Mechanisms and Efficacy of Brassicaceae Seed Meal-induced Disease Control

Development and application of non-fumigant measures for the control of soilborne diseases in field level production systems is limited by the capacity to consistently predict efficacy. Although organic amendments have repeatedly been evaluated for the potential to provide an environmentally sustainable means to manage soilborne diseases, adoption of such methods has been limited to very specific environments, such as greenhouse systems, or specific soils. In many instances, failure to resolve the source of variability in efficacy stems in part from an absence of knowledge concerning the operative mechanism of disease control. Effective application of compost amendments experience further difficulties as rates of 5-20% (vol/vol) or higher are commonly required to achieve disease control even in non-complex environments such as containerized production systems. Such rates may not be economically viable or physically practical in standard field production systems. In addition, often times the amendment suffers from a lack of consistent composition, and potentially mode of action. The inability to standardize composition and quality of compost products further obscures the capacity to reliably predict disease control performance.