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近年来在推广良种上存在一些问题。其一,种性退化快。推广一批引进良种或科研单位新育成的品种,在生产上头一两年表现增产,但三几年内穗形变劣,就失去了种用价值。其二,小麦种子的千粒重大幅度下降。比如六十年代初期引进的欧柔小麦,千粒重在45克以上,现在大部分社队所留的
In recent years, there are some problems in popularizing improved varieties. First, the rapid degeneracy of species. The promotion of a number of newly introduced varieties of introduced seeds or scientific research units has shown an increase in production in the first year or two. However, in three years, the spikes have deteriorated and the species value has been lost. Second, the grain weight of wheat seeds dropped significantly. For example, the introduction of European soft wheat in the early 1960s, a grain weight of 45 grams or more, and now most of the communes and brigades retained