Wild-proso millet differentially affects canopy architecture and yield components of 25 sweet corn hybrids

Knowledge of cultivar-specific information on crop tolerance, the ability of the crop to endure competitive stress from weeds, has garnered recent interest in organic crop production. Twenty-five commercial sweet corn hybrids from nine seed companies were grown in the presence and absence of wild-proso millet (Panicum miliaceum L.) to 1) quantify tolerance in crop growth and yield to weed interference; 2) determine associations between tolerance in crop growth and yield; and 3) identify hybrids differing in tolerance to weed interference. Despite large differences in canopy architecture among hybrids, crop height and leaf uprightness were minimally affected by weed interference. In contrast, wild-proso millet interference reduced ear number 11% to 98% and ear mass 24% to 82% depending on the hybrid. The ability of a hybrid to make small growth adjustments in the presence of wild-proso millet appeared to have no relationship to yield tolerance. The least competitive hybrids were 'ACX1413', 'Optimum', 'Quickie', 'Spring Treat', and 'Sugar Buns'. The most competitive hybrids were 'Code128', 'Coho', 'El Toro', 'EX 8716622', and 'Legacy'. Although some exceptions were observed, in general, the longer-maturity processing hybrids were more competitive with wildproso millet than the earlier-maturing fresh market hybrids.