Page 16 - GM Spring 2023

Test plots from a Turf Fuel study at University of Arkansas to Photo of severe localized dry spot on golf course immediately compare the impact of different wetting agents vs. untreated after Cleanse from Turf Fuel was applied.
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contact angle of around 30 degrees and a Draves test rating of less than one second. If you find an anionic surfactant that has a larger contact angle and longer Draves Wetting time, this means larger polymers have been added to the anionic surfactant.
Many newer wetting agent products are built with a multi-polymer strategy where materials for quick wetting are combined with larger polymers to provide longer-lasting hydration in the root zone or to provide some other desired performance characteristics.
WETTING AGENTS VS SURFACTANTS
Wetting agents are surfactants but not all surfactants are wetting agents! A wetting agent impacts the surface tension between a liquid and a surface whereas a surfactant impacts the surface tension between two substances. For example, a surfactant could be used to impact the surface tension between a liquid and a solid, a gas and a liquid, or perhaps between two liquids.
Surfactants, or surface-active agents, can be wetting agents, emulsifiers, foaming agents, and more. Most wetting agents on the market today are classified as non-ionic surfactants. This means, unlike the previous anionic example that has a negative charge, non-ionic surfactants have no charge. The advantage of a non-ionic material can include attributes like very low to no phytotoxicity potential, excellent compatibility with other chemistries, easy on equipment, and low foam potential, just to name a few. The first wetting agents to be used on fine turf decades ago were single surfactant chemistries. As previously mentioned, modern wetting agents can consist of five or more surfactants and may even contain biostimulants to promote plant health and drought stress resistance.
BLOCK COPOLYMERS, REVERSE BLOCK COPOLYMERS, METHYL CAPS, AND MORE!
A very popular and common class of wetting agents used today falls under the title of Block Copolymer. These types of polymers can be straight block or reverse block. A straight block copolymer’s structure can be imagined by picturing a straight chain of polymers connected, alternating between ethylene oxide and propylene oxide. A straight block copolymer’s chain begins with ethylene oxide whereas a reverse block copolymer’s chain begins with propylene oxide. Straight: EO-PO-EO Reverse: PO-EO-PO.
From a performance standpoint, these block copolymers perform differently. The straight block copolymer tends to facilitate water movement through the soil whereas the reverse block tends to retain more moisture in the soil. Understanding these performance
16 • CGSA • GreenMaster