2002 Corn Performance Tests
The Georgia Agricultural Experiment Stations
College of Agricultural and Environmental Sciences
The University of Georgia

Research Report Number 684
October 2002

Environmental conditions in Georgia during the 2002 growing season were favorable for buildup of insect populations large enough to cause damage to corn. Generally, this damage is greatest in late-planted corn left in the field for an extended period past maturity.

It is recommended that hybrids resistant to insects be planted. These hybrids are presently the only economical means, in late plants, for the reduction of damage by corn earworm, fall armyworm, maize weevil, and pink scavenger caterpillar. Consult your local county agent and/or extension entomologist for additional control recommendations for other insects.

Percent yield losses attributable to all insects for individual hybrids varied from 1.2% to 7.3% and are reflected by VG, G, F, P, and VP ratings in the tables. Hybrids in the tests sustained average yield losses of 3.6% and 4.3% in the mid and full-season, and short-season hybrid tests, respectively. The mean level of overall yield loss for all tests was 4.0%. Of the total loss, about 34% was attributable to ear injury by the corn earworm, 58% to the pink scavenger caterpillar, and 8% to the maize weevil. Losses to the pink scavenger caterpillar and maize weevil are based on damage by multiple generations of these insects as the corn dries in the field. Timely harvest will substantially reduce losses to these two insects.

Evaluations for resistance to corn earworm and fall armyworm, maize weevil, and pink scavenger caterpillar are given for hybrids in the following tables. Lettered ratings refer only to relative resistance to insects and are not indicative of yield. Thus, a hybrid rated poor for resistance to insects might possibly be among the highest yielders and vice-versa. See the yield data in other tables for this information.

Husk tightness ratings were assigned using a scale of 1 to 5, in which 1 = very loose and 5 = very tight. No average rating was greater than 4.0; therefore, only loose, medium, and tight ratings are given in the tables.

Both the hybrid tests (mid and full-season, and short-season) were planted April 24, 2002. Plantings were delayed in 2002 due to dry field conditions during March and April. Plots were thinned to 20,000 plants per acre. Ratings for overall insect damage were completed during October.

Data for this section were compiled by J. M. Cook, J. C. Mullis, and Robert Giddens of the United States Department of Agriculture, Crop Genetics and Breeding Research Unit, and Georgia Coastal Plain Experiment Station, Tifton, Georgia.