| Maize is an important food and feed crop in China.The research and break through on superhigh yield of maize plays an important role in ensuring food security in China.The light and temperature resources are sufficient in Qi tai of Xinjiang province,which is an important basis for maize high yield exploration.This study was conducted using Regional plant design(50 cultivars,two densities including 120,000 and 135,000 plants/hm2)under the ideal condition without water and fertilizer stress,in order to analyse the growth process,yield components,photosynthetic characteristics,material production and other population structure characteristics of high yield spring maize and revealed the growth and development law of high yield spring maize population,which can provide theoretical basis for high yield cultivation of maize.The results were as follows:1.In 2020,the yield of MC670 reached 24.95 t/hm2 under 135,000 plants/hm2 density,which set a new spring maize high yield record in China.The growth and development characteristics of this population included:the plant height was 331.0 cm,the ear position coefficient was 0.392,the LAI was 8.9 at silking stage,the dry matter accumulation was 4135 t/hm2,the dry matter accumulation after silking was 23.86 t/hm2,the ear number was 129600 ears/hm2,the grain number per ear was 549.4 and the 1000 grain weight was 378 g.2.Among the 56 treatments in this study,the yields reached 21 t/hm2 in 87.5%of the treatments,and were more than 22.5 t/hm2 in 40.8%of the treatment.By comprehensive analysis of the treatments between 21～24.5 t/hm2,it can be found that the number of days in the whole growth period(145～163),the number of harvested ears(10.82～13.82),the grain number per ear(268.50～630.40),and the 1000-grain weight(294.24～445.45),plant height(228.33～337.67),ear position coefficient(0.33～0.64),spinning stage LAI(5.17～9.99),LAD after silking(279.67～573.19),total dry matter(31.49～44.81),the dry matter accumulation after silking(16.71～30.37)all showed increasing trend with the yield increases,and they were all significantly positively correlated with the grain yield,indicating that the increase in grain yield was accompanied by a synergistic increase of various indicators.Based on the path analysis of the population growth characteristics index,the relative importance of its to the grain yield was as follows:LAI at silking stage>total dry matter production>LAD after silking These three indicators can be used as the basis for whether the population can obtain high yield.3.The utilization efficiency of light and temperature,partial productivity of nitrogen fertilizer and water use efficiency of high yield maize increased with the increase of yield level.The plant type of MC670 was compact and close planting,which made the utilization ratio of light energy reach 2.49%,the heat energy use efficiency was 27.75 kg/hm2 ℃,the partial productivity of nitrogen fertilizer was 47.25 kg/kg,and the irrigation water use efficiency was 4.16 kg/m3.The results showed that although the inputs of fertilizer and water were high,the yield of drip irrigation was increased greatly,and the utilization efficiency was still at a high level. |
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