Response of Seashore Paspalum Turfgrass Grown in Two Different Soil Types to Spraying with Plant Growth Regulators

Seashore paspalum ( Paspalum vaginatum , Swarts) is often used as a recreational turf. To achieve quality turf, special maintenance such as frequent mowing is required. This investigation studied the effectiveness of two growth-regulating chemicals at different rates in retarding paspalum vertical growth and thus reducing the mowing frequency, as well as evaluating their impact on paspalum visual quality with a special focus on photosynthetic pigments to determine the optimum concentrations of the used retardants. Two plant growth regulators, paclobutrazol at the rates of 50, 100, 150 mg/l, and cycocel at the rates of 1000, 2000, and 3000 mg/l were applied to seashore paspalum turf grown in alluvial or sandy soil during the two successive seasons of 2020 and 2021. The obtained results showed that spraying paspalum turf grown in alluvial or sandy soil with either paclobutrazol or cycocel led to a significant decrease in clipping fresh and dry weights, where spraying the plants with cycocel caused more suppression than spraying the plants with paclobutrazol. Also, the plants untreated possessed the highest values of clipping fresh and dry weights, while the lowest values were recorded from plants sprayed with cycocel at a rate of 3000 mg/l followed by those sprayed with 2000 mg/l and those sprayed with 1000 mg/l then those sprayed with paclobutrazol at the rate of 150,100 and 50 mg/l, respectively. Furthermore, the untreated plants possessed the highest contents of photosynthetic pigments. Also, plants treated with cycocel gave lower values of photosynthetic pigments than those treated with paclobutrazol.