Variation of Protein and Fat Concentration among Commercial Corn Hybrids Grown in the Southeastern USA

Protein and fat concentration (percent) are factors in determining corn ( Zea mays L.) grain feeding value. Our objective was to examine the variation among commercial corn hybrids for concentration and yield (lb/acre) of protein and fat in grain grown with or without irrigation. The field experiments were conducted in Georgia in 1985 and 1986 with no irrigation at Tifton and Midville and with irrigation at Tifton and Plains. Eleven short‐, thirteen mid‐, and four full‐season commercial hybrids were evaluated. Irrigation increased grain yield 127 bu/acre and decreased protein concentration 1.9% averaged across maturity groups. Maturity group had no effect on any of the variables that were measured. Hybrid affected grain yield, protein and fat concentration, and protein and fat yield. Protein and fat concentration ranged from 7.8 to 12.4% and 2.6 to 3.5%, respectively. Protein and fat yield ranged from 93 to 920 and 206 to 323 lb/acre respectively. Protein yield was positively correlated with grain yield. Protein yield was negatively correlated with protein concentration for mid‐ and full‐season hybrids in the nonirrigated test, and positively correlated for all maturity groups in the irrigated test. Fat yield was positively correlated with grain and protein yield, and fat concentration for all maturity groups, but not correlated with protein concentration. Corn producers should consider grain yield when selecting a hybrid for nonirrigated production. Those producers that have irrigation available should consider both grain yield and protein concentration when selecting a hybrid.