What's Happening Now?

RECENT CREEPING BENTGRASS PROBLEMS

Over the past several weeks, we have received many creeping bentgrass putting green samples.  In every case, samples were submitted to check for a disease and in EACH case absolutely no pathogen activity was discovered.  Therefore, our diagnosis was "a disease was not responsible for the damage".  The common thread has been the combination of core aerification and topdressing with the unusually arid weather for this time of year. When the putting surfaces are opened up after aerification, they are more susceptible to drought stress, especially if the humidity is very low. This effect is exacerbated in areas that are already stressed such as clean up laps, heavy on/off traffic spots, etc.

This is a fine example of why receiving a diagnosis of "no disease" is just as important as receiving a diagnosis of an actual disease. Because symptoms developed during excellent growing conditions for creeping bentgrass, a safe assumption is a disease is responsible for the damage.  Yet, in this case an accurate diagnosis can save time and money by preventing unwarranted fungicide applications.  If you don't agree, feel free to make a fungicide application for drought stress and see what happens.

Typical Stress Symptoms Observed with Recent Samples

TREAT FOR LARGE PATCH NOW!

With soil temperatures starting to approach 70°F across portions of NC, now is the time to treat for large patch.

Average Daily Soil Temperatures as of 10/01/13 via NC State Climate Office

Large patch, which is caused by the fungus Rhizoctonia solani, is a common disease of centipedegrass, St. Augustinegrass, zoysiagrass, and bermudagrass grown for lawns, landscapes, golf turf, and athletic fields. Centipedegrass and St. Augustinegrass are particularly susceptible to severe damage from this disease.

Symptoms of large patch appear in roughly circular patches from 2 feet up to 10 feet or more in diameter. The affected turf will initially be orange, yellow, or reddish-brown in color but will then turn tan and collapse to the ground. The disease can spread rapidly to encompass large areas of turf, and distinct circular patches may not be obvious in these cases.

Fungicides are available for large patch control, but they must be applied preventatively for best results. The first application should be made in the late summer or early fall when average daily soil temperatures are 70°F or below.

One fungicide application will control minor cases of large patch, but two to three applications on a 4 to 6 week interval may be needed to control severe cases. Fungicides are not very effective once the symptoms of large patch appear. Curative applications will help to reduce further spread of the disease, but the affected turf will be very slow to recover.

For more information about Large Patch, including images and specific control recommendations, click here.


TREAT FOR SPRING DEAD SPOT NOW

So, your first question may be "Why on Earth are you telling me to apply fungicides for a spring disease in the fall and for something that will not show up for another 6-7 months?!"  The answer is simple.  The causal fungus, Ophiosphaerella spp., is active RIGHT NOW and you can bet it's infecting your bermuda and zoysia grass plants as I type this blog.  We know through years of research that fungicides are most effective when the soil temperatures are between  60 - 80°F in the fall of the year.

Choosing the right fungicide and applying at the right time will not result in acceptable levels of control if you do not apply them correctly.  Spring dead spot infects below ground plant parts.  With that being said, you must either water-in your fungicide applications IMMEDIATELY  with 1/4" of irrigation or apply with a carrier volume of 5 gal/water/1,000 sq. ft.  You need to be running your irrigation the moment the applicator is out of the way.  Do not wait until the following evening or night with your routine irrigation schedule or else you may be severely disappointed come next spring when these grasses green back up.

Just recently we have made some fantastic discoveries with fertilizers in regards to controlling this disease without having to use fungicides at all!  To learn more about this, please click here.

To learn much more about spring dead spot, including control recommendations, please click here.

It's Back! Large Patch that is ...

You know it's officially spring in North Carolina when there are giant patches of brown grass in bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass. These giant patches of brown grass are better known as large patch, caused by the fungus Rhizoctonia solani, and if you've ever had an outbreak of this disease, you now know why the disease was coined large patch.

What you may not know however, is what your control options are this time of year. You shouldn't worry too much if you have this disease on bermudagrass. Bermudagrass tends to grow out of the damage once the temperatures are consistently warmer and the daylight longer.

Large Patch Symptoms on St. Augustinegrass

As for our other warm-season friends, damage tends to be most severe on centipedegrass and recovery may take all summer in extreme cases. Unfortunately, there isn't much you can do to make for a magical recovery. We rarely recommend fungicides for large patch in the spring of the year, however in worst case scenarios, a fungicide application might help prevent the disease from spreading further. Fungicide applications are best when they are applied preventatively in the fall. If you choose to spray a fungicide this spring, don't expect a miracle to happen overnight. Also, remember that recovery will be even slower and tougher if you've applied a root pruning herbicide as your pre-emerge for summer weeds.

In most cases, the best thing is to stay the course with management practices that will encourage each type of grass to do well. In severe cases, treating damaged areas like a new establishment with light and frequent fertilizer and water inputs may help encourage faster lateral spread. This doesn't mean you should apply more fertilizer, just smaller doses more often. Applying too much fertilizer will make the disease worse this fall!

Finally, be sure to map the affected areas now while they are clearly visible. You will save yourself some money this fall by spot treating these areas instead of having to make a whole property application, since the disease tends to reappear in the same areas.

For more information about large patch, click here.

For more information about warm-season grass maintenance, click here.

Treat for Large Patch Now!

With soil temperatures starting to approach 70°F across portions of NC, now is the time to start thinking about treating for large patch.

Average Daily Soil Temperatures as of 9/18/12 via NC State Climate Office

Large patch, which is caused by the fungus Rhizoctonia solani, is a common disease of centipedegrass, St. Augustinegrass, zoysiagrass, and bermudagrass grown for lawns, landscapes, golf turf, and athletic fields. Centipedegrass and St. Augustinegrass are particularly susceptible to this disease.

Symptoms of large patch appear in roughly circular patches from 2 feet up to 10 feet or more in diameter. The affected turf will initially be orange, yellow, or reddish-brown in color but will then turn tan and collapse to the ground. The disease can spread rapidly to encompass large areas of turf, and distinct circular patches may not be obvious in these cases.

Fungicides are available for large patch control, but they must be applied preventatively for best results. The first application should be made in the late summer or early fall when average daily soil temperatures are 70°F or below.

One fungicide application will control minor cases of large patch, but two to three applications on a 4 to 6 week interval may be needed to control severe cases. Fungicides are not very effective once the symptoms of large patch appear. Curative applications will help to reduce further spread of the disease, but the affected turf will be very slow to recover.

Click here for more information about Large Patch, including images and specific control recommendations.

Severe Large Patch Outbreaks in NC

You know it's officially spring in North Carolina when there are giant patches of brown grass in bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass. These giant patches of brown grass are better known as large patch, caused by the fungus Rhizoctonia solani, and if you've ever had an outbreak of this disease, you now know why the disease was coined large patch.

What you may not know however, is what your control options are this time of year. You shouldn't worry too much if you have this disease on bermudagrass. Bermudagrass tends to grow out of the damage once the temperatures are consistently warmer and the daylight longer.

As for our other warm-season friends, damage tends to be most severe on centipedegrass and recovery may take all summer in extreme cases. Unfortunately, there isn't much you can do to make for a magical recovery. We rarely recommend fungicides for large patch in the spring of the year, however in worst case scenarios, a fungicide application might help prevent the disease from spreading further. Fungicide applications are best when they are applied preventatively in the fall. If you choose to spray a fungicide this spring, don't expect a miracle to happen overnight. Also, remember that recovery will be even slower and tougher if you've applied a DNA type of herbicide as your pre-emerge for summer weeds.

In most cases, the best thing is to stay the course with management practices that will encourage each type of grass to do well. In severe cases, treating damaged areas like a new establishment with light and frequent fertilizer and water inputs may help encourage faster lateral spread. This doesn't mean you should apply more fertilizer, just smaller doses more often. Applying too much fertilizer will make the disease worse this fall!

Finally, be sure to map the affected areas now while they are clearly visible. You will save yourself some money this fall by spot treating these areas instead of having to make a whole property application, since the disease tends to reappear in the same areas.

For more information about large patch, click here.

For more information about warm-season grass maintenance, click here.

It’s Almost Time to Prevent Large Patch!

With soil temperatures starting to approach 70°F across portions of NC, now is the time to start thinking about treating for large patch.

Average Daily Soil Temperature on 9/14/11 from the NC State Climate Office

Large patch, which is caused by the fungus Rhizoctonia solani, is a common disease of centipedegrass, St. Augustinegrass, zoysiagrass, and bermudagrass grown for lawns, landscapes, golf turf, and athletic fields. Centipedegrass and St. Augustinegrass are particularly susceptible to this disease.

Symptoms of large patch appear in roughly circular patches from 2 feet up to 10 feet or more in diameter. The affected turf will initially be orange, yellow, or reddish-brown in color but will then turn tan and collapse to the ground. The disease can spread rapidly to encompass large areas of turf, and distinct circular patches may not be obvious in these cases.

Fungicides are available for large patch control, but they must be applied preventatively for best results. The first application should be made in the late summer or early fall when average daily soil temperatures are 70°F or below. Depending on your location and weather patterns, this can be anywhere from late August to late September.

One fungicide application will control minor cases of large patch, but two to three applications on a 4 to 6 week interval may be needed to control severe cases. Fungicides are not very effective once the symptoms of large patch appear. Curative applications will help to reduce further spread of the disease, but the affected turf will be very slow to recover.

Click here for more information about Large Patch, including images and specific control recommendations.

Spring rings on MiniVerde greens

We don't have a whole lot of MiniVerde in North Carolina yet, but we've had several reports of widespread rings appearing on MiniVerde greens as they are greening up this spring. Interestingly, we haven't had similar reports from superintendents with Champion or Tifeagle greens.

The rings on MiniVerde are typically about 1 foot in diameter and are very irregular in shape, not perfectly circular. The turf on the outer edge has a yellow or reddish-brown cast to it.

Any time we see this type of spring symptom on warm-season grasses, we automatically think that it is large patch caused by Rhizoctonia solani. Based on our initial look at samples, it is definitely a Rhizoctonia disease, but we are isolating to confirm exactly which species is the culprit.

Either way, recovery should be very quick once sunlight and warm temperatures come and the bermudagrass starts growing aggressively. In fact, two superintendents reported that the symptoms have already become less noticeable as the bermudagrass continued to green up.

A fungicide application probably isn't necessary, but could help to speed up the recovery process if the symptoms are very severe or widespread. Any systemic Rhizoctonia fungicide, such as azoxystrobin, flutolanil, or fluoxastrobin should provide good control. Check out the Disease Management Utility for a complete list of products labeled for large patch control.