NMSU researchers looking at chile plants for salt tolerance
A good chile crop is a big deal in New Mexico.
Effects of drought are evident in New Mexico, especially in agriculture, but the chile crop will not be left behind if New Mexico State University researchers have any say about it.
Evan Call, a 2010 NMSU graduate with a master’s in Plant and Environmental Sciences, began the study “Evaluation of Two Methodologies to Screen Capsicum for Salt Tolerance” in 2009. Call was advised by Paul Bosland and April Ulery, plant and environmental science professors.
Call began the study partly in response to the steady decrease in main water sources for New Mexico farmers. Such reductions, especially with the water level decreasing at Elephant Butte Lake, make it more challenging and expensive to irrigate, and many farmers are forced to tap into underground water sources, which typically have a higher saline content. Also, plants grown in soil with high saline content often are stunted and have lower yield because salts inhibit nutrient and water uptake.
“It takes so much effort for a plant to grow in high saline soil that it expends more energy trying to stay alive than in producing fruit,” Ulery says.
Chile seeds are typically planted a half-inch to 1 inch deep in soil. The saline content is commonly higher in surface soil because water moves toward the surface in response to heat from the sun, and when the water evaporates, it leaves salt behind. Ulery says farmers have some control over saline content by irrigating the soil before planting crops to drive salt farther down into the soil. She emphasized that careful management is crucial when using poor-quality water.
The study examined 13 accessions representing five species of chile plants in a germination test to see what percentage of each species showed signs of making it through the growing process when grown in seven saline solutions. The 13 species were narrowed to eight to see which species would emerge through the soil when grown in a saline soil mix.
Early Jalapeño had the highest emergence percentage at 81%. NuMex Sweet and P.I. 140375 also finished in the top three performers for saline tolerance, with emergence percentages of more than 70%.
In the future, Bosland says he would like to look at inheritance of the salt tolerance trait in chile peppers and developing cultivars that are salt-tolerant.
Olmsted and Medley are with New Mexico State University.
This article published in the December, 2011 edition of THE FARMER-STOCKMAN.