Field evaluation of early maturity group IV soybean cultivars for resistance to southern stem canker, 2006

摘要

The susceptibility of 61 very early maturity group IV soybean cultivars to stem canker was evaluated in a trial at Stoneville, MS. Soybean cultivars were planted in sandy loam soil on 25 Apr 06 at a rate of 10 seed per row ft in a randomized completeblock design with four replications. Plots were one row wide, 13.3 in. spacing,and 20 ft long. The first 12 plants of each plot were inoculated with Diaporthe phaseolorum var. meridionalis by inserting infested toothpicks in the upper 1/3 of the plant at an internode on 5 Jun 06 for both trials. Disease resistance was rated on 31 Jul 06 based on a 1 to 5 rating scale where 1 = resistant, 2 = moderately resistant, 3 = moderately susceptible, 4 = susceptible, and 5 = very susceptible. Disease rating was reported as an average of eight replications (two trials, each with four replications).