我县部分社队贫下中农有食用白玉米的习惯,过去大面积种植白马牙,产量较低。1971年我县农业科技人员和贫下中农一起,推广了白单4号玉米。“白单4号”比“白马牙”一般增产20％以上,而且品质好。但“白单4号”的突出缺点是:1、不抗玉米大小叶斑病;2、易秃顶;3、苗期长势弱,不适合麦田套种;4、制种产量低,一般亩产种子不过百斤,大面积普及有困难。根据广大贫下中农的反映和要求,在认真分析了一些单交种和自交系的基础上,选配了几个杂交组合,当年冬季赴海南岛育成了第一批 Some of the communes and communes in our county have the habit of consuming white corn because they have poor peasants. In the past, the White Horse teeth were planted on a large area with a low yield. In 1971, our county’s agricultural science and technology personnel and the poor and middle peasants joined together to promote Baidian No.4 corn. “White No. 4” than the “white teeth” generally increase production of more than 20%, and good quality. However, “Baidan 4” outstanding shortcomings are: 1, not resistant to leaf spot disease of corn size; 2, easy to bald; 3, seedling growth is weak, not suitable for intercropping wheat; 4, seed production is low, However, jin, large-scale universal difficulties. Based on the reflection and requirements of the vast majority of poor and middle peasants, on the basis of careful analysis of some single cross-breeding and inbred lines, several hybrid combinations were selected and the first batch was made in Hainan Island in winter