Fw: [Arid_gardener] Question from Home-Hort WWW page
Dick Gross
rkgross3 at cox.net
Sun Mar 18 22:58:22 MST 2007
----- Original Message -----
From: Dick Gross
To: Sonya Christensen
Sent: Sunday, March 18, 2007 10:52 PM
Subject: Re: [Arid_gardener] Question from Home-Hort WWW page
I grew up in Nebraska where winters are bitter cold and winds are brutal.
I assume that your daughter lives in Arizona or a location in which citrus can survive. I have five of various variety and a recent rare frost severely damaged nearly everything in my yard except the Citrus most over 30 years old and still producing well.
I never calculate the amount of water nor the time of irrigation and never use automatic drip, etc.
I have a shallow trench a couple to three feet wide and no deeper than about an inch and a half. The middle of this shallow trench is approximately the drip line--a line in the center of the trench outlining the outer extremety, or reach, of the tree's foliage. This is the center of a band of feeder roots that can adsorb water and neutriants. I have never irrigated any other place around the tree and the basin is never wet unless it rains and you can imagine how seldom that can be in Arizona.
I put a hose end in the trench with a fast trickle just emough to fill the trench all the way round the tree a half to an inch deep and adjust the flow to maintain a level for as long as it takes to soak the root zone at least three feet deep all around the tree. I have made a soil probe from a 36 inch length of brass rod from the hardware store. File a dull point in one end and use a 5" piece of round stock (a shovel handle) to make a handle. When I can easily sink the probe down to the hilt all the way around the drip line, I shut the water off. Depending on your soil texture it can take anywhere from 8 to 15 hours but be patient. That is how deep I always go. This probe can be a dangerous weapon in the hands of a youngster playing Zorro. Treat it the same way as you do your 38 calliber pistol if you have one but this "weapon" doesn't need shells to be lethel.
I irrigate again only when the soil in the trench is quite dry at least 3 inches deep. It can run from weekly during the dead heat of summer to monthly or not at all during the cool months when soil temps are in the high 30s and 40s. If you pay attention to foliage you can usually tell from lack of luster or leaf droop when your tree is thirsty. I irrigate usually when the basin is qiute dry 3 inches below the surface in a shady spot.
I still can't picture these concrete barriers. A tree can only use water where it has feeder roots and shallow frequent watering and feeding would I'm qiute sure leave a tree in a weakened condition susceptable to disease. I think you will have to work around them and using the instructions above get the right amount of water where the tree can use it enen if it has to be irrigated in sections in shifts. If I've raised further questions, Sonya, don't hesitate to speak up.
Dick Gross, Master Gardener Volunteer
Maricopa County Cooperative Extension
----- Original Message -----
From: Sonya Christensen
To: Dick Gross
Sent: Saturday, March 17, 2007 8:55 AM
Subject: Re: [Arid_gardener] Question from Home-Hort WWW page
Thank you so much for your response about the orange trees with the peeling bark. I will check for the Texas root rot. The concrete things I believe were meant as bearms to contain water. Would it be helpful to move them to the drip line? Also I dowloaded the Uof Arizona publication on irrigating citrus tress and it semms fairly complicated. My daughter has a sprinkler (or emiter system) and each tree has one sprinkler. They put out varring amounts of water per hour. The person who comes to maintain and mow the grass had been watering for 15 minutes every 3 days year round which I know is not good. He show me how to manually overiride and I let the water run for 3 hours because I also fertilized the trees and it said to let it soal in deeply. How can one measure how much comes out in gallons per the publications chart with these fixed heads? Is there some rule of thumb about so many hours would be good and then adjust it for the month of the year-heat dryness etc? When I let it run for 3 hours, the soil was wet down at least 12 inches. Thanks for your help. I'm back in New YOrk where we just got 10 inches of snow and it's 20 degress outside.
----- Original Message ----
From: Dick Gross <rkgross3 at cox.net>
To: Leo A. Martin <leo at possi.org>
Cc: sonyac218 at yahoo.com
Sent: Friday, March 16, 2007 11:53:12 PM
Subject: Re: [Arid_gardener] Question from Home-Hort WWW page
I have five 20 to 30 year old citrus that that have no sign of root rot but show some sunburn that I could have easily prevented early on. The key to long life and good production is deep irrigation at the drip line only when the tree needs a drink fed with the proper amount of Nitrogen three times yearly. I sometimes use 16-20-0.
Roor rot compromises the vascular system and the first signs of the condition is unexplained leaf wilt in usually a few branches at the start.
To kill citrus in this climate, one almost has to work at it. Almost the only thing still living in my neighborhood after that recent devastating frost is the citrus just now exploding with blossom..
Dick Gross, Master Gardener Volunteer
Maricopa County Cooerative Extension
"Leo A. Martin" <leo at possi.org>
To: "Dick Gross" <rkgross3 at cox.net>
Cc: <sonyac218 at yahoo.com>
Sent: Friday, March 16, 2007 11:58 AM
Subject: Re: [Arid_gardener] Question from Home-Hort WWW page
> The two commonest causes of this are sunburn and infection with Texas root
> rot. This is a common fungus disease here in the desert that causes just
> this peeling and death of citrus.
>
> There is no cure for Texas root rot. Keeping the trees well-watered,
> mulched, and fertilized prolongs their life for some time. But the problem
> will never go away.
>
> Cut one of the branches back into live wood, including a portion with the
> damaged bark. You will see a discoloration in the light wood underneath if
> the problem is Texas root rot.
>
> The fungus is in the soil. If you plant another susceptible tree in the
> same spot it will get infected too. I don't have a list of susceptible
> trees at hand, but most fruit trees are susceptible.
>
> If the trees are still living, get to work. Water and fertilizer well, and
> keep the soil well-mulched to maintain cool roots. Give the trees a year
> or two to show some signs of recovery. If they don't respond, get rid of
> them.
>
> As to sumburn, the treatment is to keep the bark covered. In the future,
> don't prune citrus into tree form here. Let them carry branches down to
> the ground. This shades the trunk. The fruit from lower branches tastes
> better as well.
>
> Leo Martin
> Phoenix
>
>> Depending on their age and care, the problem is sunburn or age or some of
>> both.. Citrus, by nature, grows a skirt all the way to the ground all the
>> way around. Exposure of bark to direct sun is incidental as the sun moves
>> across the sky and any patch of bark is exposed for only brief windows,
>> Citrus bark cannot tolerate extended direct exposure. Home owners,
>> however,
>> prune branches high enough to park a semi beneath and all the bark exposed
>> is subject to sunburn. It is probably too late to save the two but you can
>> reserect weak branches that have some life left in them and you can paint
>> all exposed bark with white latex paint avaliable, I think. at any
>> nursery.
>> It will give 100 % protection against sun burn but an old, old tree might
>> be
>> struggling with something else and prior damage is here to stay..
>>
>> I will see if any other members of our Rare Fruit club have ideas.
>>
>> I have never seen concrete barriers as you describe them. Citrus roots are
>> fairly deep and the foundations of these barriers may not hinder
>> irrigation.
>> If you can water and feed in the drip zone where the feeder roots are
>> located, you might be able to work around them. Just pretend the barriers
>> are not there and that is okay unless they hinder the movement of water in
>> the root zone.
>>
>> Dick Gross, Master Gardener Volunteer
>> Maricopa County Cooperative Extension
>>
>> ----- Original Message -----
>> From: <sonyac218 at yahoo.com>
>> To: <arid_gardener at Ag.arizona.edu>
>> Sent: Thursday, March 15, 2007 2:59 PM
>> Subject: [Arid_gardener] Question from Home-Hort WWW page
>>
>>
>>> SONYA CHRISTENSEN
>>> 14621
>>> sonyac218 at yahoo.com
>>>
>>> My daughter has recently moved to Phoenix and I went out to try and help
>>> her with some gardening. She has 10 orange trees. Two of them have
>>> peeling bark and dying limbs. What is the cause and more importantly
>>> what
>>> is the solution. All the trees still have concrete barriers around them
>>> that were probably put in many years ago when they were planted. They
>>> are
>>> about 2 feet from the tree trunks. Should they be moved to the drip
>>> line?
>>> Thanks for your help.
>>>
>>>
>>> _______________________________________________
>>> Arid_gardener mailing list
>>> Arid_gardener at CALS.arizona.edu
>>> http://CALS.arizona.edu/mailman2/listinfo/arid_gardener
>>>
>>
>>
>>
>>
>
>
>
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