为提高玉米单位面积产量和适应农业机械化的发展,急需选育早熟、抗病、高产、优质、适于夏直播的玉米杂交种.但早熟单交种一般制种产量低,不利推广.因此,近年来我们研究走三交种的路子.但三交种选育年限长,为了加快育种步伐,自1978年起,对三交种的经济性状和籽粒产量进行了一些预测工作.一、供试材料1978年用Mo17×330、聊202×330、Mo17×聊202三个单交种的平 In order to improve the yield per unit area of ​​corn and adapt to the development of agricultural mechanization, it is urgent to select the maize hybrids that are early-maturing, disease-resistant, high yield, good quality and suitable for summer seeding, but the low yield and unfavorable promotion of common early- In recent years, we study the way to take the three cross-breed, but the three cross-breeding variety of long-term, in order to speed up the pace of breeding since 1978, the three cross-breeding economic traits and grain yield some predictions. Materials 1978 with Mo17 × 330, chat 202 × 330, Mo17 × chat 202 three single cross-breeding level