Have you hugged your agricultural scientist today? Considering that national and multinational corporations are leaving the St. Louis area like popcorn from a fire, it's time to appreciate the much-maligned Monsanto, one of the few multinational corporations to still call St. Louis home. Monsanto, which is controlled by Peapack, N.J.-based Pharmacia Corp., not only funded the new research center near the Missouri Botanical Garden on Vandeventer Avenue, it also sponsors global programs designed to help Third World nations feed themselves, programs such as the Cassava Project. In Africa, nearly half the cassava crop is lost to disease. Monsanto scientists in St. Louis and Nairobi, Kenya, are studying ways to protect it.