Study on Regulation Effects of Uniconazole on Population Characteristics and Yield during Seed Filling Stage of Soybeans under Different Fertilization Levels
To explore the effect of chemical control technology of uniconazole plant growth regulator on the population characteristics and yield of soybean at the seed-filling stage,a two-year field experiment was conducted in 2022 and 2023 using Heihe 43 as the experimental material.The experiment set three fertilization levels:low fertility treatment(Fl),conventional fertility(F2),and high fertility treatment(F3).At the initial flowering stage,foliar application of uniconazole at concentrations of 0,25,50,75,and 100 mg·L-1(CK,S1,S2,S3 and S4)was applied under different fertilization levels.The effects of applying different concentrations of uniconazole under different fertilization levels on the morphological characteristics of the soybean population during the pod-filling stage,photosynthetic parameters,light attenuation coefficient,yield,and yield components were analyzed.Applying different concentrations of uniconazole,a plant growth regulator,during the initial flowering stage can to some extent inhibit the plant height of soybeans but can also significantly promote the increase in stem thickness,node number,and leaf area index.Under low and medium fertilization levels,100 mg·L-1 uniconazole is most effective in reducing plant height and increasing stem thickness,while most uniconazole treatments significantly increase the leaf area index,with the 50 mg·L-1 showing the most significant increase.At high fertilization levels,the treatment of 100 mg·L-1 uniconazole remains the most effective in inhibiting plant height and increasing stem thickness,while the 75 mg·L-1treatment results in the most significant increase in leaf area index.Further increasing the fertilization can improve the photosynthetic rate,stomatal conductance,intercellular CO2 concentration,and transpiration rate of soybeans at the R5 growth stage,where under low to medium fertility levels the 50 mg·L-1 uniconazole effect is still the most significant,while in high-fertility soil,the 75 mg·L-1 concentration is optimal.As the plant canopy height increases,the canopy light attenuation coefficient decreases,with significant differences in the effect of uniconazole treatment under various levels of fertilization;the effect of 50 mg·L-1 uniconazole is significant in low fertility,while in high fertility soil,the 75 mg·L-1 concentration performs the best.Also,the increase in fertilization level and uniconazole concentration also helps to improve the theoretical yield and yield composition elements of soybeans,with the 50 mg·L-1 concentration of uniconazole showing the most obvious effect under low and medium fertility conditions.Under high fertility conditions,the effect of 75 mg·L-1 uniconazole is the most significant,achieving respective yield increases of 2.98％,3.79％and 4.12％compared to the control.Proper concentration spraying of uniconazole can effectively improve the growth condition and yield of soybeans,enhance photosynthesis efficiency,and optimize the canopy structure,thereby promoting an increase in soybean yield.
万方数据
维普
