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Studies on the sowing date of cotton in the Sudan Gezira: II. The relationship between sowing date of cotton and the incidence of insect pests

Published online by Cambridge University Press:  27 March 2009

L. Razoux Schultz
Affiliation:
Gezira Research Station, Wad Medani, Sudan
J. E. Jackson
Affiliation:
Gezira Research Station, Wad Medani, Sudan
R. C. Faulkner
Affiliation:
Gezira Research Station, Wad Medani, Sudan

Extract

In factorial experiments covering a range of sowing dates and insecticide treatments the numbers of fleabeetle, jassid and whitefly on cotton in the Sudan Gezira were shown to be strongly influenced by the date of sowing and the age of the crop.

Attack by fleabeetle was most severe on cotton seedlings from July and early August sowings. Few fleabeetle were found on either more mature plants from these sowing dates or on seedlings from later sown cotton.

Whitefly numbers were highest on late July and early August sown cotton. Peak numbers were attained attained in late September and October and then fell to very low levels in November irrespective of date of sowing.

Jassid numbers were related both to plant age and to time of year, more being found on cotton sown, in July and early August early in the season and on later sown cotton later in the season. The highest numbers were found in November and December at which time populations were higher on cotton sown in mid-August or later than on earlier sown cotton.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1967

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References

Cowland, J. W. (1947). The cotton jassid (Empoasca libyca, Berg.) in the Anglo-Egyptian Sudan and experiments on its control. Bull. ent. Res. 38, 99115.CrossRefGoogle Scholar
La Croix, E. S. A. (1961). Observations on the ecology of the cotton flea beetles in the Sudan Gezira and the effect of sowing data on the level of population in cotton. Bull. ent. Res. 62, 773–83.CrossRefGoogle Scholar
Crowther, F. (1948). Organization of agricultural research and the experimental farms. In Agriculture in the Sudan, (ed. Tothill, J. D.), chapter 20. Oxford University Press.Google Scholar
Joyce, R. J. V. (1954). Entomological Section. Rep. Res. Div. Minist. Agric. Sudan. 1953–4.Google Scholar
Joyce, R. J. V. (1959). Recent Progress in Entomological Research in the Sudan Gezira. Emp. Cott. Grow. Rev. 36, 179–86.Google Scholar
Joyce, R. J. V. (1961). Some factors affecting numbers of Empoasca lybica (De Berg) (Homoptera: Cicadellidae) infesting cotton in the Sudan Gezira. Bull. ent. Res. 52, 191230.Google Scholar
Joyce, R. J. V. & Roberts, P. (1959). The determination of the size of plot suitable for cotton spraying experiments in the Sudan Gezira. Ann. appl. Biol. 47, 287305.CrossRefGoogle Scholar
Knight, R. L. (1954). Cotton breeding in the Sudan. Part 2. Egyptian Cotton (continued). Emp. J. exp. Agric. 22, 8192.Google Scholar
Snow, O. W. & Taylor, J. (19521953). The large scale control of the cotton Jassid in the Gezira and White Nile areas of the Sudan. Bull. ent. Res. 43, 479502.CrossRefGoogle Scholar