Development, Feasibility Testing and Economic Viability of Solar Powered Over-The-Top (OTT) Sprayer for Vegetable Crops

The study focused on exploiting the physical characteristics of Chilli and Capsicum crop to design the working components of solar powered mobile APP controlled over-the-top (OTT) sprayer. The average height and width of Chilli and Capsicum was recorded as 32.3 ± 2.73 cm, 28.4 ± 1.45 cm, 24.6 ± 4.72 cm and 25.7 ± 1.92 cm, respectively. The sprayer comprised of mainframe, power management system, solar panel, delivery pipes, nozzles, water pump, handle, and tyres. The developed prototype was tested in greenhouse and field conditions with crop (Chilli, Capsicum), nozzle type (Flat cone, Hollow cone) and nozzle aperture angle (0°, 90° and 180°). The responses were measured in terms of droplet density (no. of droplets cm⁻²), field capacity (ha h⁻¹) and field efficiency (%) for both greenhouse and field conditions. The optimization with the help of Design Expert 13.0 revealed that operating the sprayer in greenhouse with flat cone, 0° aperture angle can yield 22.23 droplet density, 0.075 ha h⁻¹ field capacity and 87.91% field efficiency for Capsicum crop. In field conditions, the optimum condition of 8.40 droplet density cm⁻², 0.063 ha h⁻¹ field capacity and 76.07% field efficiency was recorded at 180° aperture angle, flat cone for Chilli crop. The economic assessment revealed the operating cost of Rs. 72.07 per hour, 7.52 ha break-even point and 324 h pay back period. The benefit cost ratio of the sprayer was calculated as 1.33:1. The sprayer can be beneficial to ensure the judicious application of chemicals in greenhouse and field conditions.