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美国南部得克萨斯州传统种植的棉花品种一般生育期都较长(160—180天),从而使棉铃虫的为害严重,喷药次数多,成本增高。同时,在收获季节正赶上雨季,使棉铃霉烂,造成减产。近年来,美国农业部设在得克萨斯州的水土保持研究室的育种家培育出一批生育期短的棉花新品种,这些新品种分别是“TX-CAMD-E”、“Tamcot SP-37”和“McNair220”。它们一般在13D—140天即可成熟收获,因而比传统的棉花生育期要短30—40天。连续三年(1976—1978)的田间试验里,新培育的棉花品种“Tamcot SP-37”平均单
The cotton varieties traditionally planted in southern Texas of the United States generally have relatively long growth periods (160-180 days), causing severe damage to cotton bollworms, frequent spraying, and increased costs. At the same time, the harvest season is catching up with the rainy season, so that bollworm rot, resulting in reduced production. In recent years, breeders at USDA’s Soil and Water Conservation Laboratory in Texas have developed a number of new cotton varieties with short growing periods, such as “TX-CAMD-E”, “Tamcot SP-37” and “McNair220”. They generally harvest well after 13 days to 140 days and are therefore 30-40 days shorter than the traditional cotton growth period. In a field trial for three consecutive years (1976-1978), the average number of newly cultivated cotton varieties “Tamcot SP-37”