The Never Ending Abuse of Phosphorous (Bloom foods) to Enhance Flowering

t0ny4n said:

Dear Uncle Ben,
I'm newbie here, this is my first time in growing herbs
I've 2 plants here (Super Lemon Haze & Diesel Ryder) and i switched light to 12/12 6 days ago, and my lower leaves at both plants are turning yellow like you said.
I don't know what should i do now?
I never use nutrients before, just watering by nature water.
Can i use this NPK 10-30-20 now ?

N: 10%
P2O5: 30%
K2O: 20%
Mg: 0,05%
Ca: 0,05%
B: 0,03%
Zn: 0,05%
Cu: 0,05%
Fe: 0,075%
Mn: 0,05%
Mo: 0,005%
GA3, αNAA, bNOA

Sorry, i'm in Vietnam (country with Dalat city if you remember Di Wee Dalat) , so i can't find other brand with 10-30-20, it's hard in my country.
I've some pictures of my plants here, pls give me some advice

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t0ny4n said:

My buds at 32 days in flowering times, is it small ?
I'm using 8 CFL 20watt bulbs.

http://i.imgur.com/jyFjK2m.jpg
http://i.imgur.com/5m0SnVq.jpg

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HeartIandhank said:

Hey UB.. someone copy and pasted your "Never ending abuse" write up on 420magazine.com

I wrote up a post suggesting that they might add the author back into the write up.. fucking people..

maybe this link is breaking rules,, fuck, i don't know... oh well.
http://www.420magazine.com/forums/how-grow-marijuana/71652-never-ending-abuse-phosphorous-enhance-flowering-2.html#post2389996

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Uncle Ben said:

How uncanny. I had just gotten ready to post that particular part here and found you had beat me to it.

Here's another really important point, balancing foods with water quality:

First, the ideal fertilizer for any crop, not just
orchids, is one that balances you water quality.
Probably the most important aspect of this comes with
the management of the substrate pH. .......That means that the amount of acidic nitrogen should be balanced by the alkalinity of your irrigation water.

My well water is neutral in pH, but the alkalinity is high (high Ca bicarbs), so, the 21-7-7 that I sometimes use is a good choice.

...and........

In addition, an ideal fertilizer should supply a
sufficient amount of each nutrient for growth. That
means that the nutrients contained in the fertilizer
should complement those supplied by the irrigation
water. If the water does not contain a specific nutrient,
like calcium or magnesium, then it needs to be supplied
by the fertilizer. It also needs to be supplied at a
concentration high enough that it influences plant
growth. For example, some 20-10-20 fertilizer contain
magnesium, but the amount supplied is so low that it
really doesn’t influence the nutrition of the plant.

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wyteboi said:

this should be the very first thing you learn about any plant.

3 stupidest myths i still see everyday:

1. leaves need to be yellow at the end.
2. take all the big fans out of the way so the flower gets more light.
3. take all the fans off and the spider mites dont have anywhere to live.

If you own 28 different foods , 65 different additives and 14 jugs of molasses and not one single book on plants then that is the problem.
Read folks, not just on RIU but on plants in general.

wb

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Growerguy420 said:

That's much to complicated for me. I run straight promix with jacks citrus feed every watering $9.99 for a 1.5lb tub through the whole cycle

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chicofrito said:

Bump for Dr. Bugbee

View attachment 5143970

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Uncle Ben said:

I wrote this years ago and thought I'd share it here.

The never ending abuse of Phosphorous to enhance flowering

A common mistake for growers when they reach the flowering stage is to start hitting the plants with a high P fert like a 10-50-10, continuing to use this blend exclusively, and when their plants start experiencing a deficit of N, Ca, Mg or micros as reflected by the dropping of lower leaves and chlorosis, they wonder why. Plants flower as a response to long nights, not because of fert blends high in P. A ratio of 10-60-10 is WAY too high in P. The plant will only take what it needs and compete for other elements that may be more important at the time.

You may have heard that too much N can inhibit flowering. No question about it, exclusive use of a plant food that is rich in N such as blood meal, a 5-1-1 blend, or ammonium nitrate/sulfate may inhibit flowering especially if the phosphorous level is low, but most balanced blends have sufficient amount of P to do the job. The question is - "how much P is enough to support a good flowering response and still retain my leaves?"

Manufacturers/horticulturists will give you element analysis and what effect the elements have on plant growth, but remember this does not necessarily mean you will get better yields. Using a high P fert exclusively during flowering can actually work against you due to impending leaf drop. It's an abundant amount of healthy leaves going into 12/12 and maintaining their health that produces a lot of bud, not high P ferts.

I rotate fert blends as the plant *requires* them, not because it is "the thing to do." For example, when your plants are going thru the stretch phase during early flowering, they may need more N, especially if you're getting some yellowing in the lower leaves. Give up the cannabis paradigms and give them what they need. Go back to mild high P fert when the stretch ends, maintaining the foliage in a healthy state of growth until harvest for maximum yields. A 1-3-2 blend such as Peter's Pro Blossom Booster, 10-30-20, is one of the best flowering blends on the market because of several factors - it is higher in nitrate N and Mg. It is sold under the Jack's Classic label. An added benefit of Peters blends is their use of high quality, very pure salts that will eliminate root burn if used judiciously.

Uncle Ben

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2cent said:

Didn’t you say don’t use high p then advise using a high p?

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chicofrito said:

According to this study, 30ppm of P was enough to get 80% of the maximum yield.

View attachment 5303433
https://www.frontiersin.org/articles/10.3389/fpls.2021.657323/full

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BeauVida said:

Ignore bad science. 30ppm. What NKCaMGMNZnCuMoCo ppms? We pretending ppm means more than ratios now? What transpiration rate, light spectrum, temperature, etc. The majority of Cannabis plants are visibly phosphorus deficient.

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