China Joint Trials on Dispatch: Kunming Sunshine Golf Club, Witgang & Aquatrols
Witgang coordinated with Kunming Sunshine Golf Club to test Dispatch wetting agent in reducing irrigation requirements – saving water and electricity – and improving turf quality. Kunming Sunshine’s fairways are bentgrass, and the course is built across a hillside at high altitude in Kunming, Yunnan.
Dr. Stan Kostka of Aquatrols helped structure the trials, based on his work in dozens of locations worldwide, to ensure they followed scientific method and the results would be scientifically reliable. These tests are designed to give a true picture of Dispatch effectiveness in China by removing potential variables such as changes in microclimate or imprecise testing locations.
From November 2008 to June 2009, Sunshine’s team sprayed Dispatch monthly at recommended rates (4 litres/ha) from tee to green on one half of fairways 8 and 12. Sunshine then followed their standard daily irrigation program, checking each hole visually to decide whether or not to irrigate, and for how long.
Every week, Sunshine’s team measured soil-water content using a Theta moisture probe at 20 locations on each fairway. Half of the measurements were taken in Dispatch-treated areas and half in untreated areas, with precise replications across the 100-yard and 150-yard markers, five measurements one meter apart on each side of the center line of Dispatch treatment, every week, for proper comparisons over time. Sunshine also recorded their irrigation times and pump electricity requirements, and tracked turf appearance, dry-patch occurrence, and weather conditions. The Sunshine trials generated over 400 pieces of data in the first two months.
Fairway areas treated just twice with Dispatch required on average 49% less irrigation in November and December. And despite receiving just half the irrigation, those treated soils contained 17% more water on average than the untreated soils just a few meters away.
In January, concerned about the dry, windy season, Sunshine chose to continue to apply Dispatch, but to irrigate treated and untreated areas the same. During the spring and early summer, Dispatch-treated areas retained more water, not once falling below the optimal 25% soil-moisture target, and showed far less variation in soil-water content from week to week. Rootzone cores taken near the end of the trial, after six months of equal watering, showed cores in the treated area with thicker, longer roots and far less black layer.
Over the full eight months of the trial, Dispatch-treated areas had both better overall turf quality and more consistent turfgrass from week to week.
Conclusion: Independent field trials done by superintendents on golf courses in China show Dispatch can reduce water, and irrigation, requirements by 50% or more – while at the same time improving turfgrass quality.
