![]() Regular, supervision of the crop is must for detection of whitefly incidence. Affected leaves and seed cotton turns black due to development of sooty mold on the plants. Whitefly adults and nymphs suck sap from leaves and excrete honey dew on leaves which become sticky. cotton provides effective protection against cotton bollworms, but sucking pests namely whitefly, jassid, aphid and mealy bug are the most serious in Bt. ![]() The decrease in use of insecticide sprays associated with Bt crops could enhance bio-control services. Broad-spectrum insecticides kill arthropod natural enemies that provide biological control of pests. Over the past several years, plantings of transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) have helped to control several insect pests and reduced the need for insecticides. Leading cotton producing countries worldwide in 2020–2021 are China with the production of 6.42 million metric tons followed by India with 6.16 million metric tons accounting for about 58% of the world cotton production. Automatic controller can be fitted on these sprayers for adjusting the discharge and to reduce missing or overlapping of spray. Selection of nozzle is also important for these type of sprayers. Multipurpose high clearance sprayer mostly preferred by the farmers has three types of spraying arrangements namely auto rotate gun, boom type and drop up type nozzles can work at all stages of the crop and saves time, labor and cost of operation as well as it reduces drudgery of the operation. Air assisted electrostatic sprayer, Auto rotating gun type sprayer, Multipurpose high clearance sprayer and even drones are now a days used for spraying in cotton crop. These sprayers can also be used for crops like sugarcane, potato etc. Different type of sprayers are being developed especially for the control of white fly in cotton crop. The sprays with conventional sprayer do not enter at the bottom of the plant canopy and at lower side of the leaves. In field crops like cotton the pest attacks is on the lower side of the leaves during vegetative as well as reproductive stages of the cotton crop. The pest can be controlled effectively if pesticides are applied properly at the right rate, right time and on the target by right equipment. Distribution of pesticide is not uniform especially at the underside of the leaves. ![]() The pesticide with conventional sprayers is not so effective because non-uniform spray and of lesser width of coverage. ![]() There is a need of an efficient, precise and high capacity machine for spraying. Spraying is very tedious and time consuming operation. ![]()
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