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Evaluation of Field Damage and Chemical Control of Outbreak of Sahlbergella singularis Haglund in a Cocoa Plantation in Ibadan, Nigeria
BibTeX
@MISC{Anikwe_evaluationof,
author = {J. C. Anikwe and F. A. Okelana},
title = {Evaluation of Field Damage and Chemical Control of Outbreak of Sahlbergella singularis Haglund in a Cocoa Plantation in Ibadan, Nigeria},
year = {}
}
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Abstract
Abstract:Field evaluation of damage caused by the brown cocoa mirid, Sahlbergella singularis was based on three parameters, namely, lesions on pods, cankers on trunks and dieback of twigs. Damage assessment based on scoring exceeded 75 % for damage to the trunks and fan branches while damage to the pods was more than 50 % by the second cocoa season. Laboratory evaluation of endosulphan 35 EC applied at 0.25 % active ingredient compared favourably well with the standard miricide as all mirid populations were knocked down 40 minutes after exposure to filter paper impregnated with endosulphan. The endosulphan was found to be faster acting than the standard at 0.25. Control of mirids in the field was similar to results obtained in the laboratory. There was only 12 % recovery 28 days after spray application with endosulphan in the field while the standard th miricide gave a similar result of 15 % recovery on the 28 day. No mirid mortality was recorded in the control plots. The control of mirids with endosulphan was very efficacious but cocoa beans treated with endosulphan must be analyzed to determine its residue content before final approval or rejection of the insecticide for use on cocoa.
Keyphrases
chemical control cocoa plantation field damage sahlbergella singularis haglund second cocoa season laboratory evaluation similar result spray application damage assessment fan branch sahlbergella singularis mirid population brown cocoa mirid control plot active ingredient cocoa bean residue content field evaluation standard miricide standard th miricide mirid mortality final approval
