voyager

I'm getting ready to harvest the first bunch from this group.
I went out and began cutting the old dead leaves from the group today, and noticed this on only one plant in the group of 10.
All the others in this group look OK.




Anyone have an idea as to what is happening with this plant?
I had not noticed this happening with any of the previous leaves, and none of the dead leaves trimmed off looked to have this going on with them.

EDIT:
In case, it is not clear what I'm asking about.
From the upper side of the leaves, the RH edge of all three of the remaining leaves is curling up and there are some chlorotic areas on them. Plus, there are only 3 emerged leaves growing right now. I've yet to see another leaf begin to emerge.
The plant doesn't look to be very energetic.
Something is not right.

venturabananas

Looks like calcium/boron deficiency.

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voyager

OK, I think you might be right.
Some dolomite and borax should make a difference, then.

I was worried that it might be something much more serious, like a virus.
This I can deal with.

voyager

Hey, robguz, or anyone from the East side of BI, where can one find a cost effective source for dolomite and borax?
Today is Sunday, not a good day for checking around.

I need dolomite for my citrus trees and others as well as my bananas.
So, a 50 to a 100# bag wouldn't be out of the question.
I'm pretty sure a 50# bag of borax might be a bit overkill though, for my needs.

HD has dolomite in too small of quantities and no borax.
Could boric acid [ant & roach killer] be substituted?

venturabananas

Be real careful applying the borax. At most, a couple of level teaspoons (not tablespoons) per mat. Boron is toxic to plants at really low doses, but is also an essential micronutrient. A 1 pound box of laundry/cleaning borax will last you years unless you are growing hundreds of mats.

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Island Brah

Doesn't too much fertilizer make the leaves twist like that too?

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Growing: Basjoo, Blue Java (The Real One), FHIA-01 American Goldfinger, Manzano, Tall Orinoco, Raja Puri (USDA TARS), Veinte Cohol (USDA TARS), Patupi, & SH-3640 High Noon (USDA TARS)

venturabananas

Yes, but only because the macronutrients (e.g., nitrogen) get into the plant faster than the micronutrients (boron and calcium) that make strong "skeletons" in the leaves. So, technically I guess it's still boron/calcium deficiency in that the new tissues are deficient in one or both of those.

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voyager

These have been planted in a newly cleared and created growing area. The new "soil" is made from black cinder soil [a fine screened black cinder] and mulch that had composted for over a year. If anything, it might be a bit short on nutrients. One of the 10 plants placed here has grown very well. It is next to a compost bin that is undoubtedly feeding nutrients to it.

I picked up a bag of dolomite from the Farmers CoOp and have ordered some borax through Amazon. I have applied the dolomite and a high K, low P - PCU Zn type fertilizer. I will be adding more composted mulch in the very near future.
I've also moved my Dwarf Brazilians into a new area and am treating them the same.

I've read that borax can be used as an herbicide. I'm thinking of dissolving some in water, putting it into one of those garden hose spray attachment bottles and spraying the new growing area with it.

Where to find info on how to go about setting the dilution rate for applying the borax: concentration into the bottle, and dilution rate when applied with the hose?

robguz24

I just saw this thread. Sounds like your found some solutions. I get lime at BEI in Hilo and Borax from Amazon.

I have put hundreds of pounds, maybe actually a couple thousand of dolomite on my half acre in the past year or two. On the lot I've been farming for 8 years it doesn't need much, but on my my lot I've only farmed 2 years it needs more every 2-3 months or I get signs of calcium deficiency. Eventually it will make its way further down and get like my older lot. I'd think where you are you may even need more fertilizer and lime than I do, given you get about twice as much rain.

Be on the lookout for bunchy top! It's in lower Puna now and some of the initial signs can look a lot like boron/calcium deficiency, but also boron toxicity.

__________________
My micro-farm

Stay on my Big Island banana farm cottage

voyager

I checked BEI.
They were less expensive for the dolomite. But, with the minimum purchase I'd of had to spend much more than I needed to. The best buy for my needs was at the CoOp. Plus, I needed Tango to do more LFA treatments.

In looking around for info on boron and calcium deficiencies, I saw pics of calcium deficient leaves. People had been telling me that was normal for older banana leaves. Maybe it is because of widespread calcium deficiency in the area. Hopefully, the dolomite will decrease the necrotic spotting of the leaves.


EDIT:

How do you apply the borax to your bananas?

robguz24

I just mix a little bit in with all the dolomite and spread at the same time.

__________________
My micro-farm

Stay on my Big Island banana farm cottage

venturabananas

I'd be real careful using borax. The difference between helpful and toxic is not much. Personally, I wouldn't mess with using it as an herbicide -- that concentration must be in the toxic range.

I haven't applied borax with a spray attachment. I have applied Solubor (a similar product) as a foliar spray. If you do the math with the boron concentration difference between borax and Solubor, the following link might help you figure how much to apply.
http://www.compostwerks.com/images/S..._mix_rates.pdf

Personally, I just sprinkle a couple of level teaspoons of borax around each mat every 6 months. That's the easiest approach unless you have lots and lots of plants.

__________________

George Webster

Back when I was in college in California some Olive orchards were found to be short on boron. The solution was one pound borax per acre ever 10 years.

voyager

I have applied dolomite, #10 AG. It should react slower than the #65 AG, also available. But, I have applied it heavier than normal on top of a new layer of compost that I have also just applied, along with some 13-3-37 PCU-Zn applied at a more reasonable rate.
I am still waiting for the borax to get here.

The Solubor is a concentrated version of the borax, almost 2X the boron.
I want to drench the plants with a very dilute borax solution.
From the link to the pdf, I can figure how to mix the borax, thank you.
Then, using a borax solution in an applicator that add the solution to the garden hose stream at so many ounces per gallon should give me a good application rate.
I do still need to actually do the calculations.
But, that is trivial.
I'll do that after the borax arrives, and I'm ready to get it done.

robguz24

I imagine the rate would be much higher where we are. 100-200" of rain and nothing but porous rock or at most a few feet of soil above such rock.

__________________
My micro-farm

Stay on my Big Island banana farm cottage

voyager

@ robguz

The solubor pdf venturabananas linked to is for foliar application. That would be my preference as far as application methods for our high rainfall climate. The high precip leaches everything out of our thin soil very quickly, especially something as soluble as borax. I'd just need to get into a regular foiar boron feeding program.

voyager

OK, the borax has finally arrived.

I'll apply it per this:
Foliar Spraying of Micronutrients in Banana | agropedia

@1mg/liter to the entire plant: leaves, stems, and trunk.

Now to figure out how to get 1mg boron/liter of water out of the end of the hose.
The applicator can be set to meter from 1 tsp to 8oz per gallon.
It would probably be most accurate somewhere in the mid range, about 1 to 2 oz per gallon.

From other articles on foliar feeding, it would help to add a surfactant [soap] to give better contact on the leaf surfaces.

Check my numbers:

1mg/liter = 3.785 mg/gal
128oz/ gal

Borax = 11% Boron

Adding borax solution @ 1oz/gal = 3.785mg/oz solution
Adding borax solution @ 2oz/gal = 1.89mg/oz solution
[Dilution rate change at 1 or 2 oz/128 oz is negligable]

To mix a gallon of solution:

1oz/gal:

3.785mg/oz water = 485 mg /gal

[X grams Borax]/gal = 0.485g Boron/gal

4.5gram borax /gallon water = 495mg boron/gallon water

495mg boron/gal = 3.87mg/oz
-------------------------------------
2oz/gal =

cut solution concentration in 1/2 =

2.5grams Borax/gal = 0.242g Boron/gal

495mg/gal/2 = 3.87mg/oz/2

250mg/gal = 1.87mg/oz
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I didn't take my boots off while figuring this.
So, I had trouble after going past 10.
Check my numbers for me to make sure I'm not off in La-La Land.

If I'm right, my 2# bag of borax will last a very, very long time.