Evaluation Of Lodging Resistance And Effects Of Lodging On Yield & Rice Quality During Grain Filling Stage

From 2005 to 2007, more than twenty varieties were used as materials, in the research on the effect of different lodging stage on rice yield and rice quality, the application of stem lodging resistance mechanics index in rice stem, and on the relationship between variety of stem structure character and fracture force resistance ,the results were as follows:(1) In the mechanics analysis model of stem lodging index, analysis lodging resistance safety coefficient of 11 rice varieties, the result of correlation analysis in the second basal internodes indicated that, compared with stem pull, these two indexes are in positive and significant correlation, safety coefficient in stem node is in high marching rate with real measured result, it is in high utility value when analysis rice lodging resistance in this model.(2)The ratio of lodging resistance moment between Rice stem with leaf sheath and without leaf sheath is stable during productive phase, so the main analysis here is the lodging assistance of stem without sheath. ANOVA of lodging resistance moment of stem node indicated that, lodging resistance moment is the smallest in 30 days after heading, lodging risk is rather heavy; in basal internodes, the lodging resistance moment is bigger. ANOVA of inner diameter, outer diameter and stem wall thickness indicated that, there is some difference in both inner and outer diameter, some stems are thin but can resist lodging, some stems are thick but can't resist lodging, in further analysis, the stem wall thickness greatly effected stem lodging resistance, enhance the stem wall thickness of basal internodes can effectively prevent lodging. The ratio of stem wall thickness to outer diameter changed in a small range from 15 days after tassel period to 45 days. it is significantly increased than tassel period. the starch in mainly in the upper internodes, the steerage function of basal internodes is decreasing, mostly take on the supporting function; the content of usable carbohydrate(soluble sugar+ starch) is significantly decreased in 30 days after tassel period. Cellulose as the most important basis in supporting stem cell walls, the more close to the basal internodes, the more resistance of stem. The correlation analysis indicated that, both stem wall thickness and cellulose content is in positive significant correlation with lodging resistance moment.(1) The effect of lodging to rice yield indicated that, lodging earlier, the yield getting lower, when lodging appears in early productive stage, it greatly effect grain yield. seed-setting rate and 1000-grain weight these two yield components are effected by lodging. In rice machining quality, brown rice rate is stable during different lodging stage; Lodging later ,the head milled rice rate getting higher, there are significant differences among treatments; the changing trend of full head milled rice rate and head milled rice rate is identically, but the difference among treatment of full head milled rice rate is more significant. In appearance quality, there is no significant effect to the length and width of rice grain among different lodging stage; chalk grain and the ratio of chalky grain are decreasing with the deferring of lodging stage. In the nutrition quality of rice, the content of amylase is decreasing when lodging later, if lodging earlier , the content of amylase and protein is higher ,the quality is getting worse; when the grain in low gel consistency ,with the deferring of lodging stage , gel consistency will increase, when the grain in high gel consistency, it is little effected by lodging stage; with the deferring of lodging stage, all the three rice variety are in the same changing trend , peak viscosity and break down are increasing, set back is decreasing.