Weather
Lots of rain, wind, hail and hot temperatures on Sun. Aug. 9th and tonight we are forecast to get the same again, maybe with less intensity. Night-time temperatures were high on Sun. and are forecast to be high again on Mon. Luckily, for the rest of the week, temperatures will be high in the day with a humidex but are going down to the mid-teens at night. This has an influence on what diseases are likely to occur over the next week.
Diseases
Dollar spot has slowed down a bit with the hot temperatures but should pick up again by the middle of this week. There is a slight risk of brown patch and Pythium blight developing tonight, but this will be reduced over the remainder of the week because of the low night temperatures. There is also a risk of summer patch developing with the saturated soils and hot temperatures. Anthracnose basal rot could also be developing. If you are observing symptoms that resemble yellow patch now that the temperatures are hot, it is possible that it is Waitea patch. Rust pressure is still very intense. Usually a light application of nitrogen will help the turf grow out of the rust symptoms.
There are still abiotic symptoms showing up such as waterlogged, thinning turf and scalped turf. Moss and algae have also been problematic over the last several weeks, as well as black layer. Turf roots have been declining over the last 2-3 weeks with all the wet conditions and the recent hot temperatures will contribute to further root decline. Once this week of hot weather is 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
I saw some chinch bug damage last week. We are still 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. A second round of cutworms are damaging short mowed golf course turf at the moment.
I have been scouting again late last week for European chafers and still only finding the very smallest 1st instar. A colleague here at the GTI found a 3rd instar Japanese beetle grub late last week, so the Japanese beetles are quite far behind this season. I have had a few phone calls from various areas of the province looking for advice on timing for nematode treatments against European chafer grubs. In most areas, the last two weeks in August will probably be the ideal time for nematode treatments. They could extend into the first week in September as well. 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 ‘; document.write( ‘<a ‘=”” +=”” path=”” ‘\”=”” prefix=”” ‘:’=”” addy71047=”” ‘\’=””>’ ); document.write( addy_text71047 ); document.write( ‘<\/a>’ ); //–>\n or phone me at (519) 824-4120 x 52597.
Weeds
White clover and bird’sfoot trefoil are still in flower in lawns that have not been fertilized regularly for the last few years. This is possibly a result of last year’s wet summer, combined with this year’s wet summer. Now is a good time to scout for crabgrass to make note of areas that should be treated in the spring with corn gluten meal. Areas with weed problems other than crabgrass can get the fall treatment with corn gluten meal which will target germinating winter annuals and it should be applied from mid-August to mid-September. Dr. Nick Christians, who was the first to discover the herbicidal properties of corn gluten meal has a very extensive site devoted to it. See the link.
Last week I recommended that turf could use a shot of nitrogen. I would hold off on that for this week, but once temperatures return to more seasonal values, it would be a good idea to fertilize. – See more at: https://lawnsavers.com/turf-hotline-2009/turfgrass-management-agriphone-for-august-10-2009.html#sthash.0CBFWAhH.dpuf
