Automated lettuce thinners reduce labor requirements and increase speed of thinning

been hindered by a declining supply of farm labor (Taylor et al. 2012), generating interest among growers in methods to reduce labor requirements for thinning, weeding, irrigating and harvesting (Fennimore et al. 2010; 2014). Thinning lettuce is particularly labor intensive, and most lettuce fields in California are hand-thinned (manually thinned). Automated lettuce thinners that use machine vision and computer image processing, and a spray system to remove unwanted plants, were introduced to the Salinas Valley 4 years ago. Growers are evaluating their cost and performance to see if they have a fit in their operations. An automated thinner, which typically needs only one person to run it, removes plants to ensure accurate final plant spacing and provide a measure of weed control (Chu et al. 2016). Machine vision technology RESEARCH ARTICLE