Nearly 20 years after the close of the Vietnam war, the effects of the conflict still linger in the landscape and food supply of Vietnam, according to a nutritional geographer at UC Davis. "Military defoliants have left hundreds, if not thousands, of acres unsuitable for farming and have accelerated soil erosion and river siltation," says Louis Grivetti, a professor of nutrition and geography. The economic fallout from the war also has resulted in a decrease in the overall caloric intake of the people of Vietnam, as that nation moved to export the bulk of its rice crop -- one-third of which is lost to mold and mildew due to traditional harvesting and storage methods, Grivetti notes. Extensive toxicological studies should be done to determine to what extent military-related heavy metal compounds and herbicides remain in the environment and food supply, he says. Grivetti spent three weeks touring Vietnam last year to initiate a cooperative program with scientists in the Socialist Republic of Vietnam and will return in May with two Vietnamese-American graduate students to teach short courses on nutritional geography and provide training. He will discuss his work at 12:30 p.m. Saturday, April 2.