The never ending abuse of Phosphorous to enhance flowering

[skinnyspliff]

to add to the last post.... if you cant control the nutes then you could easily find yourself having nute lockout

 

[Slowpuffer]

My advise is buy the fox farm tri pack. 1 qt. grow big, 1 qt. big bloom and 1qt. of tiger bloom. Costs about $50 in New England. This is what I started with, and only thing I have used . Why mess with success !!

 

[alex801]

Hey slowP I came across this thread by accident and seen ya name. U tagged along to one of my grows a couple years ago. How's it going

 

[xtrchessreal]

The gist I get from this post is that although P is usually pushed onto you when you ask about what nutes you should give during bloom the reality is that you should give all the nutes you normally give to your flowering plants. In the least follow an even NPK 10-10-10 maybe push the P a little higher once in a while. But don't forget your micro nutes either such as Fe, Mn, Mg, Ni, Zn, Molly-B-Denum, Cu, and while you are at it do your vitamins too B1 etc. No over watering, no under watering (unless you have pests or fungus), keep your humidity low and delta temps small. Also when you are one to two weeks from harvest start flushing with molasses to get the N down (less harshness) and denser, sweeter, buds, also add CFLs in the 5000K range to help bring out the trichomes.

X

 

[happydog420]

This is a very dense post!

 

[GreatLife4All]

I think the hardest thing to understand about nutrient management is the concept of the "limiting factor."

As far as anyone has ever been able to prove, plants require a certain balance of nutrients. This balance of nutrients changes over time as the plant matures. A great nutrient management plan will take this into account.

Adding P without also ensuring that the plant has the correct ratio of N,K, Mg, S and etc does nothing... unless P was the limiting factor in growth. Which means you had the ratios wrong for that part of the plants life cycle.

Some good ratios for N-P-K? Here are suggestions that I use:

For Veg: close to 2-1-3 ratio

For Flower: 1-2-3 ratio​

Some people would even add a period at the end of flowering where the plant receives 0-2-3. I don't personally use this, but do see some possible benefits to limiting nitrogen late in the plant cycle - you should be able to do away with the flush entirely (I believe I am going to try this on my next grow).

So how do you use this information? First - these are beginning points. You can optimize growth for any variety of MJ by varying these slightly during the plants veg and flowering phase. But if you stick to these - you will get a good yield of high quality bud. But what it means is if I am flowering and I am using 200PPM of P - then I need to ensure that I have 100PPM of N and 300PPM of K in the mix as well.

Now lets say that we switch the ratio of nutrients to 1-1-1. If we duplicate the amount of P from the previous example - then we would have 200PPM of P. But we also end up with 200PPM of N and 200PPM of K. Let's take a look at our ratios - 100-200-300. K is now the limiting nutrient as we only have 200PPM. Also note that we have more Nitrogen than the plant needs at this stage (which CAN produce lots of leaves late in the plants life). So the plant will actually see something like this: 68-136-200 - even though more P and N are available.

Adding P without also adding N and K (in a balanced nutrient management plan!) does nothing beneficial for the growth of the plant.

 

[sully508]

i usually flush 2 weeks prior to harvest using carbo load. agave nectar. and sugaree 0-0-2 by cutting edge solutions. the last week flushing w/ water only and wait for the trics to turn 50% amber. i change from hps to mh during the last ten days or so. i use FF nutes/and soil i also use supplements from advanced and humbolt (dark energy) never had a problem. but makes perfect sense that is alot of P. advanced changed big bud and lowered the P. im in the last 3 weeks of flowering jst gve them a dose of overdrive and B-52.
alot of companies still load up w/ like 2-48-17 bloom boosters. thanks for the info

 

[Highdroponic]

I've seen 6 days, and seems to be fine, however it's a stepping down, and citric acid is added to the water to enhance flavors

 

[heartlandhank]

A common mistake for growers when they reach the flowering stage is to start hitting the plants with a high P fert like 10-60-10, continuing to use this blend exclusively, and when their plants start experiencing a deficit of N 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 to 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 may inhibit flowering especially if the phosphorous level is low, but most balanced blends have sufficient amount of P to do the job. 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. It's an abundant amount of healthy leaves going into 12/12 that produce 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/mid 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 Peter's blends is their use of high quality, very pure salts that will cut down on root burn.

Nice copy and paste.. you forgot to C and P the most important part though.. the author.

It is puzzling to me.. no one ever includes the author on the MJ grow sites..?

It would make a nice addition to this thread.. The author is Uncle Ben.

 

[Conradino23]

I personally think that optimal NPK is closer to 3-1-2 with nitrogen being less used in the last stage of flowering. The thing is that going overboard with any of these will create problems, either in taste, weight or any other department. Gas chromatography of cannabis tissue clearly shows that from these three phosphorus is the least important one as it constitutes a tiny fraction of stems, leaves and flowers. I found an analysis somewhere that claimed 50-85 ppm of phosphorus in soil to be enough for healthy flowering cycle. Cannabis really needs just a bit to be triggered into it and continue to the end while nitrogen and potassium are in high demand till middle flowering when the plant starts eating itself no matter what cause it's much easier than absorbing nutrients from the roots. Then, overabundance of potassium creates problems in micronutrient balance while too much nitrogen screws up the taste (I actually confirmed it). It's really hard to pinpoint it really without analysing your soil in the lab, but it's much better to provide less to your plant via soil and observe how she copes with it than risk going balls out with nutrients for your own satisfaction ending with mediocre bud.

 

[CamelBack]

Won't P factor in the root growth? I've read somewhere that the more roots your plants have, the bigger the yields will certainly come off. I'm doing a grow right now, in what appears to be a multitude of failures due to space and equipment constraints. I was wondering if it would make a difference (to the pre-flower and to almost all aspects of the plant) if I introduce P earlier, perhaps splice it in and replace one week of veg nutes for nutes higher in P, maybe a 1-2-0 micro ratio or 1-2-1?