Studies On Simplified High-yielding Cultivation Technology And Physiological Mechanism Of Ratoon Rice

Ratoon rice is a second harvest, obtaining from tillers originating from the stubble of the previously main rice. In Hubei Province, cultivation by hand planting and hand harvesting in rice, restricts the planting scale of ratoon rice. Mechanized, simplified cultivation in rice is the fundamental to develop cultivation for ratoon rice in large scale. In this experiment, series of studies on ratoon rice are to explore mechanization, simplified cultivation techniques of ratoon rice.We utilize the regeneration characteristics of rice and explore a feasible way to achieve double high yields of main and ratoon rice from2010to2011. In2010, study is conducted in the field of Wuxue city, but in2011, we change the place in the field of Ezhou city.Series studies are conducted on several different sections:1. screening experiments on varieties and stubble height of ratoon rice;2. simplified cultivation technology on Main rice;3. chemical control techniques on increasing buds and the growth of ratoon rice. The main results are obtained as follows:1. In Hubei province, early-season rice varieties such as LP112, EZ18, LY42, LY287and JFZ are suitable for ratoon planting. They have good characteristics for ratoon varieties, such as strong tiller, moderate number of spikelet per panicle, moderate leaf area index in head stage; Considering growing period of varieties, medium-season rice varieties, such as SY63, LY8, Ⅱyouhang2, GLY476are good for ratoon planting.2. Varieties have significant different yield of ratoon rice under different stubble heights. When cutting different heights, yields of most ratoon rice varieties are higher under high (40cm) than low height (20cm), because they have more panice per square meter. Dynamics of buds in ratoon rice are different between varieties under different stubble height; Good ratoon varieties have characters of early buds germination, early emergence, high uniformity of rice group, good Ratoon ability.3. Compared on four different cropping production patterns (early-season rice+ratoon rice、medium-season rice+ratoon rice、single medium-season rice、early- season rice+late-season rice), we find there is a big difference on the total yield and efficiency of agricultural input of rice in one year between them. Both early-season rice and medium-season rice can used for ratoon rice after harvest, and total yields of main and ratoon rice are higher than single medium-season rice. Under ratoon production model, despite the total yield of main and ratoon rice is not higher than early+late rice, but it can save time for growth of the next season crop, so it is appropriate to build ratoon rice in some region of Hubei Province.4. When main rice is used simplified cultivation measures, yield of ratoon rice is not higher than hand transplanting, but it can reduce production costs, save time and effort, and net income and the effort is increased. Harvest of the main rice in machine is better than conventional hand harvesting, it can greatly reduce the labor intensity of production. Considering cost and benefits, harvesting in machine is better than the conventional hand harvesting, and it will be productive to planters.5. When we use chemical modifiers in ratoon rice, the effect of exogenous spraying of single growth regulator on promoting buds of raooning rice growth is different. Effect of spraying growth regulator material of GAs is the best, and it can make rice plant height higher and more consistent than spraying other growth regulators and water (CK). Effect of spraying other growth regulator material is different between varieties; The mechanism that spraying of ethephon increased regeneration bud is not cleared, needing to be further studied. The effect of compound growth regulator, cytokinin and gibberell compound growth regulators is the best, and other substances compound effect is not very obvious.6. Ratoon rice is closely related to growth status of the main rice. The marginal effect is found in both of main and ratoon rice. Marginal effect of main rice is manifested as:the increase in panicle、spikelet、1000-grain weight、grain yield was10.2%、39.3%、7.3%、52.5%than inside line, respectively; Marginal effect of the ratoon rice is manifested as:the increase in panicle、spikelet、grain yield is59.2%、11%、89.7%, respectively, but1000-grain weight is not increase.