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.12-19, 2005.
Weather
The 5 day forecast is calling for temperatures in the mid to high 20’s during the day and lows hovering around 20ºC at night. The difference from last week is that there are actually showers in the forecast until mid-week next week and then it is supposed to be cooler by Thursday the 18th with a high of only 20ºC. The rain is welcome because we are still in a deficit situation where rain is concerned in the southwestern part of the province.
Diseases
The disease situation has not changed much over the last week and it will continue to be the same for the upcoming week unless we get some of the cooler temperatures that are forecast for later next week. There will be a risk of the hot weather diseases such as Pythium blight, brown patch and anthracnose this week. Expect the root diseases to continue to be a problem. The samples that have been coming into the GTI Turf Diagnostics lab run by Erica Gunn have either summer patch, take-all patch or anthracnose basal rot. Summer patch has been very severe with the heavy rain associated with thunder storms and the hot weather last week and again this week. The turf with summer patch will die very quickly if it is windy because it can’t take up the water that it is giving off. The other problem with annual bluegrass at the moment is that it has lost a lot of roots due to the high soil temperatures. The saturated soils are making it difficult for the roots to function. Roots need air to do their job. This problem is most severe on heavy textured soils. All of this is spelling disaster for stands of annual bluegrass on golf 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 preserve some of your annual bluegrass roots.
The good news is that dollar spot has not been much of a problem. This may change if we do get some cooler temperatures.
Insects
Japanese beetle adult feeding is slowing down. Unlike European chafer, the adult Japanese beetles feed on a variety of flowering plants and the adults can be observed in the landscape. Merit is registered for control of Japanese beetle grubs in turf. Applications of Merit targeting Japanese beetle should be made as soon as possible. The ideal window is during peak adult flights and these are tailing off now.
We are probably at the peak of both hairy chinch bug and bluegrass billbug damage. Hairy chinch bugs suck the sap from the grass plants and the plants are still well rooted. With bluegrass billbug damage, the damage plants will pull out easily when you tug on them. In another two weeks or so, when the temperatures cool down the adult chinch bugs and bluegrass billbugs will be mowing into their overwintering sites and insecticide treatments will not be effective.
It turns out that the caterpillars that were causing problems on our greens at GTI were army worms. These have been a problem on several golf courses, home lawns as well as agricultural crops. The soap flush technique works well to determine if you have them. Again, it is 4 litres of water and 15 mls of dishwashing liquid. Pour that on 0.1m2 of turf and wait for roughly a minute. If there are caterpillars of any sort (cutworms, armyworms or sod webworms) they will surface in about a minute.
The second generation of black turfgrass ataenius adults are still flying in the southwestern part of Ontario now. If you have not had damage from the first generation, it is unlikely that you will have damage from the second generation.
All is quiet on the leatherjacket front. They should be pupating soon and 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 we get cooler and wetter weather. These treatments work best when the weeds are actively growing.
Cultural Practices
Once we get cooler weather , you can start up again with core aeration, verticutting, topdressing, overseeding, etc.. If you are overseeding damaged areas, make sure to keep the seedbed moist. This might take several light irrigation cycles a day. 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. 19, 2005.
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