Alterations of Yield, Test Weight, and Protein in Lodged Grain Sorghum1

Lodging can be a detriment to yield and quality of grain sorghum (Sorghum bicolor (L.) Moench). However, the magnitude of the changes which occur in yield and quality has not been determined. An experiment was conducted to measure the alteration in yield, protein, and test weight of this crop by artificially simulating two types of lodging observed to occur naturally in the field. Plants were manually forced to a 45‐degree angle (root lodging) or the stalk broken in the vicinity of the peduncle node (stalk break) at heading, early dough, and hard dough growth stages. Lodging treatments decreased yield and test weight for all years studied. Results for 1973 showed a general increase in protein concentration from lodged plants, but 1974–75 increases were not significant. Grain yields were lowest in the earliest and most severely lodged treatments. Yield reductions were due primarily to reduced test weights. Total protein production (concentration × yield) was determined by level of grain yield rather than protein concentration of the grain. It was concluded that yield losses occur in lodged plants due to a hindrance of physiological function and this loss is independent of that which may occur mechanically during harvest.