"organic" treatment of brown patch

[thill]

I have used Milorganite on my St Augustine lawn for the last two years and have been very pleased with the lush green carpet through the spring and summer.

Prior to that, I used "chemical" fertilizers relatively low in nitrogen.

I have had recurring problems with brown patch each fall for the last four or five years and have treated with chemical fungicides.

It's that time of year again and I am seeing early signs of BP.

I water infrequently but deeply and never late in the afternoon or at night. BTW - The soil is a dark heavy clay.

Other than aerating, what can I do in the "organic" arena that will help control this years crop of BP?

This new site has indeed started off with a bang!

Tom

[Popsicle]

A couple of conditions that make BP favorable are:

Warm temps (highs above 65f and lows above 60f)
Rainy or humid weather with prolonged leaf weness
Increased serverity with excessive N and low P and K

Some options are:

Maintain moderate, balanced fertlility (I'd get the soil tested)
Minimize leaf wetness (sounds like you have already addressed this)
Alleviate soil compaction and maintain thatch less than 3/4"
Promote good soil drainage
Selectively prune trees and shrubs to increase air circulation

Are you applying any microbes for soil conditioning?

[Dchall_San_Antonio]

Ordinary corn meal is the organic fungus controller. When used at a rate of 10-20 pounds per 1,000 square feet every 90 days, corn meal will keep all (yes all) turf fungus at bay. If the fungus has already gotten a foothold, use it at 20 #/k.

The research for this was done on peanuts at Texas A&M at Stephenville. To quote from their website...
http://stephenville.tamu.edu/~clee/pdncr/index.html

Biological Control of Soilborne Fungi
It is known that certain fungal species in the genus Trichoderma feed on mycelium and sclerotia of Sclerotinia minor. Sclerotium rolfsii and Rhizoctonia sp. All peanut fields in Texas tested to date have a natural population of Trichoderma. For several years, tests have been conducted in Texas using corn meal to stimulate Trichoderma development as a way to control the major soilborne disease fungi. When yellow corn meal is applied to fields in the presence of moist surface soil, Trichoderma builds up very rapidly over a 5 to 10 day period. The resulting high Trichoderma population can destroy vast amounts of Sclerotinia, Sclerotium and Rhizoctonia. This enhanced, natural biological control process is almost identical to the processes that occur when crop rotation is practiced. The level of control with corn meal is influenced by: 1) organic matter source 2) soil moisture, 3) temperature, and 4) pesticides used. Seasonal applications of certain fungicides may inhibit Trichoderma. Testing will continue to determine the rates and application methods that will give consistent, economical control.

Number 4) in the quote means that if you have already used a fungicide, the corn meal trick doesn't work. The fungicide will kill the Trichoderma fungus and negate any antifungal benefit.

Now the question comes up, can you licensed pest control applicators use corn meal against fungal disease in turf? I'm not at all sure you can. The normal label for corn meal reads as follows...

"Feed"

That's all. However, if you use it on a 90 day schedule as a fertilizer throughout the season, you should not have any fungal problems.

[Grassmechanic]

For those that are concerned about applying cornmeal without an EPA #, you can try Turfshield (Bio-Trek 22G). It contains Trichoderma strain 1295-22. This strain has shown ability to colonize in plant roots.

[Dchall_San_Antonio]

Grassmechanic,
Do you have a bookmark for Turfshield? Some time ago I read about it coming to the market but had not read that it is here already. I believe I was reading the patent for it, so that was probably way out of date at the time.

[Grassmechanic]

You can purchase it from Turfgrass,Inc. South Lyon, MI 1-800-521-TURF or email: tgrass@ismi.net . They will UPS it. It shows in their catalog back to 2000-01 season. 40# treats 33,000 sf. HTH.

[dvmcmrhp52]

Can corn meal be used for spot treatment or is it neccessary to treat the entire area for effectiveness.Total area contol is obviously better but how effective would it be as a spot treatment for lawns with only minor problems.

[Dchall_San_Antonio]

Corn meal can be used as a spot treatment but it is also a fertilizer. You might end up with spots of tall green grass.

[NAT]

I have good results with neem oil . neem oil comes from a plant.its good for treating brownpatch and as well as a insectcide .safe for lawn and veg garden.love the new site .