Entomology and Plant Pathology

Hatch Project TEN00341 (Regional Project S-1028): Ecological and Genetic Diversity of Soilborne Pathogens and Indigenous Microflora. Objectives: (1) Examine commercial and non-commercial biocontrol agents for use as seed treatments, in-furrow treatments or as potting mix amendments. (2) Examine the effect of cultural practices on soilborne pathogens and plant growth. Approach: The ability of biocontrol agents to control soilborne pathogens will be evaluated in a series of field experiments. Their effectiveness will be tested under various field conditions and compared with the chemical control standards used to control the pathogens attacking Tennessee’s numerous vegetable crops. These pathogens include Rhizoctonia solani, Pythium spp., Macrophomina phaseolina, Phytophthora spp., and Sclerotium rolfsii. Vegetable crops include snap bean, tomato, cucurbit crops, and greens. Depending on the nature of the biological agent, treatments will either be applied to seed, applied in-furrow, or mixed with the peat-based potting mixes used to grow vegetable transplants. The effects of treatments on disease incidence, plant survival, growth, and yield will be recorded. Greenhouse and growth chamber experiments may supplement the field tests to gain additional insights on treatment efficacy. Broccoli will be used in regional trials as a test crop for field evaluation of biocontrol agents and to determine their effects on plant growth and yield under different field conditions. Split-plot and factorial designs will be used to evaluate the effects of cultural practices on soilborne pathogens and on biocontrol efficacy. Cultural practices that might be studied in this way include cultivar, fertilizers, growth enhancers, herbicides, insecticides, tillage practices, irrigation, and crop rotation.