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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #209260
Title: Evaluating Brassica species as an alternative control measure of root-knot nematode (M. incognita) in Georgia vegetable plasticulture

Author
item MONTFORT, W - UNIV OF ARKANSAS
item CSINOS, A - UNIV OF GA, TIFTON,GA
item DESAEGER, J - DUPONT
item SEEBOLD, K - UNIV OF KENTUCKY
item Webster, Theodore
item DIAZ-PEREZ, J - UNIV OF GA

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2007
Publication Date: 9/1/2007
Citation: Montfort, W.S., Csinos, A.S., Desaeger, J., Seebold, K., Webster, T.M., Diaz-Perez, J.C. 2007. Evaluating Brassica species as an alternative control measure of root-knot nematode (M. incognita) in Georgia vegetable plasticulture. Crop Protection Journal. 26(9):1359-1368.

Interpretive Summary: Vegetable producers in Georgia lost an estimated $44.3 million from diseases in 2004. One of the economically important disease organisms producers are faced with on an annual basis is plant parasitic nematodes. In Georgia, many nematode species infect and cause damage to vegetables. For the last 50 years, producers have used methyl bromide, a broad-spectrum fumigant that is efficacious on fungi, nematodes, insects and weeds, and have effectively controlled nematodes in vegetable plasticulture systems. However, methyl bromide was identified as a contributor to the depletion of the stratosphere ozone layer and is being phased out. One potential cultural alternative to methyl bromide for management of nematode pests is the use of cover crops, particularly Brassica species, as green manure amendments prior to planting. The results of this trial, although variable, did show some promise of Brassica species as a biological control option in vegetable production in Georgia. Further research is needed to determine which Brassica species are most effective in Georgia’s environment as a biological control option and determine the level of susceptibility of the various Brassica species to M. incognita. There is also a need for more studies to examine the effects of seeding rates, timing of incorporation, and types of incorporation on the nematicidal activity of select Brassica species.

Technical Abstract: Multiple Brassica species commonly grown in Georgia were evaluated as a potential alternative to methyl bromide for management of root-knot nematode in vegetables. Brassica species produce general biocides called glucosinolates and were grown as cover crops and incorporated as green manures prior to transplanting of vegetable crop. Nematicidal activity of the Brassica species was based on net changes in nematode population and root damage caused by root-knot infection and feeding. Plant growth and crop yield was also evaluated to determine the response of the subsequent vegetable crop to the incorporated Brassica species. Incorporation of select Brassica species reduced root-knot populations and root damage caused by root-knot infection comparable to non-Brassica species cover crops with metam sodium in most years; however, the level and consistency of the nematicidal activity varied between and within Brassica species. Variations in plant growth and yield were also observed among and with Brassica and non-Brassica species. Generally, increased growth and yield corresponded with cover crop treatments that had the lowest levels of root-knot nematode populations at planting of the subsequent crop. Several cover crop treatments had a negative affect on the growth and yield potential of the vegetable crops. Therefore, a producer will need to choose a Brassica species cover crop that can significantly reduce nematode populations without adversely affecting the growth/yield of the subsequent vegetable crop.