one is an orange tree. the other three are an avocado. they are about 20 feet apart. both trees are mature. they are at my new home where i have only been for a month so i don't know much history but think they are both around ten years old. they are planted on a hillside in Sunset zone 20-21.

Carl

to ATP

The orange plant in the first pic could have a nutrient issue. Are the symptoms primarily on the newest leaves or the oldest ones? Or, if it is all over, is it worse on the youngest or oldest?

The avocado problem looks like it is most likely a leaf spot disease, compare with these images:

https://www.google.ca/search?q...

The citrus looks like iron deficiency.
The avocado looks like Persea mites.

i will look at the orange tree tomorrow. i think the older leaves. it is just starting to leaf out for the season.
the avocado tree seems to have all the spots on the veins. if it is mites what is the best treatment?

http://www.crfg.org/pubs/ff/av... This may be of help. On the citrus trees, Iron deficiency usually does show in the mature leaves. This can be solved with Chelated Iron feeding. BUT the drought has prevented the bad stuff from leaching out of the root zone, so all of our plants are under stress. Deep watering can ,but the bottom line is WE NEED lots of rain.

Iron deficiency in plants typically appears on the youngest leaves first, which is why I asked which leaves the problem starts on. Where the symptoms start helps narrow down the nutrient involved, if it is a nutrient issue, because some nutrients can be moved around to where the plants need them and others can't. Symptoms on the youngest leaves first suggest a nutrient that can't be moved around, symptoms on the oldest leaves first indicates a mobile nutrient so the plant takes it from the older leaves to give to the younger growing ones. This article has some pictures of nutrient issues in citrus that may help:

https://edis.ifas.ufl.edu/ch14...

Do you have any idea what your soil pH is? That can also help narrow things down.

Brilliantly helpful article!

It is! Now I need to check my Citrus and Avocado food for these elements.