Angelina County Ag News: Fungal problems showing up in lawns

East Texas Ag News
East Texas Ag News
Published: Sep. 8, 2022 at 11:57 AM CDT
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ANGELINA COUNTY, Texas (KTRE) - Before church started last Sunday, I was kneeling our the church courtyard, not in a religious manner, but rather answering questions about the lawn issues that were evident there and in the yards of others asking questions.

Every fall when the weather starts to cool just a little bit and the rains pick up, I get calls about dying lawns and most of them are disease related. While lawn disease issues can happen anytime during the growing season, I hear about them mostly in the fall. Additionally, the call will typically come from the homeowner who normally has the greenest and most pampered lawn on the block. Most times, the most pampered lawns that receive copious fertilizer and an abundance of water are the most affected.

Trying to understand all the factors that can lead to disease can be complex. Some of these factors include excessive thatch, low soil fertility, too much nitrogen, improper soil moisture, compacted soils, heavy/prolonged dews, or uncontrolled infections from previous year.

Turf areas that remain wet are most prone to disease. When you think of where molds will grow in your house, we all agree it’s a problem in areas that stay moist. Following the same concept, let your lawn dry out between waterings. To reduce the time your lawn stays wet during any 24 period, only water in the mornings when the lawn is already wet from the dew. Watering your lawn in the afternoon and early evening prolongs the time that moisture-loving fungus can develop.

Avoid over watering or improper watering. It is better to water deep and infrequently (6 to 8 inches deep) than to give the grass frequent, shallow waterings.

Have your soil tested and fertilize grass based on the test recommendations. Do not apply excessive rates of nitrogen fertilizer. Excessive use of an individual element, such as nitrogen, makes plants more susceptible to disease attack. Do not apply more than 4 pounds of nitrogen fertilizer per 1,000 square feet per year for St. Augustine grass, or 5 pounds per 1,000 square feet per year for Bermuda grass.

Soil also should be aerified if it is compacted. Soil compaction keeps water and air from moving into the soil and reduces plant shoot and root development. Aerification of compacted soils once or twice a year helps break up packed soil layers to allow air and water to reach plant root systems.

If diseases are currently a problem in your lawn, you will probably want to apply a fungicide. Fall and spring are the best times to do this. Fungicide should be applied in a high volume of water or watered in thoroughly right after application. This will ensure that the product moves into the grass root zone rather than drying on the leaves.

Common hose-end applicators work well for soaking the fungicide into the root zone. Fungicides are most effective as preventative treatments and much less effective after the disease has become well established. However, it is usually effective to treat diseased areas after the easily removed, infected stolons are raked out or lifted away. Two applications 3 to 4 weeks apart may be required.

What products are recommended? There is a long list of products and many common active ingredients from which to choose. The two active ingredients that are easiest to find are Azoxystrobin and Propiconazole. They will be under several brand names, but will can be found in the active ingredients. As always, read the label for application instructions.

Finally, remember that in your quest to have a lush, perfect lawn, even the golf course professionals who have a college degree in turfgrass management still have problems to contend with.

Cary Sims is the County Extension Agent for agriculture and natural resources for Angelina County. His email address is cw-sims@tamu.edu