Asian Journal of Soil Science and Plant Nutrition

Herbicides are normally applied by manually operated knapsack sprayers, which are laborious, uneven and prone to human mistakes. Unmanned aerial vehicles (UAVs) are a promising agricultural spraying alternative to manual operation. Drone herbicide spraying was compared to knapsack sprayers in this study. A two year field experiment was conducted at Regional Agriculture Research Station, Research Farm, Palem, Nagarkurnool, Telangana during rabi 2022-23 and 2023-24. A ready-mix post emergence herbicide with combination of Imazethapyr 3.75% + propaquizafop 2.5% ME was applied to groundnut at 20-25 DAS. The experiment consisted of 12 treatments viz., 75% recommended dose (RD), 100% RD and 125% RD which were applied with drone using 20 and 40 L ha^-1 spray fluid and sprayed from 2.0 and 2.5 m height from canopy, Checks (5) were also maintained (manual spray of 75% RD,100%RD and 125% RD, weedy check and weed free) in the experiment for comparative evaluation of drone applied and manually applied herbicides. Experiment was laid out in 3X2X2 FRBD and replicated thrice. Results of the experiment showed that application of different doses of ready mix herbicide did not significantly influence the soil physical and chemical properties observed after harvest of the crop. Similarly, the available macro-nutrient status was also not significantly influenced by drone sprayed herbicide application compared to manual spraying using knapsack sprayer.