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一、引言洋葱植株在营养生长期间,地上部只有7—9条细长直立的管状叶,它的根系也不发达,所以这种作物能满足于较小的营养面积。但目前各地农民栽植洋葱,一般距离过大,是造成产量不高的一个主要原因。例如沪宁一带洋葱栽植密度每亩为14,000株,产量在3,000斤左右。浙江金华地区栽培洋葱,距离更大,而且由于采收时期过早,以致产量很低,一般每亩只有1,500斤左右。据华东农业科学研究所的试验(1954—1955),每亩栽植株数由12,500株增加到24,000株,可使产量增加94.17%。北京市李景隆以行距4.5寸
I. INTRODUCTION Onion plant growth during vegetative, shoots only 7-9 slender upright tubular leaves, and its root system is not developed, so this crop can meet the smaller nutrient area. However, the current planting of peasants across the country is generally too far away, which is the main reason for the low yield. For example, the Shanghai-Nanjing area planted onion density of 14,000 per acre, the output of about 3,000 pounds. Zhejiang Jinhua growing onion, a greater distance, but because of the harvest period is too early, resulting in low yields, generally only about 1,500 pounds per mu. According to the test of East China Institute of Agricultural Sciences (1954-1955), the number of plants planted per acre increased from 12,500 to 24,000 and the yield increased by 94.17%. Beijing Li Jinglong line spacing 4.5 inches