Nutrient Science

[hithisishal]

So I have been growing a single Bhut in DWC for a couple of months, and it got huge, but keeps dropping it's flowers. I moved it outside today, but shocked it thoroughly, and broke a couple of branches, so I'm not sure if it will survive.

Now, there were a lot of factors working against Casper the ghost chili plant, but I'm convinced that I was doing nutrients all wrong as well. I see a TON of misinformation out there, and I'd really like to see some solid science.

The best sources that I can find suggest peppers need about 3:1:3 N:K, with a healthy amount of Ca as well. I think these are generally figured by tissue analysis - figuring out what the plants actually take in and maintain, since they don't really get rid of any of these elements after incorporating them. But I've been doing my whole grow with Maxibloom (the so called lucas formula), 1:3:3 - way short on nitrogen. They say this encourages budding, but even with access to university journal subscriptions, I can't seem to find any science to back this up. In fact, the New Mexico State University suggests fertilizing with nitrogen, not phosphorous, around flowering time to increase yields. Granted, that's for soil, but I imagine the general trend holds.

I found this: http://www.howardresh.com/hydroponic-culture-peppers2.html

But again, it's lacking rigor and detail, and it's just a list of nutrient values. It makes no reference to different stages of growth.

Does anyone have any better sources?

Also, can anyone suggest any commercial nutrient solutions that will give me closer to appropriate levels for chilis? (hopefully at a limited expense, since anything I buy is going to be a lifetime supply).

 

[Arenal Botanical Garden]

We use 10-30-10. That's the standard for bell pepper varieties in this area.

 

[Scarlet Fire]

I use 4-3-3 during early growth, then switch to 2-4-4 for the rest of the season once I see flowers. You don't want to go too low on the Nitrogen before your plants have finished their structural growth (branches and leaves), but they don't need nearly as much to set fruit.

 

[millworkman]

I use General Hydroponics Maxibloom with a tiny bit of Epsom salt added. The plants grow a tad slower but obviously bloom like mad and do set most flowers.

 

[LGHT]

What type of feeding schedule are you on now and how are you applying the ferts? I've moved over to foliar feeding exclusively because it's a lot more efficient, but using DWC you shouldn't have any problems with a 1:3:3 fertilizer.

I use the GH flora Series and follow the drain to waste feeding chart without all the "flavors" and just use the base nutes. I'm on the mid bloom stage of the cycle and the flora bloom is 0-5-4.

If your not sure what week your in or what you should be focusing on check out the GH feeding charts. You may also want to consider using one of the drain the waste cycles to avoid fert buildup and start off with a fresh batch of prepped water for your DWC bucket. You can find all of the GH charts here.

http://generalhydroponics.com/site/index.php/resources/feeding_schedule/

You should also look at the temps as peppers need temps from 70-90 to pollinate. If you don't have a good amount of fresh air and a fan blowing on the flowers that may also be the cause.

 

[spongey600]

Don't over think it. I use general hydro flora "bloom" only I keep the ppm at 800 and every 2-3 days I add 2 gallons of water and just monitor the ppm and ph I no longer change out all the solution its in an 18 gal tote

 

[hithisishal]

Thanks for the advice, but all I really want to do is over think it I've all but given up on this plant (although I moved him outside, and he's still alive, so we'll see), but I'm still very interested from an academic perspective.

What I'm really looking for is some sort of controlled study, preferably published in a peer reviewed journal, that tests the validity of using phosphorous to boost production. I see a lot of anecdotal evidence, but nothing very scientific. I got my hands on Howard Resh's book, which states "In general, plants harvested for their leaves can tolerate higher N levels...Plants grown for fruit production should have lower N and higher P, K, and Ca levels...." but this isn't referenced, so even though it's said with some authority, it still doesn't satisfy my curiosity.

This is following a table of 30 or so academic hydroponic nutrient formulations, most of which have at least 3:1 N

I also found this (I think it should be free for everyone): http://hortsci.ashsp...9.full.pdf html a paper which analyzes the effects of N and K on pepper production. Unfortunately, P is not analyzed, which is the biggest question for me. Maybe I'll start punching through some of the references to see if I can find anything else.