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ExperimentalGrower

Beccariophoenix alfredii leaf spotting

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ExperimentalGrower

Hi all, happy thanksgiving (to my Americans). In the last several days I’ve noticed this spotting appearing on my young alphie seedling (large five gallon planted out last spring). This isn’t frost damage, we haven’t been close. This is a middle aged leaf, not old, but not new. I believe this leaf flushed out only maybe 9 months ago. It gets no overhead watering beyond rain, and is well fertilized with Palm Gain, last time being a couple months ago. The only environmental changes would be cooler temps and recent rain after a long period of dry. Also, I removed a small bromeliad a couple feet away but didn’t disturb much from what I could tell. Any thoughts on what the problem is and if it requires resolution?

Thanks!

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GottmitAlex

Is this presenting itself in all the leaves?  

Soil conditions?

 

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D. Morrowii

Do the uneven light colored lines across the the short side of the leaflets indicate anything? 

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PalmsandLiszt

This might be relevant: https://idtools.org/id/palms/symptoms/factsheet.php?name=Leaf+Spots+and+Leaf+Blights

If it's a nutrient deficiency, the older fronds will be affected first/worst. If it's a pathogen, there'll likely be no rhyme or reason to which are affected. Also, if it came on very rapidly after recent rain, that sounds very pathogen-y.

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ExperimentalGrower
6 hours ago, GottmitAlex said:

Is this presenting itself in all the leaves?  

Soil conditions?

 

Not all leaves. Generally absent from new leaves, progressively more apparent as the leaves get older. 
 

Soil conditions are good from what I can tell. I heavily amended the bed down to around 1.5-2ft with organics and small lava pebbles. Heavy clay beneath that.

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ExperimentalGrower
5 hours ago, D. Morrowii said:

Do the uneven light colored lines across the the short side of the leaflets indicate anything? 

Those uneven perpendicular lines across the leaflets are a typical feature of this species.

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ExperimentalGrower
3 hours ago, PalmsandLiszt said:

This might be relevant: https://idtools.org/id/palms/symptoms/factsheet.php?name=Leaf+Spots+and+Leaf+Blights

If it's a nutrient deficiency, the older fronds will be affected first/worst. If it's a pathogen, there'll likely be no rhyme or reason to which are affected. Also, if it came on very rapidly after recent rain, that sounds very pathogen-y.

Yes it was perfectly fine until this stretch of somewhat wet and cool weather.

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ExperimentalGrower
3 hours ago, PalmsandLiszt said:

This might be relevant: https://idtools.org/id/palms/symptoms/factsheet.php?name=Leaf+Spots+and+Leaf+Blights

If it's a nutrient deficiency, the older fronds will be affected first/worst. If it's a pathogen, there'll likely be no rhyme or reason to which are affected. Also, if it came on very rapidly after recent rain, that sounds very pathogen-y.

This is helpful, but I wish it indicated how to treat for pathogens causing the issue because it seems like that’s what’s going on.

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PalmsandLiszt
2 minutes ago, ExperimentalGrower said:

This is helpful, but I wish it indicated how to treat for pathogens causing the issue because it seems like that’s what’s going on.

They are mostly fungi, so some sort of systemic fungicide might help. However, I can't find a photograph that exactly resembles your spots, so there could be another cause. But if it were my palm, I'd probably investigate fungicides if I were satisfied that soil/nutrients/water were all as they should be. If you have a microscope, snip off a section of the worst affected leaf and have a look at it at high magnification; a fungus wants to reproduce and will produce spores at some point. If I were satisfied that it was fungal, I'd remove the affected leaves to slow the spread.

I could be wrong, however, and someone might turn up saying 'this is a classic case of di-trition deficiency!'/something else I've never heard of, so not laying down the law, only telling you what I'd do.

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sonoranfans
9 hours ago, ExperimentalGrower said:

Not all leaves. Generally absent from new leaves, progressively more apparent as the leaves get older. 
 

Soil conditions are good from what I can tell. I heavily amended the bed down to around 1.5-2ft with organics and small lava pebbles. Heavy clay beneath that.

Never seen this in any of mine in 11 years.  I see mild potassium deficiencies on older leaves, but my palms carry ~20 leaves so only on the bottom.   What is your drainage like?  Do you irrigate the palm regularly on a timer?  My suspicion is that this palm is suffering wet roots in the cool season.  Wet roots may lead to pathogen attack this time of year.  I will say I never heavily ammended mine with organics, its not necessary and probably suboptimal for the species.  Alfredii evolved on low nutrient, minimal organic matter rivertine soils on madagascar with wet summers and dry winters.  Like bismarckia which evolved nearby at slightly higher elevation, Alfredii are not sensitive to nutrient deficiency and are drought resistant, they are not jungle palms.  Many drought resistant palms also hate wet roots in the cool weather( W. Filifera, phoenix sp, bismarckia etc).  The heavy clay part of your soil may make the palm even more sensitive to an especially wet cool season.  Out west, sloped ground might help prevent this susceptibility to continually wet roots by runoff, but flat ground with heavy clay does not sound good.   My only advice a this time is that if you are still watering stop for 2-3 weeks at least.  Once the soil has dried, I would do a humic acid drench with a soil penetrant/surfactant like SDS to try to reset oxygen/C02 balance in the soil.  The palm may pull through with a minor setback in growth if its a cool/wet problem.   

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sonoranfans

Here is a read about wet soils and low oxygen.  https://extensionpublications.unl.edu/assets/html/g1904/build/g1904.htm#target2

Exerpt: Oxygen Content and Microbial Activities Under Wet Soil Conditions

"Maintaining adequate oxygen in the crop root zone is critical for healthy crop growth and yield. Plant roots need oxygen. When soil is too wet or waterlogged, the oxygen content is reduced and minimal oxygen is absorbed by the plant roots. With excess water, plant beds may behave like sponges in a bowl of water, holding in water and excluding oxygen. When oxygen is limited, microorganisms compete with plant roots for available oxygen. Also, since the oxygen is limited, microorganisms may turn to pathways of metabolism that can affect the availability and uptake of certain plant nutrients.

One of the most common symptoms of limited oxygen content in wet conditions is the yellowing and dying (leaf chlorosis and necrosis) of lower leaves on the plant. Some researchers have attributed this to the upward movement of toxic substances from the dying roots. However, other researchers have concluded that leaf chlorosis results from a lack of some essential substance in very wet conditions. One of these substances is cytokinin, which is ordinarily synthesized in the roots and translocated to the upper portions of the plants. These nutrients are mobile elements that can be translocated from older to newer leaves if their supply from the soil becomes limited and the young leaves become deficient. Translocation depletes the older leaves of essential nutrients, leading to chlorosis and necrosis. Diagnosing nutrient deficiencies can be difficult because other problems can cause similar symptoms.

Wet soils are usually unfavorable for most beneficial bacteria because when pore spaces fill with water, soil aeration reduces. In general, for row crops, including corn and soybeans, wet conditions and/or free water must be present in the field from 24 to 48 hours or more (depending on the degree of soil wetness, temperature, and organic matter content) before the oxygen levels in the soil are reduced to levels detrimental to plant growth. The amount of time it takes depends on the depth to water table, soil type, the fraction of the soil volume occupied by air, the initial oxygen content of the soil air, the rate of oxygen consumption from the soil structure, the rate of drying, and soil temperature.

In a warm soil with high organic matter content (i.e., more than 3.0 percent), the organic matter may decompose more easily and the rate that oxygen is used may be so rapid that the reserve oxygen supply is exhausted in a short time. If the soil drains within 24 hours, the plants usually recover with little or no obvious injury, although it is reported that only 24 hours of flooding can reduce the yield of some crops.

The rate of oxygen use in soil containing actively growing plants is 3 to 6 pounds per acre per hour. Researchers have found that oxygen levels of less than 10 percent in the soil atmosphere may inhibit plant growth. It is reported that corn and soybeans can tolerate up to 20 percent soil carbon dioxide concentration. Under well-managed soils, the carbon dioxide concentration rarely exceeds 5 percent to 10 percent. Researchers also have found that root growth is more likely to be limited by a low concentration of oxygen than by a high concentration of carbon dioxide.

Most arable soils, in the absence of a growing crop, accumulate nitrate nitrogen, sometimes as much as 100 lb/ac. This nitrogen may be removed from the soil by leaching when excess water is present. However, nitrogen also may be lost from the soil by the process of bacterial denitrification. This occurs when the supply of oxygen in the soil becomes inadequate for microbial activities. In this case, the nitrate nitrogen is converted to gaseous nitrogen, which in turn escapes from the soil to the atmosphere."

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thallo

I think we decided in another thread that our Beccariophoenix are from the same “litter”. I purchased mine from Flora Grubb 8/30/2020 and planted in Nov 2020.
 

I’m in San Francisco and my palm has similar spots but only on older leaves. The new leaves are spot-free (see photos below … first is a lower leaf that’s been on the palm since purchase and the second is a new leaf that grew since being planted). My palm is planted on a mound inside a retaining wall. The drainage is excellent. It’s been on drip irrigation since April 2021. It receives full southern sun from early morning until late afternoon.  I fertilized very lightly with PalmGain in July and again in September

I noticed the spots *before* our recent atmospheric river that dumped 5 inches of much-needed rain on my garden. We had a foggy summer so I haven’t ruled out fungal infection completely, but I think it may just be the palm adjusting to the site while it’s putting energy into the root system. I’ve also noted that the petioles on new leaves grown since planting are spotted purple (older leaf petioles are solid green)

 


 


 

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Tyrone

I think it’s bacterial leaf spot caused by cool damp conditions that are below the optimal temp range of the palm. Too wet soil will show yellowing of older leaves first, and in bad cases a rapid transition to dead leaves starting with the oldest leaves first again maybe leaving the spear green. That’s how B alfredii reacts too it as I’ve had an extremely wet winter and I’ve lost a couple of my alfredii’s exactly this way. Others got damaged but are recovering. I’m establishing better drainage on the property and all new plantings will be in raised areas away from potential floodwater levels. Some of mine sat in wet soil for months.

In regards to bacterial leaf spot, there is nothing you can do about it once it shows. It’s all preventative with bacterial leaf spot. In cool damp weather in winter I will get some leaf spot with alfredii just like someone else has posted. I’ve found that fungicides with copper in them can help stop this. But bacteria can affect cells in the leaf that are a bit soft and have thin cell walls. If you can feed the palm up on good fertiliser that doesn’t just create a burst of green growth (like high nitrogen will) but also has good amounts of potassium and calcium in it, the cell structure will be stronger and bacteria will have more trouble invading during cool wet periods. Also as the palm ages it will harden up and get used to your conditions but a good nutrition program is the best medicine. 

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rprimbs

I have a layer of clay under my decomposed granite.  It has proven fatal to my Encrphalartos,  but my palms spot like yours -- and then grow out of it.

My unexpert opinion is that you don't have to worry.  It probably won't hurt the palm, but there will be periods -- like when it is wet -- when the palm will show spots.

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rprimbs

If your soil is like mine you will only be able to grow Encephalartos in the locations with the best drainage, but Cycas will do just fine.

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ExperimentalGrower
3 hours ago, rprimbs said:

If your soil is like mine you will only be able to grow Encephalartos in the locations with the best drainage, but Cycas will do just fine.

 

3 hours ago, rprimbs said:

I have a layer of clay under my decomposed granite.  It has proven fatal to my Encrphalartos,  but my palms spot like yours -- and then grow out of it.

My unexpert opinion is that you don't have to worry.  It probably won't hurt the palm, but there will be periods -- like when it is wet -- when the palm will show spots.

Good to know, thanks! That might be it, it doesn’t seem serious at this point… yet. I’ll be keeping an eye on it. 
 

That sucks to hear about your Encephalartos and the clay. I just put E. cerinus and E. caffer in the ground but after planting them was concerned I didn’t amend the soil enough. Hmmm. How easy are Encephalartos usually to transplant?

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rprimbs
On 11/25/2021 at 4:26 PM, ExperimentalGrower said:

 

Good to know, thanks! That might be it, it doesn’t seem serious at this point… yet. I’ll be keeping an eye on it. 
 

That sucks to hear about your Encephalartos and the clay. I just put E. cerinus and E. caffer in the ground but after planting them was concerned I didn’t amend the soil enough. Hmmm. How easy are Encephalartos usually to transplant?

I don't know if amending would work if they put down deeper roots.  Some people just grow them in pots -- and even sink pots into the ground.

I haven't had any experience with E. cerinus, or E. caffer.  Some like E. paucidentatus, and E. heenanii are difficult to transplant.

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