2018 ASHS Annual Conference

New Mexico green chile (Capsicum annuum L.) is one of New Mexico’s most valuable horticultural crops; however, large-scale production in New Mexico is at risk due to the high cost and unavailability of labor for hand harvest. Harvest mechanization is critical for the continued strength of the industry. Specific plant architecture is necessary for optimal green chile mechanical harvest efficiency. Taller plants, fewer basal branches, higher primary branch angle heights, and thicker main stem diameters are all plant traits that have been noted to increase the mechanical harvest efficiency of NM type chile. The second year evaluation of green chile breeding lines developed with traits for mechanical harvest efficiency was completed in 2017 at New Mexico State University’s Agricultural Science Center in Los Lunas, New Mexico. Six breeding lines and two commercial cultivars (‘NuMex Joe E. Parker’ and ‘AZ-1904’) were evaluated for plant architectural traits and harvest efficiency with a double, open-helix Moses 1010 mechanical chile pepper harvester. The field was direct seeded on 4 Apr. 2017 in a randomized complete block design with seven replications, then managed according to standard production practices. Plant attributes including plant width, plant height, height to primary branch angle, length between primary branch angle and first node, and stem diameter were measured before harvest. Mechanical harvest yield components, including harvested marketable green fruit, damaged fruit, trash (sticks and leaves), ground fall losses, and unharvested fruit remaining on plants were assessed 29 Aug. 2017. Breeding line 54W17 had significantly higher marketable yield and the highest harvest efficiency (81%), and breeding line 61W17 had the least marketable yield and lowest harvest efficiency (60%) when mechanically harvested. Breeding line 54W17 also had the highest primary branch angle height, while 61W17 had the shortest primary branch angle height. ‘AZ-1904’ had the thickest pericarp (fruit wall), but also significantly more broken, harvested fruit, indicating that there was no benefit to higher pericarp thickness for reduced fruit breakage in this study. ‘AZ-1904’ had the most ground fall losses and unharvested fruit remaining on plants. We found breeding line 54W17 to be most suitable for mechanical harvest in this trial compared to commercially available cultivars based on overall mechanical harvest efficiency and plant architecture traits.