Hi. We had 15 ligustrums planted a few years ago. They seemed to be doing fine until this summer when the leaves started turning brown. I assumed it was due to the drought so I watered them a lot. Recently, we have also had a ton of rain, so I don't think it's due to lack of water. It is worse on one end and gradually gets better, but all the plants have some brown leaves. Attached are some pictures. Thanks for any advice!
This seems to be fire blight, or Erwinia amylovora. Since this has no real cure, management will be the only way to keep it at bay. All that you can do is keep your tools clean, keep any debris cleaned up, and try some bactericides until you find something that is able to manage it.
https://www.gardeningknowhow.com/plant-problems/disease/fire-blight-remedies-and-symptoms.htm