C
Carl Carlson
from the March/April 2010 issue, by William Texier
http://maximumyield.com/download_issue.php
http://maximumyield.com/download_issue.php
Many companies sell H2O2 with the claim of miraculous effects, from improving the oxygen level in the nutrient solution to killing all pathogens on site. They often use anthropomorphic images such as: “the oxygen ion search for the bad guy.” Of course, there is some truth behind all that, but the presentation is rather misleading. When H2O2 is dissolved in water, it rapidly loses an oxygen atom that becomes a free radical. As you probably know, free radicals are extremely reactive oxygen ions. They have an electric charge and they attach themselves very easily to any other particle with an opposite charge. “Attach” in this case means oxidize, or kill. It is this same process that transforms iron into rust.
All micro-organisms, as well as every living cell, have electrical activity, and thus attract a free oxygen ion...and die! The free radical does not have a selection mechanism that makes it target the bad guys. It will indiscriminately oxidize spores and pathogens, but also root cells. At the same time that it is cleaning the nutrient solution, it is weakening the plant. In fact, the quantity that you can introduce in the nutrient solution without killing your plant is so small that it is not enough to completely free the solution from pathogens. It is true that their population will be reduced, but they will rapidly come back in even greater numbers to attack the weakened plants. As a general principle, doing something that weakens your plants when they are already attacked by pathogens does not strike me as the brightest of ideas.
The claim of extra oxygenation is also greatly exaggerated. It is important to realize that this ionic form of oxygen is not the one that the plant can use. Plants absorb O2, the gaseous oxygen that is in the air, the reunion of two oxygen atoms.
What happens to that oxygen ion when it is released? Since it is very reactive, it will not live long, or travel far. It will, most likely, encounter something to attach to. It will then precipitate out of solution with that “something.” Once again, that can be a cell, a spore, but also a metallic ion such as iron. If some of those ions, obviously a small portion, manage to turn into gaseous oxygen, they will simply get out of the solution, at least for the larger part. The reason is simple: there is a maximum of dissolved oxygen that you can have in the water. This maximum varies mostly in relation with the temperature. Once that saturation in oxygen is attained, any extra would simply dissipate in the air. Granted, a minute fraction might be absorbed by the plant, but certainly not enough to make a difference.
Don’t get me wrong, hydrogen peroxide is a very good product. There is nothing more efficient to rid a system from pathogens between two crops. I highly recommend the use of H2O2, especially if you experienced root problems in your previous crop. The use of a strongly acidic solution to dissolve the salts that might accumulate in the line, as well as using a strong solution of H2O2 to get rid of pathogens should be your routine practice between crops. It is only the idea of using it with plants in the system that makes the hair on my neck curl backward!
All micro-organisms, as well as every living cell, have electrical activity, and thus attract a free oxygen ion...and die! The free radical does not have a selection mechanism that makes it target the bad guys. It will indiscriminately oxidize spores and pathogens, but also root cells. At the same time that it is cleaning the nutrient solution, it is weakening the plant. In fact, the quantity that you can introduce in the nutrient solution without killing your plant is so small that it is not enough to completely free the solution from pathogens. It is true that their population will be reduced, but they will rapidly come back in even greater numbers to attack the weakened plants. As a general principle, doing something that weakens your plants when they are already attacked by pathogens does not strike me as the brightest of ideas.
The claim of extra oxygenation is also greatly exaggerated. It is important to realize that this ionic form of oxygen is not the one that the plant can use. Plants absorb O2, the gaseous oxygen that is in the air, the reunion of two oxygen atoms.
What happens to that oxygen ion when it is released? Since it is very reactive, it will not live long, or travel far. It will, most likely, encounter something to attach to. It will then precipitate out of solution with that “something.” Once again, that can be a cell, a spore, but also a metallic ion such as iron. If some of those ions, obviously a small portion, manage to turn into gaseous oxygen, they will simply get out of the solution, at least for the larger part. The reason is simple: there is a maximum of dissolved oxygen that you can have in the water. This maximum varies mostly in relation with the temperature. Once that saturation in oxygen is attained, any extra would simply dissipate in the air. Granted, a minute fraction might be absorbed by the plant, but certainly not enough to make a difference.
Don’t get me wrong, hydrogen peroxide is a very good product. There is nothing more efficient to rid a system from pathogens between two crops. I highly recommend the use of H2O2, especially if you experienced root problems in your previous crop. The use of a strongly acidic solution to dissolve the salts that might accumulate in the line, as well as using a strong solution of H2O2 to get rid of pathogens should be your routine practice between crops. It is only the idea of using it with plants in the system that makes the hair on my neck curl backward!
