化控对不同种植密度东北春玉米叶片叶绿素荧光特性及产量的影响
本文研究化控对不同种植密度下东北春玉米叶片叶绿素荧光特性及产量的影响。研究选用东农253为试验材料,设置5万株/hm2、6万株/hm2、7万株/hm2和8万株/hm2四个种植密度,于拔节期叶面喷施“玉黄金”(主要成分为胺鲜酯和乙烯利)。结果表明,增加种植密度是增加玉米群体产量的有效途径,但会导致玉米植株叶片叶绿素含量降低,穗位叶茎叶夹角减小,株高、穗位高增加,单株干物重降低,且倒伏风险增加,光合效能降低。“玉黄金”处理能降低株高、穗位高,增加单株干物质积累量,增加抗倒伏能力。喷施玉黄金增加了穗位叶茎叶夹角,减轻前期相互荫蔽,增加灌浆期高LAI持续时间,延缓了叶片衰老进程,改善了冠层的通风透光性能,这为获得更高的产量奠定了基础。同时,玉黄金的施用还改善了叶片的光合性能,其中叶绿素荧光参数Fv/Fm、Y(Ⅱ)、qP增加,Y(NO)、qN降低,这为保障灌浆期稳定高效的光合作用创造了条件。研究表明,在7万株/hm2种植密度下,玉黄金处理后获得最高产量11428.18kg/hm2,密植和化控定向调控相结合是玉米增产的有效途径,研究为东北春玉米化控密植增产提供理论和试验依据。
英文摘要:
Abstract: The aim of this experiment was to analyze the effects of chemical regulation on chlorophyll fluorescence characteristics and yield of spring maize under different densities in northeast China. ‘Dongnong 253’ was used as material in this experiment and was planted under the densities of 50000 plants/hm2, 60000 plants/hm2, 70000 plants/hm2 and 80000 plants/hm2, and sprayed the chemical regulator of “Yuhuangjin” with DA-6 and Ethephon as the main material at the jointing stage. The results showed that the increase of planting density was an effective way to increase the production of maize populations, while it could lead to a decrease in content of chlorophyll, angle between stem and leaf (ABSL)in the ear leaf, single plant dry weight and photosynthetic efficiency, as well as increase plant height, ear height and lodging risk. The application of “Yuhuangjin” decreased plant height and ear height, and increased dry matter accumulation per plant and lodging resistance. The treatment of sprayed with “Yuhuangjin” increased angle between stem and leaf (ABSL)in the ear leaf, reduced the degree of overshadow each other in prophase, extended the duration of high LAI, delayed senescence process of leaf and improved canopy aeration and transmittance capability, which created the foundation for obtaining high yield. Meanwhile, the application of “Yuhuangjin” could improve photosynthetic capacities and could maintain higher and stable photosynthesis through significantly improving chlorophyll fluorescence parameters, such as Fv/Fm、Y（II）、qP and decreasing Y（NO）and qN. This study showed that, the highest yield was 11428.18kg/hm2 after the treatment of “Yuhuangjin” with the planting density of70000 plants/hm2, the combination of high density planting and directional regulation of chemical regulation was an effective way to increase production of maize, and provided theoretical and experimental evidence for the effect of increase production of chemical regulation and high density planting cultivation on spring maize in northeast China.
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