培杂山青始穗期氮钾营养对剑叶光合速率及稻谷产量效应

Effects of Nitrogen and Potassium at Initial Heading Stage on Photosynthetic Rate of Flag Leaf and Grain Yield

两系杂交稻培杂山青始穗期供给氮、钾营养，可提高结实期剑叶光合速率、叶绿素（ａ＋ｂ）含量和稻谷产量，但对叶绿素ａ／ｂ值影响小。始穗期供给氮及氮钾营养对培杂山青的效应比对三系杂交稻汕优６３的效应更明显。

Using two-line hybrid rice Peizashanqing and three-line hybrid rice Shanyou 63 as the materials, the effects of nitrogen and potassium at initial heading stage on photosynthetic rate of flag leaf and grain yield were studied by way of pot culture with four treatments, i.e., Blank (B, no fertilizer application), NPK (check, applying N、P、K as basal fertilizer), NPK+N (applying nitrogen fertilizer at initial heading stage besides N、P、K basal fertilizer) and NPK+NK (applying nitrogen and potassium fertilizers at initial heading stage besides NPK basal fertilizer). The results showed that the effects on increasing photosynthetic rate of flag leaf, chlorophyll (a+b) content in late stage and grain yield were distinctly different among the four treatments (NPK+NK>NPK+N>NPK(CK)>Blank), while the effect on a/b ratio was similar. Furthermore, the effects in Peizashanqing were greater than in Shanyou 63, resulting in a higher grain yield of Peizashanqing (13.9% and 12.2% higher than that of Shanyou 63 by NPK+NK and NPK+N, respectively).