Studies On Effect Of Transplanting Pattern On Different Panicle Type Mechanical Transplanted Rice

With 6 widely used late-maturing medium japonica rice divided into 3 panicle types as the mechanical transplanting materials, the effects of yield and its formation , rice quality ,nitrogen absorption and utilization,plant population quality and plant types under 15 different transplanting pattern were studied during the year 2006-2007, at Diaoyu Town, XingHua county, LiXiaHe area, Jiangsu province. The main results were as follows:1st, along with the increase of transplanting hills and transplanting seedlings per hill , the number of panicles of all mechanical transplanting rice was increased, the glumous flowers per panicle, the 1000 grain weight and grain filling rate were straightly dropt. The small panicle type mechanical transplanted rice increase the yield mainly depend on the increase of the panicles, The medium panicle type rice increase the yield mainly depend on the coordinate of the panicle and the glumous flowers per panicle, The large panicle type mechanical transplanted rice increase the yield mainly depend on the increase of grain filling rate. The more transplanting hills the higher the yield. The mechanical transplanted rice got the highest yield when rice was transplanted with 4 seedlings per hill for small panicle type rice, 3 seedlings per hill for medium panicle type rice and with 2 seedlings per hill for large panicle type.2nd, along with the increase of transplanting hills and transplanting seedlings per hill , the number of the max number of stems and tillers increased, while the effective panicle rate dropt, The leaf area increased along with the increase of transplanting hills and transplanting seedlings per hill till the baby earing stage, and achieved the biggest leaf area at the baby earing stage, then the leaf area began to drop, the LAI drops, the SPAD value drops, the larger the density, the quicker the LAI and the SPAD value drops .The small panicle type rice drops the quickest, then the medium panicle type rice and the large panicle type rice is the slowest. The changes of the dry matter accumulation under the different transplanting patterns follows the Logistic dynamic curve. it's benefit for the dry matter accumulation when the density increased in a certain degree .but when it out of the degree, the dry matter accumulation drops. The dry matter accumulation between the heading stage and the maturity and the dry matter accumulation of the maturity had a significant positive relationship with the yield. the different panicle type rice got the critical index of dry matter accumulation differently, the changes of the grain filling under the different transplanting patterns follows the Richards dynamic curve. along with the increase of transplanting seedlings per hill ,the grain filling rate drops. the difference of the grain filling rate of the grain at different position increases, the duration of grain filling became shorter, Initial grain filling potential of the vigorous grain drops, the time arrives the maximum grain filling rate delayed, the competition became fierce between the vigorous and weak grains and finally leads the lower percentage of the grain filling rate and the grain weight.3rd, along with the increase of transplanting hills and transplanting seedlings per hill, the plant height increases, all the internodes elongates, the out diameter of the basic stalk reduces, the stalk index drops, the stem and the filling rate of the stem drops, the leaf length and the leaf width shorter, the leaf area smaller, the specific leaf weight drops ,the ear turns shorter, the number of the primary and secondary branches as well as the total amout of grain,total amount if filled grain and the grain filling rate drops, which leads the number of the glumous flowers per panicle, the grain density on the branches reduces, the ear type reduces and the grain filling rate drops.4th, along with the increase of transplanting hills and transplanting seedlings per hill, the chalkiness rate and chalkiness degree extremely obviously rises, the brown rice rate, the milled rice rate and the head milled rice rate drops, the protein content is lower, the amylose content increases, gel consistency became longer, all the mechanical transplanting rice displays so. But the variation of coefficient of the main grain quality characteristics was different. the peak viscosity, hot viscosity, breakdown, final viscosity and the pasting temperature of the RVA profiles assume the tendency increases first and then decrease along with the increase of density , while the setback has no significant changes. the variation of coefficient of the RVA profiles was different. The chalkiness rate and chalkiness degree can easily effected by density.5th, The changes of the nitrogen accumulation of the whole growth period under the different transplanting patterns follows the Logistic dynamic curve. It is benefit for nitrogen accumulation in a certain density degree, and the nitrogen accumulation amount and the nitrogen absorption rate drops when the density surpasses the certain degree. different panicle type mechanical transplanted rice got the same index of nitrogen absorption and utilization at different densities. higher the transplanting hills higher the nitrogen utilization efficiency. While the nitrogen utilization efficiency trends to be increase first and then decrease along with the increase of the transplanting seedlings per hill. different panicle type of mechanical transplanting rice got the most suitable nitrogen utilization at different transplanting seedlings per hill.To sum up the yield, grain quality, nitrogen absorption and utilization,plant population quality and plant type of different genotypes in different transplanting patterns, we could see that the yield, rice grain quality and production efficiency were easily harmonized when the transplanting hill was high for all panicle type rice and 2,3 and 4 seedling per hill each for the large,medium and small panicle type rice .