The Persistence of Methidathion and Its Effect on the Chemical Composition of Grapes PDF

Keywords

methidathion, grapes, agriculture

Abstract

The persistence of methidathion and its effect on the chemical composition of grapes was studied under field conditions during August 1982. Methidathion 40% EC was sprayed on grapes at 0.2% concentration. Samplings of grape fruits were done at 0 hr, 1, 3, 4, 7, 9 and 15 days after application. GLC method was used for residue analysis of grapes prior and after washing with water. The data indicated that the half life time of methidathion was less than one day. The residue in grapes after washing with water was still high and ranged from 47.9 to 92.1% of the total residue. The safe period for harvesting the grapes was found to be 15 days after spray. Methidathion application had positive effect on the total soluble solids (T. S. S.) and reducing sugars, while Ca, Mg, K, Na, and pH did not show any change due to methidathion application