Too much water

ernie, it's zinc deficiency. It's caused by the lousy tap water in the valley. You can spray zinc on the leaves, but don't do it now- too hot.

Thank you. I need to research this. Odd that it would happen all of a sudden.
I wonder if it could be related to the chlorosis of the lemon tree that I have been battling for quite some time - with no improvement. They are near each other in the yard.
Tell me again why I do this gardening thing?

haha, I know. Gardening in the valley sometimes is more work than it's worth, I agree. Constantly battling micronutrient deficiencies like zinc, iron, etc. But then, who else besides southern AZ gets such lovely winters besides Florida and So. Cali? NO ONE !!

Az doesn't get lovely winters. Way too cold.

Looks like it needs iron. Same thing happened to my orange and pear tree. Started out looking good then bam!
Added iron granuals to buckets of water, let it sit and mix, poured it at the base of the trees. You can buy it in a liquid form(this is what I already had). Took care of the problem. Next year I am going to add the granuals to the soil in the spring.

Plants can only absorb iron in a soluble form and most iron granules won't provide this even if you dissolve them in water. Look for 'chelated' iron which is usually available in liquid from.

Here is a link that might be useful: Treating iron deficiency

Hi Cathy!