Effects Of Cultivation Methods And Row Spacing On Yield Formation And Proportionality Of Ningjing 3

To explored affection of cultivation methods and row spacing on yield formation and proportionality of japonica rice (Ningjing 3). The field experiment was conducted in experimental base of Nanjing Agricultural University in Danyang city of Jiangsu province in 2009 and 2010. The different treatments were random designed, different cultivation methods were machine transplanting (MT), broadcast seeding (BS), drill seeding (DS), hole-drop seeding (HS), equidistance hand transplanting(ET), precise hand transplanting (PT), cycle hand transplanting (CT), different row spacing were M1 (16.7 cm×16.7 cm, single seedlings), M2 (10.3 cm×26.7 cm, single seedlings), M3 (20 cm×20 cm, single seedlings), M4 (13.3 cm×30.0 cm, single seedlings), M5 (16.7 cm×33.3 cm, double seedlings) and M6 (23.3cm×33.3cm). Rice was seeded in late-May, and transplanting in mid-June, and direct-seeding was seeded in mid-June. The LAI, dynamics of tillers and dry matter accumulation were analyzed, panicle structure were investigated to explicitly the process of grain yield formation at mature stage, and the population uniformity was examined through coefficient of variation (CV), the population proportionality was better while CV was greater. The results were showed as following:Grain yield of different cultivation methods were different significantly, the grain yield of PT was the highest, MT was 2nd, ET was 3rd, BS was 4th, CT was 5th, HS was 6th, and DS was the lowest among these treatments. The yield of precision transplanting was highest because its LAI was suitable, leaf length and SPAD value of up four leaf and plant height were higher than other treatments, then there were large amount of dry matter accumulation from heading to maturity stage, and adequate panicle was formed to achieve big panicle goal. Panicle length of direct-seeding was shorter although it had more panicle, so the grain yield was lower. MT had mostly the same amount panicles with PT, the panicle type and plant type were better than direct-seeding, but there were still lower than PT, the grain yield was also lower than PT.Plant type was not different in three hand planting ways, the panicle type in ET was smaller than PT, although productive panicle was not different, so grain yield in ET was lower than PT, panicle type and productive panicle in CT were smaller than PT and then the yield of CT was lower than PT. Among the three kinds of direct-seeding, BS had the highest grain yield, but with low plant density, DS and HS had bigger panicle and plant type. Some studies showed that increasing seedlings, and accompanying by appropriate fertilizer and water management measures, the yield in ET and CT could be improved significantly.The grain yield in different row spacing was different, and the grain yield was not higher while the density was bigger or smaller. Leaf length and color were not affected by row spacing and grain weight and filled rated in yield components were not changed, but the productive panicles and grain number was different. The panicle was increased when single seedlings were bigger, so productive panicles were increased by expanding row spacing and planting with single seedlings. It was not favor for high yield when row spacing of transplanting was larger, and maybe increases the risk of lodging. It was one of key indicators of population that the dry matter accumulation during heading to mature stage, the grain yield was higher when row spacing was M4 (13.3 cm×30.0 cm, single seedlings).Spikelets of per panicle, primary and secondary branch number and panicle location uniformity of Ningjing 3 were significant positive correlation with grain yield. The population proportionality of Ningjing 3 was different in machine transplanting, hand transplanting and direct-seeding because vegetative periods of different cultivation methods were different, and difference of the light transmission rate after heading was the reason why population was different among in BS, DS and HS, the same to PT, CT and ET. The grain yield of PT was highest because vegetative periods of tillers in all leaf ages was longer, uniformity of panicle location was better and panicle type was uniformity and bigger, however, direct-seeding was opposite to PT, so its yield was lower. The population proportionality of Ningjing 3 was improved in DS and HS and the yield would be increased through adjusting row spacing. The population proportionality of MT was more than direct seeding, but it was lower than PT.Plant traits and panicle uniformity were positively related with grain yield, including spike weight uniformity in 2009, spike weight uniformity and secondary branch in 2010 were positive correlation significantly. Weight per plant CV in M1 was lowest with higher planting density, and M6 with lower planting density was the largest. With the increasing of plant hill, the panicle spikets panicle weight and panicle length CV became shorter, uniformity was improved. Expanding row spacing could reduce the panicle weigh CV and increase uniformity. The tillering mergence were different significantly after productive tillering stages, it may be the key reason of difference of treatments.