Abstract: In order to explore the effects of transplanting periods on growth and yield of rice and optimize the suitable transplanting date and rice varieties, the dynamic change laws of agronomic traits, carbonitride and yield factors of rice were analyzed using Yangliangyou 6, Shenliangyou 5814, Gangyou 1237, Yixiangyou 1577 andⅡyou 1259 as the experiment materials. Two transplanting periods for each of the five varieties were set up:4 leaf stage and 6 leaf stage. The results showed that the plant height, LAI and dry matter accumulation in vegetative growth stage, as well as the spike number per square meter and theoretical yield at mature stage were lower in 6 leaf transplanting treatments than in 4 leaf transplanting treatments. For the 4 leaf transplanting treatment, the plant height of Gangyou 1237, Yixiangyou 1577 and Ⅱyou 1259 were higher than that of other varieties at 90 days after planting and heading stage, and the LAI of Gangyou 1237 and Yixiangyou 1577 were also higher at 75 d and 90 d after planting, which quickly decreased substantially at heading stage, 40.0% and 32.7% lower, respectively, compared with that at 90 d after planting.At 90 d after planting, the fresh of Yixiangyou 1577 transplanted at 4 leaf stage was extremely significantly higher than those of other varieties, and its dry weights was significantly higher than other varieties.In the growth stage, the soluble sugar content of Gangyou 1237 transplanted at 4 leaf stage was the highest, followed by Yixiangyou 1577. The nitrogen content, mature spike number per square meter, seed setting rate and theoretical yield of Yixiangyou 1577 transplanted at 4 leaf stage were higher than those of other varieties, and its theoretical yield was 32.2% higher than that of Yixiangyou 1577 (6 leaf), followed by Gangyou 1237 (4 leaf). The plant height, dry weight and soluble sugar were positively correlated with mature spike number per square meter, grain number per spike, 1000-grain weight and theoretical yield at 90 d after planting and heading stage. LAI at heading stage was negatively correlated with yield factors, and its correlation coefficient with theoretical yield was-0.779, reaching the extremely significant level. In summary, the plant height, LAI, dry fresh quality, carbon nitrogen compound and yield index of Yixiangyou 1577 and Gangyou 1237 transplanted at 4 leaf stage were better at 90 d after planting and heading stage. To distribute photosynthetic products effectively and increase the grain yield, the LAI decreased greatly at heading stage. Therefore, Yixiangyou 1577 and Gangyou 1237 should be transplanted at 4 leaf stage so as to achieve the high yield of rice.

Key words: Rice, Transplanting periods, Growth and development, Yield

CLC Number: 

• S511