【摘要】 通过３个玉米杂交种、２个播期、４次收获的研究表明：在玉米生理成熟即玉米子粒千粒重最大时，粗脂肪含量最高，质量最佳、尽管粗蛋白相对含量有所降低，但由于子粒产量的增加，使单位面积收获的蛋白产量仍有提高。因此，适时收获不仅可以提高玉米的产量，而且可以改善玉米的品质。更多还原

【Abstract】 Four different harvesting dates of three corn hybrids with two sowing timeswere studied. The results showed that during disappearance of milkline,or indication ofphysiological maturity in corn kernels,higher protein yields and oil contents and iodine val-ue could be gained.更多还原