Effect Of Paclobutrazol On Growth And Drought Resistance Of The Six Turfgrasses Under Drought Stress

The function of turfgrass on improving the environment has resulted in an rapid growth of lawn area. the shortage of water resource can’t settle the large water requirement of turfgrass in the north of our country. Therefore, the key to solve the problem is to improve water use efficiency and reduce the amount of irrigation. The use of exogenous substances is simple but effective for turfgrass management, improving drought resistance of turfgrass.Greenhouse experiment and field experiment were conducted to determine the morphological and physiological effects of different concentrations of paclobutrazol on drought resistance of six turfgrass cultivers:two each of perennial ryegrass (’Bomber’and ’Esquire’), red fescue (’Beifang’ and’Rubra’) and kentucky bluegrass (’Kentucky’ and ’Merit’). The best concentration was screened out by comparing the performance between different varieties and the same variety indoor and outdoor. PP333 has improved drought resistance of the turfgrasses and the suitable concentrations were different.1、Different concentrations of PP333 slowed down turfgrass growth, improved the appearance quality, increased the RWC, chlorophyll content and SOD activity, decreased leaf relative electrical conductivity and MDA content of the six turfgrasses.2、’Bomer’、Rubra’ and ’Merit’ from field endured less injury than greenhouse, showing that drought resistance of turfgrass outdoor was better than indoor.3、The effect of PP333 on drought resistance of’Bomber’was better than’Esquire’, ’Rubra’ and ’Beifang"s difference on drought adaptability was not obvious,’Merif’s sensitivity to drought stress was higher than’Kentucky’. The optimal concentration of PP333 to increase drought resistance were 100 mg/L for’Esquire’, ’Rubra’ and ’Beifang’,200 mg/L for’Bomber’ and ’Kentucky’, and 300 mg/L for’Merit’.