| In this study,6 early-cropping hybrid rice combinations, and 6 middle-season hybrid rice combinations were selected as experimental materials. Applying shade treatment both in field and screen-house by stages, the differences in plant height, tillering, flowering time, photosynthetic rates and yields were studied. The main conclusions are as the following:1. After shade treatment in different periods of the materials, plant height of the early-cropping and middle-season super hybrid rice combinations were significantly higher than, in which the shade effort on Luliangyou 996's height outstanding than the Zhuliangyou 819's. The differences were remarkable on Plant height at seedling stage and full panicle stage. One middle-season super hybrid rice combinations.2. After shade treatment, tiller number of the early-cropping rice was significantly less than the controls, specially at the seedling stage, the differences were notable; tiller number of middle-season rice C liangyou 396 and Liangyoupeijiu, reduced in different degrees at seedling stage, booting stage and full panicle stage respectively, in which Liangyoupeijiu performanced obviously at the seedling stage.3. After shade treatment, leaf area of Luliangyou 996 is larger than the control, particularly at the seedling stage; leaf area of middle-season rice Liangyoupeijiu is also larger than controls, in which the differences of top third leaf were distinct mostly; at seedling and booting stage, leaf area was obviously differences between the treatment and control; it's significantly performanced of Liangyoupeijiu's leaf area in screen-house.4. After shade treatment, it effected greatly to C liangyou 396 and Liangyoupeijiu's flowering time; the first flower day of per plant was different, treatment during the booting age was later than the others; the bloom day of treatments were longer than the control in screen-house, especially for Liangyoupeijiu and Tianyouhuanzhan. It demonstrated that shade treatment had impacted greatly on the flowering days, the material with shade treatment can blossom longer than the controls.5. Studies showed that shade treatment to middle-season rice combinations in the heading and flowering date both in field and screen-house will affect photosynthesis. By surveying the photosynthetic index of C liangyou 396 and Liangyoupeijiu at head date in the field, it was lower than the control. In screen-house the greatest difference is Liangyoupeijiu.6. To the early-cropping rice,shade treatment had impact each factors that determine the yield. The seed setting rate and grain weight of Zhuliangyou 819 and Luliangyou 996 significantly decreased after the shade treatment, What had shifted for the worse is seed setting rate decline seriously in the full panicle stage. We got the same result in screen-house, the seed setting rate and grain weight also decreased significantly, which is the most obvious decline in Luliangyou 996 and Zhuliangyou 819.The declined sequence of shade treatment at four stages impact to seed setting rate of the mid-season rice in field are as follows:Grain Filling Stage>Booting Stage>Full Panicle Stage >seedling stage; the order of Shade treatment to grain weight decreased:Full Panicle Stage> Grain Filling Stage> Booting Stage> seedling stage. Shade treatment Carried out in screen-house, the seed setting rate of C liangyou 513 and the two superior Liangyoupeijiu has fallen remarkably. The seed investigation test results show that yield per plant of early-cropping rice and middle-season rice was significantly higher than those the shade treatment, the production structure characteristics is as follow: The greatest diversity period on effective panicles is seedling stage, The greatest difference period on grain weight is full panicle stage; The greatest diversity period on seed setting rate is full panicle stage; grain yield per plant with shade treatment were significantly lower than the control, in which the greatest difference at full panicle stage。...
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