2019 ASHS Annual Conference

Currently, New Mexico type green chile is harvested and destemmed (removal of pedicel) by hand during harvest. The pedicel must be removed from fruit destined for commercial processing because stem and calyx material adversely affect product quality. Removal of the pedicel is a continuing challenge in transitioning to a mechanical harvest system that must be addressed by both the development of mechanical destemmers and development of cultivars with relatively easy and clean removal of the pedicel from the fruit. Advanced breeding lines developed for mechanical harvest efficiency were compared to three commercial control cultivars (NuMex Joe E. Parker, AZ-1904, and Big Jim) for force needed to remove the pedicel and efficiency of pedicel removal. Pedicel removal force was measured using a methodology developed in coordination with researchers from UC Davis using a Tohnichi Torque Meter, model BTG90CN-S, fitted with a fork with a chuck gripping mechanism. Using a 1 to 5 rating system, with “1” indicating a failure to remove any of the pedicel (broken stem) and “5” given fruit with complete pedicel removal and no fruit damage. The experiments were conducted at the New Mexico State University Agricultural Science Center in Los Lunas and the Leyendecker Plant Science Research Center in Las Cruces. Random samples of 60 representative full-sized green fruit from each accession were hand harvested with the pedicels intact. Fruit were evaluated for force needed to remove the pedicel and rated to determine how cleanly the pedicel detached. Based solely on “5” rated fruit, torque force units were similar among the accessions. However, when evaluating the percent of fruit that were rated as “5”, breeding line 74W18 (90% fruit rated at “5”) was a superior destemming line compared to the standard control cultivars, Joe E. Parker and AZ-1904 (13.3% and 20.0%) in the Los Lunas plots. Breeding lines 10W18 (70% fruit rated “5”), 13W18 (66.7%), 14W18 (70%), 17W18 (83.3%), and 18W18 (66.7%) all provided more efficient pedicel removal compared to Joe E. Parker (23.3%) and Big Jim (13.3%) at the Leyendecker ASC. Although the removal force was similar in all the lines, based on efficiency of pedicel removal, breeding lines in development for mechanical harvest efficiency were shown to have superior pedicel removal. This attribute will increase the utility of these lines with mechanical destemmer equipment in development that pulls the pedicel off the fruit, but will also aid in pedicel removal by hand harvest.