Among the top 10 disorders or diseases of American-grown lettuces, tipburn causes inner leaves of vulnerable lettuces to turn brown. After six years of testing, ARS this year offered the dark-green lettuce to seed companies and breeders for planting in Arizona and California. Those states produce 95 percent of the nation's iceberg lettuce. Tipburn occurs when hot weather, too much water or too much fertilizer causes leaves to grow too fast and run out of calcium. Leaf edges killed by tipburn are vulnerable to slime-producing bacteria and fungi that can rot the whole head.
Iceberg lettuce is America's second favorite vegetable.
A new southernpea for gardeners and farmers fights off damaging nematodes, insects and diseases. Now available to seed producers, the new variety, Tender Cream, is ideal for southeastern states, where it also gets high grades as a canned pea. It produced 18 percent more peas than the top commercial varieties during 1994 region-wide field tests. Its pods are slightly curved, about six inches long, and contain about 14 peas. In the field tests, it had 75 to 98 percent fewer cowpea curculio larvae than susceptible varieties.