If ever there is a mountain made of a mole hill in the indoor gardening industry, where the logic of 1+1=3 is reasonable and ten products can be justified from two elements – I think bloom boosters fit the bill. In contrast to field-crop agriculture, horticultural nutrient companies often recommend combining base nutrients with various bloom boosters in the early, mid, and near-end of the flowering cycle. To the inquiring hobbyist grower redundancy can seem like an understatement since similar minerals are present in various boosters; and, in contrast, the science they’re founded on might seem as hypothetical as opinion when the grower seeks clarification on the reasoning behind their differences. In the end, to some, it seems surety is abandoned for a faith-based trust in nutrient companies to provide us with bigger, better, and more profitable yields. Are bloom boosters based on science or snake oil? Let’s take a look at a few products that hopefully serve to represent the numerous boosters available.

Turn the N knob to Low:

So the first thing you noticed is the mass majority of “boosters” have little or no nitrogen. Boosters are traditionally phosphorus and potassium at various ratios, and often a bit of other stuff like magnesium or sulfur. This is not the recent brain child of growers in Mendocino or B.C. but an older wisdom passed down from the agricultural field crop researchers from the 17th through to the 20th century. Early testing showed that soils with too little NPK, or lacking the conditions for availability of the elements, responded well to fertilization – and furthermore that too much nitrogen when the plant’s metabolism is shifting to reproduction delays the transition as the nitrogen induces vegetative growth. A trial published in 1951 further concluded that, though the reproductive stage requires a higher ratio of PK to N, without the nitrogen yields dropped over 50%. Because high-PK boosters are recommended for use in conjunction with regular nutrition, the general absence of nitrogen in the boosters serves to tip the scales while continuing to provide regular “base” nutrients.

Early bloom

Historically farmers would use sun-dials and count the hours of the day. Once the days became 14 hours or less the farmers would apply a hefty dose of phosphate and potassium, irrigating it in using bamboo shoots as tubing and a water wheel to pump the nutrient solution. They would mark their calendars “week 1″ and this would begin their “bloom chart” for the season. For real? No.

Looking into the “first week of bloom” booster phenomenon, and where it originated – and particularly some data to support the notion – has left me stumped. From what I can surmise the appearance of early bloom boosters originates many years ago with Rambridge’s Blossom Blood, which is to be used once the first flower or fruit is initiated. The premise is that a slightly-acidic nutrient solution promotes flower development, and the product holds the solution at a stable optimal pH. The label states it is a “selective pH control water treatment” and peripherally notes Monobasic Phosphate as an ingredient. This may entail a phosphate buffer as a mixture of K2HPO4 and KH2PO4 or maybe Na2HPO4 with citric acid – we can only guess. At just over $220 for 300g it’s certainly not an inexpensive ‘”buffer.”

Grotek, who produced the next generation of early bloom boosters, have included a fairly sizable PK into their flatteringly named Blossom Blaster. With an NPK of 0-39-25 this Grotek booster is used in weeks 1 and 3 with the allusion that an immediate alteration of the nutrient ratios will “contribute to proper plant maturation.” Blossom Blaster’s mainstay salt is monopotassium phosphate [MKP] and retails for around $240.00 for 500g.

Advanced Nutrients then marketed a similar “first week of bloom” booster called Bud Blood (bless their shamelessness, all of them) with the same NPK as Grotek’s. Bud Blood is derived from a few different source ingredients than competitive products and retails in the zone of $273.50 per 500g.

Alltek brand’s Flower Blood reinvents the 0-39-25 with the inclusion of Phloxine, a phytotoxic red dye alleged to stimulate leaf senescence, and Allantoin, a plant hormone present in plants during flowering and considered to induce or quicken the metabolic shift to bloom.

Other boosters used early in the bloom cycle include: Top Load, Dr. Node’s, Phosphoload, Megabud, et al. These products are sometimes used for controlling vertical growth or reducing the space between nodes in blooming plants – which can be ideal for indoor gardening in restricted spaces. Consideration should be made to ensure your chosen early bloom booster is appropriate for your crop demands; and, if required, that it meets criteria for human consumption.

Mid-Bloom

Years ago if a person ventured into using a bloom booster it would have likely been an 0-50-30, whereas, in recent times, that tendency has evolved into the confusing lower-NPK boosters and stimulants often packed with bio-active ingredient. The “old school” realm of 0-50-30 includes Grotek’s Monster Bloom (0-50-30), FHD’s Ton O Bud (0-49-42), Rambridge’s Monster Blood (0-50-30), and Advanced Nutrients’ Bloom Booster Pro. There is not only a commonality between these products’ stated mineral profiles, but as well of labelling – the Rambridge, Grotek, and Advanced Nutrients products all feature a reddish composite flower; Ton O Bud being unique in that regard. Prices are around $65 for 500g of the 0-50-30.

General Hydroponics’ Liquid Koolbloom (0-10-10), Canna’s PK 13/14, and competing Hammerhead PK 9/18 by Advanced Nutrients continue along the mineral path, each presumably delivering the perfect ratio of P and K to compliment the manufacturers’ respective base nutrient schedule. In the zone of $30 a liter these boosters are likely WYSIWYG – a safe bet to boost your plants without including hormones or other undeclared compounds which may or may not be proven safe and effective.

Among the bio-stimulant bloom boosters is Massive which claims “over 80 different organic compounds” and labels Gibberellins [GB] and Triacontanol [TRIA]. Oddly enough Massive also hosts a higher N percentage than P! GB are a much discussed plant hormone without a lot of data relative to its use with short-day annual plants, and though claims are made within hobbyist circles they are ambiguous. Numerous amateur trials have been conducted on GB to reproduce the dramatic cell elongation that caused it to be discovered initially in rice patties presuming it would deliver larger blooms, yet the tests are not entirely conclusive. TRIA is a plant hormone found in alfalfa (cuticula of various plants) and beeswax. When tested in nanomolar concentrations TRIA has shown to increase cell density, total chlorophyll, and drastically increase photosynthetic CO2 assimilation. Numerous articles on various plant species are available in scientific journals citing the benefits of TRIA, and rest assured Massive is not the only product which contains it; however debate still exists as to the plant-availability of TRIA without adequate solvency.

Listed as a “beneficial” but commonly considered a booster is Advanced Nutrients’ Big Bud (0-10-40 and 0-1-4 hydrated) which includes a hearty dose of magnesium as well as an assortment of L-amino acids. L-amino acids have been found to affect numerous plant processes from root development, protein synthesis, enhancing photosynthesis – as well as providing nutrients and improving the microbial conditions of the soil. During times of stress plants do not synthesize all L-amino acids, so Big Bud may make a suitable transplant nutrient in the right dilution.

Late Bloom

The repository of old feed charts speaks volumes about how much variability there is to late boosters. The base nutrients in each recipe are not identical, and though one may assume for simplicity that each recipe will, in the end, target a similar nutrient ratio, that is not necessarily the case. Without clear evidence of what might be “the best” the consumer is often left to chose a recipe based on gut instinct and advice from other growers.

Keepin’ it simple with the mineral salts is the time-tested Kool Bloom powder by General Hydroponics that appears fairly often in various recipes. Kool Bloom (previously Kabloom!), rockin’ the 2-45-28, comes in 2.2lb packs for only $45. Bustin’ out the Super Phosphate is Supernatural Brand’s Bud Blaster (1-52-31) used in conjunction with Super Boost (10-49-10) which is also garnished with a dash of B1. Super phosphate is not donned on a lot of labels making Bud Blaster a fairly unique and potent high-phosphate option at around $95 for 500g. A more recent addition to the late booster family is Overdrive (1-5-4) by Advanced Nutrients, which hosts a mineral profile quite similar to their 3-Part Bloom. “Overdrive” retails for around $39 per liter.

We can see a trend in high-PK boosters, leaning clearly towards the phosphates, but not all plant scientists agree that phosphorus is the key in final stages. Dr. K by Alltek is a hefty dose of potassium in its chloride form, and is claimed to be ‘designed to harden flowers at the ripening stage.’ ‘Muriate of Potash’, as it is also known, is a well utilized agricultural staple worldwide; and contrary to common presumptions the chloride is not reactive like chlorine and has not proven harmful to microbiology or roots. That said, in limited drainage situations chloride can accumulate and become toxic, so it is not often included in liquid nutrient formulas.

Finishing the late boosters is Green Planet’s “Finisher” which is the antithesis to the high-PK paradigm – as it contains none. Finisher’s ingredient includes ‘organic enzyme activators, vitamins, essential amino acids’ – aka The Other Stuff, including another dose of TRIA to spice things up. If the lack of PK bewilders you, I would get used to it. The bio-chem soup of barely pronounceable plant extracts and patented molecules is the way of tomorrow. If you understand and love your mineral salts, they will probably never disappear from the store shelves – but make way for the new generation of bloom boosters and stimulants that boggle the mind!

Previously: Grow Store 101: Base Nutes and Organic Enhancers
Next up: Grow Store 103 – Bennies and Bugs and Buffers (oh my!)

by Hydroguy

(Image credit: University of Guelph.)

If you’re one of those crazy soil-gardeners who believe that manure is heavenly and should be revered, well … clearly you don’t manage an intensive hog operation. These factory farms are dealing with an environmental (not to mention ethical) crisis: phosphorus pollution of surface and groundwater, as a result of the massive manure lagoons and run-off.

Developed in 1999, and now on its way to commercial production and a place on grocery store shelves, the Enviropig^TM is apparently the solution. Perhaps we should instead question the problem. Intensive hog “farms,” cattle feedlots, and intensive egg production and poultry facilities are creating toxic wastelands, treating the animal inmates as nothing more than animated foodstuffs.

Hog confinement operations typically consist of a sow barn containing an average of 5,000 sows, a nursery barn with about 19,000 piglets, and a finishing barn with 12,000 to 14,000 pigs. (Photo credit: Friends of Family Farmers.)

In contrast, small-scale agriculture sees manure as a necessary part of building healthy soil and producing nutritious, healthy food. “Everything in moderation” is the key to a sustainable model of agriculture, and clearly the intensive, industrial models we’ve adopted are not working.

So, What’s For Dinner?

The Enviropig is now on its way to landing on Canadian plates, with Environment Canada recently determining that the Enviropigs are in compliance with the Canadian Environmental Protection Act, and therefore can be produced outside of the research context in controlled facilities. Submissions have been made to Health Canada and other federal agencies – including the U.S. Food and Drug Administration in 2007 – to have the pigs approved for human consumption and commercialization. At this time, no country has approved products derived from genetically engineered animals for human or animal consumption.

But given our North American governments’ laissez faire attitude toward genetically modified food, Enviropigs will no doubt soon appear as bacon, sausages and ham on grocery store shelves. The best part? We won’t even be able to tell, because both Canada and the U.S. refuse to require mandatory labeling of genetically modified food.

Phosphorus is one of the ‘big three’ major elements that’s vital to the growth and health of plants. It assists in converting the sun’s energy and other chemicals, such as nitrogen, into usable food for plants. A phosphorus deficiency is definitely something that every indoor grower wants to avoid as it invariably leads to sick-looking, stunted plants that produce smaller, lower quality fruits and flowers. Not good! So is the answer to bigger yields simply to pack on the P? Well, it’s not quite as simple as that, so we asked Geary Coogler from BS Horticulture for some expert advice. Here’s what he had to say…

WORDS: Geary Coogler

What’s all the noise about phosphorus these days – this idea that plants do not need the levels of phosphorus that are generally advised? The amounts recommended by agronomists and plant physiologists are accurate; the problem comes in interpretations made by the marketing departments of some companies or in the minds of self-purporting experts. Nutrient recommendations and applications are made with numerous variables in mind based on medium composition, plant variety, pH, temperature, moisture, nutrient interactions, plant requirements, economics, etc., and not just pulled from the air nor based on a layperson’s understanding of karmic forces or scientific data.

A FIRST LOOK AT PHOSPHORUS

So how do we understand the relationship between plants and phosphorus? We start with the basics – these include many processes and other elements as well. Every element has its own weight different from all the others: one atom of nitrogen weighs less than one atom of oxygen which weighs less than one atom of magnesium which weighs less than one atom of phosphorus and so on. Molecules are combinations of atoms that are expressed in combined weights of all the elements in the molecule. Fertility components can be “elemental” (based on the pure form of the nutrient, such as calcium) or “molecular” (based on a combination of atoms, such as nitrates, sulfates, or phosphates).

This is how the plant takes up the nutrient components. It can also be how it is measured on labels and reports. Few, if any, nutritional elements are taken up by the plant as applied and must either change form, change ionization properties, or disassociate; this is especially true of phosphorus as it requires a special pathway (known as an H+-HPO42- symporter) that takes it up as a phosphate ion after activation.

All applied nutritional components are under competitive pressure in the root zone from not only the plant, but the environment as well, including temperature, pH, interaction with other elements, and other life forms. Most elements are more concentrated in certain areas of the plant based on the plant itself: for example, leaf tissue (mesophyll) will have as much iron and manganese as it does sulfur and magnesium, while phosphorus is present in larger amounts in root and flower tissues (especially seeds). It’s important to note that the only way to have a complete picture of the composition of the plant is to analyze the entire plant: roots, stems, leaves, shoots, flowers and seeds.

A DEEPER UNDERSTANDING OF PHOSPHORUS

Phosphorus is used by the plant in the formation of such things as sugar phosphates (stores and transfers energy), nucleic acids, nucleotides, coenzymes, phospholipids (membranes), phytic acid, and high energy phosphate bonds (ADP, ATP). The main entry point into assimilation pathways of phosphate occurs during the formation of ATP (adenosine triphosphate), the energy currency of the cell.

ATP is the energy for almost every process in the plant, from uptake of nutrients, conversion of nutrient complexes such as nitrate to release the nitrogen, to production of DNA and cell division. Photosynthesis is a well known general process which produces ATP through photophosphorylation. Respiration produces ATP through an oxidative process known as oxidative phosphorylation. Power used in homes and industry is measured in Watts, which gives a value for the amount of energy needed to make things work; ATP is used by biochemists to indicate the energy needed to make biological processes occur.

The phosphate group is the energy and, once incorporated into ATP, can be converted to energy or transferred by many different processes to form all the phosphorylated compounds found in a plant. These groups may also form other energetic compounds that function the same basic way in specific processes. The entire pathway and its many routes are known as “phosphate assimilation.” Phosphate is required to transport most elements into the roots, through cell membranes, and to change the nutrient into usable forms; without it, the plant would starve or, rather, not grow.

There are many different elements that compose plant tissues. Some elements like sodium can be more specific to certain plants, like cacti and grasses, while others (like nitrogen, carbon, phosphorus and potassium) are required by all life forms. Concentrations of elements in plant tissues are expressed in terms of “adequate levels,” which means that enough are present to ensure availability when needed for the many processes and metabolites present in plants. There are levels that are considered high, especially in nitrogen and the heavy metals, which can cause problems, sometimes to the plant but mostly to those animals and life forms feeding off of the plant tissues. Table 1 gives a fairly accurate yet general idea of those elements needed and the concentration they are used in. It is apparent by examining the table that, while some elements are equal in percent composition, there are differences in the actual number of atoms. This goes back to the first point made here, that each atom has its own unique mass; weights are different. Hydrogen, carbon and oxygen are considered critical nutrient elements for the plant, but are obtained through water or the air and not applicable to this conversation on applied fertilizers.

NUTRIENT LABELS: AS EASY AS N-P-K?

Let’s talk about labels on fertilizer bottles: how do you interpret them and what do they mean? There are as many fertilizer label requirements as there are countries and, in the United States, as many states. Labels are used to represent to the grower the contents of the nutrients and other constituents of a mixture, slurry, or homogenous blend of nutrient or nutrients. In most incidences, these labels are politically acceptable, not necessarily scientifically acceptable, and sometimes based on archaic methods of measuring. In the case of phosphorus, labels are based on a by-product of burning the compound in enriched air. Science, unhindered by politics, deals with getting as close as possible to an accurate reflection of true events. There are several ways to represent the content of these fertilizers, not one most accurate way, and several politically accepted ways. These are Mass/Mass (m/m) or Mass/Volume (m/v); in North America, and some other countries world-wide, this is done Mass/Mass as grams of element per kilogram of fertilizer. (The other is Mass/Volume or grams/liter.)

On all North American labels that are registered, elements are given as a percent of composition in terms of weight: for every kilogram (or pound) of fertilizer material there is X% by weight of the identified nutritive element. In general, the biggest or first three numbers that appear on the front or back (or both) of the label represent nitrogen to phosphorus to potassium (N-P-K): for example 10-10-10. The additional elements may be listed under the Guaranteed Analysis section of the label, if the company wants to guarantee those elements, in the same percentage format. N-P-K elements are macronutrients and considered major elements, but macronutrients include other elements as well (see Table 1).

Currently, nutritional elements are classified as either macro or micro elements based on the relative amount used by the plant of the measured component. The term component is used on purpose because it could be a molecule that is measured and not a single element; for example, phosphorus (P) is measured as phosphate pentoxide (P2O5), and potassium (K) is measured as potassium oxide (K2O). This means that the percent weight is not just for the element looked at but includes the additional elements: in this case, oxygen (O). Nitrogen (N), on the other hand, is given as only the N, but the Guaranteed Analysis section will state where the N is derived from and will state this as a percentage of the nitrogen component as derived, since different forms of N behave differently and possess different properties. So, while the percentages are correct on the label, not everything is that straightforward and must be calculated to arrive back at the actual amount being applied. When two- or three-part nutrients are used, for example in some liquid fertilizers, add the similar element numbers together in order to arrive at the correct concentration.

Example:

Let’s determine the actual concentrations of nutritive elements as taken from a North American label where percentages stated are Mass/ Mass. A 50 pound pail of a liquid-based fertilizer has N-P-K values given as 10-20-10 (a suspected 1:2:1 ratio). In the Guaranteed Analysis section we have the following additional information:

Total Nitrogen (N)…………………….. 10%
10% Nitrate Nitrogen
Available Phosphate (P2O5)……….20%
Soluble Potash (K2O).…….…………..10%

This means that 10% of 50 pounds, or 5 pounds, is elemental N since it is listed as N, not a compound; 20% of 50 pounds, or 10 pounds, is P2O5; and 10% of 50 pounds, or 5 pounds, is K2O. These are the Commercial Percentages of the fertilizer package. For the elemental percentages, a conversion is required since both K and P weights include oxides. In this example, the percentage of actual P in the oxide form P2O5 is 44% and the percent K is 83%, so the actual weight of elemental P is 4.4 pounds (10 x 0.44) and K is 4.15 pounds (5 x 0.83). So the corrected numbers read 10% – 8.8% – 8.3%

So the actual ratio in the fertilizer of single elements in this example is 1.0:0.88:0.83 N-P-K, not the 1:2:1 the label indicates. All other elements given, whether they are actually taken up as a complex like sulfates or in elemental form, are expressed on the label as the elemental version, like nitrogen. In different measures of Mass/Volume, the numbers would be different and are also based on specific gravities. An example would be a root/flower additive fertilizer where the North American Mass/Mass convention would show a 0-10-11 NPK value. This might have Mass/Volume percentages expressed as 0-13-14, which would be dependent on the material it is derived from. The ratio is what is truly important: how much of each element is provided. Using higher or lower numbers is relevant to the amount that is applied as long as the ratio is close. Each species or, sometimes, variety of plant has a ratio specific to its needs even though many plants have identical needs and are sometimes grouped according to these needs. So given three different fertilizers labeled 0-10-11, 0-20-22, and 0-30-33, the ratio stays close and only the amount applied needs to be adjusted based on the needs of the crop. This is because, in the end, the root zone needs to have a certain amount available for the plant across the amount of time the plant needs to take it up, and many variables can and will affect this as a nutrient moves from the bottle or bag to the utilization sites in the plant.

LIMITING AGENTS

Limiting values are the speed limits of growth and development in a plant or any other life form. This is true whether it’s carbon dioxide (CO2) in the air, water in the soil, or a single element: any of these factors that are limited in availability will determine the potential for the plant’s development. These are known as Limiting Agents. Perfect ratios and amounts of fertilizer can be applied to a plant, but if available carbon (C) is limited by a lack of CO2 in the air, the plant will not be able to utilize all the applied nutrients, nor can structural elements and other processes be built or occur, and the plant fails: the limiter in this case is C.

In any system, the goal is to ensure that adequate levels of all the input components are maintained across time and adjusted when needed. This is because a plant requires different levels of some elements at different times or stages in its development. Most nutritive elements, as mentioned earlier, should be kept close to the needed levels because they tend to accumulate in the tissues of the plant where they can become toxic to the plant or to the animal that consumes it. The ratio in the root zone closely matches overall plant tissue composition; it is the overall concentration that gets growers in trouble with salt burns. Also, other factors can greatly influence nutrient availability to the plant such as pH or substrate composition and nutrient formulation. It does no good to apply the correct ratio of NPK if the pH is out of bounds since these nutrients will be made less or more available to the plant and will express this difference in tissue composition.

There are many ways or forms that can be used to engineer a fertilizer. For instance, nitrogen can be applied as ammonium nitrate, potassium nitrate, calcium nitrate, urea, etc., but each is different and each brings other components to the table. Phosphorus can be applied as superphosphate, triple superphosphate, monopotassium phosphate, ammonium phosphate, or bone meal, to name a few. Each of these must be “activated,” broken down, or form-shifted in the root zone in order to be taken up in one of the three forms of phosphate accepted by a plant. The pH of the environment will affect the form of the phosphate’s availability and will limit the ultimate availability of the desired monovalent form H₂PO₄^- at normal pH ranges between 5.2 and 7.2 by converting the phosphates into the unusable form H₃PO₄ or the less desired divalent form HPO₄^2-.

The phosphates will bind other available elements as well as to substrate particles and become unavailable to the plant even though they’re still showing in the system. So fertilizers must be designed not only to provide the right ratios of elements in the right amounts, but also for a dynamic environment of temperature and pH fluctuations and across different substrates.

RATIOS

Ratios are the true indicator of the correctness of the fertility program. When designing a fertility program, it is critical to know all the sources of nutritive elements available to a plant, and what those ratios and concentrations are. By knowing these, the rest of the question is a math question.

If the grower is using a medium that has a starting fertility ratio of NPK 0-1-0.5, and the plant shows a total tissue ratio of 4-2-3, then they will have to add a ratio of 4-1-2.5 to get the correct fertilizer addition needed. However, it must be remembered that these are at perfect values of pH, temperature, and across the growth cycle, and the values are seldom perfect.

Plants seldom take up nutrients equally and will influence the root zone to give up more of what it needs. Plants also change their needs slightly during development whereas tissue analysis is a slice of time, so tissue taken at the end of the crop cycle will only show the cumulative value of these stages and not reflect how a plant takes these nutrients up over time. Juvenile plants take up a different ratio than flowering plants do; when a plant anticipates seed, it will begin to accumulate phosphates.

Where the nutritive elements are all correct except for one of them which is low, then the low element will be the limiter: where this is a minor (micro) element used only in a few processes, say sodium, then the effect, while present, is minimal. In the case that a major element is the limiter, say phosphorus, then the effect can be dramatic because those compounds made from phosphorus will not be complete, and those processes dependent on P will not occur such as nutrient uptake, transport, and conversions. By applying sufficient concentrations of these elements in the correct ratio, along with the proper environment, the plant never sees a limiting agent and growth will proceed at the maximum genetic possibility.

It is important to apply sufficient concentrations of these elements, but caution must be observed in not applying too much: and here both high concentrations and incorrect ratios can play a hand. Just because one nutrient is limited does not mean the plant will avoid taking up all the other needed elements. These unused elements usually find their way to the vacuole of the cell and there they remain: vacuoles not only provide water storage and structure support, they also serve as garbage dumps. Heavy metals like copper, boron, molybdenum, and manganese cause issues in animals that consume them: plants will also accumulate non-nutritive elements such as lead and uranium if present in the available or free form in the root zone. Where not enough ATP is available to totally convert nitrates to usable N, then nitrites can accumulate. Excess ammonium shunted to the vacuole converts to nitrates and nitrosamines, a cancer-causing agent. Keeping these ratios close, while avoiding limiting values, is the ultimate goal of a fertility program, and the best way to keep consumers consuming.

PLANT NEEDS

So what does a plant need in the way of phosphorus, how do we provide this, and what can we expect over time and development? The best way to know a plant’s needs is to know what makes up the plant and the ratio of these elements to each other. Once this is known, and once what exists in the substrate is known, it is fairly easy to apply the balance by using several known fertilizing materials. However, it is equally important to know these values at the different growth stages of the plant and adjust at each stage.

The other way is to use a product that was designed, based on the plant itself, from research done correctly by the company that produces the fertilizer (a complete fertilizer), based on the substrate involved. Care must be taken by the grower to get all the variables correct, such as pH and temperature, or at least to give the company what it asks for. It is equally important to use the substrate it was designed for, as these will cause those ratios discussed earlier to change. The grower must be sure to follow the guidelines of the company closely, taking care not to substitute products as most will provide different levels of the components or in a different format.

Equally important, from the balance point of view, is to provide the ratio that the plant wants when it wants it. A plant’s need for phosphorus goes up during the earlier stages of flowering, then falls back to completion; but still the need has been escalating across the plant’s development all along. This is known as the Phosphorus Utilization Curve, appearing as a bell curve on a graph. The only additional phosphorus a grower needs to apply is the amount the plant requires that the main fertilizer does not contain, and that will vary over time: the ratio game again. The plant will change the environment around the root surface to influence the activation of phosphates to bring them into the plant. The total need for phosphorus in the root zone will ultimately be based on not only the need of the plant, but also the level of activity the environment will have on ultimate phosphate availability.

SPECIAL CONSIDERATIONS

The phosphorus pathway in the plant is wide and all encompassing. Phosphorus starts out in the seeds at high levels to ensure the plant has enough to initiate all the metabolic processes it will require, as well as the growth processes. ATP is used to build structure, chemical compounds, and uptake the other elements needed for these processes. More phosphorus is found in root tissues because much is needed to move nutrients into the plant and into the transport pathways. It comes into and is turned into ATP for use locally or transported to all the other cells to be transformed into ATP or used as ATP (assimilated). Once it is the form of ATP or one of the other energy components, it is released for the energy and then is free to be used in the formation of other phosphorylated compounds. It can also be converted back to ATP. More phosphates are also found in the flowers themselves because of the decrease in produced ATP locally, and because the plant is accumulating phosphorus for the seeds and other energy-draining requirements of the flower tissues, such as pollen.

In some substrates, such as mineral soils, roughly 50% of the phosphates applied are rendered immobile and become permanently fixed in the medium. As a result, more has to be added to accommodate this capture, so while the amount added is higher, the amount realized is lower. Plant mediums that have active micro-life will also see a depletion occur of available phosphorus that is used by the micro-life since ATP serves all life forms in equal roles. The pH of the soil solution will affect available phosphorus as will temperature and overall concentrations of other elements such as potassium, a synergistic effect which is a ratio issue as well. The grower has to be aware of all these variables in designing a fertility program for their crop. Most nutrient lines are designed with the line in mind: in other words, the ratio, composition, source, and application rate of each component product adds to the final ratio of every nutrient that would be required by the plant.

THE MARKETING EFFECT

The noise level about phosphorus is just that: noise. Numbers on fertilizers are legitimate in most incidents, especially where regulated: these are not wrong. They do nothing but indicate the concentration of the constituent elements. The type or source of these elements can be a determining factor in final availability based on the overall system. Complete fertilizers are designed to provide the correct ratio of the elements required once the entire line is mixed according to instructions.

The problem with phosphorus is knowledge, and old laws that dictate how to measure and report the element. When viewed correctly, phosphorus should be in the correct range as adjusted for the root zone environment. Knowing how to read and accept both labels and reported findings, and interpret the data, is critical in determining the truth behind the advertizing and statements made about products and results.

WHAT TO LOOK FOR

What should the grower be looking for? First, a grower must decide if they are going to use an off-the-shelf version of a complete fertilizer or build their own. An off-the-shelf product must be designed for their plant/crop and the methods they will use to grow. Building a fertilizer takes some extensive knowledge of chemistry and horticulture; this is generally not the best method for growers of smaller commercial operations or hobbyists.

Phosphorus can be applied in many formulations depending on the base mineral it is derived from. Base minerals have other elements associated with them: some good, and some not-so-good. For example, monopotassium phosphate with an NPK analysis of 0-10-11 commercial and 0-4.4-9.13 elemental applies potassium (good) as well. Or sodium nitrate with an NPK of 15-0-0, elemental, but it also applies sodium as well (not so good).

The bigger the phosphorus number, the less will be used. Make sure that it is small enough to not make costly mistakes when applying smaller measured amounts. Bigger numbers may or may not decrease the unit cost of phosphorus as it is based on a different mineral which sometimes has costly other materials attached. Diammonium phosphate has an NPK of 21–53-0; the nitrate is expensive and the composition of the product is going to require some balancing with other components and care in application as it is very acid-forming. Using an off-the-shelf version will probably offset most of these issues and make for an easier process of application.

The grower should be aware of two issues: the first is nutrient contamination and the second is the fact that nutrient sources will vary in characteristics and availability. Some nutrient constituents become contaminated with other elements either through the mining or the manufacturing process. Contaminants such as lead or other heavy metals can accumulate in the plant to injure the plant or the consumer. Some nutrient constituents can have adverse effects on pH, be less soluble and therefore less available, or can be in a less than desired form. The ammonium ion, while an acceptable source of nitrogen, becomes less acceptable as the concentration increases to the point of becoming toxic. So, the grower should look for nutrients that are high quality, clean, and designed correctly. Find or request the heavy metal analysis for the nutrient line before using the products: this will tell how clean they are.

For complete fertilizers, the grower should be dealing with a quality company that has the grower’s success in mind: one that does the research, in a legitimate manner, and maintains high quality standards. This is especially true for complete fertilizers or fertilizer lines, and it goes further. The company should understand all the relationships that affect delivering nutrients to the plant and should never, never attempt to sell their products based on the shortcomings of their market’s (consumer’s) knowledge levels. A good company will educate the market and hold true to the science: a market-oriented company will sell the glitz and make the science fit its ends.

Bibliography

Brady, Nyle C., and Ray R. Wells. The Nature and Properties of Soils. 13th. Upper Saddle River, NJ: Prentice Hall, 2001.
Epstein, E. Mineral Nutrition of Plants: Principles and Perspectives. New York: Wiley, 1972.
Epstein, E. “Silicon.” Annu. Rev. Plant Physiol. Plant Mol. Biol. 50 (1999): 641-664.
Paul, E. A., and F. E. Clark. Soil Microbiology and Biochemistry. 2nd. San Diego: Academic Press, 1996.
Plant Research, B.V., interview by Geary Coogler. Conversations on Phosphorous Utilization Oosterhout, (October 27, 2009).
Schwarz, A., W. Wilcke, and W. Zech. “Heavy Metal Release from Soils in Batch pH (stat) Experiments.” Soil Sci. Soc. Am. J. 63 (1999): 290-296.
Taiz, L., and E. Zeiger. Plant Physiology. 3rd. Sunderland: Sinauer Associates, Inc., 2002.
Yamagata, M., and A. E. Noriharu. “Direct Acquisition of Organic Nitrogen by Crops.” JARQ 33, no. 1 (January 1999): 15-21.

Greetings Urban Gardeners.

Let’s take a look at how we can get the most out of our hydroponic nutrients, otherwise known as “nutrient management.” Now, to the skilled grower, nutrient management represents an opportunity to enhance plant growth, enjoy bigger yields and achieve higher overall crop quality. However, to the novice it can represent a difficult challenge or even a complete mystery! The difference is in knowledge, understanding, environment and equipment.

Here are six questions to test your nutrient knowledge. Do you already know the answers?

Your nutrient solution should be maintained at around 68 °F (20 °C) for the best combination of oxygen content and uptake by the roots.

Q2) What is the “dissolved solids” content of the water you use to mix your nutrient and does this content vary greatly from season to season? Does your water supplier provide you with good water from one reservoir at one time of the year and bad water from a different reservoir at another?

Test your water with an EC meter before adding anything to it.

Q3) Are there any components (such as high levels of calcium or magnesium) in your water that could affect the availability of other nutrient  elements? Have you considered the presence of sodium chloride from sea-water contaminating your water supply?

Ask your water supplier to provide you with an analysis of your water. Some grow stores also offer this service.

Q4) What is the “EC” or strength of your nutrient? Do you mix special nutrient blends for different kinds of plants and for each stage of the crop’s lifecycle, or in response to different environmental conditions like high temperatures and low humidity?

If you are unable to prevent temperatures in your indoor garden from rising too high, you can decrease the stress levels for your plants by decreasing the strength of your nutrient solution.

Q5) Does the pH of your nutrient stay within a reasonable range, or does it drift up and down significantly? How quickly?

It’s quite normal for the pH of your nutrient solution to rise (say from 5.8 to 6.5) over the course of a few days – but greater changes could indicate the presence of pathogens in your nutrient solution from contamination or from sick plants that may spread disease to the rest of your crop.

Q6) Do you change your nutrient often enough to prevent imbalances from salt accumulation or deficiencies from nutrient exhaustion?

It’s really important to change your nutrient solution regularly because it helps to minimize the wastes your plants discard into the nutrient. Did you know that, as plants transpire and nutrient levels drop in your reservoir, the EC or strength of the nutrient can rise to dangerously high levels?

What’s In Your Water?

Water quality is a crucial issue for all gardeners. Success comes easier with soft water. Just add the right combinations of nutrients to the water and you’re off to a great start. However, if you have very hard water, or water contaminated with sodium, sulfide, or any number of heavy metals, your first step may be to filter your water using “reverse osmosis.”

The best way to find out what’s in your water is to obtain a seasonal water analysis through a lab. If you’re on a municipal water system, call your water district and request a copy of their most recent analysis. Keep in mind that a good analysis at one time of the year does not mean that the water quality will remain good throughout the year. During dry seasons water suppliers often switch to a different reservoir with different water quality.

Another approach – highly recommended – is to check your water regularly yourself with a dissolved solids meter, also called an electrical conductivity (EC) or parts per million (ppm) meter. These instruments are one of the most important tools for a grower to use regularly. By measuring the EC (ppm) of your source water routinely before adding nutrients, you will be able to tell if your water supply is consistent, or changing.

How Does a Conductivity Meter Work?

All dissolved solids instruments work in essentially the same way: they measure the electrical conductivity of the water. It is the dissolved salts in most water that allows it to conduct electricity. Pure water is a poor conductor since there are none of the conductive salts found in impure water. Purified water will show no, or very low, salt content (conductivity) when tested with a dissolved solids meter.

It is not uncommon to find high levels of salts in well water or municipal water supplies. Calcium and magnesium carbonates are among the most common ingredients in tap water and in well water. In fact, water “hardness” is defined as a measure of the water’s content of calcium and magnesium carbonates. In some regions sulfates can also reach high levels in water supplies.

Since calcium and magnesium are important plant nutrients, water with reasonable levels of these elements can be just fine for hydroponic cultivation. However, even a good thing can become a problem if the levels are too high. Generally, a calcium content of more than 200 PPM, or 75 PPM for magnesium, is on the verge of excessive for most hydroponic applications. An excess can cause other important elements in the nutrient solution to “lock-out” and become unavailable. For example, excess calcium can bond with phosphorus to make calcium phosphate, which is not very soluble and therefore not available to the crop. If magnesium bonds with phosphate it becomes completely insoluble and unavailable to the plant. The key to success is to start with decent water and add the right combination of nutrients.

Nutrients – A Question of Quality

What makes a quality nutrient? Here are some questions to ask. Some answers may be harder to find than others!

• How pure are the ingredients?
• How consistent is the product?
• Is it properly labeled with ingredients and NPK?
• How reputable is the manufacturer?
• What ingredients are in there and how are they combined?
• Does the product contain contaminants from poor quality control?
• If it is a liquid, did the manufacturer use R/O or purified water in the blend?
• Does the manufacturer have a quality control (QC) program like safety sealed bottles so you know it is pure and has not been tampered with?
• Are there any hidden or ‘mystery’ ingredients?

Too Hot, Too Cold

The temperature of your nutrient solution is another important factor. If your solution is too cold, seeds won’t germinate, cuttings will not root and plants will grow slowly – or stop growing and die. If it’s too hot, the same seeds won’t germinate, cuttings won’t root and plants will die from oxygen deficiency, or they will succumb to pathogens that thrive in higher temperatures, or simply bite the bullet due to temperature stress. Most plants prefer a root zone temperature range between 65 and 72 °F (18 to 22 °C), cooler for winter crops, warmer for tropical crops. When adding water to your reservoir it is a good idea to allow it to come to the same temperature as the water in the root zone before starting circulation pumps.

Remember, plant roots have evolved in a soil environment where temperature changes occur slowly, tempered by the thermal mass of the earth. Rapid temperature changes in the root zone can cause shock and invite root disease.

Water pH

A subject that is often discussed but rarely understood by many growers is nutrient pH. Plants normally grow best within a pH range from 5.5 to 6.8. Generally we worry about pH and its affect on nutrient availability. For example, if pH is too high, iron may become unavailable. Even though your nutrient solution may contain an ideal amount of iron, your plants may not be able to absorb it, resulting in an iron deficiency – the plant’s leaves will yellow and weaken.

On the other hand, hydroponic plant foods usually contain special “chelates” that are designed to assure iron availability, even at higher pH ranges. The result is that your crop will grow reasonably well even at higher pH levels. Nonetheless, high pH can damage plants in other ways. The cause of a high solution pH can be fairly complex. Most city water supplies contain calcium carbonate to raise the pH of the water and prevent pipes from corroding. As a consequence you are starting with water that has an abnormal pH: typically 7.5 to 8.0 for city water.

One method of dealing with the high pH of city water is to mix in fresh nutrient, let it stand for a while to stabilize, then test and adjust the pH. With city water supplies you will often have to add a solution of pH down (usually phosphoric acid) to lower the pH to the suitable range for most plants.

As your plants grow it is a good idea to occasionally test the pH and adjust it if needed. You can safely allow pH to drift between 5.8 and 6.8 without adjustment. In fact, constantly adjusting the pH in your system to maintain a perfect pH of 6.2 can do damage. It is common for pH to drift up for a while then down and up again. This change is an indication that your plants are absorbing nutrient properly. Adjust pH only if it wanders too far, below 5.5 or above 7.0 for example.  A pH below 5.5 or above 7.0 can spell trouble but don’t overreact. An apparently sudden and dramatic shift in pH can be the result of a malfunctioning pH meter. If in doubt, double-check with a reagent (color match) pH kit before adjusting your solution. Also remember that pH meters are temperature dependent. Read and follow all of the instructions that came with your meter or test kit. I know of at least one case where a grower lost a crop due to a defective pH meter after over-correcting nutrient pH.  Use a meter as well as a color-match test kit to double-check your pH.

Big pH swings can also indicate strong microbial life in the nutrient solution and root zone.  Microbes can change the pH to meet their needs.  The best way to manage this is to introduce beneficial microbes into your nutrient solution and the plant’s root zone. These microbes are nature’s little plant helpers.  The beneficial fungi typically help plants grow bigger, stronger and more effective root systems. The beneficial bacteria typically populate the root zone and protect the roots from bad microbes and environmental stress factors.

Time For a Change?

How often should you change your nutrient solution? That’s one of the most common questions asked and one of the most difficult to answer. Many people have tried to come up with a simple, easy-to-follow rule … once a week, every two weeks – but they’re all wrong! They’re wrong because there is no simple answer. It all depends on the plant variety, the number and size of your plants, their stage of growth, the capacity of the reservoir, the kind and quality of nutrient you use, water quality, environmental conditions such as temperature and humidity, and the type of hydroponic system used; there are so many factors that the answer is not obvious. Instead of a simple answer, what we need is a procedure that takes many of these variables into account and is responsive to changing conditions.

It sounds complicated, but it’s actually quite simple. All it takes is a little monitoring and some basic record keeping.

• Start with a fresh reservoir of nutrient and make note of the date, pH, and EC or PPM of the solution.
• As you run the system, the level will drop in the reservoir. Note the EC/PPM level then top-up the reservoir with fresh water. Test again for nutrient concentration. If the nutrient strength has dropped significantly, add a bit of nutrient to bring it back up to specs. Be sure to record how much water you added to top-up the reservoir. Repeat the procedure every time you top up the system, carefully recording the amount of water added.
• When the total amount of water added equals the capacity of your reservoir it is time to drain and replace all of the nutrient solution.

For example, imagine a hydroponic system in a cool greenhouse in the spring with 24 strawberry plants and a nutrient capacity of 20 gallons. Typically, such a system might require about five gallons of added water each week. After four weeks the plants will have transpired 20 gallons – the capacity of the reservoir. You need to completely drain and replace the nutrient every four weeks in this example.

Now imagine five tomato plants with a 20 gallon reservoir. They are fully mature, growing and producing quickly. It is hot and dry. Each plant pulls in a gallon a day so you are adding five gallons a day. After four days it is time to change the nutrient. It may be best to use a larger reservoir since the EC flux in this case will be pretty high.

Fascinated? Read on in the second installment of this feature in Issue 5 …

So what’s the big deal about ‘organic’ and minerals for growing plants?

There is a conflict between definitions and scientific facts. The problem is that “organic” is not defined by ecologists or scientists – it is defined by bureaucrats, by government functionaries who often don’t have a clue what they are talking about from a purely scientific point of view and are often making decisions for special interest groups including organizations that put up a lot of money to twist the rules in their favor. ‘Organic’ has become big business.

The rules that define ‘organic’ vary from place to place. European rules that define ‘organic’ are significantly different from the rules in the United States. Canada has its own rules and many states in the US have different rules. Within the United States there is the NOP (National Organic Program) from the US department of Agriculture, there is OMRI (Organic Materials Review Institute), there is CCOF (California Certified Organic Farmers) to name a few… and there are many more regulatory groups. Their rules are not the same and their definitions are not scientific. They tend to be well meaning, non-scientific, closed minded groups that ‘know better’ and will apply their views to all who wish to use the term to make money.

On the other hand, when “organic” is looked at scientifically it’s really about protecting the environment and making more wholesome products – that’s what it should mean. But the bureaucrats and special interest groups have set different definitions. Fortunes are being made by companies selling weak and often ineffective products, and sometimes even harmful products, to a largely uneducated marketplace.

As a scientist I find value in both mineral and organic ingredients – and I am really looking at products from the point of view of what works better; what grows plants better, what gives customers higher quality and larger yields and what reduces the strain on the planet. That may or may not be ‘organic.’

Fundamental to the US ‘organic’ regulations is that purified ingredients cannot be used to make fertilizers; all ingredients need to be in their natural form … with some exceptions passed for special interests. This has led to some ‘organic’ ingredients having high levels of ‘heavy metals’ and sometimes pathogenic organisms such as E. coli and salmonella bacteria (this happens with mined ingredients and poorly composted materials that contain manures or other dead animal ingredients). If the poisons are removed, the product is no longer ‘organic.’ I consider this completely absurd.

One positive note is that fertilizer regulations in many places now require manufacturers to have their products tested for ‘heavy metals.’ This is a case where the rules provide the consumer some measure of protection from dangerous produce. I find that many state regulations for fertilizers are in fact very good rules offering the consumer assurance of product quality and consistency. Many of the state regulators I have worked with for years consider the ‘organic’ rules absurd. Nonetheless, rules are rules and regulators must apply the rules whether they like them or not, that’s their job. For more info see: www.aapfco.org.

I’m in my 32nd year in this business and I take the word “organic” very seriously. I’ve worked very hard in the field of modern plant growing technologies, always from a scientific point of view. If ‘organic’ was always based on good science and consistently resulted in better and healthier produce, faster growth rates and higher yields, as well as less impact on soil and water, I would be much happier about the definitions.

Can you describe enabling vs. triggering and the theory behind nutrient manipulation?

A good nutrient formula needs to stimulate all aspects of the plant’s growth and health – roots, stems, and leaves to start – the structural period of growth. And this means high nitrogen, appropriate phosphate, pretty high potassium, appropriate magnesium, calcium, and sulfate – and then of course the full spectrum of micronutrients. The plants go through their life cycle and they are triggered to change to the reproductive mode, typically by a change in day length – this is called ‘photoperiodism.’ An indoor gardener classically alters the light cycle from 18 to 12 hours of light per day. Within a week or so the plants start to express flowering. As we see the first evidence of flowering, we change the nutrient blend into something very different so the plants are better able to produce flowers. As the plants continue to grow we can further modify the nutrient blend, making it somewhat threatening to the plants. The plants respond by converting all their growing energy to produce flowers, to prepare for the next generation. Annual crops have a limited lifetime, of course – and they have the goal of growing up, becoming strong, and then generating seed for the next generation. It’s all about reproduction for the next generation. So you could say that plants are all about sex and they are all about their children. The essence of life is defined by a limited lifetime and preparation for the next generation.

When plants are growing in a perfect happy life, when they are young and in vegetative mode, they have no particular reason to reproduce. They’re secure and growing vigorously, becoming bigger and stronger. But when the trigger comes of day-length shortening, the plants are being told by nature that the winter is coming and the end of their life is at hand. And so, at this point the plants have to completely change priorities into reproductive growth. By switching the nutrients to something that enhances flower growth and reducing nitrogen significantly – the plants are now threatened by the nutrient regimen. They are not on a starvation diet, but a modified diet that stimulates and enables reproductive growth – kind of like a goose being fed for pate. There’s a different set of priorities going on from the grower’s point of view and the crop is responding. So now the job of the nutrient is to enable the plants to produce these wonderful flowers. So we’re really now about helping that crop to flower – tremendously, because flowers are the precursors to fruit and seed. We provide the elements needed for abundant flowering and we reduce the nitrogen that was needed for early structural growth while enhancing ingredients that enable flowering.

Remember, you cannot compel a plant to enter the reproductive phase with nutrients alone. Nutrients are enablers – not triggers. Day length change is a trigger. It’s telling the plant that winter is approaching, as the days get shorter. But when you apply a trigger you also need to apply an enabler so that the plant is able to make that transition. If we were growing in a deficient environment the plant would not be able to reproduce very well, so we provide what is needed for flower production and reduce the nitrogen that is fundamental to vegetative growth.

What is the difference between vitamins and nutrients?

Plant fertilizers are a very clearly defined group of minerals. The list is exact and they are all pure elements, or basic compounds made up of elements. Nitrogen, phosphorus and potassium are the primary nutrients. Calcium, magnesium and sulfate are secondary nutrients. Iron, manganese, zinc, copper, boron and molybdenum are the micro nutrients. Silicon has been added to the list of beneficial elements, to improve plant structure. Recent studies indicate that a little nickel and a little cobalt are also helpful (primarily for beneficial organisms that live in the root environment). We know from hydroponic studies that we can grow a healthy plant from seed to harvest on only those elements if they are provided in appropriate ratios and concentrations.

Vitamins and nutrient supplements are generally composed of complex organic molecules that are usually derived from plant and animal by-products, or synthesized from various compounds. In the case of animal-based ingredients, organic growers use blood meal, bone meal, feather meal, fish meals, and manures, literally the by-products of animals. These ingredients provide fundamental NPK as well as complex organic molecules which are broken down in the soil by microorganisms. Or plant tissue and microbial derivatives, such as compost, that also contain some NPK plus myriad organic molecules. It’s an extremely complex field.

A plant’s need for a vitamin or its production of a vitamin or other complex organic molecule are often derivatives of environmental phenomena. If a plant is threatened it will convert its chemistries internally, making whatever that plant is inclined to make. Perhaps a pheromone to attract beneficial insects, or another to drive harmful insects away. Notice the difference between essential compounds, which are the elemental minerals in fertilizers, and beneficial compounds, which include many of the ‘organics’ that people are showing interest in today. You can use some of these organic products to improve a crop’s quality, growth rate, yield, vigor and health but the plant can grow without them as a general rule. Take away any one of the mineral compounds required for plant growth and that plant cannot live – it cannot fulfill its genetic destiny.

Can plants absorb vitamins through their root system?

We didn’t used to think so. And for many years I would speak the old party line of “big organic molecules can’t fit through plant roots – just the mineral elements.”  I believe I was mistaken about that and I think that we are now learning that larger and more complex molecules can travel in and out of the plant whether through root tissue or foliar – there are various modes, usually with symbiotic microorganisms acting as doorkeepers to help the molecules into or out of the plant tissue.

Microbes living in the root zone help the plant absorb many of these natural compounds. Plants have a synergistic relationship with many of the organisms living in and on the roots. Ecto (living on the surface of roots) and Endo (living within the roots) Mychorrizae are good examples of beneficial fungi that live symbiotically with plants. By populating the root zone with beneficials, the bad organisms become challenged by the beneficials. Without the beneficials the roots have no protection. We have found with studies at the University of California that in many cases the complex organic compounds become most effective when the crop is under extreme stress: for example, high temperatures, inadequate moisture, or a disease are generally high stress situations. I’ve seen treated plants recover from moisture stress (not watered for a long time) next to untreated plants that never come back; this is an osmotic pressure imbalance model where plant tissue becomes dehydrated. A lot of crops are lost due to inadequate irrigation.

Another group of compounds that help plants absorb nutrients include the Humic and Fulvic acids. These organic acids often come from Leonardite, sort of an ancient or fossil form of compost. Many regulations do not recognize ‘Fulvic acid’ since there is not a standardized test to prove the presence or concentration of Fulvic acid. Technically speaking, Fulvic acid is a low molecular weight Humic acid. Fulvic acid works especially well with hydroponics. Humic acid is slower at enhancing nutrient absorption, and much less expensive. It is favored for soil cultivation though Fulvic is superior for both soil and hydroponics. Our product called Diamond Nectar is Fulvic acid derived from Leonardite, although we can’t make label claims due to regulations.

What other compounds are used by growers?

A group of compounds called Plant Growth Regulators (PGRs) have been developed to enhance certain characteristics in growing plants. For example, rooting stimulators are used to make cuttings grow roots and become copies or clones of the original donor, or mother plant. In this case the PGR is usually IBA (indole butyric acid) or NAA (naphthaleneacetic acid), or a combination. Plant tissue naturally contains IAA (indole acetic acid), a naturally occurring rooting hormone, and as a result cuttings will root without the added PGR if given adequate moisture and oxygen. The synthetic IBA is preferred because it is stable in a bottle and quite effective; IAA rapidly breaks down and does not store well.

There are many PGRs that are used by professional growers to enhance rooting, ripening, stem elongation or shortening, and numerous other unique characteristics. The entire family of PGR compounds is highly regulated, some are natural and safe, and some are synthetic and quite dangerous. Generally they are mutagens that cause radical changes in plant morphology. Labels will warn users to use skin and respiratory protection. They are generally regulated, not as fertilizers, but as pesticides. It is a bit strange that they all fall under the rules of pesticides even though they do not function as pesticides, another case of the rules being off track. The bottom line is that PGRs are often approved for ornamental plants but not for consumables. In some cases special licensing is required to purchase and use PGRs, as is the case with many pesticides and fungicides. This is heavy chemistry and not for amateurs. This is the antithesis of ‘organic’ cultivation even though most of the compounds fall under the scientific definition of ‘organic chemistry.’

I am aware of cases where manufacturers have added PGRs to fertilizers or supplements without proper registration or even a mention on the label. This is an area of moral responsibility and too many people are drawn by a desire for profit at the expense of the consumer’s safety. It is especially troubling for those who consume the produce grown with these powerful chemicals.

I will close by saying that, though I have issues with regulatory definitions and the way the rules are written and applied, the rules exist to protect the consumer and the environment. Growers should educate themselves and apply commonsense based on real knowledge when they grow produce for consumption. We all have a responsibility to use technology in a proper way, to grow better produce and to protect the environment. Just being an ‘organic’ grower is not enough. We are learning new things all the time and with the accumulation of knowledge and experience we can be productive and profitable while also being ethical.