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Further studies of crop loss following insect attack on cotton in Uganda

Published online by Cambridge University Press:  10 July 2009

W. R. Ingram
W. R. Ingram
Affiliation:
Department of Agriculture, Kawanda Research Station, Kampala, Uganda
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Extract

Earlier studies of crop loss following insect attack on cotton in the elephant-grass zone of Uganda were followed up for two more seasons (1965–67), using large plots and routine spray schedules with different insecticides. The spray schedules were four or six fortnightly applications of insecticide, beginning at week 8 from emergence in the 1965–66 season, and four fortnightly or eight weekly sprays in the 1966–67 season. The insecticides used were DDT, endrin and dicrotophos in the first season and DDT, endrin and endosulfan in the second.

Estimates of Taylorilygus vosseleri (Popp.), Heliothis armigera (Hb.), Earias biplaga Wlk., Cryptophlebia leucotreta (Meyr.), Pectinophora gossypiella (Saund.), Dysdercus spp., Aphis gossypii Glov., Tetranychus sp. and Eotetranychus sp. showed that, although one or other of the insecticides reduced the different pests to very low levels, yield increases were not obtained. In the 1966–67 trial, when the more important pests were present in very low numbers, DDT and endosulfan significantly reduced yields of clean seed cotton and it is suggested that these formulations are slightly phytotoxic to Uganda cottons.

The relationship between the shedding of fruiting bodies and the harvesting of the crop showed that sprays applied after week 14 did not affect the total crop in any way. Increased soil fertility caused the plants to form more fruiting bodies and, although many of these were shed, a higher proportion were retained with or without protection from pest damage.

It is concluded that the pest damage is too light to affect yields of early-sown cotton where varieties of indefinite growth habit can compensate for early loss of fruiting bodies in the extended growing season. Routine spraying gives no benefit and, in some seasons, can be harmful.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 59 , Issue 1 , July 1969 , pp. 65 - 76
Copyright
Copyright © Cambridge University Press 1969

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References

Coaker, T. H. (1957). Studies of crop loss following insect attack on cotton in East Africa. II.—Further experiments in Uganda.—Bull. ent. Res. 48, 851–866.CrossRefGoogle Scholar
Coaker, T. H. (1958). Entomology.—Prog. Rep. Exp. Stns Emp. Cott. Grow. Corp., Namulonge 1957–58, 38–43.Google Scholar
Coaker, T. H. (1960). Entomology.—Prog. Rep. Exp. Stns Emp. Cott. Grow. Corp., Namulonge 1958–59, 32–37.Google Scholar
Darling, H. S. (1946). Annual report of the agricultural entomologist.—Rep. Dep. Agric. Uganda 1944–45 pt. 2, 25–30.Google Scholar
Davies, J. C. (1963). Observations on the effect of DDT formulations on the yellow tea mite, Hemitarsonemus latus (Banks), in Uganda.—Bull. ent. Res. 54, 425–431.Google Scholar
Davies, J. C. & Ingram, W. R. (1965). Insecticides on cotton in Uganda. Comparison of DDT, DDT plus toxaphene, endosulfan and trichlorphon.—Emp. Cott. Grow. Rev. 42, 300–315.Google Scholar
Farbrother, H. G. (1952). Plant physiology.—Prog. Rep. Exp. Stns Emp. Cott. Grow. Corp., Namulonge 1951–52, 11–12.Google Scholar
Farbrother, H. G. (1954). Plant physiology.—Prog. Rep. Exp. Stns Emp. Cott. Grow. Corp., Namulonge 1953–54, 15–21.Google Scholar
Ingram, W. R. (1962). Effect of Rogor (dimethoate) and DDT on cotton mites in Uganda.—Nature, Lond. 195 no. 4847, 1224–1225.CrossRefGoogle Scholar
Ingram, W. R. (1967). An evaluation of five insecticides for the control of late-season cotton pests in Uganda.—E. Afr. agric. For. J. 33, 206–211.CrossRefGoogle Scholar
Ingram, W. R. & Davies, J. C. (1964). Insecticides on cotton in Uganda. Comparison of DDT, toxaphene, DDT plus toxaphene, BHC and DDT & BHC.—Emp. Cott. Grow. Rev. 41, 124–136.Google Scholar
Ingram, W. R. & Davies, J. C. (1965). Recent advances in pest control on cotton in Uganda. E. Afr. agric. For. J. 31, 169–174.CrossRefGoogle Scholar
McKinlay, K. S. & Geering, Q. A. (1957). Studies of crop loss following insect attack on cotton in East Africa. I.—Experiments in Uganda and Tanganyika.—Bull. ent. Res., 48, 833–849.CrossRefGoogle Scholar
Pearson, E. O., Geering, Q. A. & McKinlay, K. S. (1952). Entomology.—Prog. Rep. Exp. Stns Emp. Cott. Grow. Corp., Namulonge 1951–52, 15–22.Google Scholar
Perimmer, T. R. & Merkl, M. E. (1962). Field insecticide tests against several cotton pests.—J. econ. Ent. 55, 121–124.CrossRefGoogle Scholar
Taylor, T. H. C. (1945). Lygus simonyi, Reut., as a cotton pest in Uganda.—Bull. ent. Res. 36, 121–148.CrossRefGoogle Scholar