Effects Of Different Irrigation Methods On Growth And Development Characteristics, Yield And Water Use Efficiency In Paddy Rice

The experiments have four irrigation methods, including four treatments in dry cultivation (DC), damp irrigation (DI), the treatment C (controlled damp irrigation before booting stage, rational irrigation at booting stage, wetting-drying alternation irrigation from heading stage to mature stage.) and submerged irrigation (SI). Some growth and development characteristics, photosynthetic productivity, eco-physiological characteristics, grain yield and water use efficiency were studied to supply theoretic and practical gist for the water-saved and drought resistance cultivation under four different irrigation methods with three hybrid rice of Gangyou 527, Diyou 363 and Shanyou 63. The main results were as follows:1. Both the treatment C and DI obviously promoted effective tiller rate, and reduced inefficacious tiller compared with those of SI. Under the treatment C and DI, the dry weight of root was increased obviously, and the ratio of root-shoot was enhanced. Root activity and bleeding intensity in basal internode were significantly higher of the treatment C and DI than those of SI. Under the treatment C and DI, the senescence of root was obviously delayed compared with which under SI. DC reduced the growth of root, and decreased effective tiller rate. Under DC, root activity and bleeding intensity in basal internode were lower than that under SI, and the senescence of root was accelerated after heading.2. Under the treatment C and DI, leaf area index (LAI) was higher obviously, the descending rate of LAI was slower and had much higher percentage of efficient LAI and grain-leaf area (cm~2) ration of top three leaves than that under SI. The chlorophyll content in the top three leaves was higher and decreased slowly after heading under the treatment C and DI. The photosynthetic rate (Pn) and water use efficiency of flay leaf were higher in the treatment C and DI than those of SI. Compared with SI, the top three leaves of the treatment C and DI was erecter, and the leaf angle of flag leaf, 2nd and 3rd leaf from top increased in sequence. Therefore, in the treatment C and DI had an ideal plant type, and improved photosynthetic gesture of group canopy, and improved photosynthetic productivity. Under DC, the LAI, percentage of efficient LAI and chlorophyll content of the top three leaves were lower than that under SI. But the senescence of top three leaves was descended rapidly. Under DC, stomata density was significantly higher than that under...