April showers bring May plant diseases. Especially with the wet spring we’ve had, fungal diseases have started to show up in force. The calls to my office about oak trees alone are testament.
The reason for this is we are in the sweet spot of what pathologists call the “disease triangle.” When a susceptible host (such as a live oak) meets a potential pathogen (an oak blister) in a favorable environment (humid, mild spring) there is an excellent chance for disease.
I use trees as an example because they are a popular topic, but I could have easily used tomatoes or turf grasses. Unfortunately, often by the time we notice disease symptoms it is too late to act. Occasionally, we are blessed with the opportunity to intervene.
Many diseases are misdiagnosed and therefore mistreated. It’s hard to tell the difference between nutrient deficiency and an early disease symptom. But say you are on the ball and had your soil tested so you can rule out infertility. A reverse image search may point you towards a few different potential diseases. Is that yellow blotch on the leaf from a virus, bacteria, or fungus? To an untrained eye it is impossible to say.
On species outside of my specialty, I will not venture a guess without consulting a specialist because the diagnosis matters. County agents tend to be generalists because of the scope of the issues we handle. To choose an effective treatment, you must have a correct diagnosis. Applying a chemical based on a wrong diagnosis will not only cost money without solving the issue, it will most likely cause other problems down the road. The answer is always “know.”
So what do you do when you notice something is off in your garden, lawn, or in your trees? Seek out expert help. A certified arborist will be able to get to the bottom of why your trees are losing leaves out of season. Texas A&M has a team of plant pathologists who look up different diseases in their spare time. The AgriLife Extension center in Dallas has turf grass specialists who have seen it all. If you cannot find an expert on your own, your county agent can put you in contact — and that goes for more than agriculture or natural resources.
The right information from an expert can help you correct the problems you have now and prevent them from occurring in the future.
Marshall Tolleson is a county extension agent for the Texas A&M Agrilife Extension. The AgriLife office is located at 100 W. Houston St., Sherman. For more information, visit www.Grayson.AgriLife.org.