氮肥施用时间和植物生长调节剂对小麦氮吸收和利用的影响

研究了氮肥施用时间和植物生长调节剂对小麦氮吸收和利用的影响。结果表明，氮肥施用时间和植物生长调节剂对小麦植株氮含量、积累和利用有显著影响。烯效唑 (S₃₃₀₇)和GA₃处理均能增加植株的氮含量，二者又以GA₃处理的效果更为明显。S₃₃₀₇和GA₃混合使用能明显提高各生育期的氮含量。植株氮含量在基因型之间差异显著，孕穗期叶片和茎杆扬麦5号显著高于浙农大941，而成熟期则以浙农大941较高。S₃₃₀₇由于抑制干物质合成而减少了氮的积累，而GA₃则增加氮的积累并减轻S₃₃₀₇的抑制作用。氮利用效率(NUE)和氮效率比(NER)在基因型和不同植物生长剂处理之间存在着显著差异。扬麦5号的NUE和NER高于浙农大941。与S₃₃₀₇或GA₃单独使用相比，两种生长调节剂混合应用显著增加了NUE和NER。

Effect of Timing of N Fertilizer and PGR on N Uptake and Utilization in Wheat

The effect of timing of N fertilizer and plant growth regulators (PGRs) on N uptake and utilization in wheat plants was studied. It was shown that both N and PGRs applications had significant effect on plant N content, accumulation and utilization. Treatments involving S3307 had higher N content than the untreated ones. GA3 treated plants contained higher N compared to S3307 or control. The combined treatment of S3307 and GA3 contained higher N in all growth stages. There were genotypic differences in N content with Yangmei 5 having higher N content at booting in leaf and stem, but the results were opposite at maturity. S3307 reduced N accumulation by inhibiting dry matter production, while GA3 increased N accumulation and modified the inhibiting action of S3307. Differences also existed in terms of Nitrogen utilization efficiency (NUE) and Nitrogen efficiency ratio (NER) between cultivars and among PGR treatments. Yangmei 5 had higher NUE and NER than ZAU 941. The combined treatment had significantly higher NUE and NER than the S3307 or GA3 alone treated plants.