SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/726375
16 SportsTurf | October 2016 www.sportsturfonline.com FIELD SCIENCE anti-microbial or algaecide components. The opacity of the pigment in the paint that covers the turfgrass' surface alters the normal microclimate around the plant. Although research has shown that paint may positively influence turfgrass, it routinely has the opposite effect. After repeated applications of athletic paint, we typically see a decrease in turfgrass quality, or in extreme cases, complete death. A positive influence has been noted during cooler, sunny weather when a paint-darkened surface can result in heating of the turfgrass plant, which may produce limited growth enhancement. However, in most situations paint provides an additional stress. When considering the "quality" of a turfgrass, we look at the combination of turfgrass color, cover, and density. The decrease in quality that is seen after multiple applications of athletic field paint is mostly due to a decrease in turfgrass stand density as the frequency of athletic paint applications increase. Like most plants, turfgrasses are unable to survive without light. Light is emitted from the sun through wavelengths of particles known as photons. There is a broad range of wavelengths that determine the energy state of light that is emitted from the sun but we are only interested in photosynthetically active radiation (PAR), which is the group of wavelengths (400-700 nm) that is visible to the human eye. Most importantly, PAR is also the range of light that is used by plants. PAR is separated into three different colors of light. The 400-500nm range is considered to be blue light, the 500-600nm range is green light, and the 600- 700nm range is red light. So what happens when light strikes the leaf of a turfgrass plant? Light that comes in contact with the leaf surface is transmitted, absorbed, or reflected. From a plant perspective, the best scenario is to maximize the amount of light that is transmitted through the paint since that will be directly used by chlorophyll. PAR is separated into these different colors TURFGRASS RESPONSE TO FIELD PAINT ■ BY DR. GRADY MILLER, DREW PINNIX, AND DR. CASEY REYNOLDS A thletic fields are defined by lines and enhanced with logos. This makes painting a ritual repeated every week during the playing season for thousands of fields worldwide. Athletic paints are formulated with the intent that they will not cause harm to the turfgrass when properly applied, yet most sports turf managers have experienced some level of paint-induced damage during their career. While there is still a lot to learn about paints and painting, North Carolina State University has been testing products and application methods for several years to better understand why paints damage turfgrasses. Before discussing paint and how it can influence turfgrass health, it may be helpful to understand a few components of paint. Athletic paints are very similar to common household paints in basic ingredients. They are generally made of four components: binder, solvent, pigment, and additives. The binder (or resin) is a film-forming component of paint that binds pigments together and allows them to adhere to a surface. The solvent in turfgrass paint is water. The pigment is an organic or inorganic particle that provides color. Additives may be surfactants, thickeners, emulsifiers, etc. that give paint particular properties that make it easier to handle, mix and extend shelf life. Athletic paints have less volatile components than household paints and consequently there is no need for Early evaluation of paint's influence on photosynthesis in a controlled environment.