Submitted to: Biological and Cultural Tests for Control of Plant Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 1998
Publication Date: N/A
Technical Abstract: Breeding selections and standard cultivars were evaluated for their reaction to diseases that commonly occur in Idaho. Verticillium wilt, early blight, and common scab evaluations were done in fields at the University of Idaho Research Center, Aberdeen. Trials were grown in two fields as randomized complete blocks in 3 replications. Both sites were sprinkler irrigated, and normal fertility practices were followed. Natural soilborne inoculum of V. dahliae occurred at both sites, and early blight spreader rows of cv Pioneer were interplanted with plots at one site. It is expected that early blight symptoms would have been more severe if contact fungicides for late blight control had not been used. No late blight occurred in the plots. The growing season was unusually cool and wet through July. Soft rot evaluations were done by inoculating tuber samples harvested from one of the test sites in mid Sep using 10 6 cells/ml Erwinia carotovora var. atroseptica. Tubers were evaluated after 5 days incubation in a mist chamber at 20 degrees C. The least significant difference test was used to separate means. Advanced breeding selection A83008-8 showed the best Verticillium and early blight resistance of all clones tested and also had good soft rot resistance. The new variety, Umatilla Russet, showed Verticillium wilt susceptibility similar to Russet Burbank but was slightly more susceptible to early blight. Another new variety, Legend Russet, was resistant to Verticillium and moderately susceptible to early blight. Four Russet Norkotah clonal selections, CORN8, TX NS112, TXNS223, and TXNS278 tended to have less susceptibility to early dying disease than the standard variety (not significant however at P=0.05).