I read some research papers a couple of years ago and realized that the best and most efficient way to feed plants is by "Foilar Feeding". I had just brewed a nice batch of worm tea and was in the process of feeding my plants yesterday just before dark when a neighbor asked why do I spray my plants so often. I explained the process of worm tea and foliar feeding and she was shocked to here how more efficient foilar feeding was and asked if I had any literature on how to do it. Well I pointed her to my favorite online resource and thought I would post that same link here as a good point of reference on what and why foilar feed is a must for my plants and should be for yours as well in addition to it's standard soil feedings.
Enjoy the read!
Foliar feeding is the application or feeding of a plant with a liquid nutrient or additive through the leaves instead of via the roots. Foliar spraying was first proven to work by the notable plant researcher Dr. H.B. Tukey. His early experiments used radioactive labeled/tagged phosphorus and potassium to view the uptake and transport of these ions by the leaves and their transport around the plant. Dr. Tukey found plant nutrients moved at the rate of about one foot per hour to all parts of the plants. Comparing efficiency of plant use of foliar-fed nutrients versus soil-applied nutrients near roots, he found foliar feeding provided about 95 per cent efficiency of use compared to about 10 per cent of use from soil applications! This early work showed that foliar spraying has great potential as an additional feeding program to allow for increased growth rates and development of plants.
In fact, a recent study of foliar-sprayed leaf versus root absorption of radioactive tagged complex carbohydrates and amino acids at a Canadian university indicated that these molecules are just too big to be effectively absorbed by the roots, but can be easily and effectively absorbed by the leaves.
"To get the best out of foliar feeding, you must apply something that directly affects one of the many production pathways inside the leaf."
Why should we foliar feed?
If we think of a plant as a city, then the leaves would be the manufacturing centers of that city. Almost everything a plant requires to grow and develop is manufactured in the leaves. Hormones, metabolites, proteins and amino acids—the list goes on, and they are all manufactured in specialized cells contained within the plant's leaves. Sunlight is the main catalyst for this, as everything begins with a photon of light received from the sun or an artificial source. The roots, too, produce some hormones but it is insignificant compared to what is produced in the leaves. If we look at a plant in this way, we can see that the best opportunity to increase the plant's production capacity, and hence our yield, is to go direct to the factories themselves, the leaves. Foliar spraying is the only practical way that most of these little leaf-based factories can be accelerated due to two primary factors:
1. The presence of a specialized root structure called the Casparian strip. This strip is located inside each and every root and acts as a specialized barrier that blocks the uptake of all elements or compounds except simple sugars and regular plant nutrients like nitrogen and potassium. Numerous studies conducted at a Canadian university have indicated that plants cannot uptake things like amino acids and complex carbohydrates effectively through their roots. Root-based supplements or growth and flowering stimulants based on these things can never really work unless they are foliar-fed, because, quite simply, they are never taken up by the plant's roots.
2. The negative feedback loop system. Even if some elements such as hormones are taken up by the roots, this feedback loop stops almost all of these additives from ever working. It does so by detecting the basic hormones contained in these performance additives and correspondingly slowing or completely stopping the plant's own internal production of these compounds to compensate and keep everything in balance—almost like a plant veto! However, when used in conjunction with a high-quality commercial delivery agent, foliar feeding defeats this system easily by temporarily and suddenly flooding the plant's negative feedback loop system, overwhelming it and allowing for a temporary increase in growth and development. It is by this systematic and periodic flooding of the plant's metabolic systems that we can increase overall growth and development when using foliar feeding—and of course obtain that maximum yield!
What should I foliar feed?
Foliar feeding should never be used as the sole source of plant nutrition. Instead, a good foliar program supports the plant via the foliar application of carefully selected plant additives that accelerate or enhance the action of one or more of the plant's metabolic subsystems, in some cases helping to speed up the plant's use of light itself. To get the best out of foliar feeding, you must apply something that directly affects one of the many production pathways inside the leaf. Using a commercially available delivery agent, it is possible to directly increase the production pathway associated with light energy conversion into plant energy (sugar, carbon and so on)—also known as photosynthesis. Other things that can be successfully used are a ⅓-strength grow nutrient solution. This can quickly correct any nutrient deficiencies, but remember to use a delivery agent with any foliar application for best results.
I've tried foliar feeding before but it didn't work like it was supposed to. What can I do?
"Almost everything a plant requires to grow and develop is manufactured in the leaves."
For any foliar program to be completely effective in enhancing that maximum yield, you must be able to deliver your specialized plant stimulants and nutrients inside the leaf of your plant. Now, this is not as easy as it sounds—because you first have to get past the protective waxy layer that surrounds every leaf. Once past this layer, you must then get it inside the cells where all the action is taking place. This is not as simple as just madly spraying your leaves with plant nutrients or additives, as most of what you apply to the leaves will never be absorbed. For many years it was believed that by allowing a solution to remain in contact with the leaf surface for an extended period of time, the effective absorption of that solution would take place through tiny openings in the leaf's surface called the stomata. The plant uses its stomata to absorb and exchange gases (CO2, O2) and to regulate water flow (transpiration). Modern research now shows, however, that only a tiny portion of what you spray can actually get inside the leaf surface via the stomata. In fact, typically less than 10 per cent of the stomata uptake any plant nutrients. This inefficiency is then further compounded by the fact that even once taken up, most of the supplied material is immobilized on the inner side of the leaf surface by ion exchange membranes. This certainly explains the very hit-and-miss effects of traditional foliar spraying when trying to get that maximum yield with plant nutrients and additives. The only way to effectively deliver large amounts of specialized elements inside the leaves of your plant is to use a new type of product known as a delivery agent, which is not to be confused with a wetting agent. The difference between a wetting agent and a delivery agent is very simple and very important. A wetting agent is designed to make water wetter, so that it sits more evenly over the leaf and extends the contact area and time of contact when applied to a leaf. A delivery agent is primarily designed to actively deliver, or translocate, plant stimulants from the outside of the leaf surface to the inside, past the ion-exchange membranes and directly to the cells where they are needed to achieve a maximum yield. A delivery agent is designed to do this independently of the stomatal openings in the leaves, giving you a unique opportunity to profoundly affect the development and growth patterns of your plant. Make sure you use a delivery agent—not a wetting agent—if you want to be able to maximize the results from a specialized foliar spraying program.
Here is an article taken from Maximum Yield Dec 2010 article written by Craig Gibble.
Full artcile on Maximum Yeilds website
Enjoy the read!
Foliar feeding is the application or feeding of a plant with a liquid nutrient or additive through the leaves instead of via the roots. Foliar spraying was first proven to work by the notable plant researcher Dr. H.B. Tukey. His early experiments used radioactive labeled/tagged phosphorus and potassium to view the uptake and transport of these ions by the leaves and their transport around the plant. Dr. Tukey found plant nutrients moved at the rate of about one foot per hour to all parts of the plants. Comparing efficiency of plant use of foliar-fed nutrients versus soil-applied nutrients near roots, he found foliar feeding provided about 95 per cent efficiency of use compared to about 10 per cent of use from soil applications! This early work showed that foliar spraying has great potential as an additional feeding program to allow for increased growth rates and development of plants.
In fact, a recent study of foliar-sprayed leaf versus root absorption of radioactive tagged complex carbohydrates and amino acids at a Canadian university indicated that these molecules are just too big to be effectively absorbed by the roots, but can be easily and effectively absorbed by the leaves.
"To get the best out of foliar feeding, you must apply something that directly affects one of the many production pathways inside the leaf."
Why should we foliar feed?
If we think of a plant as a city, then the leaves would be the manufacturing centers of that city. Almost everything a plant requires to grow and develop is manufactured in the leaves. Hormones, metabolites, proteins and amino acids—the list goes on, and they are all manufactured in specialized cells contained within the plant's leaves. Sunlight is the main catalyst for this, as everything begins with a photon of light received from the sun or an artificial source. The roots, too, produce some hormones but it is insignificant compared to what is produced in the leaves. If we look at a plant in this way, we can see that the best opportunity to increase the plant's production capacity, and hence our yield, is to go direct to the factories themselves, the leaves. Foliar spraying is the only practical way that most of these little leaf-based factories can be accelerated due to two primary factors:
1. The presence of a specialized root structure called the Casparian strip. This strip is located inside each and every root and acts as a specialized barrier that blocks the uptake of all elements or compounds except simple sugars and regular plant nutrients like nitrogen and potassium. Numerous studies conducted at a Canadian university have indicated that plants cannot uptake things like amino acids and complex carbohydrates effectively through their roots. Root-based supplements or growth and flowering stimulants based on these things can never really work unless they are foliar-fed, because, quite simply, they are never taken up by the plant's roots.
2. The negative feedback loop system. Even if some elements such as hormones are taken up by the roots, this feedback loop stops almost all of these additives from ever working. It does so by detecting the basic hormones contained in these performance additives and correspondingly slowing or completely stopping the plant's own internal production of these compounds to compensate and keep everything in balance—almost like a plant veto! However, when used in conjunction with a high-quality commercial delivery agent, foliar feeding defeats this system easily by temporarily and suddenly flooding the plant's negative feedback loop system, overwhelming it and allowing for a temporary increase in growth and development. It is by this systematic and periodic flooding of the plant's metabolic systems that we can increase overall growth and development when using foliar feeding—and of course obtain that maximum yield!
What should I foliar feed?
Foliar feeding should never be used as the sole source of plant nutrition. Instead, a good foliar program supports the plant via the foliar application of carefully selected plant additives that accelerate or enhance the action of one or more of the plant's metabolic subsystems, in some cases helping to speed up the plant's use of light itself. To get the best out of foliar feeding, you must apply something that directly affects one of the many production pathways inside the leaf. Using a commercially available delivery agent, it is possible to directly increase the production pathway associated with light energy conversion into plant energy (sugar, carbon and so on)—also known as photosynthesis. Other things that can be successfully used are a ⅓-strength grow nutrient solution. This can quickly correct any nutrient deficiencies, but remember to use a delivery agent with any foliar application for best results.
I've tried foliar feeding before but it didn't work like it was supposed to. What can I do?
"Almost everything a plant requires to grow and develop is manufactured in the leaves."
For any foliar program to be completely effective in enhancing that maximum yield, you must be able to deliver your specialized plant stimulants and nutrients inside the leaf of your plant. Now, this is not as easy as it sounds—because you first have to get past the protective waxy layer that surrounds every leaf. Once past this layer, you must then get it inside the cells where all the action is taking place. This is not as simple as just madly spraying your leaves with plant nutrients or additives, as most of what you apply to the leaves will never be absorbed. For many years it was believed that by allowing a solution to remain in contact with the leaf surface for an extended period of time, the effective absorption of that solution would take place through tiny openings in the leaf's surface called the stomata. The plant uses its stomata to absorb and exchange gases (CO2, O2) and to regulate water flow (transpiration). Modern research now shows, however, that only a tiny portion of what you spray can actually get inside the leaf surface via the stomata. In fact, typically less than 10 per cent of the stomata uptake any plant nutrients. This inefficiency is then further compounded by the fact that even once taken up, most of the supplied material is immobilized on the inner side of the leaf surface by ion exchange membranes. This certainly explains the very hit-and-miss effects of traditional foliar spraying when trying to get that maximum yield with plant nutrients and additives. The only way to effectively deliver large amounts of specialized elements inside the leaves of your plant is to use a new type of product known as a delivery agent, which is not to be confused with a wetting agent. The difference between a wetting agent and a delivery agent is very simple and very important. A wetting agent is designed to make water wetter, so that it sits more evenly over the leaf and extends the contact area and time of contact when applied to a leaf. A delivery agent is primarily designed to actively deliver, or translocate, plant stimulants from the outside of the leaf surface to the inside, past the ion-exchange membranes and directly to the cells where they are needed to achieve a maximum yield. A delivery agent is designed to do this independently of the stomatal openings in the leaves, giving you a unique opportunity to profoundly affect the development and growth patterns of your plant. Make sure you use a delivery agent—not a wetting agent—if you want to be able to maximize the results from a specialized foliar spraying program.
Here is an article taken from Maximum Yield Dec 2010 article written by Craig Gibble.
Full artcile on Maximum Yeilds website