Commercial seed companies in Texas, Arkansas and other southern states have requested 201,500 pounds of seed to grow Jefferson, a new, long-grain rice cultivar developed by ARS scientists. In 1996, the researchers released about a thousand acres' worth of Jefferson seed to the Texas Rice Improvement Association. The association propagates supplies for commercial seed companies that produce the seed growers will plant. Earlier this year, the association sold the companies more than $160,000 worth of Jefferson seed. The new cultivar's popularity stems from potent genes that protect it from two of the worst fungal diseases of rice, sheath blight and blast. Blight is caused by Rhizoctonia solani fungi. The blast culprit is Pyricularia grisea. Both diseases are prevalent in the South as well as around the world. Severe outbreaks can cause losses of up to 50 percent. Jefferson offers yield, milling and cooking qualities comparable to the popular commercial varieties Cypress and Gulfmont. But growers can harvest a second (ratoon) crop from Jefferson 1 to 2 weeks sooner--a boon in Gulf Coast states during the hurricane season.
Rice Research Unit, Beaumont, TX
Anna McClung, (409) 752-5221

Some like it cold--including seeds of winterfat, a nutritious native rangeland shrub. The seed should be chilled to 0 degrees F to keep it in peak condition during long-term storage. Twenty years ago, scientists recommended winterfat seed be stored at 41 degrees F. They now know that seed stored at 41 degrees retains its ability to sprout, but that it loses vigor. Zero-degree storage of winterfat seed (Eurotia lanata), and of some other shrubs' seed, prevents age-related changes that occur at warmer temperatures. Scientists found that after two years of storage at 41 degrees, micro-structures like mitochondria and other organelles inside the cells of the winterfat seed embryo began to break down. They were able to see those changes with an electron microscope. When mitochondria age, they become less efficient at converting sugar to energy, so sprouting and growth take longer. Seed usually is tested by its ability to sprout, but a growth test is a better indicator of winterfat seed vigor.
High Plains Grasslands Research, Cheyenne, WY
D. Terrance Booth, (307)772-2433, tbooth@lamar.colostate.edu

Last Updated: July 11, 1997
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