Diseases
Rainfall impact on sodium leaching at Denver Country Club
In the July 13, 2011 Super Journal report, "Rainfall impact on sodium leaching at Denver Country Club" (1.3 MB pdf document), we show the dramatic and positive impact that spring rainfall can have on reducing soil sodium and salinity.
In short, we saw that a 2.5 inch rainfall, which occurred over a 36 hour period during the spring of 2011, resulted in a 41% reduction in sodium, and a 19% reduction in overall soil salts.
In addition to causing general stress to turf and potential issues with soil physical properties, high sodium and high salts are also associated with rapid blight, a disease caused by Labyrinthula terrestris. In years when winter and spring rainfall is low, it may therefore be necessary to leach greens with good quality domestic water in order to avoid reaching the maximum levels of 110 ppm sodium that can result in rapid blight infestation.
Project title: Rainfall impact on sodium leaching at Denver Country Club
Principal investigator: Doug Brooks, Denver Country Club and Larry Stowell, Ph.D., CPAg, PACE Turf LLC
Further reading:
- PACE Turf Super Journal Report, "Rainfall impact on sodium leaching at Denver Country Club" (1.3 MB pdf document) posted 7/13/11
- Spreadsheet for calculating sodium hazard of irrigation water (18 KB Excel spreadsheet)
- Video: sodium accumulation
- PACE Super Journal report: Evaluating the sodium hazard in your irrigation water
Nematode Control Options
Our recent presentation at the 2011 Canadian International Turfgrass Conference, "Nematode Damage on Turf: An Increasing Threat and How to Manage It", is now available for viewing on the web (6.9 MB pdf).
We cover recent advances in cultural, chemical and biological control, with special attention paid to options that are available in Canada.
Research on biorationals for control of nematodes
Nematodes are causing increasing problems on golf course greens (read more here), and, with the cancellation of Nemacur (fenamiphos), there are few effective products available for their control. For this reason, we conducted a field study on the efficacy of several different biological control agents for control of nematodes — particularly the root knot nematode, Meloidogyne. We found that:
- An experimental product based on the beneficial bacterium Bacillus firmus had the best results, causing significant reductions in root knot nematodes (RKN) without any associated phytotoxicity
- The amino acid methionine also caused reductions in RKN, but also caused significant damage to bentgrass at the rate tested
- The other products tested included Biofence, which is based on ground mustard plant tissue) and Inoculaid (a mixture of beneficial bacteria). Neither of these products had an impact on nematode populations
Bottom line: Bacillus firmus, which has been shown in previous studies to have potential as a nematicidal agent, showed promise in this trial for control of root knot nematode. Further work is needed to confirm this, and to identify optimal use patterns. This product, which is under development at Bayer Environmental Sciences, is not yet available for sale, but if research continues to confirm its promise, we hope expect to see it made available very soon.
Project title: Biorational products for nematode control
Principal investigators: Larry Stowell, Ph.D., CPAg and Wendy Gelernter, Ph.D., PACE Turf LLC and Michael McClure, Ph.D., University of Arizona
Cooperator: Troy Mullane, Rancho Santa Fe Farms Golf Club, Rancho SAnta Fe, CA
Sponsor: PACE Turf LLC
Click here for the full report (206 KB pdf)