Environmental Sustainability: Bioactivity of Leucaena leucocephala Leaves and Pesticide Residue Analysis in Tomato Fruits

Field studies were conducted on the application of Leucaena leucocephala leaf extracts as an alternative to carbofuran a synthetic nematicide, while possible residues of carbofuran in tomato fruits were also analysed. Acetone, methanol and petroleum ether fractions of the leaves of L. leucocephala were applied at 200 mg/mL in variants of 100 mL, 150 mL and 200 mL to a naturally nematode infested field. Comparison was made with carbofuran a synthetic insecticide and nematicide. Samples of tomato fruits from carbofuran treated and untreated beds were extracted with ethyl acetate for residual pesticide analysis to ascertain the exceedance of the maximum residue limit (MRL). Results revealed that pesticide residue was significantly (p = 0.05) higher in plots treated with carbofuran compared with standard MRL for carbofuran in tomatoes. Crude extracts of L. leucocephala were as effective as carbofuran, while the fraction was however significantly better in producing higher numbers of fruits and reduced nematode population in root and soil of tomato plants.