Effects of Different Cultivation Methods on Accumulation and Transformation of Assimilation Products and Lodging Resistance of Stem-sheaths of No-tillage Rice-不同栽培方式对免耕水稻茎鞘物质积累转运与抗倒伏能力的影响

Abstract

The effects of different cultivation methods on accumulation and transformation of assimilation products and lodging resistance of stem-sheaths of no-tillage (NT)rice were investigated with hybrid riceⅡ you 498as material. At the same time, the relationship between transformation of assimilation products and lodging resistance of stem-sheaths was also studied. The results showed that there was no significant difference between NT rice and plowing-tillage (PT) rice in accumulation and transformation of assimilation products before heading, but photosynthetic productivity after heading of NT rice was much smaller than that of PT rice, resulting in significantly smaller grain yield of NT rice than that of PT rice. Under PT, triangle-planted system of rice intensification (TSRI) not only gained the highest grain yield but also maintained a small lodging index (LI)of the fifth internode from top. In NT, the interaction between wide and narrow row cultivation (WNR) and NT not only boosted dry matter accumulation after heading to increase grain yield effectively but also reduced the lodging risk at the bottom of the plant largely, which made WNR the optimal cultivation method among the four in NT. In this research, rice plants got flattened most easily at the 5th internode (N5) from top, while among a list of physical characters of stem-sheaths, only internodes length of N5and flat ratio of N4, closely related to LI, could be affected by cultivation measures, thus lessening the internode length of N5 and flat ratio of N4 was just the orientation to enhance lodging resistance. In both PT and NT, there were significant negative correlations between LI of N5 and dry matter accumulation after heading, and an increasing grain yield would not push rice plants fall down significantly, on the contrast, an increasing grain yield would help to reduce the risk of plant lodging from the bottom in PT.