. The main plots were planting dates and the sub‐plots were hybrids. Results indicate that planting date had a small but inconsistent effect on grain sorghum yield. The effects on yield of planting earlier or later than mid‐May were small and inconsistent among years, and we believe a rather wide planting date window exists for grain sorghum production in Missouri. We found no evidence that Missouri growers should switch to early‐maturing hybrids if planting is delayed into mid‐June.