不同生育时期追氮对超高产小麦生育后期光合特性及产量的影响

研究了在超高产条件下，不同生育时期追施氮肥对超高产小麦光合特性和产量的影响．结果表明，拔节期、孕穗期追氮有利于延缓小麦生育后期旗叶中 Ｃｈｌ含量、Ｐ_ｎ与 ＲＵＢＰｃａｓｅ活性及植株 ＬＡＩ， ＣＡＰ的下降速率．拔节期追肥较其它时期追肥产量构成因素较为协调，产量最高；孕穗期追肥能明显增加粒重与粒数，增产效果也十分显著；返青期追肥由于粒重较低，产量略高于氮肥全部底施．

Effects of nitrogen application at different growth stages on photosynthetic characteristics and yield of super-high-yielding wheat in the later growing period

Effects of nitrogen applied at different growth stages on the wheat photosynthetic characteristics and the grain yields in the later period were studied under the super-high-yielding conditions. The results indicated that nitrogen ap- plication at jointing and booting stages helped alleviate the decreasing rate of Chl content and Pn, RUBPcase activity in the flag leaves and LAI, CAP in the wheat plants in the later period. Nitrogen treatment at jointing stage had more rea- sonable components of the yield than those of other treatments and the yield of the former treatment was the highest; ni- trogen application at booting stage greatly raised 1000-kernel weight and kernel number per spike, and the yield-in- creasing effect was also very obvious; because of its low grain weight, the yield of the treatment of nitrogen application at regreen stage was slightly higher than that of the nitrogen application at seeding stage.