Effects Of Row-Spacing And Transplanting Density On Approach To Super-high Yielding Rice

The experiments were conducted in the farm of YangZhou University during 2006-2007,with ChangYou 1 hao,YongYou 8 hao,WuJing 15,NingJing 1 hao,Yangfujing 7 hao and WanJing 94. The effects of different transplanting density on yield,quality and growth in mechanical transplanting rice were studied, with the the same Zhuju (4-inches) and different row-spacing set (6-inch,7-inch,8-inch, 9-inch, 10-inches). The main results were as follows:(1) The effect of transplanting density and spacing allocation of rice on yield as well as the components of the yield formation was significant. Increasing row-spacing and decreasing transplanting density,the yield will increase at first and then decrease. The 4×8-inch (density of 19,000 xue /mu) of WanJing 94,Yangfujing 7 hao,NingJing 1 hao,WuJing 15 achieved the highest yield. 8-inch (density of 19,000 xue /mu) and 9-inch (density of 17,000 xue /mu) of ChangYou 1 hao and YongYou 8 hao reached the unremarkable level. Differences of yield in the other transplanting density was significant. Among different varieties,Wujing15 got the highest yield, ChangYou 1 hao next,Yangfujing 7 hao's the lowest.Increasing row-spacing and decreasing transplanting density, the number of panicles, spikelet per panicle, seed-setting rate and the kilo-grains weigh will increase at first and then decrease. The different varieties had significant difference in panicle number,number of spikelet per panicle,seed-setting rate and kilo-grains weight. Yangfujing 7 hao's panicle number was biggest; YongYou 8 hao's number of spikelet per panicle was biggest; WanJing 94's seed-setting rate was highest; NingJing 1 hao's kilo-grains weigh was biggest.(2) Along with increasing row-spacing and decreasing transplanting density,the rice quality was improved. Increasing row-spacing and decreasing transplanting density,amylose content,brown rice rate,milled rice rate and head milled rice rate increased,while chalkiness,chalkiness ratio,protein and gel consistency decreased. Among different varieties , increasing row-spacing and decreasing transplanting density, peak viscosity and breakdown will increase at first and then decrease, while trend of the setback was on the contrary .The effects of transplanting density and spacing on brown rice rate,milled rice rate and head milled rice rate were different. The sequence of different varieties was in the order of Head milled rice rate > Milled rice rate >Brown rice rate. The results showed that the rice quality was highly affected by transplanting density and spacing, especially the chalkiness,amylose content and chalkiness ratio. The protein, gel consistency and head milled rice rate followed. The effect of transplanting density and spacing was small on head milled rice rate.(3) The supper-high yielding cultivation should both have a high number of panicles and seed-setting rate. The seed-setting rate of supper-high yielding rice were higher,not only because of first rachis branch's seed-setting rate,it is more important to secondary rachis branch's seed-setting rate. Along with increasing row-spacing and decreasing transplanting density, the first rachis branch,secondary rachis branch,number of spikelet per panicle increased, while the seed-setting rate reversed. The conventional Japonica variety's seed-setting rate was larger than the hybridized Japonica variety's seed-setting rate , mainly because secondary rachis branch's seed-setting rate was lower. Along with increasing row-spacing and decreasing transplanting density , different varieties of the three function leaves's length increased,while the width decreased. With the spacing increased and transplanting density decreased, plant height, the length of stalk were reduced and shorted, while the ratio of the internode under panicles with the length stalk increased at first and then decreased. Thus,appropriate space helps to to build more healthy groups to prevent lodging.(4) With the increased spacing and density decreases, different varieties of Enough seedling, Jointing stage, Heading's the production of population dry matters straightly plummeted, the maturity of the production of population dry matters first increased and then decreased, six varieties has the same trend. With the increased spacing and density decreases, absolute incremental of the production of population dry matters from Heading to maturity first increased and then decreased. There are differences between the varieties, the ratio of hybridized Japonica variety of absolute incremental of the production of population dry matters from Heading to maturity to the total dry matters was more than 40%,as conventional Japonica variety was less than 40%.(5)With reproductive process advanced, adsorbing nitrogen in different phase of conventional Japonica variety and hybridized Japonica variety increased. ChangYou 1 hao and WuJing 15's adsorbing nitrogen in Jointing stage, Heading and the maturity were more than the other varieties. With the increased spacing and density decreases, adsorbing nitrogen of different varieties in Transplanting- Jointing stage straightly plummeted, as the ratio of adsorbing nitrogen to the total adsorbing nitrogen reduced first and then increased; With the increased spacing and density decreases, adsorbing nitrogen and the ratio of adsorbing nitrogen to the total adsorbing nitrogen in Jointing-Heading stage and Heading- maturity stage increased first and then decreased.With the increased spacing and density decreases, different varieties of the total N of population, N use efficiency and productive efficiency increased first and then decreased. Between different varieties, the highest of conventional Japonica variety of the total N of population and productive efficiency was 8-inch spacing and density of 19,000 xue / mu , while hybridized Japonica variety was 9-inch spaced and the density of 17,000 xue /mu. The adsorbing nitrogen of 100 kg grain was no obvious correlation to spacing and density. (6) On all accounts,Wujing15(conventional Japonica variety) and ChangYou 1 hao(hybridized Japonica variety) got the highest yielding and other superior advantage. Among 5 different row-spacing set and transplanting density,spaced 8-inch,as the density of 19,000 xue/ mu was more help to get high-yielding and high-quality for conventional Japonica variety; spaced 9-inch, as the density of 17,000 xue/ mu was better to hybridized Japonica variety.