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Dutch Bucket tomato and pepper problems

Posted by SidneyJoe none (My Page) on
Sun, Jun 29, 14 at 0:46

We have an NFT system of lettuce which is doing well in our garage. Next to it, we have a system of ten Dutch Buckets, which are not doing so well. Both systems are from Farmtek. We just started working with hydroponics and these systems in March.
Four of our Dutch Buckets have peppers. The plans are large and pretty, but the flowers keep dropping.
In the same system, we have six tomatoes, Roma and Beefsteak. These were started in February in Rockwool cubes and then transplanted to the Dutch Buckets in Perlite. We use Botanicare's CNS17.
Once the tomatoes started to bloom, we switched over to bloom from the grow and that is when the leaves started to yellow around the edges, starting with the bottom 2/3 first, then curl up, and die. One tomato grew and then suddenly stunted to about the size of a golfball. We thought the environment was too wet (system was on a timer of watering for ten minutes every two hours). We then changed it to five minutes every three hours. We flushed the system with Clearex, and then used Ripe with the Calmag supplement, thinking the nitrogen must of been to high. All nutrients were mixed per package directions; Ph has been about 5.8-6.0 through the entire time. After one week, nutrients are added half-strength. The entire reservoir is replaced every two weeks.

Our lighting system is a 400 watt metal halide, running on a schedule of 12 hours on, 12 hours off per day. We do have a dehumidifier in the garage; humidity has averaged anywhere between 55-65%, temperatures range from 84-95 degrees.

We are stuck as to what direction we should take these plants. Any help is greatly appreciated! Thanks!

Follow-Up Postings:

RE: Dutch Bucket tomato and pepper problems

high temps and low frequency watering can induce water stress. The plant relies on transpiration to transport water and nutrients internally from root to leaf. When a plant is under water stress, its ability to uptake nutrients is adversely affected (no water = no nutes) calcium deficiency is usually the first to appear, adding more calcium to the nutrient solution will only make things worse as its not a lack of calcium its a lack of water moving through the plant :)
A mature tomato plant will get through half to one gallon of water per day.

RE: Dutch Bucket tomato and pepper problems

The flower drop on the peppers may be from a lack of pollination. I do a few DWC peppers in a greenhouse and I pollinate them with a small artist brush. Wait until the flower is fully open then lightly brush the inside of it. It works for me.

RE: Dutch Bucket tomato and pepper problems

Thank you both!
We immediately changed over to 300 watt daylight CFLs 6500k. Temp is down to 78-81 degrees and humidity is 70 tops. Seedlings on the side are doing much better and tomatoes have improved and are taking up water again with some new coming on. The first one is still green but growing. The peppers look better and I will begin pollinating them-I was sure that they didn't need that but obviously they do!
Our future goal is a ventilation fan for further cooling.
So do you see a problem with the tomatoes and peppers sharing the same tank of water? This does not have to do with the two not getting along, right?
Thank you again!

RE: Dutch Bucket tomato and pepper problems

The toms will need a slightly different feed to the peppers in the flowering/fruiting stage so it would be a compromise.
The CNS17 Bloom and Ripe look hellishly heavy in phosphorus and toms dont need all that much. The cns grow supplemented with a little potassium nitrate (KNO3) looks like it could fulfil all stages of growth depending on the micro-nutrient content (which i couldnt find values for).
The peppers should do fine with 6.5ml/L CNS Grow + 0.75g/L KNO3, (EC: 2.1). The toms use the same feed upto the 4th true leaf at which point they`d need 7.5ml/L CNS Grow + 0.993g/L KNO3 (EC: 2.5)
To make the KNO3 additions easier, put 4L of distilled water into a 5L container with a lid, add 500g of KNO3, wait for it to dissolve and topup to 5L with distilled water. The 0.75g/L becomes 7.5ml/L and the 0.993g becomes 9.93ml/L, but 10ml/L will be close enough.

RE: Dutch Bucket tomato and pepper problems

Purchased the potassium nitrate tonight(in the form of spectracide stump remover granules).Plan to try your suggestion soon.
Now I was told or read somewhere that the CNS17 Grow was too high in nitrogen once the tomatoes started to flower and you must switch to a lower nitrogen formula at that time, or else no tomatoes. Is there any truth to that?
Also, should I still consider the cal mag supplement in addition to your regimen?

CNS17 guaranteed analysis
Total nitrogen 3.0%
.14% ammoniacal nitrogen
2.86% nitrate nitrogen
Available phosphorus P2O5 2.0%
Soluble potash K2O 4.0%
Ca 2.8%
Mg .5%
Sulfur 1.1%
Mn .05%
Mo .0005%

I am really desperate for some results although I know it will take time. Thanks again.

RE: Dutch Bucket tomato and pepper problems

A lot of growers reduce the N in flower, i guess its carried over from soil growing where high levels of ammoniacal/ureic N caused soft lush growth and very little fruit.
Hydro nutrients have very little ammoniacal N and no ureic N. Most hydro growers that drastically reduce N in flowering also say its normal for the lower leaves to look sickly and die off when its indicative of the plant relocating N from the older leaves to make up for the missing N in the feed.

This post was edited by hex2006 on Mon, Jul 14, 14 at 0:29

RE: Dutch Bucket tomato and pepper problems

OK, now that I've went to try that regimen, I found that I am confused about using the g of potassium nitrate. Following your "To make the KNO3 additions easier," which I assume is to be used at full strength, I would have to go through alot of potassium nitrate to get to 40 gallons. Also, do you know of other sources as this is $5.49 per 453 grams at Menards here and if the above is correct it would not be an option for us at that price, especially every two weeks.

What I was thinking from your suggestion of 0.75g/L KNO3:
40 gal x 2.2L/gal = 88L x0.75gKNO3/L = 66g KNO3 total, and
6.5ml/L grow x 2.2 L/gal =14.3 ml grow x 40gal = 572 ml x 1oz /30ml = 19.06 oz grow total

Now, I will admit that I had been only filling the tank to 30 gal and calculating for that to save on nutrients. Now I realize that may be part of the problem.
What are your thoughts? Am I really off here? I am not seeing any changes in my plants again so I would like to change to something like the above soon if I could do it long term financially. Thanks again!

RE: Dutch Bucket tomato and pepper problems

Stump remover will be a lot more expensive per lb than horticultural potassium nitrate. I pay the equivalent of $0.77/lb for mine (Yara Krista K+) but its probably even cheaper in the states.

Haifa Multi-K, Greenhouse grade Potassium Nitrate seems to be a fairly common one in the US.

This post was edited by hex2006 on Fri, Jul 18, 14 at 3:46

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