Evaluation of Engeo K 247 SC for routine protection of cocoa farms against the brown Cocoa Mirid – Sahlbergella singularis in Nigeria

Abstract

Laboratory and field screening of Engeo K 247 SC was carried out at three concentrations, 0.0625%, 0.125% and 0.25% active ingredient between 2005 and 2007 to determine its suitability for use on cocoa farms in Nigeria. The mortality rates of mirids on exposure to the various concentrations of Engeo K 247 SC increased with period of exposure of the mirids in the laboratory. Engeo K 247 SC and the Standard Miricide were similar at 0.125% concentration as both gave a 100% kill of mirids at the 70 th minute. No mortalities were recorded in the control petridishes throughout the exposure period. The insecticide did not produce any adverse side effects on cocoa seedlings and mature plants sprayed with the various concentrations over the years. The mirid mortality recorded after the first year's initial and residual treatment applications at Ibadan, Owena and Ikom at the lowest concentration of 0.0625% was 78 to 100%, while 70 to 100% was recorded in the second year. They all compared effectively with the mortalities recorded at 0.125%, 0.25% and the Standard Miricide concentrations (80.4 to 100%). Spraying of mature and fruiting cocoa farms at application rate of 0.125% was found adequate taking into consideration the impact of the product on the environment and for economic reasons. However, final recommendation is yet to be given for the use of the insecticide on cocoa in Nigeria.