Effects Of Liquid Fertilizer With Paclobutrazol On The Growth Of Turfgrass

In this study,two common grasses-Taiwan grass(Zoysia tenuifolia Willd.ex Trin.)and Carpetgrass(Axonopus compressus(Sw.)P.Beauv.)were selected in Guangzhou as the test grasses.Six treatments were arranged as five liquid fertilizer treatments with paclobutrazol and one CK treatment as compound fertilizer(18-6-18)commonly used by growers.The aim of this research was to evaluate the effects of paclobutrazol on the growth,the green period and the drought resistance of turfgrass,on the basis of conventional application of liquid fertilizer,and to provide theoretical basis and technical support for the development of water-soluble fertilizer for lawn,which encountered with those problems of excessive irrigation water,short green period and high pruning cost.Results were as follows:1.In the field and the greenhouse,the application of liquid fertilizer in the case of 2 to 4 times with paclobutrazol,could be better inhibited the aboveground growth of the Taiwan grass and Carpetgrass,but with the best effect of 4 application times.The plant height of Taiwan grass and Carpetgrass in the field were reduced by 23.9% and 38.6%,respectively,and were reduced by 23.6% and 38.1%,respectively,in the greenhouse.2.The effect of liquid fertilizer combined with paclobutrazol could significantly suppress the elongation of lawn leaves.The effect of 4 application t imes on leaf length was the most obvious,and the maximum decrease of leaf length in Taiwan grass was 42.2%.And the liquid fertilizer combined with paclobutrazol can increase the width of lawn leaves,with 3 application times as the best result,and its maximum increase was 50% in the field.3.The leaf chlorophyll content in Taiwan grass and Carpetgrass increased first,and then showed a decreasing trend,with the increasing application times of paclobutrazol.Thebest effect of liquid fertilizer was 2 to 3 application times with paclobutrazol.The chlorophyll content was about 40% higher than that of the control,after the fourth fertilization.4.Compared with conventional fertilizer,liquid fertilizer combined with paclobutrazol could significantly increase the root length of Taiwan grass and Carpetgrass,the biomass of rootand deepen their roots,thus improve their drought tolerance.However,the excessive spraying of paclobutrazol would probably inhibit the root elongations,so 3 application times with paclobutrazol of the liquid fertilizer is appropriate.For Taiwan grass and Carpetgrass,the liquid fertilizer with 3 application times of paclobutrazol can effectively increase their root and shoot ratio,which could control the growth of the abovegro und,soas to achieve the purpose of controlling the overluxuriant growth.In summary,the effect of liquid fertilizer with 3 to 4 application times of paclobutrazol was the most significant for the growth,the green period and the drought resistance of tur fgrass,but we'd better set the 3 application times of paclobutrazol as the best choice,when taking the possibility of phytoxicity into account.