Answer: It is possible to overdo, so hold off on further applications of B1. The yellowing leaves are just a symptom of stress, brought on by being transplanted. All you can do at this point is water your Pistache tree deeply once each week and wait patiently until it establishes its root system. Some of the dropped foliage will be replaced (that's when you'll know for sure that it is recovering). Next spring it will produce lots of healthy new foliage. Best wishes with your tree!
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