By Andy Sherrod, Orchard Manager
This has been an unusually wet spring in Texas, but the pecan trees here at Royalty Pecan Farms are looking healthy and happy.
Can Pecan Trees Get Too Much Water?
As I draft this blog post, the Brazos River just a mile from my office is predicted to crest eight feet above flood stage. Meanwhile California is drying up like the prunes the state is famous for. On the flip side, just four years ago Texas experienced its worst drought in decades while Californians battled mudslides.
Water is crucial for all life, but is it possible to have too much water? Early in my career, an old timer gave me his opinion about that. He said, “Son, too much water on a pecan tree is just enough.”
If you are growing pecan trees in a particularly wet or humid environment, you should take steps to protect your trees from a disease called Pecan Scab that is always present in humid climates. Here’s what you need to know about it:
• Pecan Scab can be suppressed but not cured.
Once your trees have it, they have it, so it’s best to take steps to prevent Pecan Scab from ever happening. The spores are always present in humid climates. Once lesions form on the leaves and shucks, reversal is impossible, so control measures are strictly preventative. Too many growers make the mistake that if they don’t see the symptoms, they don’t need to spray. Adopt the philosophy that if you don’t see the symptoms, good! Keep spraying.
• Scab can grow even when it hasn’t rained.
There’s a misconception that Scab development is associated only with rain events. The fact is Scab spores can germinate and grow when the temperature is above 70 degrees AND the relative humidity is above 90% (or thereabouts). In our central Texas orchard, that happens almost every night from midnight to 6:00 AM all summer long, every summer.
• There are no Scab resistant pecan varieties.
Wichita is highly susceptible to Scab. That’s why it’s grown almost exclusively in the arid west. Choctaw, on the other hand, is extremely tolerant to Scab. As yet, there has never been a totally Scab resistant variety developed but really smart people are working on that. The point here is that, in humid climates, no cultivar is completely safe from the damaging effects of Pecan Scab, so steps must be taken to suppress it.
• You reap what you sow.
We are reaping the benefits of our hard work with healthy trees that remain Scab-free despite all the recent rain. But pecan growers who have not taken steps to control Scab during the dry years are paying the price during this wet season.