The growth and yield of a wet-seeded rice-ratoon rice system in central China

A ratoon rice system is one method to increase food production in areas where the period of favourable temperature for rice production is too short for double rice, and where labour scarcity constrains crop establishment. Changing from traditional transplanting to direct seeding on the puddled soil (wet seeding: WSR) further reduces the labour requirement for the rice-ratoon system. Therefore, we compared the performance of a wet-seeded rice-ratoon rice system (WSR-RR) with a traditional transplanted rice-ratoon rice system (TTR-RR) in central China in 2015 and 2016. The ratoon season yields (4.05-5.83 t ha−1) and annual grain yields (12.4-15.7 t ha−1) of WSR-RR were comparable to those of TTR-RR. In short, WSR-RR is an alternative rice planting system to TTR-RR. The higher panicle number per m2 contributed to the ratoon season yield in WSR-RR, by contrast, the ratoon season yield in TTR-RR was attributed to a higher number of spikelets per panicle. The regeneration rates of inbred rice variety (Huanghuazhan) in WSR-RR were significantly lower than those in TTR-RR, while there was no difference in the regeneration rate between WSR-RR and TTR-RR for hybrid rice variety (Tianyouhuazhan).