Effects of pre-household treatment procedures and Dissipation of Chlorpyrifos Residue on Lactuca Sativa

Loading...
Thumbnail Image
Date
2011-06-23
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This research was organized into two phases. Phase I dealt with the administration of questionnaires to farmers to examine the pesticide use pattern in the study area. Phase II dealt with evaluating the residue levels of chlorpyrifos on Lactuca sativa that are likely to have accumulated on Lactuca sativa during application and also examining the effect of various household pre-household treatment procedures on reducing the residue levels. Structured questionnaire which was used at the Phase I of this work was to find the knowledge, attitudes and pesticide use practices of farmers. Chlorpyrifos was chosen as the insecticide to be used for Phase II of this work. Chlorpyrifos was then applied at different stages of growth of lettuce. Samples of lettuce were collected at different days after pesticide application [0 (1 hour), 1 day and 7 days] and their residue levels detected using Gas Chromatography. Pre-household treatment procedures such as washing under running tap water, salt water treatment and mild detergent treatment were used to evaluate their effects on chlorpyrifos levels on lettuce. From the questionnaires, it was realised that, the farmers in the study area apply insecticides on their crops to improve the yield and enhance profitability. However, farmers could not state precise application doses to use at specific crop stage and that inappropriate application of pesticides leads to high levels of residues on crops. The results obtained confirm that pesticide residues were indeed present in the lettuce. The highest residue level of 0.059 mg kg-1 was observed on lettuce 0 day (1 hour) after pesticide application. The lowest residue level of 0.002 mg kg-1 was observed on lettuce 7 days after pesticide application.The results also showed that, all the pre-household treatment procedures caused significant reduction in residues levels of chlorpyrifos on the crop. Mild detergent treatment was however more effective compared with the other treatments.
Description
A Thesis submitted to the Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi in partial fulfillment of the requirements for the degree of Master of Science (Environmental Science), June-2011
Keywords
Citation