根据USDA三月份的调查预测,今年美国转基因大豆、玉米和棉花的种植面积都将有所上升。玉米总的种植面积将上升4.3%，达7900万英亩，而大豆总的种植面积将下降1.5%，为7300万英亩。 2002年大约有74%的大豆作物将种植转基因耐除草剂品种，去年为68%。据预测，所有大豆主要种植州 According to the USDA survey in March, the area under cultivation of genetically modified soybeans, maize and cotton in the United States will increase this year. The total area planted to maize will rise 4.3% to 79 million acres, while the total area planted to soybeans will fall 1.5% to 73 million acres. About 74% of the soybean crop in 2002 will be planted with GM herbicide-tolerant varieties, up from 68% last year. It is predicted that all the major soybean growing states