Formation characteristics of ratoon rice yield and key cultivation techniques in Chongqing:A review

Ratoon rice,which refers to the second rice production from the dormant buds on the stubble after the harvest of the main crop,is a kind of rice production system with low cost,green and high efficiency. The temperature and light production potential of ratoon rice in this area is as high as 6.75-7.50 t/ha,while the high yield demonstration formula of ratoon rice is 3.0-7.2 t/ha,rice yield of ratoon season can be further improved.This paper summarized the research progress of ratoon rice in Chongqing in the past 40 years. The results showed that strong ratoon ability of rice variety was a comprehensive trait regulated by multiple micro-effect genes and affected by environmental factors. The size of ratoon ability was closely related with non-stractural carbohydrate of stem in main season. And the initiation and growth of axillary buds was controlled by endogenous hormones as well as light and temperature condition. Also,this paper analyzed the high-yielding key cultivation practice of ratoon rice,such as the regulation effects of selecting rice varieties with strong ratoon ability,sowing and harvesting at proper time,planting methods,fertilizer management,water management,cutting height and harvesting methods in main season on the yield. In response to the prominent problems lack of strong ratoon rice variety breeding technology, lack of standardized selection standards for mechanically harvested ratoon rice varieties, unstable yield levels, lack of interdisciplinary research, and insufficient supply of core technologies for machine and agronomy integration in Chongqing,it was proposed to strengthen the key gene mining and variety breeding of strong regenerative traits in rice in the future. Based on temperature and light resources,precise evaluation of mechanically harvested ratoon rice varieties should be carried out,and the collaborative laws of high-yield and high-quality ratoon rice production and suitable agronomic measures for mechanical harvesting should be optimized. Multidisciplinary cross cultivation of high-quality ratoon rice and deep integration of machinery and technology should be carried out to improve the yield potential of harvested regenerated rice. The paper aimed to further explore the potential for synergistic improvement of yield and quality of regenerated rice,adapt it to future mechanized production,increase land production efficiency,and provide theoretical reference for achieving the goal of increasing yield and promoting high-quality agricultural development.