Lack if nut meat inside is an indication of problem with the tree from early August on. Lack of filling may be due to drought (not this year!), or diseases of the foliage or shucks on the pecans. There are also worms that feed inside the shuck that surrounds the pecan thereby preventing good filling. I suggest you take a sample to your County Extension Office and see if they can identify the problem and if necessary prescribe an appropriate remedy. They also have free spray schedules for pecan on hand to guide you should you choose to try and spray those trees.
Thanks for the question. Please stop in again soon!
Q&A Library Searching Tips