Evaluation of Maize Hybrids for Resistance to Fusarium Stalk Rot

Stalk rot is one of the main diseases of maize, causing stalk lodging and trouble for harvesting. The most effective way for controlling the disease is cultivation of resistant hybrids. In order to determine the susceptibility of maize hybrids, to stalk rot, an experiment was conducted with 60 hybrids arranged in RCBD at Karaj and Sari Research Stations in 1998. Inoculation was carried out by using Drill/ toothpick method in the first extentded internode of maize plants at tasseling stage. Inoculated Plants were cut at the third internode after physiological maturity and vertical stalk sections of each hybrid were used for disease assessment using disease severity index based on the discoloration of pith tissue. Significant differences in response to stalk rot were observed among the hybrids. The majority of the hybrids were highly susceptible to stalk rot. The most susceptible hybrids were K1263/14-2 K1264/1 and B73 K12641. A few hybrids such as K3153 KC103/8 and K3153 K582/1-22 were moderately resistant. The overall results demonstrated that, early-maturing hybrids are more succeptible to stalk rot disease compared with late-maturing hybrids.