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一九七○年以来,玉米杂交种的推广工作,一直积极而又稳妥地向前发展,到一九七八年全市玉米杂交种种植面积已达240万亩,占玉米种植面积的80%;对促进郊区粮食增产起到了很大作用。予计一九七九年的种植面积可能扩大到270～280万亩。由于杂交种种植面积逐年扩大,相应地加大了制种任务。增产种子的途径不外两条,一是扩大制种面积,一是提高制种单产。从目前看,制种面积不断增加。一九七八年已达11.1万亩。但制种产量却不高。多年来一直徘徊在百斤上下,各县区之间也不平衡。一九七八年
Since 1970, the promotion of maize hybrids has been actively and steadily moving forward. By 1978, the acreage of maize hybrids in the city has reached 2.4 million mu, accounting for 80% of the acreage of maize. To promote suburban grain production has played a significant role. It is estimated that the planted area in 1979 may be expanded to 270-280 million mu. As hybrid acreage expanded year by year, correspondingly increased seed production tasks. There are only two ways to increase the seed yield. One is to increase the seed production area. The other is to increase the seed production per unit area. Seen from the present, the area for seed production has been continuously increasing. In 1978 it reached 111,000 mu. However, seed production is not high. Over the years has been hovering in the top and bottom, the counties and districts are not balanced. In 1978