Maximum Yield USA October 2016 | Page 66

DWC HYDROPONIC SYSTEMS F or years, people were under the impression that size does matter thanks to Godzilla’s powerful marketing slogan. Fast food chains even climbed on board, offering super-sized this and that to consumers, making a huge push toward the more is more principle. As time went on, consumers began recognizing this strategy as a money-making scheme to sell more product, which then spawned the next revolution: less is more. Just as those at the top had previously done, lessis-more enthusiasts began doing the same, limiting their consumption in many areas of their lives toward a more sustainable existence. Crop cultivators eventually followed the trends of both campaigns, but as soon as science-based evidence was brought to the surface regarding the ineffectiveness of overfertilization, the less-is-more mentality began making its way into crop cultivation as well. DEFICIENCIES IN DWC While less-is-more can be highly effective in many arenas, it has started to become overhyped and overemphasized in some cases. I will focus the conversation on the undernourishment of plants in a deep water culture environment. Although it is true that plants in a DWC setting can flourish with less nutrients than 64 Maximum Yield USA  |  October 2016 plants in other hydroponic and soil settings, there is always a threshold that needs to be maintained. When it comes to feeding your plants appropriately, the range for optimal nourishment is narrow. When growers subject their plants to the lower end of what is normal or even outside of that range, symptoms of deficiency will likely occur. Signs of deficiency can vary depending on which nutrient(s) the plants are lacking. In comparison to nutrient toxicities, deficiencies may manifest in a more isolated manner. For example, plants that are overfed will likely exhibit multiple symptoms simultaneously, demonstrating toxic levels of more than one element and will look like they are dying. Deficiencies tend to be harder to spot because the plants may be getting enough of one element but not another, producing plants that may look healthy overall, but not quite right. The progression of deficiency worsens over time, so early stages may be hard to recognize until the problem has advanced significantly. In this scenario, nutrient lockout becomes a major concern because the plants may selectively uptake sufficient quantities of one element but fail to nourish their need for another. A key to understanding deficiencies is being familiar with mobile versus immobile nutrients. Once immobile nutrients are taken up by the plant and directed to where they are needed, they tend to remain in that place indefinitely. This is why deficiency symptoms of immobile nutrients manifest in the newer growth because that deficient nutrient remains immobilized in another area of the plant, unable to move to the area of need. Some examples of immobile nutrients “ IN COMPARISON TO NUTRIENT TOXICITIES, DEFICIENCIES MAY MANIFEST IN A MORE ISOLATED MANNER. ”