established citrus yellowing
I searched the Citrus forum but most of the questions about yellowing were about potted plants or recent plantings. So here goes.
I have an established tangerine tree, bushy and about eight feet high by about six feet diameter, near some other healthy citrus in a sunny spot. Has been productive in the few years we've owned this house, and currently has a lot of young fruit growing on it. It gets dripline watered once or twice a month in hot weather, and an occasional shot of fish fertilizer or some all-purpose food (not enough or accurate feeding, I think, but I'm learning!).
Lately I've noticed that this tree has become....yellow. Especially compared to the other nearby citrus. It looks to otherwise be in okay health.
And, oddly, there is a 6" ring of missing bark right at the base of the trunk. I presume a critter gnawed that off, but don't really know.
I wonder if anyone can advise if this yellowing is a typical symptom of.....a nutritional deficiency?......a disease?.....hot weather stress? (cause we sure have that lately).