Turf Management Blog

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Here’s What You Can Do Now To Control Anthracnose

Of the best fungicides available to treat anthracnose, three-chemical classes are most effective as a curative measure: Benzimidazole, DMI and QoI. Though they will effectively pull your feet out of the proverbial fire, we don’t suggest relying solely on them as they are susceptible to developing resistance issues. We recommend carefully monitoring how much you use them and of course rotating chemistries is also important. Once you have things under control, better cultural practices will allow you to manage any potential anthracnose outbreaks.

How to Treat Anthracnose On Turf

You are the best resource to understanding the environmental conditions and patterns of disease formation for your course. They say the best time to plant a tree is 40-years ago… well the second-best time is today. So be sure to add a preventative chemical to your tank mix. A preventative approach, guided by your own expertise, will keep your turf strong and healthy and is the most effective management technique to controlling anthracnose. We suggest starting a preventative tank-mix program at least a month in advance of when your turf would typically be affected by anthracnose. The available chemistries in the market are such that the overall health of your turf will be improved and allow you to manage any outbreaks much more effectively.

Anthracnose in Turf: How to Diagnose, Control and Treat it.

They say only the strong will survive and when it comes to anthracnose it’s really true. Anthracnose is a destructive fungal disease (caused by the fungal organism Colletotrichum cereale) that preys on weakened turf, in particular annual bluegrass.

Nowhere is the severity of anthracnose fungus experienced more harshly than on the greens. That’s where practices to improve playability exacerbate stressors and reduce turf health. Research and our own experience prove that a preventative approach is far more effective than a curative one.

Diagnosing Anthracnose Fungus

Anthracnose infects leaf, crown, stolon or root tissues resulting in foliar blight or basal (stem) rot. The key to diagnosing the existence of Anthracnose is the black, sterile hairs called setae that extend out of the leaf. Also produced are spores called conidia that spread the infection when scattered by water, foot traffic and machinery.

Foliar Blight
Foliar Blight is normally detected during summer months when heat stress is at its worst. Symptoms include large, irregular shaped patches with little turf density that appear yellow to bronze. It first infects older leaves and then progresses to the younger ones.

Basal Rot
Unlike foliar blight, basal rot can occur throughout the year. Symptoms include orange and bronze spots that get bigger until they eventually join. Kind of like what happens to bananas. Stems and crowns end up looking waterlogged until they eventually turn black and rot.

How to Control Anthracnose Turf Disease with Cultural Practices

Nitrogen Fertility
In our relentless pursuit of increasing ball-roll on putting greens we have exacerbated the frequency and severity of anthracnose on our courses. The greens are our prime real estate so it’s understandable but there are other ways. By starting in late spring and carrying on throughout the summer with repeated low-nitrogen-rate fertility applications we can effectively reduce the severity of anthracnose.

Verticutting
During periods of environmental stress, wounding turf at inappropriate times can increase its susceptibility to developing anthracnose turf disease. This includes the effects of deep verticutting: severing crowns, stolons and removing thatch. Instead we recommend light verticutting or light brushing of the leaf canopy.

Mowing and rolling practices
Increasing playability doesn’t necessarily have to make your course vulnerable to anthracnose. Double cutting and lightweight rolling will improve ball roll without increasing the risk of developing anthracnose or the severity of it.

Topdressing
For the most effective relief from anthracnose, we recommend light applications every 7-14 days. At the beginning, it may temporarily increase anthracnose but in the long run it reduces its severity. Topdressing effectively “fools’ the turf into believing it is being mowed at a greater height of cut. For the best control of anthracnose, we suggest playing the long game.

Water management
Strong, healthy turf is better equipped to cope with stress and is therefore the best way to make turf less susceptible to anthracnose. So, to ease stress on those scorching hot days of summer we recommend syringing putting greens on sunny, dry afternoons. That being said overwatering also stresses turf as it reduces the amount of oxygen that gets to the roots. So like most things in life, balance is everything.

Air Circulation
To reduce the conditions that lead to fungal infections it’s important to ensure constant air movement - especially on greens. We recommend careful pruning of the trees surrounding the greens. Spiking and hydrojecting also provide roots access to oxygen without stressing the turf. Some have even gone so far as to install fans at each green. We can almost hear the impersonations from here – “Luke, I am your father”.

Controlling Anthracnose Turf Disease will make you the envy of the golf world

Superintendents are the unsung heroes of our courses. As the last line of defense we are the protectors - battling the elements and the proliferation of diseases that plague our courses. The primary defense against Anthracnose is to maintain strong, healthy turf. Much like how a healthy person cruises through flu season unscathed, healthy turf is stronger turf and is better able to protect itself. It’s less prone to disease and better able to shrug off the effects when exposed to it.

So, follow the wise adage that an ounce of prevention is better than a pound of cure. Start early in the season by taking preventative measures and your turf will be less affected by anthracnose fungus. It saves a lot more time, effort and money to keep your turf healthy, strong and better able to protect itself. Then you can spend less time worrying about your greens and more time doing what you’d rather be doing – accepting praise from your membership for all your hard work.