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New Mexico State University

New Mexico State University

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Hanson New Agricultural Biotechnology Expert at NMSU

LAS CRUCES - New Mexico State University has a new tool in its arsenal against costly chile diseases. Stephen Hanson, a molecular biologist familiar with new biotechnology methods, has joined the university's entomology, plant pathology and weed science department as an assistant professor.


New Mexico chile producers face a number of problem diseases, led by the curly top virus. When chile is infected with the devastating disease, it survives but is yellow and stunted. Thick, crisp infected leaves roll upward, providing a visual cue to the disease's name.

A tiny insect called the beet leafhopper spreads the virus. Infected plants produce a few dull, wrinkled peppers that ripen prematurely. No chemicals control the virus, leaving producers with a few options to help reduce or eliminate infections.

"Beet curly top virus is a huge problem on peppers and there are currently no effective management practices to control it," Hanson said. "But this is one disease that is a prime candidate for a biotechnology solution. We're going to look at the molecular details of how the
virus replicates and see if we can devise a control strategy based on that information."

Green chile and its ripened version, red chile, are among New Mexico's most popular cash crops. In 2002, some 16,800 acres produced 96,400 tons of chile. Once picked and processed, chile is the state's most valuable vegetable, raking in more than $200 million annually.

Another target on Hanson's list of diseases is the fungus that causes chile wilt, a root rot caused by the water mold Phytophthora. Diseased plants wilt and die, leaving brown stalks and leaves, and small, poor quality fruit.

"We are going to look at the possibility of using antagonistic bacteria to control Phytophthora capsici, one of the fungal pathogens that contribute to chile wilt," Hanson said. "Several other groups working on similar problems in other crops have found bacteria which protect plants from disease causing fungi. These bacteria grow harmlessly on the roots of crop plants and can produce antibiotics that protect the plants from the disease causing fungi."

In addition, Hanson will also teach graduate and undergraduate courses on agricultural biotechnology. He joins NMSU after earning a bachelor's degree in bacteriology and a doctorate in plant pathology from the University of Wisconsin-Madison.