Abstract

                                Pesticides are widely used in agriculture for the management of pests (weeds, insects or pathogens). They are generally applied as a spray to cover the target (e.g. an insect, leaf surfaces or part of a plant) with pesticide-laden droplets. Spray may, however, be lost to non- target areas within a crop through deposition on to the soil or on non-target plant surfaces. The plant architecture of the crop and weed species can influence the distribution of the spray droplets. The action of wind may also result in spray moving away from the spray area. By selecting and using spray equipment and techniques that maximise deposition of pesticides onto the target, it is possible to both maximise the effectiveness of the pesticide application and reduce the amount of off-target deposition and damage. Hence, it is necessary to measure the distribution of spray deposits in the leaves of different crop canopies in relation to droplet size, droplet trajectory, spray application volume and canopy structure. A study on the deposition of spray chemicals on cotton crop was conducted using three methods namely i) Gravimetry method ii) Leaf Area Index and iii) QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method and the efficiency of the methods on the requirement of effective volume of spray chemicals for unit cropped area was determined.

Key words : Spray Deposition, Leaf Area Index, QuEChERS Method