Effect Of Cultivation Measures On Rice Yield And Quality

Using rice cultivars bred recently in Liaoning as materials,the rice yield,physiological trait and quality in different cultivation measures were researched.The objective was to determine that the effect of cultivation factors on yield,physiological trait and quality,the optimal application amount of nitrogen,phosphorus and potassium,and the relationship of quality traits and yield traits.The results showed as follow:1.The results showed that 36 cultivars could be classified into lax,semi-lax,semi-dense and dense panicle types.Significant difference was found in grain yield and semi-lax and semi-dense panicle cultivars had higher yield.Compared with the others,dense panicle cultivars was inferior in quality traits.The semi-lax and semi-dense panicle type cultivars had higher net photosynthetic rate at the filling growth stage,dry weight and ratio of grain to straw at the ripening stage.In a word,grain yield and eating quality in semi-lax and semi-dense panicle type cultivars were higher than those of others.According to spikelet density,the cultivars with high yield and good quality could be easily selected.2.Using semi-erect cultivars,Shengdao 9 and Shengdao 3,as materials,the study was conducted to determine the effect of cultivation factors on rice yield.The results showedd that the key factors were spacing and nitrogen application amount.Higher nitrogen application amount could help to improve yield but it was also influcened by the reward descending rule. Panicle number in yield traits was appearly affect by cultivation measures.While number of grains per panicle and 1000-grain weight were affected by cultivation measures and panicle number.Hence to improve nitrogen application amount could conduct higher panicle number per unit area,lower 1000-grain weight.And to widen hill spacing could conduct higher panicle number per hill,higher grain per panicle and lower panicle number per unit area.3.The modle for dry matter accumulation in the growth period was fit well by Logistic equation.To improve nitrogen application amount could result in higher dry matter.Total dry matter weight and panicle weight were significant affected by hill spacing(p<0.01;p<0.05). And dry matter weight was significant affected by seeding rate(p<0.05).The cultivars with high yield had faster growth in early period,especially in full heading,which prepared for heading filling.Significant difference was found in growth rate among cultivars with different grain yield.From elongating to full heading,two cultivars maintained higher growth rate(p<0.01).From heading to maturity high-yielding cultivars had higher growth rate.4.Application for nitrogen and phosphorus could promote chlorophyll content in the later growth period.The relationship beteen application amount of potassium and chlorophyll content presented parabola shape.High yield cultivars could retain high level Pn and high dry matter accumulation in filling period.Therefore,application of nitrogen could promote Pn, application of nitrogen and phosphorus could promote Ci(μmolCO₂·mol·l^-1 air).5.Chalky area,percentage of chalky kernel and chalkiness were restricted with inherent factors,and they were also affectted by cultivation measures.Higher application amount of nitrogen and lower potassium could result in higher brown rice rate and milled rice rate.And application amount of phosphorus affected head rice rate(p<0.01),the relationship bwtween application amount of phosphorus and head rice rate presented parabola shape.There was positive correlation between percentage of chalkiness and application amount of nitrogen. Widen hill spacing could result in lower percentage of chalkiness and L/W.There was positive correlation between seeding rate and chalkiness(p<0.01).Higher application amount of nitrogen could conduct high protein content and poor eating value.6.Leaf had higher nitrogen content(mg.g^-1).The nitrogen content and yield presented second-degree parabola shape,and the highest yield could be gotten when aborbing nitrogen content was 150 kg·ha^-1.Application amount of nitrogen had negitive correlation with phosphorus content.There were positive correlations between nitrogen content in leaf and NRG,nitrogen content in leaf at the full heading stage and grain yield(p<0.05).And application of nitrogen helped the absorbing for Mn,while hill spacing and phosphorus affected absorbing for Mn.The hill spacing also affected absorbing for Zn,Cu and Fe.But Mg was a variable element.Application of nitrogen and phosphorus could promote absorbing for Mg.