Winter Synopsis
Winter in most parts of Ontario was memorable for the least amount of snow on record and record warm temperatures. What weather forecasters were not paying attention to was the torrential rain followed by flash freezing on Boxing Day in many areas of southern Ontario. This formed a thick ice cover that had a big impact on how golf course turf overwintered in the province. Many golf courses attempted to remove snow and ice starting as early as the first week of February. The documented methods included using a core aerator with bayonet tines to physically disrupt the ice or using dark materials such as black sand and/or milorganite to melt the ice. Results of these ice removal techniques appear to be very variable and depend on the timing of the ice removal, how much ice was actually removed (with some of the black sand treatments, there wasn’t enough sand used to completely melt of ice or even to create air channels for gases to escape through. Most superintendents who did make attempts to disrupt or break up the ice, reported smelling a foul odour from the greens once the ice was disrupted.
The ones that did still report damage after removing snow and ice, felt that the damage that they had was a result of crown hydration injury in the spring when the banked up snow melted on to the lower areas of the greens and pooled there through some freeze thaw cycles. In many cases, it appears that the winter injury might be a combination of anoxia that may have weakened or killed the turf followed by some crown hydration in the late winter/early spring. Some of the damage was superficial and once the temperatures warmed up a great deal of the turf actually came back.
Every spring there is also this phenomenon that occurs where greens look very healthy when the snow and ice have melted but once the turfgrass plants have to start taking up water and growing they actually take a turn for the worst. This can be very widespread and very rapid. This damage is probably crown hydration damage that isn’t evident until the plants start to grow. Some researchers and turf agronomists have called this delayed winter injury.
In some cases the greens where the ice was removed came through best, in some cases they were the worse greens. In some cases where nothing was done, there were greens that came through perfectly where others came through the winter with a lot of damage.
No matter what the mechanism, golf course superintendents are scrambling to recover from winter injury. Many have overseeded the damaged areas. Some have the luxury of using permeable covers at night (and sometimes during the day on courses that are not open yet) to help warm the soils to encourage seed germination.
It is very difficult to make general statements or recommendations based on what happened last winter. Most superintendents felt that they would be worse off if they had not made attempts to remove the ice. Some admit that they did not apply enough black sand to make a big difference and may have been worse off because they removed the snow layer that may have protected the greens from the cold temperatures in late February.
Still on the topic of winter injury, there was very little snow mould, probably because of the ice and also because we did not have the extended periods of snow cover that we sometimes get. Thank goodness for small mercies.
Spring came early this year
This spring has probably been a bit of a mixed blessing. The snow melt was early and so was spring, we are probably almost three weeks ahead of normal. Many golf courses were open by the last week in March and certainly there was pressure to be open on Easter weekend because of the incredible weather that we had that weekend. This pressure to open may not have been the best thing for damaged greens, tees and fairways. but the warm temperatures went a long way towards warming the soils for early germination of overseeded areas. Of course, it was too good to last and we have had a mix of warm and cool weather since then making it difficult for the soils to warm up as quickly as we would have hoped for. All that being said, we are still as I mentioned about 2-3 weeks ahead of where we would normally be phenologically speaking.
If you have been looking at the calendar, you know that this is the week where golf courses, specialty turf and public works have to come into compliance with the cosmetic pesticides ban. There are still some changes coming as far as forms for the desk audit. I would encourage you to stay tuned to the Ontario IPM Accreditation program for Golf website for last minute updates. See the Related Links below.
The GTI Turf Diagnostics is up and running again for the season. Dr. Katerina Jordan is back in the lab ready for turf samples to arrive. Information on this service is available at the link below on the GTI web site. You can email them at
diagnostics@guelphturfgrass.ca or telephone at (519) 824-4120 x 58873. The diseases that you can expect to see on golf courses in the next couple of weeks are Fusarium or Microdochium patch and maybe some anthracnose basal rot that started last fall. If things get cool and wet there is a chance of seeing some yellow patch or cool weather brown patch.
Early emergence of annual bluegrass weevil
I have never heard of annual bluegrass weevil being spotted as early as they were this year. I guess it shouldn’t surprise us because the forsythia have been in bloom for about at least two weeks. Monitoring for annual bluegrass weevil adults should be going on now. A soap flush (15-30 mL of dishwashing liquid in 4 L of water) will work well. Monitor the edges of fairways, near tree lines where there is a history of annual bluegrass weevil damage. Unfortunately, the thresholds that have been developed for annual bluegrass weevil are numbers of larvae per area and the controls that are available are best to target the adults as they migrate from their overwintering sites, so we don’t really know the relationship between the number of adults in a soap flush and potential damage. According to Dr. Pat Vittum, entomologist from University of Massachusetts, the best time for applying Acelepryn™ is when forsythia are at the half green/half gold stage. I would say that we are very close to that in most areas. Another recommendation is to only spray a swath of turf on the perimeter of the fairway because we know based on research observations that the first generation of ABW infest the edges of fairways. More information is available on the Cornell University Annual Bluegrass Weevil factsheet.I have not had any call yet this spring about grub damage, this could be because there is very little grub damage or because no one is calling me. If you are encountering grubs on a golf course, it is best to wait until June or July and apply one of the preventative products that are listed in OMAFRA Publication 384, Recommendations for Turfgrass Management. If you are a lawn care operator, municipal sports field or homeowner, you need to wait until Aug. or September and apply insect parasitic nematodes.
Leatherjackets are feeding at the moment but they are not causing any damage. I am keeping an eye on soil temperatures and if leatherjackets do start to cause some damage and soil temperatures are > 12ºC then it may be warranted to apply Steinernema carpocapse nematodes. Research results from spring trials conducted at the Guelph Turfgrass Institute gave 30% control using the Steinernema carpocapse . The timing of this treatment would very much depend on soil temperature. I have just started taking soil temperatures and here at GTI the temperature at 5 cm is 8-10ºC.
Weed control products and timing
Well, if you are in lawn care you are probably thinking about your options for weed control for this spring. It is my understanding that the product Fiesta™ is not available yet, but the registrant is hopeful that it will be available sometime in the next couple of weeks. Temperatures are still too cold to apply Sarritor. It works best when daytime temperatures range from 18-24ºC. It is difficult to predict when we will have sustained temperatures in that range so keep you eye on the Weather Channel.
We are coming up to the application window for corn gluten meal for pre-emergence crabgrass control. The timing is usually around the time that the forsythia are in full bloom. In Guelph, forsythia are in mid-late bloom at the moment. You have until late bloom of forsythia to get corn gluten meal down. We know that crabgrass germinates much later than forsythia full bloom, so there is still a good window for corn gluten application. For best results either apply corn gluten meal when rain is expected or water the product in.
– See more at: https://lawnsavers.com/turf-hotline-2010/turfgrass-management-agriphone-for-april-20-2010.html#sthash.irrhrYHX.dpuf
