The threat posed by superweeds on US corn and soya plantations have rekindled the demand of militant farmers and scientists for an end to the cultivation of hybrids. [...] Output also declined markedly after the soil was bombarded with chemical inputs and Masipag suspects that this is the culprit for soil sterility. The annual Asian rice growth rate of 3.4 percent in 1977 slid to only 1.5 percent in 1997.