Weather
Conditions were becoming dry before we received rain mid-week last week. Since then there has been rain, rain and more rain. Some areas were flooded and soils are saturated and some soils are actually starting to smell because they are becoming anaerobic. Unfortunately, there is more rain in the forecast for 3 out of 7 days next week. There is a little blast of heat for Saturday and Sunday which have temperatures in the mid-twenties, but have a humidex of 30. Even though the day time highs will be in the mid-twenties, the night temperatures will be going down to the mid-teens. Next week we are down to lower than seasonal temperatures for the next 10-14 days. The rain forecast if for up to 20 mm over the next 5 days. Turf is green and this is unusual for this time of year.
Diseases
Dollar spot pressure has continued over the past week. There has been red thread and anthracnose basal rot reported. Necrotic ring spot symptoms are also prevalent at the moment. Rust pressure is very intense also. In some sod fields that I visited last week it was very heavy and the grass was yellow to orange from all the spores. Usually a light application of nitrogen will help the turf grow out of the rust symptoms. Things are setting up nicely for summer patch. The only missing ingredient is the hot weather and let’s keep our fingers crossed that we don’t get any now. There have been some samples submitted to the GTI Turf Diagnostics that have Rhizoctonia mycelium. This could be either yellow patch or Waitea patch. So far conditions have been too cold for brown patch. Even with the higher temperatures forecast for the weekend, the low night temperatures will inhibit the summer diseases such as brown patch and Pythium blight from becoming active.
Some abiotic symptoms that are showing up are scalping because the turf is growing fast and turf thinning because of saturated soil conditions, especially on poorly drained sites. Another abiotic symptom that has been showing up in turf is etiolated tiller syndrome. Young newly emerging bentgrass leaves appear yellow and etiolated. Turf pathologists have no idea what causes this syndrome. It does appear to be related to the use of plant growth regulators and biostimulants, but not always. See the link below on etiolated tiller syndrome. Their recommendation is to skip an application of your growth regulators to see if this has any effect on the symptoms. Generally speaking, turf could do with some sunshine and some dry conditions.
Turf roots have been declining over the last 2-3 weeks with all the wet conditions. Once the few days of hot weather are over, it might be a good idea to aerate to help the saturated soils dry out and to promote some new root development. If you encounter a disease that you can’t diagnose, there is information on submitting a sample to the GTI Turf Diagnostics at the link.
Insects
This is the time when we start seeing hairy chinch bug damage. There has been some reported in the field, but my sense is that it isn’t as bad a previous years. In our monitoring, we are finding the second generation black turfgrass ataenius adults and also the second generation of annual bluegrass weevil. Generally speaking, there is less damage from the second generation of these two insects.
There have been a few lonely European chafers flying this week, but for the most part the flights are over. I have been out scouting for grubs and finding only very, very small 1st instar grubs. Japanese beetle adults are still very active and will probably be feeding on ornamental plants for another couple of weeks. All of the wet weather is good for grub egg hatching. On that note, I am still looking for a European chafer grub infested large residential/estate property for a grub trial with some alternative products within an hour of Guelph. A golf course might work, but it would have to be an out of play area. We need an area that is roughly 15x15m2. If you have a client with such a property or you have an area on your golf course could you please email me at pamela.charbonneau@ontario.ca or phone me at (519) 824-4120 x 52597.
White clover and bird’sfoot trefoil are still in flower in lawns that have not been fertilized regularly for the last few years. I am curious about why there is so much clover in lawns at the moment. Evan Elford, a former graduate student of Dr. Lyons, in his overseeding trials found more white clover in his irrigated plots than in the non-irrigated plots. White clover completely died out in the non-irrigated plots during 2005, which was a very dry summer. I am wondering if last year’s wet summer, combined with this year’s wet summer is what has contributed to all the clover that we are seeing. With the cosmetic pesticide ban, white clover in lawns is going to become a more familiar site and we probably need to learn more about it as lawn species. Anyone with any insight into this is welcome to share it with me.
One thing we usually don’t recommend this time of year is a shot of nitrogen, however, in a summer like this, with turf growing throughout July it is probably in need of an extra shot of nitrogen about now. – See more at: https://lawnsavers.com/turf-hotline-2009/turfgrass-management-agriphone-for-july-31-2009.html#sthash.ul2oVqCs.dpuf
