Welcome to the “Turf Agriphone” sponsored by the Ministry of Agriculture, Food and Rural Affairs. This message is being recorded for the week of July 22-29, 2005.
Weather
The weather summaries for the season so far show that we are equal or ahead of the normal growing degree days for the season now in most areas with the exception being Ottawa which is slightly behind. There was some rain last week, but from our weather data it shows that it was spotty, heavy in some areas and light in some. We are still way behind normal precipitation for the season and this ranges anywhere from as little as 20% normal rainfall to nearly normal.
It looks like we are in for another hot weekend and early week. The temperature is supposed to fall by Tuesday or Wednesday to the mid 20’s. The relative humidity is also supposed to drop.
Diseases
Of course the weather that we have had over the last few days has been perfect for disease development. There has been a lot of Pythium blight, brown patch, summer patch and anthracnose. Over the last two mornings we have had a lot of aerial mycelium on the outer edges of the brown patch and some Pythium blight mycelium as well. Dollar spot has not been active over the past couple of nights. I am sure that all of the golf superintendents are looking forward to the time when the weather does cool off so that they can sleep better at night knowing that there is less disease risk.
Along with all the disease damage there has also been a lot of scalping of turf. The rain softened greens and the mowers are sinking into the thatch and the result has been scalping. The intense heat and humidity compromises photosynthesis and the result is that the plant may run out of energy reserves for growth. If this is coupled with high soil temperatures and saturated soil conditions the roots will not function well either. It can be a recipe for disaster. All these conditions will certainly weaken plants and make them more susceptible to the stress diseases such as anthracnose.
Insects
European chafer flights are pretty well finished. Japanese beetle adults are out now. 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.
In lawns that are dormant, it is a good idea to monitor for hairy chinch bug. By now they will be causing damage. It can go undetected in a dormant lawn however. There are several ways to monitor, but the easiest is to look just on the edge of a damaged area. Part the grass and stare at the soil for a moment or two. It is best to do this in a sunny location during the heat of the day. If chinch bugs are present, you will see them scurrying around. The other method involves a coffee can with both ends removed. Place this into the soil, deep enough to create a seal. Fill with water and wait for a few minutes. If chinch are present they will float to the top. A similar technique involves putting a piece of turf in a bucket of water and waiting for the chinch to float to the top.
Heat and Drought Stress
The stress on turf has eased only somewhat in areas that did receive rain. What is really noticeable is that the turf that was dormant has gone from a straw colour to a darker brown with the rain. This is nothing to be alarmed about.
Just a few reminders of the do’s and don’ts of dormant turf. One other thing that you should not do if the turf is dormant is fertilize. If possible keep traffic off the turf during times of high stress. It is important however to keep monitoring for insect pests even if the turf is dormant.
Also, cultural practices should be suspended until it is cooler. Topdressing, verticutting and all of those cultural practices are very stressful for turf at the best of times and may just push turf over the edge when the temperatures are hovering above 30ºC.
Water Quality
As irrigation source water levels reach their seasonal lows, now is a great time to sample these water sources for pH, EC and various salts. This will give you a good picture of your water quality at its worst. Extreme values for pH, EC, bicarbonate levels and various salts may help explain problems with turf health or ineffectiveness of pesticide applications. A new chapter in OMAFRA Publication 384, Recommendations for Turfgrass Management discusses some of the most common water quality problems where turf is concerned. You can find information on how to order this publication you can call 1-888-424-1300 or visit the OMAFRA web site for more ordering options.
Thanks for phoning the turf agriphone message for this week. The next agriphone message will be recorded on Fri. July 29, 2005.
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