Rain, rain go away
Most areas of the province received rain (or snow) most of last week. This week looks to be much the same last week with rain in the forecast for every day except Thurs. Temperatures are below normal as well. This means the slow start to the season is going to continue for the upcoming week.
Microdochium patch has had almost optimal conditions for its growth and spread. The rainy, overcast cool weather is just about perfect for this disease. When you are scouting you will be able to see new infection sites developing that look like small to medium sized copper spots. The edges of any pink snow mould scars will also be active with that coppery/brown outer ring. Given the inoculum load and the forecast conditions, a fungicide treatment is probably warranted if you haven’t put down one already.
If you do encounter a turf problem that you can’t identify, you can always send a sample to GTI Turf Diagnostics. Information on this service is available on the GTI web site. You can also email them at diagnostics@guelphturfgrass.ca or telephone at (519) 824-4120 x 58873.
As people are getting out and about and spending more time on the turf, the grub damage is being noticed. As far as control goes, there is very little that can be done this time of year except to rake the dead areas overseed now. Make a note of the damaged areas and plan to apply grub control in the mid summer on golf courses or in August for home lawns.
This paragraph is a repeat from last week – a new strain of nematode is being marketed in Ontario for spring grub control called Steinernema glaseri (S.g.) It is interesting because it is more infective against scarab pests such as European chafer and Japanese beetle than the other nematodes species on the market. It still has an optimum temperature range of 16-25�°C, working best at the higher temperatures. They have also been shown to infect third instar grubs in fall trials in a lab study in Quebec where the temperature was held at 23�°C and third instar grubs in potted yews that were treated in the beginning of May and held in a greenhouse for 2-3 days after treatment because of cold weather in Geneva, New York. In this study, the S.g. were very effective against Japanese beetle grubs and to a lesser extent European chafer grubs. That is all good news. I would like to point out, however that the current soil temperatures in our area are around 10-11�°C at the moment. I would be very cautious about using S.g. in the spring. I would definitely wait until the soil temperatures have warmed up substantially and even then, I am not sure how effective the treatments will be. The preferred time for using nematodes to control grubs is in the late summer (August and September) and we definitely plan to use this new species in grub trials that we plan to conduct this fall.
The cool weather continues to stall migrations of annual bluegrass weevil. Monitoring is still a good idea now. There is a great resource put together by Dr. Pat Vittum from University of Massachusetts on various annual bluegrass weevil monitoring methods in the related links below. Also, she advocates spraying to control migrating adults when forsythia is half green/half gold. She also advocates applying a sprayer boom width swath of insecticide in the roughs adjacent to fairways and tee areas and a sprayer boom width swath of the outer edge of fairways that have had heavy annual bluegrass weevil infestation in the past. At the moment forsythia are just starting to bloom in the Guelph area.
Weed control products and timing
For selective post-emergence weed control, Fiesta is available this season. The perennial weeds are just starting their re-growth now. It is still best to hold off on Fiesta use until the all the weeds are actively growing. Dandelions have started to grow as well as clover but the plantain is still not growing yet. It would be even better to wait until the end of May and that way the spring annuals would have germinated as well.
As mentioned earlier forsythia is just beginning to bloom in Guelph, but has been blooming in Niagara for at least a week. We are now approaching the application window for corn gluten meal for pre-emergence crabgrass control. For best results either apply corn gluten meal when rain is expected or water the product in within 2 days of application.
Again, keep the emails coming. I appreciate the feedback. You can reach me by phone or email at (519-824-4120 x 52597) or by email at pamela.charbonneau@ontario.ca.
– See more at: https://lawnsavers.com/turf-hotline-2011/turfgrass-management-agriphone-for-may-2-2011.html#sthash.RANFxIkd.dpuf
