不同施氮量对杂交稻茎秆性状及抗倒伏性的影响

以超高产两系杂交稻品种广两优676为材料,研究不同施氮量处理对水稻茎秆性状及抗倒伏性的影响。结果表明,随着施氮量的增加,水稻各节间特别是基部的倒4节和倒5节间的长度增长,与施氮量间呈极显著的正相关,施氮可以增加水稻节间长度;各节间粗随着施氮水平的提高而增粗;施氮对茎秆壁厚无影响;各节间至穗顶高及至穗顶重与施氮量间呈极显著相关;各节间抗折力随施氮量增加而降低,但均没有显著差异;弯曲力矩和倒伏指数则随施氮量的增加而显著提高,相关达极显著水平。在施氮量为20g·m-2范围内,广两优676仍具有较好的抗倒能力,当施用过量氮肥时,则易发生倒伏。

The Effect of Different Nitrogen Rates on Culm Traits and Lodging Resistance of Hybrid Rice

The effects of different nitrogen rates on culm traits and lodging resistance were studied for a two-line super high-yielding hybrid rice combination Guangliangyou 676 .The results indicated that the length of internodes,especially the fourth and fifth internode from the top,increased with the increase of nitrogen application rates,and had an extremely significant positive correlation with nitrogen application rates,showing that nitrogen application could increase internode length of rice.The diameter of each internode increased with the increase of nitrogen application levels.Nitrogen application had no effect on culm wall thickness.The height and weight of each internode to the top of the spike all had a very closely significant correlation with nitrogen application levels.The breaking-resistant strength of each internode decreased with the increase of nitrogen application rates,but had no significant difference.The bending moment and lodging index both significantly increased with the increase of nitrogen fertilizer rates,and both had very closely significant relation to nitrogen application rates.Guangliangyou676 has better resistant lodging ability below 20 g·m-2 of nitrogen application rate,but is subj ected to lodging easily under excessive nitrogen fertilizers.