Citrus Greening disease sounds like another product of mono cropping. Next will be the grapes or even worse a replay of what happened to the bananas with Panama disease. Diversity is not only important in small gardens but for mass agriculture as well. When will we all see that our food system is not working and is causing more problems than solving hunger. Thanks dyzzypyxxy for bringing CGD to our attention it will definitely be worth paying attention to.
Max as far as your plant goes, besides PH it could also be from unfinished compost in the planting hole or a mild case of nitrogen toxicity. Both of these things can cause leaf curling and burnt tips with yellowing on new growth. Whatever is going on it's a good thing you noticed it calling for help. Good luck and keep us updated.
