Progress and challenges of rice ratooning technology in Sichuan Province, China
Peng Jiang, Lin Zhang, Chao Chen, Xingbing Zhou, Mao Liu, Xiong Hong, Xiaoyi Guo, Yongchuan Zhu, Fuxian Xu
Abstract
Sichuan Province is the primary region of ratoon rice production in China. This review summarizes the research progress of theories and technologies relating to the efficient cultivation of high-yielding ratoon rice based on the following: (1) The ratoon rice planting area in Sichuan can be divided into three climatic zones based on the thermal energy availability: highly suitable, suitable, and sub-suitable zones; (2) Grain yield in the ratoon season in Sichuan is 1.8-3.9 t ha-1 lower than that in southeast and central China. The lower ratoon-season yield in Sichuan was associated with lower panicles m-2 and less spikelets per panicle (3) The effects of selection rice cultivars, optimal nitrogen and water management, timely harvest of the main crop, suitable rice stubble height and sheath blight control on improving the ratooning ability of rice cultivars were examined. (4) Factors restricting ratoon rice production in Sichuan include unstable ratoon rice yields, lack of suitable rice cultivars as simplified cultivating for ratoon rice, lack of high efficiency and specialized rice harvester for ratoon rice, and large yield gap between demonstration area and farmer’ paddy fields and mechanical harvesting of main crop destroys axillary buds that resulted in low ratoon rice yield. (5) The new ratoon rice technologies relating to future development trends in Sichuan Province are clarified, including simplified cultivation techniques, integration of agricultural machinery and agronomy techniques, screening high efficiency and specialized rice harvester, and indicators for breeding rice cultivars with strong ratooning ability and suitable growth duration in ratoon rice system.