Low-dose Application of Nonionic Alkyl Terminated Block Copolymer Surfactant Enhances Turfgrass Seed Germination and Plant Growth

Abstract

Rapid seed germination and vigorous seedling growth are desired when establishing turfgrass lawns from seed. Low-dose concentrations of nonionic, block copolymer surfactants can have a direct effect on plant physiological functions and growth. The objectives were to determine if a low-dose application of a nonionic alkyl ended block copolymer surfactant applied directly to the seed, within a film coating, would 1) influence speed, synchrony, and final germination percentage (FGP), and 2) enhance seedling emergence and the speed of turfgrass establishment under deficit irrigation. Tests were performed with tall fescue (Schedonorus arundinaceus) and perennial ryegrass (Lolium perenne). Surfactant was applied directly to the seed using a rotary seedcoater at 0.1% by weight of seed. In the first experiment, germination was compared between seeds with a surfactant film coating (SFC) and untreated seeds in growth chambers at three different constant temperatures (10, 20, and 30 °C). For both species, the SFC decreased the time for seed germination, and improved germination synchrony, with the greatest treatment response at 10 and 30 °C compared with untreated seed. Application of a SFC did not influence FGP. In the second experiment, untreated and treated seed were compared in a grow-room study, with pots watered weekly to 70% of field capacity (FC). Perennial ryegrass density, cover, and aboveground biomass from the SFC were ≈47%, 48%, and 46% greater than untreated seed, respectively. Tall fescue density, cover, and aboveground biomass from the SFC seeds were ≈22%, 23%, and 28% greater than untreated seed, respectively. Overall these studies demonstrate that SFC can promote seed germination and also enhance turfgrass establishment under deficit irrigation.