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Posted by Jim Wile --Previous Message-- There are two main categories of fungicides: 1) Systemic - These fungicides work by entering the grass plant. Some enter through the leaves, and some through the roots. They are generally longer lasting, meaning you don't need to apply them as frequently, but should not be used exclusively because fungus will develop resistance to them. The most available ones for homeowners are Thiophanate methyl and Bayleton. Thiophanate methyl is known by the brand names T-Storm by Lesco and Cleary's 3336. Thiophanate methyl seems to have the added advantage of suppressing the earthworm population in your green and eliminating worm castings. I suggest using both. They can be found in both granular form that you spread with your fertilizer spreader and flowable form that you spray on with a sprayer. Instructions come with them for rates and frequency of application. 2) Contact - These fungicides sit on the surface of the grass plant, rather than entering into the grass plant. They are not as long lasting, because within a week to 10 days, you have mowed it off. Examples of contact fungicides available to the homeowner are Chlorothalonil and Mancozeb. Chlorothalonil is known by the brand names Manicure by Lesco and Daconil. Mancozeb is just Mancozeb. These usually come in flowable forms that you must apply with a sprayer. You can buy an inexpensive pump-type sprayer at garden centers or Home Depot. A 2-gallon sprayer will cost between $20 and $30. Try to find one with a fan-shaped nozzle for better application. You want to make sure to alternate using systemics with contacts. Here is a suggested schedule to follow during the late spring and summer when disease is most active: Apply a systemic. In 2 weeks apply a contact. In 7-10 days apply another contact. In 7-10 days begin the cycle over again. This is a preventative schedule. The aim is to not let disease appear. If there seems to be a lot of disease pressure due to high temperatures and humidity, you may need to shorten the intervals between applications. If you see a lot of the little "cobwebs" (dollar spot mycelia) all over the green in the morning, you should probably spray that day. You will always see a few, even the day after you spray, but if there seem like a lot, that means disease pressure is high. Another approach that some people take is a curative approach, i.e. waiting for disease to appear before treating it. This is a bad idea. Fungicides don't work very well in curing disease, but rather in preventing it from forming in the first place. Curative rates of application are much higher than preventative rates (as you will see on the fungicide labels), so you don't end up using that much more if you spray preventatively, plus your green will look and putt much better. The one exception I make is for the disease called Pythium. I live in Michigan where Pythium is not too common (requires very hot and humid weather). The fungicides I mentioned will not cure Pythium. It requires some very expensive fungicides. I purchased one from Lesco called Banol, but I don't use it preventatively. I only plan to use it if Pythium forms (which it never has). If you live in the middle or southern states, you may want to spray for Pythium preventatively too. When using a pump-type sprayer, 2 gallons of water is sufficient to spray about 1000 sq ft at a comfortable rate. Make sure to wear rubber gloves and long pants when you mix and spray fungicides, and it's a good idea to take a shower afterwards. Don't spray if it’s real windy or there is rain in the immediate forecast, and don't water right after applying a contact fungicide. Those systemics that are taken up by the roots should be watered in after application. The fungicide label will tell you if this is the case. One more tip: In mixing your flowable fungicides, put some water in your sprayer first before pouring in the fungicide which is very thick. This will prevent it from sticking to the bottom. After you fill the water up to the 2-gallon mark, close up the sprayer and shake it up well to mix the fungicide. For snow mold, late October to November is the time to apply your fungicide. I usually apply a systemic at the end of October when the grass is still growing and can "take it up". Then I apply a contact at the end of November after the grass has stopped growing. You can also re-apply contacts during the winter if you get a thaw for added protection.
on 6/14/2005, 11:17 pm, in reply to "Re: fungicide programs"
67.167.137.53
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: http://www.usga.org/turf/green_section_record/2003/may_june/strategies.html
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: --Previous Message--
: Where can I get more info on
: preventative / regular fungicide
: routines? The manual from this
: website does not get that specific.
: I'd rather tackle the problem before
: rather than after infection.
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Fungicide Use
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