Page 28 - GM spring 2024

uFEATUREuDR. SARA STRICKER, GUELPH TURFGRASS INSTITUTE COMMUNICATIONS AND OUTREACH COORDINATOR
Research Update
Turfgrass
Perennial ryegrass NTEP cultivar trial.
The Guelph Turfgrass Institute (GTI)
serves as a hub for research, outreach, and the education on turfgrass production and management within the Canadian turfgrass industry. Field research conducted at the GTI aims to answer questions about pest management, agronomy, cultivar selection, and new technologies in the turf industry. These are some highlights from the 2023 field season.
LONG-TERM SURFACTANT TRIAL
This trial has been running since 2019 with the goal of evaluating the long- term effects of surfactants on a newly established putting green. Primarily, we are interested in understanding if localized dry spot and hydrophobicity can be prevented by proactive use of wetting agents,
soil conditioners, and surfactants. Additionally, the trial is running on calcareous and siliceous rootzones, which may impact the efficacy of these products. The products tested are OARS HS®, PBS150®, Turf Power, OARS HS with Turf Power, and Revolution® compared to an untreated control.
Soil repellency is tested using a water droplet test; water is dripped onto an air-dried soil core and our technician uses a stopwatch to quantify how long it takes for the water to absorb into the soil. An interesting discovery to come out of this trial is that the amount of time ranged from 0 to 500 seconds on calcareous soil, and from 0 to 150 seconds for siliceous soil. A previous study stated that calcareous soil exhibited a greater water-holding capacity and lower hydraulic conductivity than noncalcareous soil (Nkalai, Texas Tech University, 1983). The faster, and less variable, droplet test results from the siliceous soil in our study is likely due to the inher- ently higher hydraulic conductivity of this soil type. All of the products tested were able to speed-up water absorption, with minimal differences between the treatments. Only time will tell if a clear leader will be revealed.
#LEAVETHELEAVES AND #NOMOWMAY Twocampaignshavecirculatedsocial media with the goal of supporting biodiversity in urban spaces. The #LeaveTheLeaves campaign suggests that maintaining an undisturbed layer
of leaf litter over grass will provide overwintering habitats to moths, butterflies, snails, spiders, and other arthropods. Although the research is scarce to back up this claim, it does make logical sense that this practice would increase local biodiversity. However,inatrialconductedatthe GTI, we were able to demonstrate the damage due to smothering of the grass under Norway maple leaves (mulched or not-mulched) which, in a case where the property owner aims to maintain a functional grass lawn/field the following summer, additional pesticides, fertilizer, and seed would be needed to bring the grass back to life after the #LeaveTheLeaves campaign.
Whether the benefit of increased insect biodiversity outweighs the damage would be dependent on the sizeofthelawnandthedegreeofleaf coverage. A suggestion that came out of this trial was to convert a small area of the property to a “naturalized garden” which could serve as a year- round habitat for beneficial insects.
The #NoMowMay campaign urges homeowners and landscapers to hold-off on their first mowing of the season until June to provide much-needed food sources for pollinators in the spring. In the trial at the GTI, we were able to demonstrate that dandelion flower heads are removed by mowing activities but the total number of flowering plants in each treatment did not change with orwithoutmowing.Asuggestionto come out of this trial is to mow responsively based on local weather and plant life cycles. It was observed that many of the dandelions flowered
28 • CGSA • GreenMaster