Evolution of sweet pepper (Capsicum annuum) harvesting: From traditional practices to mechanization and robotics

Abstract

This review aims to critically examine the technological evolution of sweet pepper (Capsicum annuum) harvesting, highlighting the transition from labor-intensive manual practices to mechanized and robotic systems. The study synthesizes historical records, experimental studies, and recent engineering developments to compare harvesting efficiency, labor requirements, costs, and fruit quality across manual, mechanical, and robotic approaches in both open-field and protected cultivation systems. Manual harvesting traditionally required approximately 950–1000 labor hours ha⁻¹, accounting for nearly 40–50% of total production costs, whereas mechanized harvesting introduced during the mid-20th century reduced labor inputs by 80–85%, achieving capacities of up to 9,000 kg h⁻¹ and decreasing operational costs from about $1,260 ha⁻¹ to $210 ha⁻¹. However, mechanical systems were associated with higher fruit damage rates (2.3–3.9%) compared to careful hand picking (<1%). Recent robotic platforms such as SWEEPER and Harvey demonstrate selective harvesting success rates of 61–76.5% with cycle times of 15–24 seconds per fruit, indicating substantial progress toward precision and autonomy. Despite these advances, challenges related to fruit damage, destemming efficiency, perception accuracy, and cultivar variability remain significant. The findings underscore the need for integrating advanced sensing technologies, machine learning algorithms, and adaptive end-effectors to improve harvesting performance. This review provides practical insights for researchers, technology developers, and growers seeking to enhance labor efficiency, economic viability, and sustainability in sweet pepper production systems.