Performance evaluation of two different air injection nozzles in vineyard application

Abstract: Air-assisted sprayers are widely used in spray operations in vineyards which are cultivated in large areas in the Ege Region and vineyard production has a significant share in the Turkish economy. Generally hollow cone nozzles are used at high working pressures (> 25 bar) and high application rates. Since working with the high pressures causes more drift prone droplets, it increases pesticide losses. Especially during the full vegetation period because of high working pressures and application rates most of the sprayed pesticides run off from the canopy to the ground. The pesticide drifted from the target side is a threat for human and environment health and also may cause fail on plant protection. The objectives of this study were to make adjustments on application and to determine spray performances of some air injection nozzles in the vineyards to achieve some goals like to reduce drift amount, to increase deposit amount of sprayed pesticide on the target, to reduce pesticide consumption and its cost by reducing drift. The experiments were conducted by using three different nozzles (Conventional nozzle, Lechler ID, and Teejet AITX) at three phenological periods (blossom, ripening and full vegetation). For blossom period 700 l/ha and for ripening and full vegetation period 1160 l/ha were applied as conventional application rates and 50% of each conventional application rate (350 l/ha and 580 l/ha, respectively) were also employed. Therefore, four different application rates were applied during the experiments. In the experiments, sodium fluorescein was used as tracer dye, water sensitive papers were used to determine coverage rates and to measure droplet sizes, and filter papers were used to determine deposition and distribution uniformity. Experiments were conducted according to the ASABE S561.1 APR04 standard. Lechler ID nozzle provided better results than Teejet AITX nozzle when distribution uniformity, coverage rates, deposits and drift amount were concerned. Although conventional domestic nozzle provided good results in some conditions, generally Lechler ID nozzles were found more successful. Air injection flat fan nozzles which generate coarse and very coarse class size droplets at low and medium pressures may provide efficient application in the vineyards. These results will be supported with biological efficacy studies.