0
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Avocado tree leaves turing brown

Avocado    None Given

Hi

My 1 year old avocado tree's leave suddenly started turning brown about a month ago. At the same time all new growth stopped for two weeks. It has since grown new leaves that don't seem to be affected. The browning pattern seems to be quite distinctive.

It is in a large pot and was grown from seed. The mother plant in the garden does not show the same signs. Nothing really changed around the time that I can think caused it. There were a couple days I was away and didn't water, some leaved wilted but everything seemed to recover within an hour of watering.

Any suggestions on how I could fix this? Will it continue into the new growth or are those leaves somehow immune?

Thanks
John


Posted by: John Frost (1 point) John Frost
Posted: March 14, 2017


Amanda commented,
Where are you growing this plant? What is the climate like?
over 3 years ago.

Amanda commented,
The symptoms could also be related to phytophthora root rot - a common disease of avocado (http://ipm.ucanr.edu/PMG/r8100111.html). This disease thrives in moist soil conditions so I would make sure you soil has good drainage. Here are some IPM approaches from UC Riverside to caring for avocados with this disease: https://www.apsnet.org/publications/p...
over 3 years ago.



Answers

1
point
It is always difficult to define the nutrient deficiency or toxicity symptoms in plants because it depends on severity, stage of the plant and other conditions. But it could be magnesium deficiency as Andreas mentioned. The main symptoms are discoloration of older leaves, particularly between veins (but veins will remain bright dark colored). Under severe cases of magnesium deficiency necrosis of tissue interveinally and/or along leaf margins may occur.

There are several guides available online to diagnose the problem in avocado.
http://era.daf.qld.gov.au/1642/11/05-...
http://ucce.ucdavis.edu/files/datasto...
http://www.avocadosource.com/Journals...


Posted by: Dr. Ravishankar Narayana (11 points) Dr. Ravishankar Narayana
Posted: March 16, 2017


John Frost commented,
Thanks for the thorough help. If this is a magnesium deficiency what would be the best way to correct this? Organic options preferred.

Thanks
John

over 3 years ago.

Dr. Ravishankar Narayana commented,
Generally magnesium deficiency is common in acidic soil or soil with pH below 6.0. So it is advisable to test the soil to determine the nutrient content and pH. Soil testing kits are available online or in most of the garden stores. Normally Epsom salts are applied to the soil to supply magnesium or lime to increase the soil pH.
over 3 years ago.



0
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Where are you growing this plant? What is the climate like?


Posted by: Amanda (2 points) Amanda
Posted: March 15, 2017




0
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The patterning in between the veins looks like a nutrient deficiency to me. I would guess it's due to low levels of potassium because of the dark purple/brown color vs a yellowing color that other mineral deficiencies tend to give the leaves.


Posted by: Kelsee Baranowski (3 points) Kelsee Baranowski
Posted: March 15, 2017




0
points
Hey John, I would agree to Kelsee that the patterning between the veins is caused by nutrient deficiency. But you don´t look at potassium lack. This type of patterning is caused by ferric or magnesium lack. In case of ferric lack you would see the first damage on the young leafs. In case of magnesium lack you see the first damage on the older leafs. Because in your picture the young leafs look healthy, I would say you look at magnesium lack.


Posted by: Andreas (7 points) Andreas
Posted: March 16, 2017




0
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Thanks for the thorough help. If this is a magnesium deficiency what would be the best way to correct this? Organic options preferred.

Thanks
John


Posted by: John Frost (1 point) John Frost
Posted: March 19, 2017




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