Submitted to: Journal of Nematology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/28/2002
Publication Date: 11/25/2002
Citation: THIES, J.A., FERY, R.L. HOST PLANT RESISTANCE AS AN ALTERNATIVE TO METHYL BROMIDE FOR MANAGING MELOIDOGYNE INCOGNITA IN PEPPER. JOURNAL OF NEMATOLOGY. 2002. v.34. p.374-377. Interpretive Summary: The southern root-knot nematode (Meloidogyne incognita) infects the roots of sweet and hot peppers causing root damage, stunting of the plants, and subsequent losses in fruit yield. Fumigation of soil with methyl bromide before planting is currently used to control root-knot nematodes in peppers and other high value vegetable crops. However, methyl bromide is an ozone- depleting substance and has been targeted for removal from production and use in the U.S. and other developed countries by 2005. Thus, it is urgent that alternative methods to methyl bromide are discovered that are safe and effective for managing root-knot nematodes. In this study, we demonstrated that the host plant resistance of the pepper cultivar 'Carolina Cayenne' is highly effective against root-knot nematodes. 'Carolina Cayenne' exhibited minimal root galling, supported very few root-knot nematodes, and suffered no yield loss when grown in nematode-infested soils that were not treated with methyl bromide. The exceptionally high resistance exhibited by 'Carolina Cayenne' provides an alternative to methyl bromide for managing root-knot nematodes in pepper and will be an excellent source of resistance for the development of new resistant pepper cultivars.
Technical Abstract: A field study was conducted to compare pre-plant soil fumigation with methyl bromide and host resistance to Meloidogyne incognita (Mi) for managing southern root-knot nematode (RKN) in pepper (Capsicum annuum). Three pepper cultivars ('Carolina Cayenne'- CC, 'Keystone Resistant Giant' - KRG, and 'California Wonder' - CW) were evaluated in combination with pre-plant soil fumigation with methyl bromide [98% CH3Br : 2% Ccl3NO2] and an untreated control. CC is highly resistant, KRG is susceptible, and CW is highly susceptible. Methyl bromide treatment: None of the cultivars exhibited root galling and all had low RKN reproduction, indicating that methyl bromide was very effective in controlling Mi. Non-fumigated control: CC was highly resistant; root galling and nematode reproduction were minimal and fruit yields were not reduced. KRG was moderately susceptible; root galling was moderate and nematode reproduction was moderately high. However, yields of KRG were not reduced, suggesting that KRG may be somewhat tolerant to Mi. CW was susceptible; root galling was severe, nematode reproduction was high, and fruit yields were reduced (P<0.05). The exceptionally high resistance exhibited by CC provides an alternative to methyl bromide for managing RKN in pepper.