EFFECT OF LATTERAL WIND SPEED ON THE SPRAY DRIFT OF DROPLETS SPRAYED BY DRONE

Abstract

New environmental trends have led to the development of drone applications in agriculture. Unlike ground-based spraying techniques, they do not damage the plants in the tramlines and do not compact the soil. However, when drones spray pesticides from higher altitudes, there is the potential for greater spray drift. The aim of this study was to determine, under controlled conditions, the effect of lateral wind speed on the drift of liquid droplets sprayed by different drone sprayers, depending on the flying height. Two drones were used in the study: a four-propeller (rotor) XAG XP2020 and a six-propeller TTA M6E. The drones were lifted from the ground to altitudes of 2 m, 3 m and 4 m in separate water spraying studies. The drones had a flying speed of 2 m s^-1 during the spraying. In the drone studies, the lateral airflow velocity was varied from 2 m s^-1 to 8 m s^-1 using voltage frequency converters. The number of droplets per area of the water-sensitive papers (pcs cm^-2) was determined. Studies have shown that drone design, lateral wind speed and drone altitude have an impact on the spray drift, outside the spray zone. To avoid the risk of spray drift, it is recommended that the M6E drone sprayer should be used to spray from a maximum height of 2 m with a lateral wind of 4 m s^-1 and from a height of less than 2 m with a wind of 6 m s^-1. In lateral winds of 8 m s^-1 the M6E drone is not recommended for spraying. To avoid the risk of spray drift, the XP 2020 drone sprayer should be recommended to spray from a maximum height of 2.5 m in a 4 m s^-1 lateral wind, from a height of 2 m in a 6 m s^-1 lateral wind and from a height of less than 2 m in an 8 m s^-1 wind.