Suitable spacing in and between rows of plants by machinery improves yield of different panicle type japonica rices

It was reported that the existing row-spacing of mechanical transplanted rice was too big in some rice cultivars with small panicle. Therefore, three panicle types of rice cultivars including large panicle type (LPT include yongyou 2640 and yongyou 8) and medium panicle type (MPT include wuyunjing 24, ningjing 3) and small panicle type (SPT include huaidao 5, huaidao 10) were grown in the field in 2011 and 2012 to investigate the reasonable row-plant spacing of each type of cultivars, the characteristics of dry matter production and the rules of yield formation in mechanical transplanted rice. And the effect of row-plant spacing on grain yield and yield components, leaf area index (LAI), photosynthetic potential (PP), dry matter production and accumulation, crop growth rate (CGR) and net assimilation rate (NAR) were all studied. Results showed that with 30cm row-spacing and expanded plant spacing, it is easy for LPT to obtain high yield due to the larger size of panicle.