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Audio Blog: Spring Disease Applications

May 12, 2023 | Categories: ,
Another Day Another Dollar

Find out how to complete successful spring applications for red thread & pink patch, snow mold, summer patch, take-all patch, Pythium root rot & dysfunction, dollar spot, brown ring patch, and fairy ring on your golf course.

Red Thread & Pink Patch

Red thread is a fungal turfgrass disease that can strike pretty much any time during the year. However, conditions in the spring and fall, which typically include prolonged periods of cool and wet weather, are perfect for red thread. The pathogen prefers conditions that promote slow turf growth, and long periods of cool and wet weather do just that. Infected turfgrass areas appear as tan or bleached-white circular patches, with red, thread-like fibers present among the grass blades. Pink patch is similar in appearance to red thread and occurs at similar times. However, it produces pink mycelium rather than red stroma. Spring is a good time to make preventative applications of both red thread and pink patch. Most broad-spectrum fungicides are labeled for these diseases.

Snow Mold

Snow mold comes in two types: gray and pink. Gray snow mold needs extended periods of snow cover to develop, while pink snow mold does not. It can develop in simply cool, damp, wet weather. Depending on the weather and snow mold activity on your course, spring is a good time to clean up any snow mold from winter and apply fungicides as a preventative for further pink snow mold. Products containing PCNB, such as Turfcide 400, work well for this application. The prevention should last you through late spring or early summer. 

Summer Patch

For those managing Poa annua, summer patch is a major concern to proactively address in the spring months. Fungicide treatment of summer patch typically involves four applications, 28 days apart, starting when the soil temperature reaches 65°F. Prevention is key when it comes to controlling summer patch, so don’t be afraid to spray even before you see evidence of the disease. 

When it comes to preventative spray programs on greens, tees, or fairways, be sure to select the proper spray nozzle and volume of water for uniform coverage. Add Optimizer Green Shade to improve turf color and quality to help manage stresses and moisture.

Fungicide treatment of summer patch typically involves four applications, 28 days apart, starting when the soil temperature reaches 65 degrees. Prevention is key when it comes to controlling summer patch, so don’t be afraid to spray even before you see evidence of the disease. A good four-application program would be Lexicon, TEB 360, TM 462, and Insignia to take advantage of active ingredients across fungicide classes.

Take-All Patch

Take-all patch is a disease of creeping bentgrass that can occur on greens, tees, and fairways. The fungus that causes take-all patch is existent in almost all soils but only causes damage when conditions are favorable. Even though the fungus is not active in higher soil temps, you can still see a decline in the turf through the summer, simply because of damaged root systems that are unable to recover under summer stress.

Chemical applications applied when the soil temperatures are between 55 and 65°F are the most effective control of this disease. Since this is a root-infecting disease, it is important to get the product down to the root zone. You will have to water in the product with enough irrigation to get it into the roots or apply it before rainfall. If take-all patch is a problem at your facility, consider treating it with one of our ArmorTech fungicides labeled for take-all patch: Zoxy 2F, PPZ 143 MC, TEB 360 XL, or TM 462.

Pythium Root Rot

Pythium root rot can arise after long periods of rainfall no matter what time of year, making summer a perfect time for symptoms to pop up. Because it becomes active on cool-season putting greens in the springtime, fungicide applications for controlling it in the summer should be made before it begins, especially in situations where a history of the disease has been present.

Start preventative fungicide applications in May when soil temperatures reach 55-60°F in the spring. Begin with Insignia SC Intrinsic and Signature Xtra Stressgard, following that up in two weeks with Banol and Signature Xtra Stressgard.

Pythium Root Dysfunction

Like Pythium root rot, Pythium root dysfunction can appear at any time of the year. Symptoms of the disease seem to occur the most often in hot summer weather. With root infections beginning to occur once soil temperatures reach approximately 54 degrees and higher, spring is the perfect time to prevent Pythium root dysfunction for summertime symptoms. 

Be prepared to rotate fungicides and make monthly applications starting in the spring months to combat and stay ahead of Pythium root dysfunction. Insignia SC, Segway, and Zoxy 2F are effective fungicides against Pythium root dysfunction. Make sure to water the application into the root zone with approximately 0.10 inches of water. Soil surfactants are a great tank partner for these applications.

Dollar spot

Dollar spot is one of the most common turfgrass diseases and is particularly problematic on close-mown turf. On golf courses in the United States, more money is spent managing dollar spot than any other turfgrass disease. In April and May, staying ahead of dollar spot is a big concern on bentgrass. 

The fungal pathogen that causes dollar spot only infects the leaf blades, so infected turf can recover. However, healing can take a considerable amount of time. The disease creates a sunken area of turf that can range in size from a quarter to a silver dollar-sized patch — thus, the name dollar spot.

The dollar spot pathogen is ever-prevalent in nature and naturally exists in organic material such as thatch. It begins to grow and infect susceptible grasses in the spring when nighttime air temperatures exceed 50℉. The disease becomes symptomatic once daytime air temperatures reach the 60-90℉ range. It also requires extended periods of leaf wetness, primarily in the form of dew, to become symptomatic. Under these conditions, a heavy, white, cottony, mycelium is visible on infected lesions in early mornings. Disease activity lessens once daytime high air temperatures consistently exceed 90℉. 

Using Xzemplar will help prevent dollar spot. If it has been a problem in the past, make sure your fertility levels are in good shape. Dollar spot is a low-nitrogen disease. Moisture management, like removing dew through early mowing, is also helpful in preventing dollar spot.

Another good broad-spectrum fungicide to prevent dollar spot activity is TMI 2020. It prevents and controls fungal turf diseases on greens, fairways, trees, and other turf sites. With two powerful active ingredients (thiophanate-methyl and iprodione), TMI 2020 offers different modes of action in one convenient product.

Brown Ring Patch

Brown ring patch occurs in the spring and summer under humid conditions with low sunlight. It survives within a wide range of air temperatures, from 60 to 95°F.  The brown ring patch pathogen primarily infects annual bluegrass putting greens. It has also been known to infect creeping bentgrass.

The symptoms of brown ring patch include the namesake patch, which in fact, is more of a yellow ring early in the disease cycle. As the disease progresses, the yellow leaves on the perimeter of the patch can turn brown or even die. The patches range in size from several inches to several feet across. Brown ring patch symptoms are sometimes misidentified as necrotic ring spot or summer patch. 

Brown ring patch is more common and more severe in environments with low nitrogen. Therefore, nitrogen applications can help minimize infection and aid in disease recovery. In extreme cases of brown ring patch, the disease can take Poa annua to the crown. 

Fungicide applications also help control brown ring patch. Liquid options include Fame C, Lexicon, and TEB 360 XL. Another option is Affirm WDG, which has a concentrated, water-dispersible granule formulation to deliver disease control through foliar and translaminar systemic activity. Whichever fungicide you choose, be sure to water it in after application.

Fairy Ring

Fairy ring is frequently confused with brown ring patch and comes in three types. In type I fairy ring, fungi decompose organic matter, their mycelium covering soil particles. The mycelium covering results in hydrophobic soil conditions, which lead turf to die in rings, arcs, or patches. Type I is the most dangerous. With type II, fairy rings occur as dark green rings or arcs and grow faster than the surrounding turf. These rings or arcs occur mostly in turf that is nitrogen and iron deficient. Mushrooms or puffballs are produced in Type III fairy ring. The mushrooms or puffballs appear in rings or arcs on the surface and are generally observed after a heavy rain or on over-irrigated turf.

If you do not have time to wait for lab results and are not certain whether your issue is fairy ring or brown ring patch, TEB XL 360 is effective at treating both diseases. Regardless of which disease you encounter, it takes longer in the spring for infected/affected plants to clear up. In four to six days after treatment, new, healthy shoots will be more evident. Gray, cool weather can drastically slow the recovery.


Contact your ATS sales representative for help selecting the best preventative fungicides for any disease you face on your course.

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