Welcome to the “Turf Agriphone” sponsored by the Ministry of Agriculture, Food and Rural Affairs. This message is being recorded for the week of Aug.19-26, 2005.
Weather
With the exception of this coming weekend, the forecast is for much cooler weather, lower humidity and lower night time temperatures. This all bodes well for turf growth. We are starting to get into temperatures which will speed turf recovery and stimulate turf growth. The one missing ingredient might be rain. So far this month some areas have received normal rainfall and some have received less than normal. To summarize – Barrie, Ottawa, Ridgetown, Sarnia, Thunder Bay, Trenton, Waterloo, Wiarton and Windsor have received less than normal during the first half of August. Windsor is definitely the driest part of the province at the moment. Delhi, Hamilton, London, Toronto and Vineland have normal or more than normal rainfall.
Most areas have normal or above normal accumulated growing degree days now.
Diseases
The period where the warm weather diseases are a problem should be over now for the summer. Root diseases will probably stop spreading, but symptoms will remain. The samples that have been coming into the GTI Turf Diagnostics lab run by Erica Gunn this week have either summer patch or take-all patch. As I mentioned last week, summer patch has been very severe with the heavy rain associated with thunderstorms and the hot weather that followed. The thunderstorms this weekend could bring on some more summer patch. The cooler weather next week is going to be accompanied by lower relative humidity. This will mean high evapotranspiration rates. This will be the reason that the summer patch symptoms will persist. The roots that are filled with runner hyphae from summer patch will not be able to replace the moisture that they are giving off from evapotranpiration and there could be more wilted turf. The annual bluegrass plants that have lost roots will continue to wilt as well. Once we get cooler day and night time temperatures and cooler soils we should start to see some new root growth and some improvement in the health of annual bluegrass greens. A couple of things which may help keep your annual bluegrass alive now is to try to back off on irrigation to let air get into the roots and syringe the plants in mid-afternoon. This is especially critical on heavier soils that may be water logged and have little air in the rootzone. Another practice which will help your greens survive is to raise the mowing height. The higher the mowing height the cooler the soil. This may help your annual bluegrass produce some new roots.
Many greens have been plagued by localized dry spots. This will get worse over the next week with the high evapotranspiration rates that will be coming next week with the lower humidity.
As predicted last week, dollar spot is on the move now. We have seen it on our research greens and it is moving into surrounding areas of Kentucky bluegrass now. The weather next week will continue to be conducive for dollar spot development.
There is no sign yet of any rust on perennial ryegrass or Kentucky bluegrass, but it should be here any day now. Necrotic ring spot on home lawns has flared up again over the past week. Expect to see new symptoms developing over the next week as well.
Insects
We have been monitoring for European chafer grubs and they are in the late first instar now. Hairy chinch bug and bluegrass billbug damage has peaked. As soon as the temperatures start cooling off during the day and the night the adult chinch bugs and bluegrass billbugs will be mowing into their overwintering sites and insecticide treatments will not be effective.
We are still seeing the second generation of black turfgrass ataenius adults flying in southwestern part of Ontario now. Again, if you have not had damage from the first generation, it is unlikely that you will have damage from the second generation.
Leatherjackets should be pupating very soon. Adult emergence will probably be around the first or second week in September.
Weeds
Crabgrass is rampant still. The rain that we had in mid-late July and early Aug. has brought on an absolute explosion of crabgrass. The issue here is that turf had thinned in June and July because of the dry conditions. Add a bit of rain and heat and presto – you get crabgrass. Some of the pre-emergence crabgrass treatments that went on early may have run out of steam before the first real flush of crabgrass came on. Crabgrass germinated later than usual because it was so dry in June. Much of the crabgrass is getting too large to treat with Acclaim Super. Crabgrass can be scouted now for areas that will need treatment next spring with a product like Dimension. This fits nicely with IPM in that you can treat in the spring only those areas that had crabgrass this summer.
Broadleaf herbicide treatments should be postponed until after the winter annual weeds have germinated. The best time is in mid September. That way you can get a bigger bang for your herbicide buck.
Moss on golf greens continues to be a problem and it will very quickly colonize those areas that have thinned out from all the stress this summer.
Cultural Practices
Now that the temperatures will be cooling down, it is a perfect time to open up those greens by aerating. This will help with the summer patch symptoms. If you are overseeding damaged areas, make sure to keep the seedbed moist. This might take several light irrigation cycles a day on the sunny, dry windy days. It is also a good time to fertilize turf to help it recover from the harsh conditions that it had to withstand this summer.
Thanks for phoning the turf agriphone message for this week. The next agriphone message will be recorded on Fri. Aug. 26, 2005.
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