This is the 11th edition of the 2008 OMAFRA Turf Management Update recorded on July 14.
Just a general note about the turf updates. There will sometimes be pesticide recommendations for controlling different turf pests. If you are in a municipality that currently has a pesticide by-law, it is important that you know all the restrictions on pesticide use in your particular municipality. On that note, the legislation to ban the cosmetic use of pesticides in Ontario (Bill 64) was passed. There will be more information forthcoming over the next few months on the details. The ban will take effect in spring, 2009.
Last week was pretty similar to the week before with some very nice days and then a couple of hot, muggy days. The beauty of this is that it keeps some of the summer diseases at bay. Many of them need three to four days of the hot, humid weather for heavy disease pressure and we only seem to be getting a couple of days in a row of hot weather. The same is true for the upcoming week. It is supposed to be hot and humid during the middle of the week and cooling next weekend. Areas that were hit with deluging rain during thunderstorms may see some increase in summer patch activity. There have been several samples submitted to the GTI Turf Diagnostics lab with summer patch. Dollar spot has finally kicked in and if you haven’t sprayed for it yet, you probably should. I have also had some reports from some irrigated home lawns that dollar spot has been pretty active there too.
On perennial ryegrass, rust has been active for the past two weeks. It is just now showing up on Kentucky bluegrass. This is very, very early and it could become a big problem this summer if the weather conditions are right. Rust likes alternating hot and dry with wet weather. There has been a lot of scalping of turf over the last week caused by rain, wet conditions and rapid turf growth. Some of this might be mistaken for disease. If you have any unknown turf problems, please contact the GTI Turf Diagnostics. Information on this service is available at the link below. You can email them atdiagnostics@guelphturfgrass.ca or telephone at (519) 824-4120 x 58873.
European chafer adult flights are finally tapering off and they should be over in the next week or two. Japanese beetle flights are still heavy and adults will continue to feed for several weeks yet. We are now in the ideal window for Merit applications targeted for European chafer and Japanese beetle. The is also another preventative insecticide that has just received registration for turf from Dupont called chlorantraniliprole. It can be used anytime now for European chafer and Japanese beetle grub control. It has a very long soil half life and can be applied in April for control of annual bluegrass weevil, European chafer and Japanese beete. It also controls cutworms. If you plan to use nematodes for grub control the timing is late August to early September.
My summer student Andy and I were out looking for sites for a grub control experiment and we came across a nice infestation of hairy chinch bugs. Most of them were in the third instar. In most areas, if an insecticide application is made in the next week or two it should catch the nymphs before any damage occurs. There is some turf damage at the moment from bluegrass billbug feeding. Billbug larvae are still very small so there will be more damage occurring from billbug feeding in the next few weeks.
All the rain has been great for weed growth. This combined with the thin turf from last years drought has resulted in bumper crops of all kinds of weeds. Crabgrass plants are doing well. At this point it is best to switch to fenoxaprop-ethyl (Acclaim Super) for crabgrass control. Some of the weeds that are obvious at the moment are white clover, bird’s foot trefoil, yellow wood sorrel and black medick. The best window for broadleaf weed control is in the fall, but you will get get some control this time of year. It is best though to avoid using a broadleaf herbicide if turf and weeds are under drought stress. Also avoid herbicide applications during hot, humid weather.
Another result of all the wet weather this spring is lots of moss on golf greens. Unfortunately, there is still nothing registered for use for moss control in Ontario. Research here at GTI has shown that frequent watering (or in the case of this spring – frequent rains) is one of the largest contributing factors to moss encroachment. So be careful not to irrigate too frequently now that conditions are becoming a bit drier.
Just one observation about overall turf quality. The perennial ryegrass seedheads have now been mowed off, but what is left are straw coloured stems that give the turf a very uneven appearance. This will pass in a few weeks as the perennial ryegrass outgrows the seedheads.
Please join us for the GTI Turf Field Day which is taking place on Aug. 21, 2008. Current areas of research that you can learn about include disease and insect biology and control, pesticide alternatives, evaluation of turf varieties, velvet bentgrass establishment and management, thatch management, irrigation scheduling, sportsfield overseeding and grassland ecology, to name a few. The program runs from 8:30 -1:00 with lunch included. For registration information follow the GTI Turf Field Day link below.
Thanks for calling the Turf Management Updates. This message will be updated on Fri. July 18, 2008.
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