A systematic approach is underway to revive New Mexico’s green chili pepper industry by bringing a mechanized harvester and destemmer plus varieties tolerant of the machines concurrently to market.

NEW MEXICO’S green chili industry is researching mechanized harvesting and destemming equipment plus plant breeding to replace hand labor and regain chili acreage lost in recent years to increased imports from Mexico.

“Mechanical harvesting and destemming are married; they go hand in hand,” said Jaye Hawkins, administrator, New Mexico Chili Association (NMCA), Mesilla Park, N.M. “We can’t effectively use one without the other. If we could perfect both machines, we could potentially return to the number of chili acres once grown in New Mexico.”

New Mexico’s red and green chili acreage has declined from about 20,000 planted acres in 2000 to 11,100 acres in 2008. Production in Texas and Arizona remained steady, 6,100 acres and 3,500 acres respectively, according to the National Agricultural Statistics Service.

Hawkins cites a shortage of available field laborers and increasing labor costs as major reasons for New Mexico’s sharp acreage decline.

Green chili mechanical inventions plus new varieties could help improve production efficiencies in the Southwest by reducing hand labor requirements and hopefully allowing the New Mexico chili industry to compete better in the market place.

Paul Funk, agricultural engineer, USDA-Agricultural Research Service, Southwestern Cotton Ginning Research Lab (SWCGRL), Mesilla Park, links the shift away from domestic production to labor costs. Funk is involved in bringing a mechanical green chili harvester to market.

“Chili imports have steadily increased while domestic acreage has decreased since the North American Free Trade Agreement went into effect,” Funk said. “The main difference between production costs is not land or inputs; it’s the labor to harvest. Growers cannot find the people and cannot afford those they find, to harvest chilies by hand in this country.”

In 2007, a record 563 million pounds of fresh-market chili peppers were imported into the U.S., a 72 percent increase since 2000 and 188 percent more since 1995, according to the U.S. Department of Agriculture’s Economic Research Service (ERS). The agency says about 98 percent of U.S. fresh-market chili pepper imports come from Mexico.

For fresh and processed all chili peppers, imports accounted for about 76 percent of U.S. consumption in 2007. Per capita use of chili peppers (fresh-weight) in 2007 totaled 6.1 pounds, up nearly 1 pound from 2000.

Chili pepper is a $325 million contributor to New Mexico’s economy with 4,000 people making a living from the vegetable, according to the NMCA. Chili pepper is also important culturally, Funk says. It’s been a signature crop of the region for 400 years; it’s an icon of prosperity.

Green chili mechanized harvester

Since green chilies are sold fresh, canned, or frozen, the goal is to harvest the fruit mechanically without damaging the pods.

“If you break a green chili or bruise it during harvest, the market value is destroyed,” Funk said. “A mechanical harvester should remove the peppers from the plant aggressively, yet be gentle and not damage the pepper in the process. We’re not there yet.”

Funk tested five mechanical harvester mechanisms (heads) in five green chili varieties in two fields last fall at the NMSU Leyendecker Plant Science Research Center near Las Cruces. A 1978 John Deere cotton stripper harvester served as a platform to power and propel four mechanisms.

“We can run a harvester down the field and get 80 percent undamaged,” Funk said. “At 20 percent, damage is too much.”

Two of the five mechanisms developed by the SWCGRL included “rubber fingers,” which move vertically or in an oval path to remove the peppers. Two other systems had vertical open helixes with paddle-chain conveyors. A commercial fifth mechanism purchased in Israel featured an inclined counter-rotating open double-helix mechanism.

The Israeli mechanism won the harvest shootout with 78 percent of the crop marketable. The SWCGRL harvesters harvested 80 percent of the peppers, but half were broken.

The NCGA is leaning favorably toward the Israeli harvester for industry use, Hawkins says. The association has high hopes for a harvester under development by Elite Harvesting LLC, Willcox, Ariz., which could be available this fall.

Chili breeding

Breeding green chili varieties capable of withstanding mechanization without pepper damage is being coordinated by Stephanie Walker, Extension vegetable specialist with New Mexico State University.

Last fall’s harvester trials included five varieties including: AZ-20 from Curry Chili and Seed Co., Pearce, Ariz., and NuMex Joe E. Parker (JEP), both standard green chili varieties. Two breeding lines were tested: Despanado and PHB 109, plus a green chili accession from Texas A&M’s chili breeding program. The AZ-20 variety scored the highest with 46 percent marketable.

“Each cultivar (variety) had certain drawbacks in machine harvesting,” Walker said. “Some varieties showed some promise that we hope to build on.”

A perfect variety will never be found, Walker says, but developing a better variety for mechanical harvesting is probably three to five years away.

“This past year we made progress,” Walker said. “Having different groups working toward a common goal has helped move this project forward.”

Chili destemmer

NMSU’s Manufacturing Technology and Engineering Center (M-TEC) in Las Cruces designs engineering solutions for agriculture with funding from the state of New Mexico and other sources.

Recent successes include a mechanized onion bagger, cayenne destemmer, salt cedar carpet roller, and grid sprayer for brush control on farms and ranches.

M-TEC began engineering mechanized green chili destemmer prototypes about three years ago. The types under evaluation include water knife and compression-based systems. A destemmer would typically be placed in a processing plant.

“The water knife system shows the capability of being 100 percent efficient. It’s accurate within one-eight inch of the calyx (cap),” said M-TEC engineer Dale Cillessen.

The water knife machine uses a computer controlled stream of water to cut the stem off the pods. It’s a single-lane prototype capable of destemming 1,000 pounds per hour. The system could be scaled up with multiple lanes to accommodate the needs of processing plants.

In the compression destemmer the chili moves through a set of rollers at different speeds, creating a pulling action on one end of the pod while the other end is held. The efficiency rate is about 80 percent, but 20 percent of the fruit is damaged. The compression system prototype destems about 10,000 pounds per hour.

“This compression system is not the correct solution for the green chili industry. It was aggressive and damaged too many peppers, but the machine appears viable for cayenne peppers,” Cillessen said. “The green chili industry has indicated that a different solution is needed.”

M-TEC plans to design and fabricate another destemmer machine or fine-tune the water knife system with different electronics for testing this fall.

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