灌溉量和种植密度互作对春玉米花期光合性能及籽粒产量的影响.

【Objective】 To define the interaction model between irrigation amount and planting density of the canopy structure of spring corn population with high efficiency and coordination in the irrigated area of Tumed Plain. 【Methods】 Xianyu 335 as the test varieties,two test factors of irrigation gradient and planting density were set. Two water gradients,normal irrigation treatment(75% field moisture capacity,S1) and moderate water stress(45% field moisture capacity,S2) for irrigation amount and two planting density treatments,75 000 plants/hm²(M1) and 105 000 plants/hm²(M2) were set in the study. The samples were taken after water stress treatment to determine soil physical index,chemical index,spring corn leaf photosynthetic characteristics,chlorophyll fluorescence parameters,relative content of chlorophyll,dry matter accumulation above the ground,and grain yield. The effects of irrigation amount,planting density and their interaction on flowering photosynthetic performance and grain yield of spring corn were analyzed.【Results】 Compared with normal irrigation treatment(S1),moderate water stress (S2) significantly could reduce grain yield,water consumption(ET) of whole growth period,water use efficiency(WUE),irrigation water production efficiency(IWPE),dry matter accumulation(P<0.05). Compared with the treatment of normal irrigation combined with 75 000 plants/hm²(S1M1),in the treatment of normal irrigation combined with 105 000 plants/hm²(S1M2),the relative content of chlorophyll(SPAD) decreased by 2.859,the maximum photochemical efficiency(Fv/Fm) decreased by 0.033,the photosynthetic index(PI) decreased by 0.882,the net photosynthetic rate(Pn) decreased by 2.130 μmol/(m²·s),the transpiration rate (Tr) decreased by 1.153 μmol/(m²·s),and the stomatal conductance (Gs) decreased by 0.054 μmol/(m²·s). Leaf water use efficiency(WUEL) showed an increasing trend with the increase of planting density. Compared with S1M1,WUEL of S1M2 increased by 0.492 μmol/mmol;the correlation coefficients between grain yield and Fv/Fm,Pn were 88% and 92%,respectively. Therefore,Fv/Fm and Pn were given priority in variety selection. Moderate water stress and high planting density could significantly reduce the photosynthetic performance and grain yield(P<0.05).【Conclusion】 In the irrigated area of Tumed Plain,under normal irrigation combined with planting density of 105 000 plants/hm²(S1M2),the plant populations coordination of spring corn was better,and the grain yield was 11 507.79 kg/hm². [ABSTRACT FROM AUTHOR]