Journal of Economic Entomology (1994) 87, 1616-1621

Heather S. Costa, Marshall W. Johnson and Diane E. Ullman (1994)
Row covers effect on sweetpotato whitefly (Homoptera: Aleyrodidae) densities, incidence of silverleaf, and crop yield in zucchini
Journal of Economic Entomology 87 (6), 1616-1621
Abstract: The use of polyethylene row covers is an effective method to reduce whitefly, Bemisia tabaci Gennadius, and aphid, Aphis gossypii Glover, densities and the incidence of squash silverleaf in zucchini. Mean densities of whiteflies and aphids were significantly lower in row-cover treated plots than in untreated plots. Under conditions of low silverleaf incidence (<25% of plants with symptoms), row-cover treatments reduced the incidence of silverleaf, although no significant increase in yield per plant was found, and no relationship between silverleaf incidence and yield was found. Under high levels of silverleaf (>50% of plants with symptoms), there was a significantly higher total marketable yield per plant in row-cover treated plots than in pesticide-treated or untreated plots. In addition, increased yields were correlated with lower ratings of silverleaf severity and lower proportions of plants with silverleaf.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Marshall W. Johnson

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis gossypii	Squash/pumpkin (Cucurbita)	U.S.A. (Hawaii)
	Bemisia tabaci	Squash/pumpkin (Cucurbita)	U.S.A. (Hawaii)