EVALUATION OF METHODS FOR IDENTIFICATION OF CORN GENOTYPES WITH STALKROT AND LODGING RESISTANCE

Methods of evaluating corn (Zea mays) stalk quality at or near anthesi s and stalk rot susceptibility following inoculation were examined for 3 yr to identify those most effective in predicting premature death o f plants and stalk lodging in multiple environments. Stalk quality mea surements, including rind puncture, rind thickness, stalk push test, p ith density or pith moisture, and susceptibility to the stalk rotting fungi Stenocarpella maydis and Colletotrichum graminicola, were determ ined on eight single-cross hybrids grown in Urbana, Illinois. Data on premature death of plants and lodging were collected from the same hyb rids grown near Urbana in 1984 and at 16 locations throughout the midw estern United States in 1985 and 1986. Hybrid rank for rind puncture a t anthesis was more consistently correlated with hybrid rank for lodgi ng and premature death of plants than other stalk quality measurements or rating of stalk rot susceptibility following inoculation. Rind pun cture was the most desirable method for evaluating stalk quality becau se it was simple to use and nondestructive to plants. This is the firs t study to demonstrate that measurements taken at anthesis or prior to anthesis can predict premature death of plants and lodging of corn hy brids in multiple locations.