Development of test equipment for evaluation of pesticide protection performance and investigations on cotton fabrics

Abstract

In the present research work, as one of the objectives, design and development of a test equipment for the evaluation of pesticide protection performance of fabrics, which permits entry of pesticides following penetration mechanism, was considered. The need for the development of such equipment had become essential since the currently used standard methods of ISO, ASTM and EN or certain attempts taken by the researchers towards slightly modifying the approach used in the standard methods do not reflect the conditions prevailing in the field when pesticide applicators carry out their spraying activity. In all the above methods, either direct contact of a pesticide in bulk quantity or as a spray is made use of, in carrying out the test. When these methods are employed, it would result in, under evaluation of fabric performance and end up with prescribing fabrics beyond what is required for the situation, leading to pesticide applicators complaining discomfort while using them. Pesticide applicators never come across direct contact with pesticide in the manner as stated above, during their spraying activity. If we consider the pesticide liquor that is let out of the sprayer, bulk of it falls directly on the plant/ground and the rest remain in the air. Hence, during the spraying activity, the applicator will come in contact with pesticide borne in the air alone. Pesticide applicators take all possible efforts by way of selecting the right spraying equipment, using optimum composition of pesticide liquor, performing the spraying activity when right meteorological conditions prevail (temperature between 20°- 30°C, relative humidity above 45% and air velocity between 3-7km/h) and following the best practice of spraying (i.e., to start spraying from near the downwind edge of the field and proceed in the upwind direction) to keep the pesticide borne in the air at a minimum concentration level.