Ok, Pics of the plants coming sometime soon, tomorrow maybe if I have time. They are about 2.5 weeks into flowering and are starting to set fruit. Some colas are gonna be massive, but will be furthest from the light due to their height so probably won't yield much higher than some others that are smaller right now. My 2 more sensitive plants are finally showing growth that isn't clawing at all. But past the newest 3-4" of growth the leaves are still clawed from the
Magic Green on plant A. Stretch is still going strong, plants are at least an inch taller every time I go in there, which is at least twice a day usually. Anyways the reason I am posting is to share some new knowledge I got today from a professor at my university.
The pH of a foliar feeding solution has no statistically significant effect on yield! This professor did not do his research on marijuana, but he did do 2 years of trials on a bean crop covering multiple acres of land and conducted the research for his PhD work. It was professional and meticulous to say the least, and after discussing his results at length with him earlier today I believe there is no reason why his research would not translate to any other vegetative crop. His research also showed a 15% increase in yield when comparing a crop grown in pre fertilized soil (e.g. SubCool's Super Soil) and no foliar feeding with a crop grown in the same soil condition given a foliar feeding of macro-nutrients N-P-K and S (derived from Urea, Poly-Phosphate, and Potassium Sulfate + a surfactant).
So the 2 conclusions of his PhD were:
- pH ranging from 3.7-8.2 does not change the rate of absorption by the plant
- Foliar feeding of Macro nutrients can increase yield by up to 15%
And a fun fact for anyone ever experiencing a nitrogen deficiency that doesn't have much patients. 50% of nitrogen applied to the leaves in a foliar feeding is absorbed within the first hour!
The rates are not quite as dramatic for other nutrients, but for the most part, 50% of any nutrient that is fed to the plants through the leaves is absorbed within the first 24 hours. So if you are ever experiencing a deficiency, or think you might be, spray your plants with the nutrient you think might be deficient (pH doesn't matter remember so just mix any fertilizer up with some RO and a surfactant and your ready without adjustment) and if things don't improve visibly in 12-36 hours you have a different problem.
Also, it is generally recommended to foliar feed when it is not the heat of the day (dusk or dawn), so for indoor growing it is better to raise your lights and foliar feed shortly before lights out. Then give a very light (you don't want to wash off the nutrients) misting of just water shortly before lights come back on the next day to aid the remaining nutrients in entering the leaf.
I hope this information is as interesting and helpful to other farmers as it was to me. If anyone is curious to know more, I have a whole binder full of notes from a class I took with this guy that was focused entirely on fertilizers, and would love to share the wealth of knowledge I have gotten from this professor so just shoot me a PM or post here.
-Meeks:pimp:
