Quality and quality standards of manually operated pesticide sprayers

Abstract

The lever-operated knapsack sprayers and compression sprayers procured during 2001-2003 were studied for their compliance with the recommendations of Food and Agriculture Organization (FAO) on the standards for agricultural pesticide sprayers. The sprayers were tested for leakage, surface retention, chemical resistance, tank filling, liquid retention in the sprayer, strap and padding, strap durability, nozzles and spray quality. The quality specifications prescribed by the Bureau of Indian Standards (BIS) for pesticide sprayers were checked with the FA0 recommendations. The test sprayers complied with only 21 of the 62 recommendations. The leakage was 4.9-4050 ml compared to the FA0 limit of 5 ml. The surface retention on the sprayers ranged from 15.3 to 123.8 ml compared to the FAO limit of 70 ml. The chemical resistance was very poor in 2 sprayers. The tank-filling rate ranged from 1.2 to 16.1 litres/min compared to FA0 limit of 25 litres/min. The liquid retention in the knapsack sprayers was 113.3-356.5 ml compared to the FA0 limit of 240 ml (1.5% of the nominal capacity) and in the compression sprayers it was 209.4-1173.6 ml compared to the FA0 limit of 25 ml. The strap absorption ranged from 17.7 to 86.5% of its dry weight, compared to the FA0 limit of 10% m/m. The test sprayers produced very fine spray as per the FA0 classification based on droplet size-cumulative volume per cent. The test sprayers did not conform to essential recommendations for ensuring efficacy and safety. The BIS standards conform only to 8 of the 62 FA0 recommendations differ in 13 and have no prescription on 41 recommendations.