Comparative mechanical harvest efficiency of six New Mexico Pod-type green chile pepper cultivars

Authors: JOUKHADAR, I - New Mexico State University; WALKER, S - New Mexico State University; Funk, Paul

Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2018
Publication Date: 6/1/2018
Citation: Joukhadar, I.C., Walker, S.J., Funk, P.A. 2018. Comparative mechanical harvest efficiency of six New Mexico Pod-type green chile pepper cultivars. HortTechnology. 28(3):310-318. https://doi.org/10.21273/HORTTECH03999-18.
DOI: https://doi.org/10.21273/HORTTECH03999-18

Interpretive Summary: New Mexico production area for chile peppers has fallen from 34,500 acres to 10,600 acres since the North American Free Trade Agreement was implemented because harvest labor costs are 50% percent of the total cost of production in the U.S. and only 15% in Mexico. Domestic production costs could be reduced by harvest mechanization. Mechanical harvest requires more than machines that can pick chile peppers - cultivar traits, production practices, and processing plant cleaning equipment need to be modified to be compatible with mechanization. This research reports on two years of field trials with six commercial cultivars to identify not just the most successful genetics, but also the traits they express that are more compatible with with a picking machine. Taller plants with greater height to first branch performed better with mechanical harvest.

Technical Abstract: New Mexico-type green chile (Capsicum annuum) is one of New Mexico’s leading horticultural commodities. The crop is harvested when fruit are fully sized, but in the physiologically immature green stage, for fresh and processed markets. Cultivated acreage of green chile in New Mexico is threatened due to the high cost and unavailability of labor for hand harvest. Mechanization is necessary to sustain the industry. Successful mechanization depends on harvester design coupled with plant growth habit that optimizes harvest yield. In two trials conducted at New Mexico State University Agricultural Science Center in Los Lunas, New Mexico, six cultivars (AZ-1904, Machete, PHB-205, E9, PDJ.7, and RK3-35) provided by Curry Chile and Seed Co., Pearce, AZ were evaluated for plant habit and harvest efficiency with an Etgar® double, open helix harvester (Yung-Etgar, Beth-Lehem-Hglilit, Israel). Cultivars were direct seeded on 17 April 2015 and 14 April 2016 and managed according to standard production practices. Plant attributes including plant width (cm), plant height (cm), height to primary branch (cm), length between primary branch and first node (cm), and stem diameter (mm) were measured before harvest, and mechanically harvested yield components were assessed 01 Sept. 2015 and 31 Aug. 2016. In 2015 ‘AZ-1904’ and ‘PDJ.7’ had significantly (P = 0.05) more marketable yield than ‘Machete’, which had the least marketable yield when harvested with the Etgar® picker. No statistical differences were found in marketable yield in 2016. In 2015 and 2016 ‘PDJ.7’ had the tallest plants, while ‘E9’ had shorter plants. ‘PDJ.7’ also had the greatest height to primary branch both years. ‘E9’, ‘RK3-35’, ‘Machete’, ‘PHB-205’, and ‘PDJ.7’ all had more basal branches per plant, compared to ‘AZ-1904’ with significantly fewer basal branches in 2015. Despite differences in fruit wall thickness, no significant differences were measured in broken fruit. There were also no differences in harvested sticks (trash). Overall harvest efficiencies ranged from 64.6-39.3% during this two-year trial. We found mechanical harvest performance associated with plant height, therefore future breeding efforts incorporating plant height with other desirable characteristics should be continued.