Journal of Nematology (2006) 38, p. 289 (Roberts et al.)

P.A. Roberts, R.M. Davis and T.R. Mullens (2006)
Interaction of root-knot nematode with Fusarium wilt race 4 on cotton
Journal of Nematology 38 (2), 289-289
Abstracts of Society of Nematologists 45th Annual Meeting, Lihue, Hawaii, 18-21 June 2006
Abstract: Root-knot nematode (Meloidogyne incognita) interacts with Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) as a disease complex on cotton. In California, mild races of Fusaruim wilt (races 1 and 2) have predominated and result in wilt symptoms only in cotton fields infested with M. incognita. Recently, a virulent strain of wilt (race 4) was identified in fields without apparent nematode infestation. In greenhouse pathogenicity tests, three cotton cultivars (Gossypium hirsutum cvs. Acala SJ-2 and Acala NemX, and G. barbadense cv. Pima S-7) were challenged with Fusarium wilt race 4, with or without co-inoculation of M. incognita. The race 4 isolate caused severe wilt symptoms and plant stunting on Pima S-7 with or without nematodes. In contrast, race 4 caused milder wilt symptoms on Acala SJ-2, but the symptoms were greater in the presence of M. incognita. On Acala NemX, that has resistance to M. incognita, race 4 caused moderate wilt symptoms in the absence of nematodes, and wilt symptoms were less in the presence of M. incognita. The results indicated that M. incognita can increase wilt induced by race 4 on cotton, but the extent of the effect is cultivar-specific and may be reduced by activation of nematode resistance.
Database assignments for author(s): Philip A. Roberts

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Meloidogyne incognita	Cotton (Gossypium)	U.S.A. (SW)
	Fusarium gossypinum	Cotton (Gossypium)	U.S.A. (SW)