Summer Survival Mode
By Jim Skorulski , Senior AgronomistJuly 16, 2010
The extreme weather is impacting golf courses around the region with conditions not seen since 1988. Some parts of the region have the added challenge of drought conditions that are straining water supplies and raising concerns over water use restrictions. With soil temperatures consistently in the 85-88 degree range, significant stress on root systems abounds.
The higher-than-normal stress has ramped up disease pressure, especially dollar spot, brown patch and summer patch activity. Parasitic nematode populations also are impacting a number of golf courses. There is a potential new bacterial threat to creeping and velvet bentgrass reported by Dr. Mitkowski at the University of Rhode Island. The bacteria, Acidovorax avenae, is active during hot weather causing plants to bleach out (etiolate) and wilt. The bacteria has been isolated from infected plants collected from several New England golf courses.
The following are some basic tips for surviving the extended heat and humidity:
- Be conservative - this is not the time to experiment with new products or tank mixes. Spoon-feed with light rates of a balanced soluble fertilizer. Go with the basics that have a proven track record.
- Avoid applying DMI chemistries in the heat. Annual bluegrass is susceptible especially triticonazole and metaconazole so rotate to other fungicide classes until the heat breaks.
- Be careful using growth regulators on stressed annual bluegrass. Trimmit and Cutless are excellent products with bentgrass greens, but should not be in the mix on Poa annua surfaces in high heat conditions. Stick with Primo for Poa annua greens and keep the rates sensible.
- Avoid combining Primo, Cutless or Trimmit with any DMI fungicide. The combination can result in over-regulation of heat-stressed annual bluegrass.
- With the increased disease pressures, shorten up intervals between fungicide applications. Check sprayer calibration and nozzles, and apply at water volumes to reach your target.
- Follow your gut. If your intuition says don’t do it …don’t. Self-inflicted damage is the hardest to accept. Yes, we need to mow, roll, topdress, and vent greens during some difficult weather, but skipping a mowing or a rolling when the surfaces are saturated can make the difference between success and failure.
- Reemphasize the importance of equipment operation on and around greens. Make sure mower baskets are emptied frequently. Save the venting and topdressing practices for days when the weather breaks.
- Monitor soil moisture closely to program irrigation and direct hand-watering and syringing practices. This is not the time to saturate the root zone. Train competent staff about the difference between hand watering and syringing, and be sure they realize the importance of the task.
Stay focused and remain flexible to survive the difficult weather period. It’s the first time in a few years we have experienced an extended heat wave, and fortunately they are fairly rare in this region. Hopefully, the weather pattern breaks and brings with it the more seasonal conditions rather than one that will be long remembered.
Source; Northeast Region Green Section- Dave Oatis, Director firstname.lastname@example.org; Adam Moeller, Agronomist email@example.com Jim Skorulski, Senior Agronomist firstname.lastname@example.org.