Welcome to the “Turf Management Report” sponsored by the Ministry of Agriculture, Food and Rural Affairs. This is just a name change from the old “Turf Agriphone” messages. This message is being recorded for the week of April 30- May 7, 2007. The messages are going to be posted on the web in text and podcast versions every Mon. until October These messages are available in three forms now. You can listen to a recorded message by telephoning the local number 519-826-3414 or 1-888-290-4441. The reports are also available online at http://www.omafra.gov.on.ca/english/crops/updates/turfgrass/index.html. They are available as a written document and also as a podcast. The easiest way to get these weekly reports is to go to the subscribe/unsubscribe button at the Turf Management Report web site and subscribe. That way you will get an email and a link each time a new Turf Management Report is posted. If you are interested in subscribing to the podcast, simply click on the podcast button and follow the instructions. A new feature that I have added to these reports are growing degree days at base 5° and 10°C and 54° F.
Our little taste of summer like weather last weekend was short lived but the warmer temperatures are forecast to return. This will mean the first real flush of turf growth is probably just around the corner. The good thing about the weather so far is that it has been excellent for root growth. There has been lots of off coloured spots on golf greens that are a result of different genotypes of grass that respond differently to cold temperatures. We saw this same phenomenon in the fall. Some are dark green to purple, some are light green (probably annual bluegrass) and some are just a normal green. It leads to something that looks like a lot of different patch diseases are invading a green. The warm weather in the forecast will help give turf a more uniform colour.
Diseases
The GTI Turf Diagnostics is up and running again for the season. Considering the cool, wet start to spring, it is no surprise that they are seeing a good bit of take-all patch (Gaeumannomyces graminis) and cool-season Pythium. Both diseases attack bentgrasses primarily, although Pythium root dysfunction can be found on most cool-season turf. Microdochium patch was very active last week. This will slow down now with the warmer temperatures coming. Don’t be fooled though, heavy dew and cool nights can keep Microdochium patch active. Other diseases which could flare up over the next week are anthracnose basal rot and perhaps red thread on home lawns and roughs.
We have some beautiful symptoms of yellow patch on one of the research greens at GTI at the moment. I only expect these to persist for another week or so. Once the temperatures warm up they should be a thing of the past. 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
As predicted, the grub calls are starting to come in now. I saw a couple of lonely annual bluegrass weevil adults last weekend when the weather was warm. The first real wave of migration will probably take place sometime over the next week or two. This usually occurs between the time of forsythia petal drop and full bloom of dogwoods. There has been some good work that began in 2006 at Rutgers University by Dr. Kopenhöfer looking at the efficacy of entomopathogenic nematodes to control annual bluegrass weevil. His field trials indicated that Heterorhabditis bacteriophora and Steinernema feltiae both provided statistically significant reductions in annual bluegrass weevil populations. These applications should be targeted at the late instars in late spring. Dr. Dan Peck at Cornell is working on a day degree model to forecast annual bluegrass phenology.
We continue to monitor the growth of leatherjackets. Leatherjacket growth was slow over the last week. I still predict that they are slightly behind their normal development. Again, the good news for lawn care operators regarding leatherjacket control. Sevin T&O is now labeled to control leatherjackets on home lawns. There are several restrictions on when and how to use it 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. If you are finding significant numbers of leatherjackets they can be treated at any time now.
Again, this week I have a plea for turf managers. I would like to do some research on thresholds for leatherjackets. To do this, I am looking for sites with leatherjacket damage that I can sample before treatment is made. If you have residential or golf course sites with damage, I would appreciate hearing from you and my summer student and I can come out and do some leatherjacket counts. If you are interested in cooperating on this leatherjacket threshold research please give me a call at (519) 824-4120 x 52597 or you can email me at pamela.charbonneau@ontario.ca.
Also on the leatherjacket front, we are interested to find out if we have the common crane fly (Tipula oleracea) here in Ontario. It has been reported in British Columbia, New York State and Quebec. A colleague of mine, Dr. Dan Peck at Cornell University contacted me last week to say that the common crane fly has also been found in Michigan. So far we have not confirmed if it is present in Ontario. It can be distinguished from the European crane fly by its life cycle. Adult common crane flies fly in April/May and Aug./September. The European crane fly adult flights are in September only. Another form of evidence would be the presence of the pupal casing on low cut turf. They look like little twigs sticking out of the turf. Yet another indication of T. oleracea is turf damage during late fall, winter and early spring. If you are finding damage that is very much like cutworm damage on your greens this time of year, the culprit could be the larval stage of the common crane fly. If you are seeing some adult crane flies, pupal casings or have turf damage that looks like cutworm damage this spring, please let me know and I can arrange to get a sample from you.
Weeds
In the Guelph area the forsythia have just started blooming. Of course, this means that you should start thinking of crabgrass control. There is a degree day model that has been developed for base 54°F for crabgrass that predicts crabgrass germinates at 300 GGD base 54°F. You can see in the table below that all locations in Ontario are no where near that threshold yet.
We actually don’t recommend applying a product like Dimension until the forsythia blooms have just fallen off. Because it has the early post emergence activity, even if you have a few germinated crabgrass plants, you will still get good control if applied according to this timing. As you will probably recall, last summer was brutal for crabgrass invasion. This was a huge home lawn problem, but I also had lots of calls from golf courses saying that they had been invaded. 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 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.
– See more at: https://lawnsavers.com/turf-hotline-2007/turfgrass-management-agriphone-for-april-27-2007.html#sthash.gBpIesQW.dpuf
