Well it looks like ol' Jack Frost is slowly shedding his coat in favor of a pair of shades and t-shirts. Spring has been slow in coming, but with 80's on the horizon in the next couple of days it looks like everything is off to the races here. From a disease/stress perspective what does that mean to you in the Southeast? Well, for the warm-season grasses (like bermuda), we should be able to start seeing how bad the winter actually was by starting to see some greening up of the tissue.
Now is the time to start looking at the stolons and stems, to see if color is returning like you see in the image to the right. If the tissue seems dead and brown, it might be time to think about ordering up some sod and/or sprigs. Another disease issue that will start be the impact the winter had on the development of spring dead spot. In Tennessee, we haven't greened up enough yet to see the circular symptoms of the disease (see left image), but with the warm weather that is ahead, it is only a matter of time.
Finally, for those of you managing zoysiagrass, large patch (see image below), caused by Rhizoctonia, will begin to rear its ugly head again. This disease can also attack bermudagrass, but the damage is not usually severe enough to warrant fungicide application (see image far below- that's a large patch!) credit: Adam Nichols, Virginia Tech)
The question of how effective spring applications of fungicides are for large patch is a good one. I don't think we have enough data to conclusively answer the question. Hopefully, you made a few applications in the fall, as that is the best time to apply preventatively.However, if you have an outbreak of large patch that is actively growing, fungicide applications might be warranted to at least reduce the spread of the disease.
Our junior-year turfgrass students are setting off on their internships for the summer, so I will be posting much more frequently now that teaching is on hiatus for awhile. So I am off to start looking for large patch in my trials, but the difference is I get excited when I have a bunch of it, and it is uniformly distributed over my plots!
Stay tuned for the next couple of weeks as we look at what spring has for cool-season diseases/stresses next week, and the following week, what we need to start thinking about for summer (which will be here before we know it!).