Stonefox

Thanks for the advice Richard.
Unfortunately the growmore in South Africa is not related to the USA products in any way, and only sell 3-1-5 ; 2-3-2; etc.
I found a SA supplier of Haifa products, but they are over 1000 km away from me. I will inquire if they have a distributor in my area.

Richard

Actually the owner and vice president of marketing of Grow More Inc. are colleagues of mine -- the latter I grew up with elementary through high school. They do have a sales presence in South Africa ... but I understand that a farm supplier that carries their products could be far from you.

But no worries -- I think you understand the kind of product I'm referring to: water-soluble fertilizer with major, minor, and micro nutrients. I also think you know that the numbers on the bag are percentages by weight -- so the higher the better because each dosage will be less. Of course the numbers on a bag will never add up over 100 because we're talking about percentages, and due to chemical properties of minerals they'll rarely add over 60%. Now specifically for bananas you'd like the N:P:K ratios at 4:1:6 -- for example 16-4-24 -- but you will probably not find it because (1) it is difficult to make and (2) in low demand. Now 20-10-20 is a popular formula available from many factories and reasonably close to the optimum. The Citrus growers in northern South Africa use it so perhaps you'll find it. Another formula that Grow More makes but sold only in pallet quantities of 10 kg bags is 16-8-24 "Fruit Fuel" -- sold to some pit fruit growers in central South Africa on an annual basis.

__________________
Back in business at plantsthatproduce.com

Stonefox

Richard
You know more about fertilizer suppliers in SA than I do!

If you can let me know the contact details of Grow More Inc in South Africa I will contact them.
They may be far but there is always a way. Retired like yourself, I have the time and resources to fuel my passion. I have waited years to have the time to grow Bananas, so I wont give up easily.

Richard

Not really! I just know they ship there.

__________________
Back in business at plantsthatproduce.com

Stonefox

So could someone check my maths, these fraction / ratio calculations can be tricky for me.

I can get from the local farmers co op:
N: urea (46-0-0)
P: mono-ammonium phosphates (MAP) (10-50-0)
K: Sulfate of potash (0-0-50-18S)

If I am aiming at Richards suggested ratio of 4-1-6 and mix:

8.2 kg urea = 3.8kg nitrogen

2 kg MAP = 0.2kg nitrogen and 1 kg phosphate

12 kg potash = 6kg potassium

total weight of mix = 20.2 kg

In 20.2 kg I have 4kg N: 5kg P: 6kg K
Which is a (19.8)-(4.9)-(30) ratio , which is very close to 20-5-30, which is in the desired 4-1-6 ratio.

Have I done this calculation correctly??

edwmax

Not bad, but you weight is off. It's 22.2 from your numbers. i calculate 22.48k, but this is rounding differences. NPk from the 'as blended' mix is 18-4.49-26.96 @ 22.48k

What this shows is the target wt. being less than the actual mix wt then the actual NPK is insufficient for target wt ... IF YOU were selling and guaranteeing the mix. But it is usable as is knowing the correct NPK ratio then weight quantity doesn't matter. The NPK ratio is the same for 5 lb or 50 k.

__________________

edwmax

Using Urea (869.6 lb), DAP (217.4 lb), KCL (1000 lb) ... The closest i can get is 20-4.8-28.8 for 2087 lb batch, assuming standard analysis values. This will vary for the materials you can obtain and their actual analysis.

To scale down to a 50 lb batch (or 22.7k) multiply by .025; (50/2000 lb).

__________________

Stonefox

Thanks for the help Edwmax!

Now I need to know how much to apply to each tree at a time, and how frequently to maximize growth and more importantly fruit production.
I assume also the size of the tree makes a difference, i.e. knee high or near fruiting height (which for my trees is usually about 4 meters)

edwmax

That's simple! See the forum wiki for more info about fertilizer.

Now a banana plant needs 1lb of nitrogen and 1 1/2 lb of potassium during the growing season. You decide how many times during the season to apply the fertilizer (monthly; bi-monthly; 3 or 4 time per season). However, the type fertilizer (slow release, quick release, or standard grade types) have some bearing to application timing.

Now I use 10-10-10 for vegetable gardens. It has all the minor elements needed and economical ($10 for 50 lb bag). Applied 4 Xs during the season. For Fertilizer amount: 1lb nitrogen / 10% (aka: 0.1) = 10 lbs fertilizer for the season per plant. The same 10 lbs also furnish 1 lb of potassium. Supplement additional 1/2 lb potassium needed with murate of potash or potassium sulfate. ... The application rate for the 10-10-10 is 10 lb / 4 applications = 2 1/2 lbs per plant per application. ... The extra phosphorous has not been detrimental to the plants.

This year i may try fertilizing on a monthly schedule at 1 1/2 lb 7 Xs for a 6 month growing season. This may reduce loss due to runoff & leaching.

Knowing the fertilizer grade (NPK) you can use any grade available and that is economical. ... But for your situation, blending your own mix may be the better option over buying the low grade 'hobby' fertilizers.

Check with your locale Co-Op for when they Blend or who Blends fertilizers for the local members. You might be able to get your years supply then ready mixed. The low grade 'hobby' mixes would be too labor intensive and expensive for large farm applications.

__________________

edwmax

The size of the plant would make a little difference if the plant is very young. Less than 3 ft tall i cut the fertilizer amount to 1/4th or 1/2 that for a mature plant as the roots are in a smaller area at the base and apply the fertilizer in a 2ft or 3ft circle. ... 3 1/2 or 4 ft tall plant i apply full dose. Apply fertilizer in a 10 ft circle around the plant. Not at just the base. Roots can extend up to 15 ft or 18 ft from the mature plants. This will help to keep heavy applications from burning the roots.

__________________

Stonefox

That is very useful, many thanks.

The local farm co op sells the NPK as I mentioned but they don't contain any micro nutrients, should I worry about them?
My soil is very beach sand in nature because my proximity to the sea.

I will inquire if they do any blends for local farmers.

bananimal

I just came back from Diamond R with a 50 lb bag of 6-3-16. Called the "Super Fruiter" it lasts for a full season with number of mats I currently run. This stuff is the best for naners.

Now if the friggin H-canes leave me alone I'll get a full season of fruit bunches. Fingers crossed.

edwmax

How much of that do you apply per nana plant during the season?

__________________

Akula

I purchased an 8-2-12 fertilizer with micros recently locally at $25/50#. It uses K2O which some people don't like due to chlorine (<2%) and also has sulfur which could be a plus or minus depending on the situation. I think its actually marketed as a palm fertilizer.

Does this stuff look okay for the price?

edwmax

Wow ... That's got some jacked up minors. About 4 Xs more than fruit fuel and 2 Xs more than the 10-10-10 I use ($10 for 50 lb). ... I think the price is a little high, but that's probably brand name.

__________________

edwmax

Well ... may be your price for the 8-2-12 isn't so high. I just checked with a local manufacture their 8-2-12 Palm mix is $35.70 for 50 lb. Their label matches yours. I believe i will keep using the 10-10-10.

__________________

Akula

Thanks for the comment.

Last year I used urea and potassium sulfate augmented with st. Augustine clippings from the yard and had pretty good results. Thought I might need the minors and the price seemed attractive so picked up a few bags of this stuff. If it’s too high with minors and that might be a problem I can use this stuff every other month with my normal urea and p sulfate applied the other months.

Does this sound reasonable?

edwmax

May be some one else can weight in about the minors and have used the Palm type fertilizer. ... i haven't seen any problems using the 10-10-10 with minors which are double (+/-) the minors in Fruit Fuel.

__________________

Stonefox

I am also planning urea and potassium sulfate and would be interested how to add the minors.

edwmax

See this reference for a list of materials to blend fertilizers and for micros. NESAC-Fertilizers (Inorganic Fertilizers)

Check with your Coop or garden centers there may be concentrated blend of the micros available to use in the fertilizer batch.

__________________