Mechanical harvesting may be future for peppers

Quick Summary

  • Mechanically harvested NuMex Odyssey peppers are shown from a research field near Hatch, New Mexico. Studies are also underway in California, where perfecting and expanding mechanical harvesting is a top priority for the California Pepper Commission.

The original article was published by Ag Alert here. It is cross-posted with permission to our website.

"Labor shortages are driving mechanization in agriculture. For many commodities, it is mechanize or struggle to remain in business, and peppers are approaching that point.

Mechanical harvest is a No. 1 priority for the California Pepper Commission, and it has been for many years, according to Allen Van Deynze, director of the Seed Biotechnology Center at the University of California, Davis. He said growers are concerned about labor availability and look at mechanization as the answer.

Mechanical pepper harvest is more than just developing a machine to harvest the peppers, he said. It also requires development of varieties that will work with mechanical harvesters, Van Deynze added.

Several years ago, he reached out to Stephanie Walker, an extension vegetable specialist with New Mexico State University who is developing varieties for mechanical harvesting in New Mexico. The two researchers started a collaborative project to tackle destemming issues with green chile peppers.

What is happening currently with peppers is very similar to mechanical harvest of tomatoes in the '60s. Mechanical harvest was do or die for the tomato industry, and the UC Davis agriculture specialists worked with growers to create tomato varieties and a harvester that could mechanize the operation.

But it wasn't only the harvester that tomato growers needed. They also had to have a variety that could be married, so to speak, with the harvester being used, Van Deynze said. This union may very well be the future for peppers.

"Our goal is really to try to enable mechanical harvesting in green chile peppers and possibly sweet peppers if there's a need," Van Deynze said.

Certainly, there's a big need for it in chile peppers, he said, adding if it doesn't happen, the industry may diminish in the U.S. due to labor shortages.

A major issue for processing green chile peppers is stem removal. "You have to remove the stem for processing peppers, especially the slicers or the wagon wheels as they are called," Van Deynze said.

Walker agreed stem removal has been a main holdup in mechanical harvest of green chile peppers. While her collaboration with Van Deynze has been beneficial, she said, "it's proved to be a really difficult thing to tackle" for the researchers.

Van Deynze has found an old traditional variety, landrace, which shows promise. It has stems with easy removal and still has good quality that could be transferred to different varieties. Besides searching for stem traits, architecture traits are also important, such as how many branches there are on the plant and where the peppers are on those branches.

"Just like the tomato processing industry, you have to have varieties that work with the machine and machines that work with the varieties," Van Deynze said. "So the two sort of need to be modified along the way."

Another challenge is that green peppers are harder to remove than red peppers. "A red pepper is ready to pick, the stems come off easily," Van Deynze explained, saying green peppers want to stay on the plant.

There are currently 60 patents on mechanical pepper harvesters, but not many work well, Van Deynze said. The one researchers are using is a stripper header. With the plant still in the ground, the harvester strips peppers off the plant, leaving fewer stems and trash after harvest.

In working with this machine, Walker said, it has the most gentle, undamaged pick—and highest marketable yield of green chile fruit.

Walker's research is at the point where it may be handed over to growers, who may use the harvester in the field and make it work. Meanwhile, she is also working with some robotic engineers at NMSU for robotic manipulation to remove the stems.

There is interest for mechanical harvest of fresh market peppers, too, Van Deynze said. Mechanical harvest of fresh fruit is challenging, but it's a lesser problem with peppers than a soft fruit. Fresh market mechanical harvest is on the horizon, and as researchers learn about the genetics and how the traits work, there will certainly be testing for it, too, he added.

"Some of the other traits like architecture and uniform ripening could be useful for the fresh market," Van Deynze said.

Walker thinks mechanical harvest for fresh market peppers is close. "Our mechanical harvester did such a great job in gently picking these fruits, I think we're almost there," she said.

"It just involves keeping the research going with the machines to get a more gentle pick, and I really found that selective breeding, so that the crop can be mechanically harvested, is important, too," Walker said. She added that as researchers breed for fruit that handles mechanical harvesting, they also select for flavor and quality characteristics.

Walker has had interest in her work from other chile-producing states such as California and other countries. "It amazes me," she said. "Countries that I thought would have huge available labor force, even they're interested in mechanizing."

Walker currently has funding from several sources: the New Mexico Chile Association, the New Mexico Chile Commission and partial funding from a UC Davis pass-through grant.

Currently, Van Deynze's varieties are still in test plots, but they are working with companies to get these traits in their materials. The private sector is far better at this than universities, he said, and private companies have more resources getting new traits into varieties.

Even as this trait goes out into the private sector, Van Deynze will continue looking for new traits. "That's what we do at the university," he said.

Van Deynze said this project was complex because researchers have to put several traits together—destemming, architecture and uniform ripening.

Walker's focus over the next few years will be stem removal. "We've got to get that destemming down," she said.

Walker said such innovation happens because farmers may not have a choice anymore—and, for harvesting peppers, that time may have come.

(Kathy Coatney is a reporter in Bend, Oregon. She may be contacted at"