Submitted to: Plant Disease Management Reports
Publication Type: Other
Publication Acceptance Date: July 15, 2009
Publication Date: August 18, 2009
Citation: Porter, L. 2009. Assessment of organic seed treatments in a pea disease nursery to manage seed and root rot on peas, 2008.. Plant Disease Management Reports. 3:ST023. Online publication. doi: 10.1094/PDMR03. Technical Abstract: Twenty-one organic seed treatments consisting of biological, non-biological and a combination of each were evaluated in a pea root rot field nursery in Prosser, WA for their potential to manage seed and root rot pathogens of processed peas. Non-treated seed and a commercial seed treatment (Captan + Allegiance) were used as controls. The soil from the field site consisted of a mean of 20.8 colonies of Pythium spp. per gram of soil and 54.2 colonies of Fusarium solani per gram of soil. None of the seed treatments significantly increased emergence compared to the non-treated control (NTC). Captan + Allegiance, corn flour + Nordox, Biomin Boron, Nordox 2 and Bio N all significantly increased plant height compared to the NTC; all other seed treatments were not significantly different from the NTC. Root disease severity was significantly less for seed treated with Captan + Allegiance, and Bio N than for the seed of the NTC. Root disease severity was significantly greater for seed treated with Biomin Boron and Triggrr than for the NTC. None of the treatments were significantly different from the NTC in yield. Among the organic seed treatments tested, Bio N appears to be the most promising since it increased plant height by 2.5 cm above that of the NTC and had a significantly lower root disease severity value than the NTC that was equivalent to the Captan + Allegiance commercial seed treatment. Nordox 2 significantly increased plant height by 3.7 cm above that of the NTC. Nordox currently can only be used in organic production if there is a documented copper deficiency in the soil. It is not known if this product improved plant height due to better plant nutrition or if it was due to its properties as a biocide to seed and root rotting pathogens of peas.