Welcome to the “Turf Management Updates” sponsored by the Ministry of Agriculture, Food and Rural Affairs. To accommodate our new podcasts, I am changing the schedule a bit on the “Turf Updates”. They will be recorded on Thurs. afternoons and posted on the OMAFRA website sometime on Friday mornings. This message is for the week of May 31 – June 7, 2007.
This heat wave that has been with us now for several days is going to stay until Sat. and will break by Sun. going down to more seasonal high’s in the low 20’s. It has been hot, humid and soils are dry in many areas now and turf that isn’t irrigated is starting to show some stress symptoms. We seem to have gone from baling hay because turf growth was out of control a week ago, to some very dry looking turf. I guess this is what we call an Ontario spring.
Diseases
Dollar spot began late last week in the Guelph area. It is maybe just a little earlier than the flowering of iris, but it fits the model of 10 days with average temperatures above 16ºC. This is pretty early. I have it in my mind that on average dollar spot begins in the Guelph area in early June. This is why we need models and plant phenology to keep us straight. It always amazes me how much more susceptible annual bluegrass is to dollar spot compared to creeping bentgrass. It is always our annual bluegrass areas that show dollar spot symptoms first. Dr. Katerina Jordan has been seeing root colonization with runner hyphae on annual bluegrass in samples that have come in to the lab over the last week. This is an indication that summer patch is colonizing roots at the moment. Just a reminder to send any unknown turf problems to the GTI Turf Diagnostics. Information on this service is available at by following the link below.
Insects
We unearthed some grubs here at GTI last week during a field renovation project. They are days away from pupating, so no more turf damage and damage from skunks and other secondary pests. Full bloom of horsechestnut trees and bridal wreath spirea signal the time for peak flights of turfgrass ataenius adults. There is still time for preventative control of black turfgrass ataenius if you have seen large adult flights or if you have had a history of damage on your golf course. The type of damage that occurs with this grub species is the same as with European chafer but and usually occurs in late June to mid July. I saw a bluegrass billbug today walking leisurely through the grass. Cutworm adults will be returning from their overwintering sites in the south now and you may see them laying eggs on golf greens. I also saw the first June beetle this morning on June 1st. What a coincidence. If dry conditions persist, this will favour most insect development.
Leatherjacket damage is increasing daily at the moment with large patches of grass going down almost overnight. I have had a lot of emails about areas of infestation and I truly appreciate those. It is difficult to be everywhere so I appreciate the notes from the field. Treatments with Sevin T&O can be used any time now to control leatherjackets on home lawns, golf courses or sod farms. There are several restrictions on when and how Sevin T&O can be used on residential properties. These include: one application a year; treatment should be considered at or above 270 larvae per m2 and spot treatments only are allowed in residential areas and not more than 100 m2 area can be treated on a residential property.
The turfgrass ant is still active. They have been building mounds now for a 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, 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. Dursban is registered to control ants and according to many recent trials in the U.S. gives good control. Scimitar (lambda-cyhalothrin) is also registered for control of ants on turf in Ontario.
Weeds
Crabgrass has germinated now in most areas. At this point, a product like Dimension is still recommended because of the early post-emergence activity. An alternative approach is to wait and apply a post-emergence herbicide 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.
Dandelions are now mostly in the puff-ball stage in many areas. In Guelph, this has prompted lots of letters to the editor in our local paper challenging the city that if there are so many successful alternative to herbicides, why are there so many dandelions. I think this is a fair question. We are coming into the ideal post-emergence weed control window. It is best to wait until these last few hot days pass. Of course, it is important to be aware of any by-laws restricting the use of any kind of herbicide on home lawns.
Annual bluegrass seedhead production has probably peaked at the moment. There are some pretty unattractive putting surfaces out there at the moment. Remember that once these annual grassy weeds flower there is a lot of tiller death so there could be some thinning of annual bluegrass in the next few weeks.
Fertility
Now is the time for a shot of fertilizer. There has been good root growth so far this spring. Now that the roots are growing well, it is a good idea to fertilize turf soon so that you can promote a dense turf stand. It is also good to fertilize after a herbicide treatment so that the turf can fill in the voids where the dead weeds are.
– See more at: https://lawnsavers.com/turf-hotline-2007/turfgrass-management-agriphone-for-june-1-2007.html#sthash.i3O5XmXB.dpuf
