Cultural practices to conserve water on bermudagrass turf

Best management practices (BMPs) for water conservation on golf courses involve many key components, including proper selection of turfgrass, layout and operation of sprinklers and irrigation practices. Proper cultural practices also are important, especially use of products that can help improve or sustain turf quality and function with less water. During drought or other crises, the turfgrass industry often becomes flooded with products touted to save water or other resources. However, remembering the old adage, “If it sounds too good to be true, it usually is,” can help superintendents save money and the frustration of seeing few or no positive results.

Princess 77 bermudagrass irrigated at 40 percent ET, treated either with Revolution (right side) or untreated (left side) on July 12, 2016.

Turfgrass research at the University of California is focusing on products that have a proven track record for water conservation, including the plant growth regulator trinexapac-ethyl (Primo Maxx, Syngenta), soil wetting agent Revolution (Aquatrols) and sufficient nitrogen (N) fertilization. In 2016, a study was initiated by Riverside to determine the best possible combination of Primo Maxx, Revolution and source of N for Princess 77 bermudagrass turf under deficit irrigation. Six different fertilizer sources are being applied at a rate of 5.0 lbs. N/M/year in 1.0-lb. increments.

From May through October, the plots receive product treatments, and either 40 percent or 70 percent of previous-week reference evapotranspiration (ET) by hand watering, as determined by an on-site weather station. Typically, no natural precipitation occurs in southern California during this period. Approximately halfway through the study, plots that received both Primo Maxx and Revolution have shown improved quality in comparison to the untreated control, regardless of the fertilizer source used. All plots that were irrigated at 70-percent ET replacement showed sufficient turf quality. However, only plots treated with Revolution have sustained sufficient turf quality under 40 percent ET as the study progressed.

Preliminary results suggest that maintaining sufficient fertilization (5.0 lbs. N/M/year) and regular use of Primo Maxx and Revolution are the most powerful tools to manage bermudagrass with less water.

Marco Schiavon, Ph.D., is a postdoctoral research scientist at UCR. You can reach Schiavon at marcos@ucr.edu for more information.