I was preparing to leave town last weekend for a family member’s wedding when I was informed that one of my favorite local physicians had a minor emergency – the centipede in his front yard was looking ill. So, I just couldn’t leave town without dropping by his Cherrybark Lane residence to diagnose and prescribe. He seems to be willing to do that for me on short notice from time to time, so it only seemed fair that I reciprocate.

What I noticed were classic symptoms of a disease caused by the Rhizoctonia solani fungus. This disease goes by several different common names like “large patch,” “large brown patch,” and “Rhizoctonia brown patch.” In fact, I’ve seen several lawns around the county having very similar symptoms.

The first symptom is one or more light green patches that may range in diameter from 2 inches to about 2 feet. These have the ability to spread rapidly. Actually, the patches will continue to expand as long as environmental conditions are favorable and can spread out 20 feet or more.

The fungus begins its attack at the base of the leave sheaths, where it attaches to the stolons. This area turns dark brown and is soft when the disease is very active. The leaves will then separate from the plant if you pull them, because the base of the leaf is actually rotting. Before the leaves die, they will usually turn reddish in centipede or yellow in St. Augustine.

Typical spring weather conditions are often just right for the Rhizoctonia solani fungus to cause disease problems in lawns – relatively cool temperatures from 60-75 degrees with either rainy weather or extended dew periods. High nitrogen fertility increases turf susceptibility to the disease, too. That’s really another reason home-

owners should not fertilize their lawns too early in the spring. On the positive side, this disease will slow down its activity as temperatures climb above 75 degrees and moisture levels decrease.

Centipede and zoysia grass will recover slower from large patch than will Bermuda grass and homeowners may continue to see thinned or bare patches in the lawn through most of the summer.

Prevention is the best method of control. In addition to planting varieties adapted for our area, we suggest homeowners manage lawns properly by using recommended practices for watering, mowing and fertilization. Again, too much nitrogen fertilizer, especially from the water-soluble nitrogen sources, promotes a lush turf that is readily attacked. Watering late in the afternoon or midmorning lets the grass remain wet for long periods of time encouraging disease development, as well.

Since the brown patch was already present in the lawn I examined, the most logical approach was for me to prescribe a fungicide product with an active ingredient effective against the disease. Several products from which homeowners can choose are good, and they are available in liquid and granular form. I happened to know this homeowner already had a spin spreader, so I suggested a granular fungicide product containing Bayleton.

Reminder: “Quicken vs. Quickbooks – Which computer program is right for your farming operation or business? Extension Conference room, Friday, 9:30-11:30 a.m. Dr. Steve Murray, will share the benefits of managing financial records using these computer programs.

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John C. Coccaro is county Extension director. Write to him at 1100-C Grove St., Vicksburg, MS 39180 or call 601-636-5442. E-mail him at jcoccaro@ext.msstate.edu.