Turfgrass Management Agriphone for July 21, 2008

This is the 12th edition of the 2008 OMAFRA Turf Management Update recorded on July 21.

Weather:

The weather last week brought lots of heat, humidity and rain.  It was excellent weather for disease.  The forecast is for some slightly cooler weather and lots of rain.  We definitely can’t complain about a shortage of water so far this summer.  Temperatures are to be moderate at the beginning of the week and climbing toward the weekend.

Diseases:

There was some brown patch reported last week.  Luckily, in our climate it rarely if ever causes any turf loss.  Unfortunately, the weather last week was perfect for summer patch, especially if you have poorly drained soils.  Once summer patch occurs, anthracnose will often come in to colonize the stressed turf.  There was also some dollar spot development on fairways last week.  In spite of all the rain, some golf courses are battling localized dry spots on high areas where the turf is very thatchy.

On perennial ryegrass, rust has been active for the past three weeks.  It is just now showing up on Kentucky bluegrass.  This is very, very early and it could become a big problem this summer if the weather conditions are right. Rust likes alternating hot and dry with wet weather.  Another disease that I have seen on Kentucky bluegrass is leaf spot and melting out.  I have visited a few lawns that have some patches of dead turf.  There are no insects or signs of insects present.  When you look carefully at the dead turf plants they all have a big leaf spot lesion at the crown of the plant.  If you have any unknown turf problems, please contact 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:

European chafer adult flights are virtually finished. Japanese beetle flights are still pretty heavy and adults will continue to feed for a couple of weeks yet.   We have a couple of weeks left in the ideal window for Merit applications targeted for European chafer and Japanese beetle.  If you plan to use nematodes for grub control the timing is late August to early September.

We are starting to see some insect damage now from both hairy chinch bugs and bluegrass billbugs.  Hairy chinch bugs can be treated with deltamethrin or carbaryl.

Weeds:

All the rain has been great for weed growth.  Crabgrass plants are doing well.  We are probably past the stage where Acclaim Super can be used on crabgrass plants.  It can only be used up to the 1-4 leaf plus 3 tiller stage.  Some of the weeds that are obvious at the moment are white clover, bird’s foot trefoil, yellow wood sorrel and black medick.  The best window for broadleaf weed control is in the fall, but you may                                                                                                                                                                                                                                                                                           get some control this time of year.  Also avoid herbicide applications during hot, humid weather.

Another result of all the wet weather this spring is lots of moss on golf greens.  Unfortunately, there is still nothing registered for use for moss control in Ontario.  Research here at GTI has shown that frequent watering is one of the largest contributing factors to moss encroachment.  Be careful not to irrigate too frequently.

GTI Turf Field Day:

Please join us for the GTI Turf Field Day which is taking place on Aug. 21, 2008.  Current areas of research that you can learn about include disease and insect biology and control, pesticide alternatives, evaluation of turf varieties,  velvet bentgrass establishment and management, thatch management,  irrigation scheduling, sportsfield overseeding and grassland ecology, to name a few.   The program runs from 8:30 -1:00 with lunch included.  For registration information follow the GTI Turf Field Day link below.

Thanks for calling the Turf Management Updates. This message will be updated on Fri. July 25, 2008.

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