Dry Bean Disease Control Research Program for the Northern Plains 2002
April 15, 2003
By Luis del Río Mendoza
Department of Plant Pathology
North Dakota State University
Significant reductions in white mold incidence were observed in plots treated with 1 or 2 oz of the herbicide Phoenix (lactofen) in experiments at Oakes and Carrington. However, the generally low disease incidence prevented these from translating into significant yield differences. This compound will be evaluated one more time at two locations in this coming season. Intercept, a biofungicide based on the fungus Coniothyrium minitans, was evaluated at two locations. Experiments compared the efficacy of fall and spring applications of 1 and 2 lb/A of Intercept. Although weather conditions prevented white mold from developing in experimental plots, soil samples collected at the end of the growing season indicated that a high level of parasitism (over 30%) was present in all infested plots. The same plots used in 2002 will be visited in 2003 to collect additional data.
No field epidemics were detected in the 2002 season, although infected seed samples were identified from two fields in North Dakota. In collaboration with the NDSU breeding program more than 100 breeding lines were screened for their reaction to anthracnose race 73. Several resistant materials were identified. This activity will continue in 2003.
Twelve advanced materials from the NDSU dry bean-breeding program were evaluated for root rot and bacterial blight resistance in Fargo in this season. The best lines were identified and the information collected was provided to the breeding program. This collaborative activity will continue in future years. The impact of treating seeds with nitrogen-fixing bacteria and Bacillus spp., a biocontrol agent on control of root rots was evaluated in a field experiment with four replications established in Fargo. Traditional chemical control treatments were used as controls. Yields were significantly higher in plots treated with a mixture of captan (fungicide) and the nitrogen-fixing bacteria or with the nitrogen-fixing bacteria and the biocontrol agent than in untreated plots. These compounds will be evaluated again in this coming season.
A field survey that covered 24 commercial fields in counties in the northern tier of the state was conducted. Plant samples were collected at each place and information regarding disease incidence was recorded. No rust epidemics were detected in the 2002 season. Commercial cultivars with known rust resistance were not infected by rust. Monitoring of fields will continue in this season.
Over 20 elite bean breeding lines and cultivars included in a regional white mold nursery were evaluated for their reaction to common bacterial blight. Significant differences were detected among materials. Information was handed to the NDSU breeding program. This collaborative effort will continue in future years.
Research activities planned for the coming season include the evaluation
of new chemistries for control of white mold, as well as the evaluation
of a forecasting system that predicts peaks of apothecia production as a
tool for white mold control.