玉米杂交制种不结实现象在我县多次发生,严重的影响我县的制种产量。1977年在东河大队制的黄白单交,亩产只有30多斤,产量是正常年份的六分之一,1978年全县制的陕单1号结实极差,亩产只有平常年份的一半。同年东河大队繁殖的武105自交系也有类似现象,1979年,东河制的商单四号结实极差,亩产只有平常年份的三分之一。这种现象在我区其它地方 Occurrence of hybrid corn seedless phenomenon occurred repeatedly in our county, a serious impact on the county’s seed production. In 1977, the yellow-white single-handed delivery by the East River Brigade had a yield of only 30 kilos per mu and a yield of one sixth of that in normal years. In 1978, Shandan No. 1 in the county system was extremely poor with a yield of only half that of normal years . In the same year, a similar phenomenon was observed in the Wu 105 inbred line that multiplied in the East River Brigade. In 1979, the commercial order No. 4 on the Donghe River was poorly endowed with only one-third of the average annual output of mu. This phenomenon is in other parts of our district