Ergonomics evaluation of manually operated wheel sprayer

Abstract

Spraying is one of the most significant procedures in crop production because it protects crops from pests and diseases. Ergonomic intervention in spraying operations can give a solid foundation for recommendations on operating methods and efficient operation for increased production and safety. The ergonomic assessment of the manually operated wheel sprayer was based on heart rate, oxygen consumption rate, energy expenditure rate, and overall discomfort rating. Physiological workload increased proportionally with both variables, heart rate peaked at 118 beats min⁻ ¹, while oxygen consumption rate increases from 551 ml min⁻ ¹ to 665 ml min⁻ ¹ across the tested ranges (2.16-2.71 km h⁻ ¹ and 25-35 years). Similarly, the energy expenditure rate increased from 17.5 to 21.66 kJ min⁻ ¹. The overall discomfort rating followed this trend, reaching its maximum at a speed of 2.71 km h⁻ ¹ and an operator age of 35 years, suggesting that higher speeds and higher age of the operator significantly intensify the physical demands of the task. Average theoretical field capacity, actual field capacity, and field efficiency values of 0.44 ha h⁻ ¹, 0.32 ha h⁻ ¹, and 73%, respectively.