| It is photosynthetic production characteristics of the yield formation in super-yield corn, one essential step in the future of high-yield corn production and research. Using different varieties corn, density and controlled-release fertilizer, characteristics of the photosynthetic production of super high yield corn was discussed to optimal portfolio and the efficient way to achieve high Yield and high Quality. The main results are as follows: 1 Study on difference material production between the different varieties cornBased on years of high yield research, three super-yield corn varieties of different plant height and ear height were selected to plant in the regular high-yield research fields, and there was no significant difference between the three corn varieties, which yield were up to 15000 kg*ha. Further analysis about material production of the three varieties according to Richards equation, there was great potential of the material production in the late stage of the Deng Hai 661(DH661), and the active growth phase of the Deng Hai 661(DH661) were significant higher than the Deng Hai 701(DH 701) and Xian Yu 335(XY335). According to the model of growth active days, the potential dry matter production of the DH661, DH701 and XY335 were higher than the actual dry matter accumulation at harvesting 18.3%, 10.4% and 3.5%. 2 Study on difference of yield and the ratio of plant height / ear height ratio between the different varieties cornUnder favorable planting condition, though there were no significant differences between the grain yield of the three super-yield corn. In this study, It is better to increase the plant height / ear height ratio appropriately, when plant height, ear height decreased. Clearly, the relatively elongated structure could improve the canopy light distribution, which keeping the "Ear" a good gesture to gain light and is good to higher yield.3 Study on difference between photosynthetic characteristics of the different varieties cornIn this study, three ultra-high yield potential of maize varieties (different plant height, ear height) were used to compare the photosynthetic characteristics under high density conditions. This study will contribute to our understanding to the dry matter accumulation and help to further exploit its high yield potential. The comparison of the Leaf area during the period of growth (LAI) and photosynthetic potential (LAD) shows us that especially after flowering, after flowering 28 d, compare to DH701 and XY335, the LAI of DH661 present the slowest decline, which is bound to be beneficial to the grain yield formation. Using Chlorophyll fluorescence with non-destructive detection technology, light utilization characteristics of the three varieties corn were analyzed, whose results indicated that photosynthetic carbon assimilation capacity and the potential of solar energy utilization efficiency of DH661 was significantly higher than the other two species, which especially highlighted on 28 d (4 weeks) after flowering. The results of this study show that photosynthetic characteristics from 4 weeks after flowering to harvesting were essential to the grain yield formation. Therefore, attention should be paid on rapid completion of morphological structure in vegetative growth stage and the selection of materials with slow aging photosynthetic organs in reproductive growth stage when breeding high yield maize species. Also, in the Super High Yielding Cultivation, attention should be paid on maintenance the producing function of photosynthetic organs in the late growth stage.4 Effect of the planting density on yield and physiological characters of DH661 Based on the yield of three super yield corn varieties with different plant height, ear height were up to 5000 kg hm-2, DH661 with highest potential to gain high yield was selected as objective, planting at sixteen farmland of Deng Hai farm. The results showed that, under the density of 90000 plant ha-1, both the yield and the dry mater were gained the highest, toward 12507.5kg ha-1 and 22208.6 kg ha-1, respectively. Compared to the density of 22500 plant ha-1 and 67,500 plant ha-1, the grain yield under the density of 90000 plant ha-1 was increased 76% and 2%, and the dry matter under the density of 90000 plant·hm-2 was increased 86.8% and 15.6%, which indicated that, in high yield cultivation, the yield of the DH661,a super yield corn specie, can be significantly increased by raising planting density. Under the conditions of this study, 90 000·hm-2 is the optimal planting density.5 Effect of the controlled release fertilizer on yield and physiological traits of DH661Most previous studies were carried on the general high-yield conditions. In 2008 under the super yield conditions, study results show that compared to ordinary fertilizer, the corn yield using controlled-release fertilizer has not decreased, but showed a increase trend. a series treatments about the amount of controlled-release fertilizer and ordinary fertilizer were set in 2009, the results showed that compare to the 100%ordinary fertilizer and 100% controlled-release fertilizer(450kg hm-2), the yield, dry matter accumulation and LAI of 80% control release fertilizer treatment ( 20% reduction) performance best and also contain a increasing trend. |
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