Integrating Biorational Approaches to Control Plant-parasitic Nematodes and Weeds in Organic Vegetable Systems
Project Director
Abolfazl Hajihassani
Year Funded
2020
Award Number
2020-51106-32361
Funded Institution
University of Florida
Grant Program
ORG (Organic Transitions)
USDA NIFA Report
Project Overview
Plant parasitic nematodes and weeds impose significant yield constraints on organic vegetable crops in the Southern region. This project evaluated Bacillus thuringiensis (Bt) crystal proteins, metabolites of bacterial symbionts of entomopathogenic nematodes (EPN), NOP-allowed bio-nematicides, and cover crops against root-knot nematodes (RKN, Meloidogyne spp) and weeds in organic vegetable production.
Farmer Takeaways
(1) Sunn hemp cover crops suppress root knot nematodes, boost beneficial nitrogen-cycling nematode populations severalfold, and improve subsequent vegetable yields.
(2) The NOP-allowed neem-based products AzaGuard and EcoWorks show promise as part of an IPM strategy against the southern root knot nematode (Meloidogyne incognita).
(3) Cover crops of bahiagrass, marigold, millet, velvetbean, oats, and rye limit root knot nematodes by not hosting them, while lupine and hairy vetch are as susceptible as tomato.
(4) Costs of cover cropping and bio-nematicides can be offset by modest yield increases in high-value crops (e.g., ~300 lb/ac increase for zucchini).
(5) Crystal proteins in some Bt strains and bacterial symbionts of Steinernema entomopathogenic nematodes may contribute to control of plant-parasitic nematodes.
Project Outputs
Article: Cover Crops for Summer Nematode Management | Specialty Crop Grower
Marquez, J. and Hajihassani, A. 2023. Successional effects of cover cropping and deep tillage on suppression of plant-parasitic nematodes and soilborne fungal pathogens. Pest Management Science. 79: 2737-2747.
Marquez, J., Hajihassani, A., and Davis, R. F. 2022. Evaluation of summer and winter cover crops for variations in host suitability for Meloidogyne incognita, M. arenaria and M. javanica. Nematology, 24: 841-854.
Kicklighter, J., Kichler, J.M., and Hajihassani, A. 2020. On-farm evaluation of sunn hemp cover cropping on root-knot nematodes, 2018. Plant Disease Management Reports, 14: N030.