关键词: 国际农业发展 四阶段论 农业发展阶段特征 政策选择, 国际农业发展 四阶段论 农业发展阶段特征 政策选择

Abstract:

To study high yield physiological characteristics of the ‘Luoxushu No.9’ and provide scientific data for its high yield cultivation and wide application. ‘Xushu18’ was used as the control. After Luoxushu No.9 was transplanted for 60 days, the root investigation was done every 20 days. The investigation items include fresh and dry weight of stems and leaves, fresh and dry weight of roots, T/R rate, leaf area, index of leaf area, net assimilation rate, biomass, economic yield and coefficient of economic yield. ‘Luoxushu No.9’ had many physiological characteristics. For example, above-ground stems and leaves grew rapidly in the early stage and then slowed down; the underground tuber formed early and accumulated mainly in the middle and late stage; the root enlarged fast and lasted; coordination between sink and source; the average net assimilation rate was higher than ‘Xushu 18’; in the whole growth period the biomass and economic yield were significantly higher than ‘Xushu 18’; there was a higher economic factor. ‘Luoxushu No.9’ was an early-maturing variety with underground tuber forming earlier, higher net assimilation rate and lower consumption. Its material production belonged to “net assimilation rate” type.