International Journal of Pest Management (1999) 45, 255-258

Daniel L. Coyne, R.A. Plowright and B. Fofana (1999)
Observations on the susceptibility of Oryza sativa and resistance of Oryza glaberrima to the cyst nematode (Heterodera sacchari) and the influence of weed management in upland rice in Ivory Coast
International Journal of Pest Management 45 (4), 255-258
Abstract: The population density of the cyst nematode, Heterodera sacchari, on Oryza sativa and three O. glaberrima cultivars was assessed in a pot test and in the field under two levels of weed management, weed-free and hand weeded, once 43 days after sowing. Similar numbers of cysts developed on both species of rice, but cysts from O. glaberrima were smaller and contained fewer eggs, resulting in significantly lower population densities of H. sacchari. The successful cyst nematode development (equivalent to that on susceptible cultivars) albeit of less fecund females, could reduce selection pressure for virulence on H. sacchari resistant cultivars. Population densities of H. sacchari were significantly higher on weed-free plots, suggesting that the better rice growth from the reduced interspecific competition in weedfree plots facilitated an increased multiplication of H. sacchari. In declining order of abundance, the dominantweed species presentwere: Eleusine indica, Digitaria horizontalis, Euphorbia heterophylla and Ageratum conyzoides, all were non-hosts of H. sacchari.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Daniel L. Coyne

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.
	Ageratum conyzoides (weed)	Rice (Oryza)	Ivory Coast
	Euphorbia heterophylla (weed)	Rice (Oryza)	Ivory Coast
	Eleusine indica (weed)	Rice (Oryza)	Ivory Coast
	Heterodera sacchari	Rice (Oryza)	Ivory Coast
	Digitaria horizontalis (weed)	Rice (Oryza)	Ivory Coast