Cindy. Ask yourself a few questions:
1. Where was the Imprelis applied?
2. What plant organ was first to contact and remain in contact with the toxin?
3. If the roots were damaged, probably more than the canopy, will they be able to absorb nutrients or water as efficiently as non treated trees?
4. What is going to happen when the temperature rises and the trees need more water?
5. Why are we seeing so many "yellow or light green" tree and plant leaves on Imprelis treated property?
If the roots are injured, then they simply won't function normally. You are going to see nutrient deficiency problems, wilting, die back in the tree canopy etc.