施钾量对寒地粳稻抗倒伏能力的影响

Effects of potassium application rate on stem lodging resistance of Japonica rice in cold region

以东农425、东农427和松粳6号为试验材料,研究不同施钾量对寒地粳稻抗倒伏能力的影响。结果表明,在适当钾肥用量处理下,水稻株高增加,重心上移,基部第1、2节间长缩短,第3节间长伸长,各节间粗度、充实度、茎壁厚、抗折力和弯曲力矩都增加,倒伏指数减小,抗倒伏能力增强,茎鞘可溶性总糖含量增多,产量增加。基部各节间抗折力与节间粗度、充实度、茎壁厚和茎鞘可溶性总糖含量呈极显著正相关,与株高、重心高度和产量相关性不显著。第1、2节间抗折力与节间长呈极显著负相关,第3节间抗折力与节间长相关性不显著。东农425和东农427在K2O施用量为75 kg/hm2抗倒伏性最好,松粳6号在K2O施用量为100 kg/hm2抗倒伏性最好。

The effect of potassium application on stem lodging resistance of Japonica rice in cold region was investigated using Dougnong 425, Dongnong 427 and Songjing 6 as experimental materials. The results showed that under appropriate potassium application, plant height increased, center of gravity height moved up, the length of the first and second basal internode became short, the third basal internode length became long, stem coarseness and plumpness increased, stem wall became thick, flexural strength and bending moments increased, lodging index decreased, lodging resistance capacity strengthened, stem and sheath total soluble sugars content increased, rice actual yield improved. The flexural strength of each internode had a very sig- nificant positive correlation with stem coarseness, plumpness, stem wall thickness, total soluble sugar content of stem and sheath, whereas it had no significant correlation with plant height, center of gravity height and the yield. The flexural strength of the first and second internode showed a very significant negative correlation with the internode length, and the flcxural strength of the third internode had no significant correlation with its length. The lodging resistance of Dongnong 425 and Dongnong 427 were best under the treatment of 75 kg/hm2 K2O rate, while the lodging resistance of Songjing 6 performed best under the treatment of 100 kg/hm2 K2O rate.