Effect of Defoliation at Different Stages on Grain Sorghum

Loss of leaf area usually results in yield loss grain crops, but the amount varies with extent and timing defoliation. Grass such as corn sorghum, are particularly sensitive to near time seed set because there is little opportunity for plant compensate. An experiment quantify reductions associated various levels defoliation imposed at different stages sorghum development was conducted Manhattan, KS, 2022. Target defoli­ations 0, 33, 66, 100% were 5-leaf, flag-leaf-appearance, half-bloom, hard-dough stages. Defoliation 5-leaf resulted minimal unless rate 100%, which delayed heading reduced head size size. Leaf losses 50% or more hard dough stage caused reduc­tions only about 10–12%. Yield greatest when lost flag appearance half bloom. 60% 25% 75%, respectively. These combina­tions