Resistance of the Soybean Cultivar Archer to Pythium Damping-Off and Root Rot Caused by Several Pythium spp.

Archer, a maturity group I soybean cultivar with demonstrated flood tolerance and resistance to Pythium ultimum, was compared with Hutcheson, a widely planted maturity group V cultivar in Arkansas, for resistance to P. ultimum, P. irregulare, P. aphanidermatum, P. vexans, and group HS. Emergence and establishment assays demonstrated that Archer had greater emergence and fewer disease symptoms after 10 days for all pathogenic species of Pythium than did Hutcheson. Archer also demonstrated higher root weights and fewer disease symptoms compared with Hutcheson in assays conducted for 6 weeks. Similar results were found using two different seed lots of the cultivars, suggesting that the results were not due to seed quality differences. This study indicates that resistance in Archer to Pythium damping-off and root rot compared with Hutcheson is robust, with efficacy over a number of Pythium spp. and a range of plant developmental stages.