Variety does more than spice up the onion business in New Mexico.

Indeed, it keeps the business going, said Chris Cramer, onion researcher with the department of agronomy and horticulture at New Mexico State University in Las Cruces.

Some grower-shippers have dozens of onion varieties. Cramer said that contributes to continuity within New Mexico’s onion deal.

“The large number of varieties is required because one variety matures at a specific time and it is difficult to manipulate the maturity date,” Cramer said.

New Mexico onions are not storage varieties found in Oregon, Idaho and eastern Washington, Cramer said.

New Mexico onions, Cramer said, generally are shipped quickly after harvest; thus, the need for many varieties that mature at different times.

“To have a continuous supply of onions, you need a new variety maturing each week during the harvesting season, Cramer said, noting that New Mexico growers begin harvesting their crops at the end of May and, in some cases, continue until mid-August.

“That adds up to 11-12 weeks of onion harvesting,” he said. “With three different colors, you triple that number.”

Growers also may grow two different varieties that mature simultaneously, Cramer said.

New Mexico State’s program is continuing to develop onion cultivars well-adapted to growing in New Mexico, Cramer said.

“Each of the colors is important. Disease resistance is important,” he said. “Sometimes the development of a variety for a maturity slot in which seed of other cultivars is limited is also an important criteria.”

Some onion-producing regions have focused on developing a sweet onion that provides some marketing punch.

New Mexico doesn’t place as much emphasis on sweet onions as other states, Cramer said.

It’s not necessary, he said.

“Many of the yellow onion varieties grown here would be more mild than those onions grown in the Pacific Northwest or New York,” he said. 

TJ Runyan, owner of Las Cruces, N.M.-based Mesilla Valley Produce, said sweet onions — a number of growers say they preferred the term “mild” to “sweet” — are gaining some momentum among some growers-shippers in New Mexico, including his own company. But, he said, there are limitations.

“A lot of it depends on the more established Vidalia program and the Walla Walla affects us in that category,” he said, citing the more established products’ tradition and strong retail following. “It’s a category we’re after, but it’s not one that’s a main focus, I guess.”

Cramer said there isn’t much need to develop a variety for sizing.

“Size often depends upon plant density — the more space you give an onion plant, the larger bulb it produces,” Cramer said.

Size requirements have evolved, said Bill Coombs, salesman with Arrey, N.M.-based Desert Springs Produce.

“We grow onions of specific sizes for specific customers, and that is a big change from the way things used to be,” he said. “In days of old, everything was as big as you can get. But the market is to take care of customer needs.”