Evaluation of late maturity group IV (4.6-4.7) soybean cultivars to purple pod stain

摘要

To quantify soybean pod susceptibility to Cercospora kikuchi, purple pod stain (PPS), thirty-nine maturity group IV (4.6-4.7) late soybean lines from the 2013 Mississippi soybean variety trial were screened from a field planted at Stoneville, MS. Seeds were planted in 10 ft. long single-row plots with 8 seeds/ft. of row on 40-in. row spacing. The experimental design was a randomized complete block with four replications. Pods were manually harvested from each plot when the plants were mature. Pods were surface-disinfected in 0.5% sodium hypochlorite for 3 min, rinsed in sterile distilled water, and then placed in humidity boxes, ten pods per box for each line and rep. A total of 40 pods from each line were tested for pod infection by C. kikuchi. Boxes containing the pods were inoculated with Cercospora kikuchi. After 4 d of incubation at 24°C, the incidence of C. kikuchii growing on the pods was recorded. Data were analyzed using the SAS GLM procedure (version 9.3 SAS Institute, Cary, NC).