[Arid_gardener] Re:[Yellow Leaves, Citrus Trees

[Olin Miller]

My standard citrus trees did not exhibit an iron deficiency for the first
twenty years, then only the grapefruit tree became chlorotic - easily
remedied by applying sequesterene (KeRex).  But the dwarf varieties tend to
become chlorotic after only a few years - at least mine did.

Your problems may be due to your irrigation practices.  It isn't possible
from your description to determine how much water is being applied.   Water
requirements vary depending on type and condition of the soil and age or 
size of the tree.

The chart on page 3 of
http://cals.arizona.edu/pubs/crops/az1151.pdf
shows the recommended frequency for watering depending on the age of the
tree.  There are also several methods for calculating the quantity depending
on soil condition and the age of the tree.  But as a practical matter, the
usual recommendation is to water so it soaks to a depth of about 3' around
the edge of the canopy, then wait until it nearly dries out before watering
again.  You can use a narrow steel rod to check the depth of penetration

My mature trees are watered monthly in the winter and twice monthly in the
summer but  in the past two very hot summers, I watered theee times per 
month.

Olin Miller, Master Gardener Volunteer
U of A Cooperative Extension, Maricopa County AZ
============================================

----- Original Message ----- From: <pmcdonald15 at cox.net>
Sent: Sunday, February 17, 2008 10:00 AM
> Patrick McDonald,  85250
>...
> The leaves on my orange tree have turned mostly yellow.  They are not
> developing into large leaves and some are curling.  I water once a week
> with a finger size flow of water for about two or three hours, increasing
> to twice a week in the hot summer.  I have fertilized and added iron to
> the soil.  The soil around the tree was fine granite, but I have removed
> that and replaced it with composted mulch.  What more can I do?