Evaluation of Dry Bean Seed Treatment Products
February 21, 2007
Dry bean growers have historically utilized seed treatments as a standard practice to control losses from a complex of seed rot and seedling blight diseases and to reduce the potential for infections from surface borne bacterial blight. The complex of fungal seed rot and seedling diseases are caused by forms of Fusarium, Rhizoctonia, and Pythium. The necessity of utilizing seed treatments has been questioned by growers as they assess specific input costs during times of increasing costs of production. Both growers and industry personnel have expressed interest in an evaluation of dry bean seed treatments in the Carrington region since a moderate portion of the seed used in this and other areas is locally produced. The intent of this research is to provide current information on the response of dry bean seed treatment and the effectiveness of a broad spectrum of fungicides in controlling root and seedling diseases.
The field experiment to assess dry bean seed treatments was established at the Carrington Research Extension Center on May 26. The trial was planted on a Heimdal silt loam soil that was seeded to barley the previous year. Soil parameters on the site included: pH of 8.1; organic matter of 3.0%; phosphorous of 5 ppm; and soil nitrate at the 0 to 24 inch depth was 52 pounds N. The pinto bean cultivar Maverick was planted at a seeding rate of 80,000 pure live seeds per acre. Seeds were placed at a planting depth of 2 ½ inches to promote an extended time to emergence. Treatments were arranged as a randomized complete block design with four replications. Individual plots were four rows wide (30 inch spacing) and 25 ft in length. Seed treatments were applied based on the following rate equivalents: Captan 400 (Captan) at 2.0 fl oz/cwt; Allegiance FL (Metalaxyl) at 0.75 fl oz/cwt; Apron XL (Mefenoxam) at 0.32 fl oz/cwt; ApronMaxx RTA (Mefenoxam+Fludioxonil) at 5.0 fl oz/cwt; Dynasty (Azoxystrobin) at 0.153 fl oz/cwt; Cruiser at 1.28 fl oz/cwt; and Agri-Strep 500 (Streptomycin) at 0.83 oz/cwt. All data reported in the following table were collected from the interior two rows of the four row plots.
The trial results from the 2006 field trial are shown in the table on the previous page. Review of the data from 2006 will show that no differences among treatments were identified across the traits recorded. The growing conditions from the time of planting until the first trifoliate growth stage were very favorable for plant development. Average soil temperatures from planting until the time of emergence were 67 degrees F which created a favorable environment for rapid plant development. Limited rainfall and low humidity continued throughout the growing season that further limited potential for plant disease to impact dry bean performance. These data provide a review of the influence of seed treatments on dry bean performance in an environment unfavorable for disease development and expression. The growing season of 2006 provided a perspective of the impact of seed treatments; however the conditions were not typical of the regions long-term environment. The intent of the Carrington REC would be to continue this evaluation in another season when cooler and wetter weather conditions prevail to reflect the typical conditions for planting dry beans in the region.