Study On Inhibitory Effect Of PRIMO MAXX And Paclobutrazol To Warm-season Turfgrass

In this experiment, common lawn species in Hunan Tifgreen 328 and Zoysia japonicacv.Lantai No.3 for the study, treated with different concentration of PRIMO MAXX and paclobutrazol, through measuring a series of biological and physiological characteristics, screening the optimum concentration of PRIMO MAXX and paclobutrazol to Tifgreen 328 and Zoysia japonicacv.Lantai No.3, aims to provide reference for PRIMO MAXX and paclobutrazol on lawn maintenance and management, the main results are as follows:(1)Biological CharacteristicsCanpoy height:After treated by PRIMO MAXX and paclobutrazol for 7 weeks, canopy height of Tifgreen 328, respectively, compared to the control dwarfing the 61.4% 86.7%,65.7%～86.7%, canopy height of Zoysia japonicacv.Lantai No.3, respectively, compared to the control dwarfing the 34.8%～79.3%,37.3%～84.8%. PRIMO MAXX and paclobutrazol could significantly inhibit the vertical growth of two kinds of turfgrass, to reduce the number of trim, reduce the cost of lawn maintenance.External morphological characters:leaf width of Tifgreen 328 increased significantly, leaf width of Zoysia japonicacv.Lantai No.3 no significant changes, but leaf length and internodes length of the two were significantly shorter and plant height were inhibited. Integrated, in the certain concentration range, the higher the concentration of plant retardator, the external shape of the two changed more obvious.Turf characters:suitable concentrations of PRIMO MAXX and paclobutrazol significantly improved two turf grasses NDVI index and Grass Index, and promoted tillering, increasing the lawn coverage, improved turf density, improved turf color, high concentrations of PRIMO MAXX and paclobutrazol produced toxic effects, reduced turf quality.Green Preiod:suitable concentrations of PRIMO MAXX and paclobutrazol significantly prolong the green period of Tifgreen 328 and Zoysia japonicacv.Lantai No.3.But high concentrations shortened the green period.Biomass:PRIMO MAXX and paclobutrazol inhibited vertical growth of two kinds of lawn grass, reduced the aboveground biomass; For underground biomass, suitable concentrations of PRIMO MAXX and paclobutrazol promoted two kinds of root growth, significantly improved underground biomass, but high concentrations of PRIMO MAXX and paclobutrazol reduced its underground biomass.(2) Physiological characteristicsSuitable concentrations of PRIMO MAXX and paclobutrazol significantly reduced MDA, increased soluble sugar content in two kinds of turf grass. High concentrations of PRIMO MAXX and paclobutrazol increased MDA in two kinds of turf grass, diminished its resistance.In summary, the optimal concentration of PRIMO MAXX for Tifgreen 328 and Zoysia japonicacv.Lantai No.3 are 0.10 ml/m~2, the optimal concentration of paclobutrazol for Tifgreen 328 is 100 mg/m~2, the optimal concentration of paclobutrazol for Zoysia japonicacv.Lantai No.3 is 150 mg/m~2～250 mg/m~2.