Effects of Different Chemical Treatments on Shoot Growth and Plant Type of Ilex verticillata'Oosterwijk'
Taking 2-year-old Ilex verticillata'Oosterwijk'seedlings as the test materials,three agents,namely calcium cyclamate,mepiquat chloride,and potassium phosphite were combined in different concentrations.The treatments were applied via foliar spray when seedlings entered their rapid growth phase.Growth indicators(seedling height,basal diameter,shoot length and thickness,leaf dimensions),photosynthetic parameters(net photosynthetic rate,transpiration rate,stomatal conductance,intercellular CO2 concentration),and physiological indices(SPAD value,MDA content,soluble sugar content,SOD and POD activities)were measured to evaluate treatment effects comprehensively.The results showed that,1)all treatments effectively reduced seedling height and leaf dimensions while increasing basal diameter,shoot thickness,and SPAD value.2)Leaf photosynthetic activity was enhanced across all treatments,as evidenced by increased net photosynthetic rate,transpiration rate,and stomatal conductance,coupled with reduced intercellular CO2 concentration.3)Treatments T1 and T4 induced significant phytotoxicity in leaf development,whereas T2 and T3 demonstrated superior canopy regulation.4)Plants under T2 and T5 treatments exhibited the lowest MDA content and highest SOD and POD activities.T2 and T3 treatments increased soluble sugar content,indicating enhanced stress resistance.5)Membership function analysis revealed treatment efficacy ranking from highest to lowest as follows,T2＞T5＞T4＞T1＞T3＞T6＞CK.In conclusion,for optimal control of seedling height,shoot length reduction,and promotion of vigorous plant growth,T2 treatment(5％calcium cyclamate 1.3 g·L-1+98％mepiquat chloride 0.67 g·L-1)proved most effective,followed by T5 treatment(5％calcium cyclamate 0.67 g·L-1+98％mepiquat chloride 0.3 g·L-1+potassium phosphite 500-fold solution).
万方数据
