Chris Cramer
Professor: Plant and Environmental Sciences

• Onion Breeding Program

"The NMSU onion breeding program is one of only two active, public onion breeding programs in the United States that is releasing cultivars and/or germplasm lines. Since 1981, 28 cultivars and germplasm lines have been released. These cultivars are high-yielding, high quality, disease-resistant, and bolting-resistant. Of the onion cultivars grown in New Mexico, over 50% are from NMSU or are genetically-derived from NMSU-released cultivars. For the autumn-sown crop, approximately 75% of the acreage is planted with NuMex onion cultivars. One of the objectives of our program is the continued development of high-yielding, high-quality, well-adapted, bolting-resistant, disease-resistant, short-, intermediate- and long-day onion cultivars with varying maturities and scale colors that allow growers in New Mexico to be competitive with other onion markets in the United States.

Fusarium basal rot (FBR), caused by Fusarium oxysporum f. sp. cepae, appears initially as leaf yellowing, progresses to root dieback and basal plate degradation, and eventually results in a rot of the entire bulb. The soil-borne organism can remain in the soil for several years, can survive on other Allium species and other plant species, and requires four years of nonsusceptible hosts to reduce inoculum levels before onions can be planted again. All of those factors make control difficult and expensive to achieve. Currently, no short-day or intermediate-day onion cultivars are reported to have FBR resistance. Our current work has focused on examining the screening methods currently used in the hopes of improving these methods for making progress for resistance."

This document was submitted by Chris Cramer, Professor: NMSU Department of Plant and Environmental Science.