Relationship between culm lodging resistance and population quality of hybrids under Triangle-Planted System of Rice Intensification at different nitrogen application rates and planting densities - 不同施氮量和栽插密度下三角形强化栽培杂交稻抗倒伏性与群体质量的关系

Abstract

The effects of nitrogen (N) application rate and planting density on population quality and culm lodging resistance of rice were investigated with hybrid rice combination Ⅱyou498 as material under triangle-planted system of rice intensification (TSRI), and correlation of population quality with culm lodging resistance and grain yield was analyzed. There was an obvious regulatory effect of N application rate and planting density on grain yield, population quality, and lodging resistance of rice culm under TSRI. Compared with other treatments, 150 kg/hm2 N application rate Coupled with the suitable planting density (40cm ×40cm) improved leaf area index (LAI) and light transmission rate in rice population, coordinated bending moment and breaking resistance of basal internodes, alleviated contradiction of panicle and grain, and increased grain yield. At the nitrogen application rate of 225kg/hm2, planting density should be reduced to alleviate deterioration of population quality index and decreased lodging index. The suitable planting density was50cm ×50cm. Correlation analysis indicated population quality was significantly correlated with internode lodging resistance and yield. Middle part light transmission rate in rice population at full heading and 30 days after full heading, and amount of sap flow of rice root at 30 days after full heading might be indicators for grain yield and culm.