Control of apple scab [Venturia inaequalis (Cooke) Winter] in the Kashmir valley using Captafol and residues of the fungicide in fruits

Abstract

Amongst twelve different spray schedules tested, the best control of apple scab [Venturia inaequalis (Cooke) Winter] in Kashmir Valley was obtained with Captafol 80 WDP (Difolatan) sprayed at 2 g per litre of water at green tip stage, pink bud stage and 15 g in 18 litres of water applied at 10% petal fall followed by four cover sprays two of which were given at three week intervals with 15 and 10 g of Captafol in 18 litres of water respectively and 2 more at 10 g of Captafol in 18 litres of water at an interval of 1 month each, depending on the rainfall. The total amount of Captafol sprayed in this treatment was 73·12 g. The residues in the fruit varied from 1·22 ppm to 1·64 ppm. Even at the highest dose of 137 g of Captafol per plant, the residues did not exceed 2·75 ppm, which is lower than the tolerance limit of 3 ppm fixed by FAO/WHO.