This is the 5th edition of the 2008 OMAFRA Turf Management Update for May 30, 2008.
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.
Weather
Environment Canada is calling for showers and thunderstorms this weekend and temperatures are going to be around 20°C for most of next week with night time temperatures around 10°. Temperatures are forecast to be below the seasonal norms for all of next week and there is more rain in the forecast mid-week.
Diseases:
There have been very high evapotranspiration rates over the past few days and the turf has really dried out fast. The rain in the forecast will be welcome. The flush of spring growth that we usually get this time of year is just not happening yet. There was about one week in early May were the grass was growing like gang busters, but since then it has slowed down incredibly. The one nice thing about the weather to date is that it really has kept the spring turf diseases in check. There have been very few samples received at the GTI turf diagnostics this week. There is very little Microdochium patch out there. Golf course greens are not looking too fabulous at this point in the year. The annual bluegrass is flowering profusely. Many clones of creeping bentgrass are off colour when temperatures are cool in the spring. This is either expressed as a light yellow colour for some and a dark purple for others. Some of this off colour can be mistaken for disease development.
Just a reminder to send any unknown turf problems to the GTI Turf Diagnostics. Information on this service is available at the link below. You can email them at diagnostics@guelphturfgrass.ca or telephone at (519) 824-4120 x 58873.
Insects:
Things have quieted down on the grub front. European chafer are showing signs of pupating. They start to look like an accordion just prior to pupating and that is happening now. Turf managers may want to wait until mid-June before they apply their preventative grub control treatments this summer.
We can expect to see some annual bluegrass weevil damage soon. The first wave of migration would have been during the warm weather in mid-late April. The phonological indicators that signal peak adult black turfgrass ataenius migration are flowering now (horse chestnut and bridal wreath spirea). In areas with a history of black turfgrass ataenius damage, now would be the time to apply imidacloprid preventatively.
There have been more reports this week of June beetle adults flying. They have not been abundant, only one or two flying. They can be seen at night bumping into lamp posts and such. They are pretty clumsy, fly at night and are attracted to lights.
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The warm weather over the last few days has hairy chinch bug adults and bluegrass billbug on the move. Spring is when hairy chinch bug mating occurs, so this will be happening over the next couple of weeks. Roughly two weeks after mating the female hairy chinch bug will start laying her eggs. Bluegrass billbug females lay their eggs in the bluegrass stems at this time of year.
Leatherjackets have almost reached full size and there have been very few reports about damage. We have been doing some leatherjacket counts here at GTI and we are finding that the numbers are down from previous years. It is quite feasible that the dry weather that we had last fall during the peak adult flights did interfere with egg hatch. If there is no damage to date, it is probably unlikely that there will be damage now. Insecticide control at this point in the season is probably not warranted unless they are found on a sod farm where there would be zero tolerance for leatherjackets. Options for control for this time of year are chlorpyrifos and carbaryl for sod farms and golf courses and carbaryl only for home lawns.
Turfgrass ants on golf courses have been very active over the last couple of weeks. They do not eat the turf but feed on other insects present in the turf and soil beneath the turf. The reason that they are a problem is that they form sandy mounds in golf course greens, tees and fairways. These mounds can suffocate the turf, they increase maintenance costs by dulling mower blades and on greens they can disrupt the playing surface. They tend to be more of a problem on new golf courses that have never been treated with the persistent organochlorine insecticides that were used on older golf courses in the past. They are usually within 1-2 m of the edge of a green. Chlorpyrifos, carbaryl and lambda-cyhalothrin are registered to control ants in Ontario.
Weeds
The cool weather all last week has extended the crabgrass treatment window. In many areas it is not too late to apply a true pre-emergence product like corn gluten meal. You can also still apply Dimention. It has the early post emergence activity, so even if you have a few germinated crabgrass plants, you will still get good control if applied according to this timing. Hopefully, everyone made note of the areas with serious crabgrass problems last year so that only those areas need to be treated this spring. An alternative approach, especially if the turf has thickened up over the fall and spring, is to wait and apply a post-emergence herbicide like Acclaim, on the small crabgrass plants, once they have germinated. This might be the best approach for golf courses, especially in areas that may need to be overseeded sometime during the growing season. Post-emergence products are not residual the way the pre- and early post-emergence products are. Both of the above approaches fit nicely into an IPM program.
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This is not a really great time for home lawns or sports fields at the moment. Any turf area that is infested with dandelions looks pretty unsightly at the moment. Because the grass hasn’t been growing that fast, people are putting off mowing and the result is a sea of dandelion seed heads. If you do not have a municipal pesticide by-law, now is a good time to apply a post-emergence broad-leaf herbicide.
On the topic of weeds, I have a researcher from a pesticide company that is looking for a turf site that has white clover in it to investigate a new broadleaf herbicide. If anyone out there either has an estate property with a big white clover problem or a fairway or a rough area and if you are interested in being a cooperator for a herbicide trial please send me and email. My email address is Pamela.charbonneau@ontario.ca
Fertility:
Now is also the ideal time for the first application of fertilizer for the season. Our research here at GTI has shown that proper fertility is key to keeping weeds in check. With fertilizer alone applied 4 times a season at 0.5 kg of N per 100m2 weed populations could be kept below 10%.
– See more at: https://lawnsavers.com/turf-hotline-2008/turfgrass-management-agriphone-for-may-30-2008.html#sthash.qRbt1Clk.dpuf
