Clippings by ZachS

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RE: Grafting Heirloom Tomatoes (Follow-Up #14)

posted by: ZachS on 01.08.2015 at 07:25 pm in Growing Tomatoes Forum

Yardenman,
You seem to be thinking that a plant uses its roots like straw, to simply suck up all available nutrients that it comes in contact with. Therefore, having more “straws” will bring in more nutrients, and more flavor to your tomato. That is only right to an extent.

While the absorption of nutrient ions through the epidermis of the root is passive, they cannot breach the plasma membrane at the endodermis and enter the xylem without either facilitated diffusion or active transport proteins (cations and anions, such as K+, potassium, are charged and therefore cannot cross the membrane through simple diffusion). It has been found that ion exchange in plants works against a gradient. Therefore, nutrient ions require active transport for nutrients to reach the vascular tissue to be passed on to the cells in the stems, leaves, and fruit.
If I am remembering correctly, active transport is facilitated in part by cell signaling. IE: The cells in a leaf sending a signal that they need more nitrogen which will open up the transport protein to allow more nitrogen in. If the leaf doesn’t need any more nitrogen, then the nutrient will be “blocked” until it does.

“Plants can take up nutrients in excess of their needs … However there are feedback mechanisms that reduce ion uptake as internal concentrations increase maintaining a balance between demand and acquisition.” (Adler, et al)

So, what does this all have to do with your hypothesis that more roots = more nutrients = more flavor?

Well, quite simply, plants have selective barriers to ion uptake and they do not continue to just suck and suck and suck nutrients into themselves at an unregulated rate. So, even if you have a root ball that is half a mile across, if the plant doesn't need all the nutrients that the roots come in contact with, it won’t necessarily take them and just “unload” all the extra into your fruit, making it taste better.

And of course, this is only dealing with the flavor contributions made by the nutrient ions that are taken in through the roots, and completely ignores the fact that a great deal of flavor comes from the “upstairs” (if I may borrow from PC). The fact that many OP/heirloom plants often have more foliage to fruit than do many hybrids is not an insignificant factor that must also be taken into account.

It also ignores the role of genetics, like PC said. The flavor profile is also determined not so much by the ratio of roots to fruit, but by genetics dictating how and which molecules are configured into the compounds we can taste. In regards to your dislike of the flavor of hybrid varieties, it is much more likely that the hybridization, which was done primarily with markets, shipping, and volume in mind, was done with plants that either lacked good flavor to begin with or, through the recombination of their genes, produced a flavor that was inferior to either of the parents on their own. Not as a result of the plant producing too many fruits.

This post was edited by ZachS on Thu, Jan 8, 15 at 19:28

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clipped on: 01.09.2015 at 07:41 pm    last updated on: 01.09.2015 at 07:41 pm

RE: Pepper Plants (Follow-Up #1)

posted by: ZachS on 03.10.2014 at 03:05 pm in Vegetable Gardening Forum

I don't understand "too cloudy" as long as the temps are warm enough, cloudy is fine. Despite how our eyes see light, a plant actually receives far more light on a cloudy day outside then even under the brightest of fluorescent bulbs. Photon measurements show that under a light set up seedlings received ~50-100 µmol/m.s, on a cloudy day I was around 500-800 µmol/m.s (a sunny day was ~1500-2000 µmol/m.s).

In fact if you haven't hardened them off, cloudy days are a perfect time to start. The less intense light allows them to adjust gradually to 5-8 times more light rather then a sunny day at 15-20 times more light. It is often recommended to transplant on cloudy days as well because the less intense light and slightly cooler temps are supposed to reduce the shock.

I do recommend potting up, not matter if they are leggy or not. How long have they been in their peat pots? In reality, you can bury them up the seed leaves, especially when still very young, most people don't recommend it with peppers though. While peppers CAN grow adventitious roots along them stem, like tomatoes, they are not quite as good at it.

If you have very young seedlings, I would re-bury them up the cotyledons. If they are on the verge of transplant I would not. I would put them outside (temp. depending) and allow the sun and wind buff them up.

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SEE: More follow ups for discussion on lighting
clipped on: 01.07.2015 at 12:10 pm    last updated on: 01.07.2015 at 12:20 pm

RE: Tomato Stem Hairs (Follow-Up #10)

posted by: ZachS on 06.01.2014 at 08:48 am in Growing Tomatoes Forum

You will find that most places say "the hairs will turn into roots if buried under the soil." This is false. The hairs do not turn into roots, the roots form and emerge from a group of cells much deeper within the plant tissue.

From what I have read, and what I understand about plants, the hairs are most likely used for defense from predation, whether by insects or larger herbivores. Some of them do have glands that secrete compounds that make the tomato plant smell...tomatoey (I'm sure they serve a different function beyond smell, though).

This is a cross section of an emerging adventitious root. The hairs on a tomato are attached to the epidermal cells whereas the root is formed from pericycle cells.

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clipped on: 01.07.2015 at 12:19 pm    last updated on: 01.07.2015 at 12:19 pm

RE: Why do Home Depot tomatoes have fewer trichomes? (Follow-Up #4)

posted by: ZachS on 04.27.2014 at 11:02 am in Growing Tomatoes Forum

I would assume just to poor handling, probably from seed to sale. Course, really, you have to imagine that the companies growing for big box stores are growing thousands and thousands (hundreds of thousands? millions?) of plants at the same time, they don't have time to baby them like most home gardeners do. That all being said, people grow successful crops of tomatoes from them year after year, so the plants obviously don't seem to mind, as long as they are taken care of once they get to their forever home.

So, this comes up a lot, and it is a ever present misnomer that I doubt will ever go away. The hairs on the tomato (any plant really) do not turn into roots once buried. Those hairs (or trichomes) grow from the epidermis only and generally serve as a protective measure. Roots, whether adventitious or otherwise, grow from much deeper inside the plant tissue, adjacent to the vascular bundle which moves food and water through the plant.

This post was edited by ZachS on Sun, Apr 27, 14 at 11:03

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clipped on: 01.07.2015 at 12:16 pm    last updated on: 01.07.2015 at 12:16 pm

RE: Amount of light truly necessary (Follow-Up #3)

posted by: ZachS on 03.07.2014 at 03:12 pm in Growing under Lights Forum

To complicate things even more I'm going to throw wavelength into the mix rather then lumens, lux, or watts.

Watts is expressive of how much energy a bulb uses to produce light. It is possible to lower the amount of watts and still produce and equal amount of light. Example: An incandescent 60-watt bulb gives off 800 lumens of light. LED bulbs can deliver the same amount of light using as little as 10 watts. I would disregard choosing a grow light set up on wattage alone and wattage=/=light. However, all other things being equal, go for the lower wattage.

Lux is a factor of both illuminance over a given area and luminous emittance from a given area. Lux/unit area is going to be highly dependent on your specific set up. While the luminous emittance from a bulb may be 500lx, the illuminance of your grow area may be only 100lx based on the light being diffused throughout the area and absorbed/reflected. To find this out, you would need the gear for measuring it, but it is going to give you most accurate measurement of how much visible light (measured in lumens) your plants are actually receiving in a given area, but this brings us to the lumens factor of our growing set ups.

Lumens is a measurement of light visible to human eye. The problem is, plants don't have human eyes, and lumens are not photons, which are what the plant actually uses for photosynthesis. In this way, a plant "sees" light as a matter of wavelengths rather then lumens.

The energy of a photon is dependent on wavelength rather than lumens. A photon of red light has less energy then a photon of blue light. Thus, we can purchase a 2600 lumen blub for growing at 3500K (closer to the red spectrum) and we can purchase a 2600 lumen bulb at 6500K (in the blue spectrum) and while their lumens are equal, their photons are not, making one better then the other for growing plants.

I currently have two fixtures one has light bulbs at 2,600 lumens, 5,000K and the other has bulbs at 2,600 lumens and 6,500K. I had onions under both and the ones growing under the 5,000K lights were more yellow then then ones growing under the 6,500K lights. Anecdotal, but take it for what it's worth.

"you should ideally be between 10000 and 15000 lumens per square foot"

This goes back to the lumens/photons things. You can have 10,000 lumens/sqft, but your photon measurement (µmol/m2.s) which is what your are looking for when calculating photosynthesis, will be much different depending on the spectrum of your light.

This post was edited by ZachS on Fri, Mar 7, 14 at 15:16

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clipped on: 01.07.2015 at 12:13 pm    last updated on: 01.07.2015 at 12:13 pm