Nematode management in Florida vegetable and ornamental production

Authors: Burelle, Nancy; IRIARTE, FANNY - University Of Florida; BUTLER, DAVID - University Of Tennessee; Hong, Jason; Rosskopf, Erin

Submitted to: Outlooks on Pest Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2014
Publication Date: 8/1/2014
Citation: Burelle, N.K., Iriarte, F.B., Butler, D.M., Hong, J.C., Rosskopf, E.N. 2014. Nematode management in Florida vegetable and ornamental production. Outlooks on Pest Management. 25(4):287-293. https://doi.org/10.1564/v25_aug_10.
DOI: https://doi.org/10.1564/v25_aug_10

Interpretive Summary: Commercial vegetable and ornamental crop production occurs in humid sub-tropical to tropical climates throughout Florida. Tomato, pepper, and strawberry account for the majority of soil fumigants used in vegetable and fruit crops in Florida, with cut flowers and caladiums accounting for significant fumigant use in ornamental production. Root-knot nematodes cause severe galling and necrosis on roots of most vegetable and ornamental crops grown in Florida. Many weeds are also susceptible to these nematodes, and harbor nematode populations between crops. Root-knot nematodes cause severe root disease, restricting water and nutrient uptake, and providing entry points for other soilborne pathogens. Increasing restrictions on chemical soil fumigants have necessitated the development of new options for plant-parasitic nematode management in vegetable and ornamental crop production. USDA-ARS researchers with their collaborators are developing new tactics to manage both nematodes and weeds in vegetable and ornamental crop production systems. These tactics include the low-risk chemical ‘SPK’, steam, and anaerobic soil disinfestation (ASD), and these approaches are often integrated into site-specific management plans. The low-risk chemical SPK is a unique formulation of organic acids with efficacy against root-knot nematodes, weeds, and soilborne plant pathogenic fungi and bacteria. This material is a non-fumigant and poses minimal risk to the environment, applicators, and by-standers. Steam is another effective method for broad-spectrum soilborne pest control including nematodes, weeds, and fungal pathogens. However, logistics and expense of steam application require more research and may limit adoption in the short-term. ASD uses a combination of solarization to raise soil temperatures, organic amendments to stimulate microbial activity, and soil saturation to create anaerobic conditions in soil. In Florida field trials, ASD has reduced plant-parasitic nematodes in soil compared to solarization alone, and has provided excellent weed control in raised-bed vegetable production. While integrated nematode and weed control tactics are preferred, stand-alone approaches that can be incorporated into production systems are also being investigated for nematode control. These approaches include vegetable grafting and biological control with the nematode-parasitic bacteria Pasteuria penetrans. Grafting for root-knot nematode control in tomato has been successful in reducing nematode populations in roots and soil, and has improved yield in melon compared to non-grafted plants. Greenhouse and microplot trials on P. penetrans are ongoing while initial results indicate good potential for field application of this new biological control agent.

Technical Abstract: Increasing restrictions on chemical soil fumigants have necessitated the development of new options for plant-parasitic nematode management in vegetable and ornamental crop production. USDA-ARS researchers with their collaborators are developing new tactics to manage nematodes and weeds in vegetable and ornamental crop production systems. These tactics include the low-risk chemical ‘SPK’, steam, and anaerobic soil disinfestation (ASD), and these approaches are often integrated into site-specific management plans. The low-risk chemical SPK is a unique formulation of organic acids with efficacy against root-knot nematodes (Meloidogyne spp.), weeds, and soilborne plant pathogenic fungi and bacteria. This material is a non-fumigant and poses minimal risk to the environment, applicators, and by-standers. Steam is another effective method for broad-spectrum soilborne pest control including nematodes, weeds, and fungal pathogens. Logistics and expense of steam application require more research and may limit adoption in the short-term. ASD uses a combination of solarization to raise soil temperatures, organic amendments to stimulate microbial activity, and soil saturation to create anaerobic conditions in soil. In Florida field trials, ASD has reduced plant-parasitic nematodes in soil compared to solarization alone, and has provided excellent weed control in raised-bed vegetable production. While integrated nematode and weed control tactics are preferred, stand-alone approaches that can be incorporated into production systems are also being investigated for nematode control. These include vegetable grafting and biological control with the nematode-parasitic bacteria Pasteuria penetrans. Grafting for root-knot nematode control in tomato has been successful in reducing nematode populations in roots and soil, and has improved yield in melon compared to non-grafted plants. Greenhouse and microplot trials on P. penetrans are ongoing while initial results indicate good potential for field application of this new biological control agent.