|FIDANZA, MICHAEL - Pennsylvania State University|
|BARNEY, NICHOLAS - Brigham Young University|
|KOSTKA, STANLEY - Aquatrols Corporation Of America|
|BADRAKH, TURMANDAKH - Brigham Young University|
|MCMILLAN, MICA - Brigham Young University|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2016
Publication Date: 8/1/2016
Citation: Madsen, M.D., Fidanza, M.A., Barney, N., Kostka, S.J., Badrakh, T., Mcmillan, M.F. 2016. Low-dose application of non-ionic alkyl terminated block copolymer surfactant enhances turfgrass seed germination and plant growth. HortScience. 26(4):379-385.
Interpretive Summary: It has been discovered that a low-dose application of a non-ionic alkyl terminated block co-polymer surfactant applied directly to the seed, within a film coating, would decrease seed germination time, improve germination synchrony, and in some cases improve final germination percentage. Our data further indicates that this technology has its greatest benefit at improving germination under sub-optimal temperatures and/or drought conditions.
Technical 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. Less than optimal establishment of new turfgrass lawns from seed is often the result of slow and nonuniform germination and emergence because of poor environmental growing conditions (Christians, 1998; Frelich et al., 1973; Perry, 1980). Nonoptimal temperatures for germination and drought are two common abiotic factors that can limit turfgrass establishment from seed (Bewley and Black, 1994; Larsen and Bibby, 2005). Apart from natural drought, turfgrass establishment is also affected by the lack of water imposed by deficit irrigation, which is being implemented in many places worldwide (Fereres and Soriano, 2007). Where the environment limits stand establishment, seeding success may be improved by applying a seedcoating before sowing that will enhance speed, uniformity, and overall germination rate of the seed (Gregg and Billups, 2010; Schiavon et al., 2013). Products are commonly applied to seed, with materials added at various concentrations from thin films, to coatings that weigh as much as, or even several fold the weight of the seed (Gregg and Billups, 2010; Taylor and Harman, 1990). Treatments applied in the coating may include macro- and micronutrients, plant growth regulators, protection products, growth stimulants, inoculants, and specialized polymers (Halmer, 2008; Scott, 1989). Madsen et al. (2010, 2013, 2014), have shown that coating seeds with a nonionic alkyl ended block copolymer based on C1–C4 alkyl ethers of methyl oxirane–oxirane copolymers was effective at improving seedling emergence and plant growth in water repellent soils. This surfactant chemistry was patented by Kostka and Schuermann (2008) and is distributed under the trade name SET-4001 (Aquatrols Corporation of America, Paulsboro, NJ). The seed coating formulation is designed to use the seed as a carrier for the soil surfactant. After planting, precipitation leaches the surfactant from the seed into the soil where it absorbs onto soil particles and ameliorates water repellency within the seeds’ microsite (Madsen et al., 2012). With hydrologic function restored around the seed, soil water infiltration, p