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Author Topic: Tree Dieback??  (Read 648 times)

CarolinaCitrus

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Tree Dieback??
« on: June 01, 2019, 10:00:42 AM »
Hey guys, I currently have a Moro Blood orange and Cara Cara in 15g pots, Have had both trees for a year and a half. This year I have been having alot of twig and branch dieback on these two trees, Also some leaf drop...Any thoughts on what it could be??











Bomand

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Re: Tree Dieback??
« Reply #1 on: June 01, 2019, 12:12:47 PM »
Nutrient deficiencies is what I think. What are you using for soil. What and when are you fertilizing with? Could be a lot of reasons. Too much water will make leaves turn yellow and drop. Tell me details and I can make an educated guess at the problem.

Laaz

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Re: Tree Dieback??
« Reply #2 on: June 01, 2019, 12:19:16 PM »
Check the soil, could be root rot from the soil in the bottom of the container being saturated.

brian

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Re: Tree Dieback??
« Reply #3 on: June 01, 2019, 12:26:24 PM »
Usually when I've had twig dieback it was due to unchecked scale infestations

matt_citrus

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Re: Tree Dieback??
« Reply #4 on: June 01, 2019, 12:29:30 PM »
Brian, how were you able to defeat the scale?

brian

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Re: Tree Dieback??
« Reply #5 on: June 01, 2019, 02:45:47 PM »
I fought scale unsuccessfully for years using smothering sprays, but a strong application of systemic pesticide imidacloprid seems to have eradicated it.

CarolinaCitrus

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Re: Tree Dieback??
« Reply #6 on: June 01, 2019, 02:48:38 PM »
I foliar feed 4 times a year, fertilize every 2 months with 8-2-10 slow release, And these were planted in miracle grow cactus/citrus soil.The leaves that fell off were all still green...I had scale on my mango tree next to it but took control of them insecticidal soap, and pulling them off one by one, but havent noticed any on the citrus trees...
« Last Edit: June 01, 2019, 02:51:23 PM by CarolinaCitrus »

Bomand

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Re: Tree Dieback??
« Reply #7 on: June 01, 2019, 05:18:46 PM »
I am venture that you have a saturated soil problem...and I surmise that is from too much water. I would dig and look at the bottom of my roots to see if they are good healthy growing roots. If that is not the case I would probably wash, root prune and repot with new soil. I dont know where you got the trees from but I would doubt that you have anything else that is drastic going on. I use a good draining soil mix and I water until water runs from the weep holes. Water slowly.

Laaz

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Re: Tree Dieback??
« Reply #8 on: June 01, 2019, 05:19:50 PM »
Just a heads up, but cactus/citrus soil is not very good. Try replanting in their garden soil with turface MVP added in for better drainage. Also I use Osmocote & a bit of STEM from time to time. Again, I would check the soil at the bottom of the container.

Millet

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Re: Tree Dieback??
« Reply #9 on: June 01, 2019, 05:24:51 PM »
Looking at your pictures, I don't see any scale, or bugs of any kind.  I also don't see the symptoms of a nutrient deficiency.  Therefore, the problem must be inside the container.  Citrus and cactus soil is not the best medium to grow a citrus in, despite the name of the product.  If your tree has been in that soil for a year and a half, I believe that the medium has compacted to the point that the roots are starting to be oxygen deprived.   The addition of turface or fir bark chips to such a mix would lighten the medium and would correct this.   I totally agree with Laaz, that a medium either of turface mixed with Miracle Grow Garden Soil (MGGS) would be a much better medium to grow your tree in, or the traditional 5-1-1- mix. One word of caution: not all MGGS is the same in all sections of the country.  Examine the MGGS to insure that it contains a lot of wood chips before you purchase it. Whatever, you need to slip the tree out of the container and examine the trees root structure.   See how much water if being retained and the porosity of the medium.
« Last Edit: June 01, 2019, 05:33:37 PM by Millet »

CarolinaCitrus

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Re: Tree Dieback??
« Reply #10 on: June 01, 2019, 08:18:39 PM »
Thanks for all the replys everyone , appreciate it...Im goin to examine the roots tomorrow to check for root rot, and plant repot in a new Medium... If i can find turface , would Chicken grit work? I have used it in my mango tree pot, to make "Als Gritty mix" and it drains very well..Also how about extra perlite?

Bomand

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Re: Tree Dieback??
« Reply #11 on: June 01, 2019, 08:36:32 PM »
Here is what I use:
70% Expert garden soil...get it at Walmart
15% sharp sand...Home Depot (builders sand)
15% light weight agate....fired clay..a lightweight, porous filler.
This works for me.

tve

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Re: Tree Dieback??
« Reply #12 on: June 01, 2019, 09:10:01 PM »
I have some trees that tend to have similar problems, with leaves dropping, twigs dying back, etc. After lots of head scratching my conclusion is that it's most likely due to temperature issues ("Winter Leaf Drop"), such as warm air in the greenhouse with cold roots in the pot, excessive day/night temp variations in the GH, cold air close to the greenhouse wall, etc. Not saying this is your problem or that I diagnosed mine correctly, but something to consider...

Bomand

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Re: Tree Dieback??
« Reply #13 on: June 02, 2019, 02:51:48 AM »
https://arcosalightweight.com I am lucky in that the huge production facility is close to me. They load railcars with this and I am able toload a pickup truck with the spillage with their blessing.
« Last Edit: June 02, 2019, 03:10:49 AM by Bomand »

lebmung

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Re: Tree Dieback??
« Reply #14 on: June 03, 2019, 03:33:37 AM »
Looking at the trunk diameter I could say the pot is a little big for the size of the tree.
If during the winter you had a a root rot, probably coming from the rain splash from the soil near, then the tree need time to recover.
You use a very low P fertiliser. With that it will not grow any strong roots.  I would suggest for a month to use a high 13-40-13. Especially a solubile one.

Millet

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Re: Tree Dieback??
« Reply #15 on: June 03, 2019, 02:59:28 PM »
Citrus absorb nutrients in a 5-1-3 ratio, they do not require a lot of phosphorous.

raggashack

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Re: Tree Dieback??
« Reply #16 on: June 03, 2019, 03:36:53 PM »
i hv read an article by a german doctor stating that citrus historically learned to get along with very low P ratios, but they tend to have iron deficiency when having too much P.

if u have to overwinter them inside i can recommend a mix of 1/3 peat, 1/3 pine park and 1/3 perlite. since i read millets post to use this kind of mix (he did not say perlite, but some sand or equal stuff) my plants are doing fantastic. i can also recommend terracotta pots, if the weight isnt a problem for u.

when i experienced leaf drop, it was for 2 reasons. either the soil stood wet for too long (not a problem with millets mix anymore) or the temperature in the room was too high for the light we get in the winter.
« Last Edit: June 03, 2019, 03:38:47 PM by raggashack »

lebmung

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Re: Tree Dieback??
« Reply #17 on: June 03, 2019, 05:44:25 PM »
Citrus absorb nutrients in a 5-1-3 ratio, they do not require a lot of phosphorous.

Yes you are very right. However if the roots are damaged by root rot, after cleaning the roots or changing the soil I apply a high P so that it starts to grow roots fast again. A low P even in pots would take a long time to grow new roots.
Even for seedlings I apply a high P to promote fast growing roots, once they are strong enough to repot I stop using it.

Quote
i hv read an article by a german doctor stating that citrus historically learned to get along with very low P ratios, but they tend to have iron deficiency when having too much P.

That would not be a problem with soluble iron available over pH 7. Anyway in pots P washes away fast.

Millet

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Re: Tree Dieback??
« Reply #18 on: June 03, 2019, 09:28:12 PM »
Lebmung, how do you actually know that phosphorous washes away fast.  Do you have the knowledge and equipment to analyze the removal of phosphorous from the medium.  I do not think that phosphorous is easily removed, at least not rapidly.  Citrus roots seem to grow fast enough with a 5-1-3 fertilization.  However, it your trees and you can certainly grow them as you wish.

Vlad

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Re: Tree Dieback??
« Reply #19 on: June 03, 2019, 10:24:05 PM »
Lebmung, do you have evidence that a 13-40-13 fertilizer promotes root growth better than a 5-1-3 fertilizer?

lebmung

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Re: Tree Dieback??
« Reply #20 on: June 04, 2019, 04:37:34 AM »
Not laboratory evidence, only my own visual experience.
Yes indeed P doesn't wash away fast in some forms.
What I use is soluble mixture that can wash away
fast with rain. My example is only in case of root rot, not a normal fertiliser regimen.
500ppm P weekly promotes better root growth for a month in case of root rot with minimum root temperature 15 C.

Ilya11

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Re: Tree Dieback??
« Reply #21 on: June 04, 2019, 08:34:52 AM »
Citrus plants do not need much phosphorus because they get it through symbiosis with mycorisal fungi.
 Excess of phosphorus disrupts this interaction  that also affects other aspects of citrus growth.
Best regards,
                       Ilya

lebmung

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Re: Tree Dieback??
« Reply #22 on: June 04, 2019, 09:40:19 AM »
Citrus plants do not need much phosphorus because they get it through symbiosis with mycorisal fungi.
 Excess of phosphorus disrupts this interaction  that also affects other aspects of citrus growth.

If someone adds mycorrhizal fungi to the pots, yes. Peat based potting mix doesn't have so much if at all, they have some sterilization in factory.
The question here was what to do with the trees, I just gave a potential solution to the problem. I would also spray the plants with phosphonic acid.

Ilya11

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Re: Tree Dieback??
« Reply #23 on: June 04, 2019, 10:36:21 AM »
Ectomycorrhizal association is always there, 5:1:3  ratios were deduced for poted plants in groundless substrat.
Actually, I am challenging  your experience. At least theoretically its possible that higher phosphate suppress pathogenic fungi, that probably use the same means as mycorrhizal ones to penetrate roots. Just this is probably depends on exact nature of substrate, the time for phosphate washing out and should be done case by case with a possibility of negative effect.
« Last Edit: June 04, 2019, 11:08:14 AM by Ilya11 »
Best regards,
                       Ilya

Millet

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Re: Tree Dieback??
« Reply #24 on: June 04, 2019, 11:09:05 AM »
All hearty citrus trees already have mycorrhizae, otherwise they would not be healthy.  It is believed that it would not  be possible for a tree to take up phosphorous regardless of how much fertilizer you used without mycorrhizae.  Mycorrhizae is ubiquitous, their spores are in the air everywhere. For long term plants like citrus, even if you planted sterilized seed in sterilized ground, as long as the plant was grown in open air, it would become reinfected with mycorrhizae within weeks. (taken from notes by Dr. Manners)
« Last Edit: June 04, 2019, 11:26:31 AM by Millet »

lebmung

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Re: Tree Dieback??
« Reply #25 on: June 04, 2019, 11:34:10 AM »
I really don't have any doubt about mycorrhizae and agree with you.
I am just relating from my experience. For root rot I apply phosphonic acid both drench and foliar spray then after a week high P fertiliser at 500ppm weekly for a month.

 

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