Browsing by Author "Dankwah, Kofi Adu"

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    Assessment of Organophosphate Pesticide Residues on Cabbage (Brassica oleracea) at the Farm Gate in the Atwima Nwabiagya District, Ghana
    (2015-02-10) Dankwah, Kofi Adu
    The use of pesticides to control insect pest has gradually increased over the past decade. In Ghana, the increase and inappropriate use of pesticides in vegetable production has led to accumulation of pesticide residue on vegetables. This study sought to find out the types of organophosphate pesticides farmers use and their knowledge about its use, determine the level of organophosphate pesticide residues on cabbage and the level of pesticide residues in the various leafy layers which forms the cabbage head in the Atwima Nwabiagya District of the Ashanti Region of Ghana. Most farmers (82%) do not use a mixture of pesticides as the practice leads to chemicals harmful to the health of farmers. Majority of the respondents (46 %) do apply pesticides 1-5 times before harvesting. For the same period of the cabbage life cycle, spraying intervals also vary. Most farmers (66 %) apply pesticide within 7-14 days after the previous application. All the respondents use knapsack sprayer in controlling insect pest. The organophosphates pesticides that farmers use include Sunpyrifos, Pyrinex 48EC, Dursban 4E, Perferthion, Frankophos and Termex. Using gas chromatography technique, 11 organophosphates pesticide residues (ethoprophos, phorate, dimethoate, fonofos, pirimiphos-methyl, fenitrothion, malathion, chlorpyrifos, parathion, chlorfenvinphos and profenofos) were detected in the cabbage samples. The highest pesticide residue concentrations detected (0.02 mg/kg) was recorded for profenofos and chlorpyrifos. However, none of the pesticide residues detected was above the recommended Maximum Residue Limits (MRL) for cabbage. Fourteen (14) organophosphate pesticide residues were detected in all the various leafy layers of the cabbage samples. Only chlorpyrifos (0.01 mg/kg) was in the third layer which is far below the permissible level. The lower concerntrations and low degree of variability of pesticide residues found in cabbage this study suggests that farmers are adhering to appropriate use of pesticides as recommended by Agric Extension Agents (AEAs), colleague farmers, agro-input dealers and development workers. This shows that cabbage from the study area relatively wholesome for human consumption.