Water repellency of turf can lead to localized dry spots and can cause waste of irrigation water. Not only that, it also can cause the turf to repel other products, such as pesticides, that after application need to reach the root zone of turfgrasses to be effective. Wetting agents are surfactants used to increase water penetration.
One of our MGCSA-member partners noticed that a surfactant that was labeled as an adjuvant for pesticide applications had chemistry that indicated it might also function as an infiltration tool/penetrant. They found that while using this product in the growing season of 2016, there were no dry spot problems; however, 2016 was also the wettest growing season in MN history. In early August of 2017, we partnered with this superintendent to compare this surfactant and other products to combat wilt from dry spots.
Which wetting agent would assist in recovery the quickest?
Centerbrook Golf Course (Superintendent – Steve Makowske)
9 wetting agent treatments and an untreated check (see table below). Treatments were applied in plots on two fairways.
- Very wet August resulted in a lack of significant conclusions.
- No soil water repellency was evident.
- All treatments had similar visual recover, soil moisture, and soil moisture uniformity (Figure 2).
Wetting agents were not useful in this situation due to the wet month of August allowing all treatment plots to recover. We can’t make recommendations on the wetting agents based on this small trial that occurred during a period with plentiful rain.