EVALUATION OF METHODS FOR IDENTIFICATION OF CORN GENOTYPES WITH STALK ROT AND LODGING RESISTANCE

Methods of evaluating corn (Zea mays) stalk quality at or near anthesis and stalk rot susceptibility following inoculation were examined for 3 yr to identify those most effective in predicting premature death of plants and stalk lodging in multiple environments. Stalk quality measurements, including rind puncture, rind thickness, stalk push test, pith density or pith moisture, and susceptibility to the stalk rotting fungi Stenocarpella maydis and Colletotrichum graminicola, were determined on eight single-cross hybrids grown in Urbana, Illinois. Data on premature death of plants and lodging were collected from the same hybrids grown near Urbana in 1984 and at 16 locations throughout the midwestern United States in 1985 and 1986. Hybrid rank for rind puncture at anthesis was more consistently correlated with hybrid rank for lodging and premature death of plants than other stalk quality measurements or rating of stalk rot susceptibility following inoculation. Rind puncture was the most desirable method for evaluating stalk quality because it was simple to use and nondestructive to plants. This is the first study to demonstrate that measurements taken at anthesis or prior to anthesis can predict premature death of plants and lodging of corn hybrids in multiple locations.