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Symptoms of Deficiency In Essential Minerals

Iron – (Fe) (immobile in plant, immobile in high ph soil)

Iron deficiency is common in many plants, especially those grown indoors.

Deficiencies initially show as interveinal chlorosis in young leaves, with leaf veins green in color and older leaves unaffected. Leaves are smaller than normal.

Iron deficiency is especially a problem in alkaline conditions, or in wet, poorly root zone media. Iron becomes more bioavailable when root zone and nutrient water becomes more acidic, or when the proper chelates are bound with the iron.

Iron deficiency also reveals itself as interveinal chlorotic mottling of immature leaves. In severe cases, new leaves lack chlorophyll but show little or no necrotic spots. Chlorotic mottling of immature leaves starts first near bases of leaflets so that the middle of the leaf appears to have a yellow streak.

Cool temperatures, high humidity and wet root zone conditions create Fe deficiencies, especially if Fe is already in short supply.

Iron is difficult for plants to absorb and to transport. That’s why you should only use Advanced Nutrients nutrient formulas- they are properly chelated for fast and easy absorption of iron and other key micronutrients.

Plant uptake of Fe decreases with increased soil pH, and is adversely affected by high levels of available P, Mn and Zn in soils. Excessive iron causes bronzing of leaves with tiny brown spots.

Plants use iron for protein and nucleic acid metabolism, chlorophyll formation and electron transport. Enzymes (catalase, peroxidase, cytochromes) and photosynthesis components require iron.

The ratio of iron and sulfur available to plants directly affects their ability to take in nitrogen.

Iron in plants and root zones are mostly found bound to chelates; that’s why free iron levels are extremely low (10mM). Iron has to be reduced to Fe+ at the root surface before being transported to the cytoplasm (only grasses can absorb iron in the form of Fe3+). In the xylem iron is transported in the form of a iron-carbohydrate complex.

Silicon – (Si) (immobile in plant)

Silicon is a very important plant nutrient. It is a vital component of epidermal cell walls. It strengthens plants so they can fight off diseases and resist insects, drought, heat and stress.

The performance-enhancing benefits of potassium silicate are most easily provided by using a packaged potassium silicate product purchased at a hydroponics retail store. Potassium Silicate substantially strengthens plants’ ability to transport nutrients and other substances in roots and internal plant cells.

Potassium Silicate increases cell wall stability, speeds up root cell replication, builds stronger and more extensive root systems, increases nutrient absorption and resistance to stress/drought, and enhances plants’ ability to resist pathogens and insects.

Silica is a buffering and balancing substance that helps plants deal with potentially-toxic levels of salts, minerals and pollutants.

Potassium Silicate will help give your plant a larger, stronger, more vigorous living infrastructure.

Zinc – (Zn) (mobile in plants, immobile in high ph soils)

Zinc deficiencies are among the more serious of micronutrient deficiencies and should be corrected as soon as they are diagnoses.

Deficiency first shows itself as pronounced interveinal chlorosis in young leaves and mid-shoot leaves. You might also see interveinal yellowish areas starting at leaf tip and margins and eventually affecting all growing points of the plant.

Interveinal chlorotic mottling may be mimic iron and manganese deficiencies except for that it is accompanied by tiny leaves, and rosetting (short internodes).

Other signs of zinc deficiencies include grayish brown spots that form on leaves halfway up the plant and then spread. When zinc deficiency onset is sudden, such as when zinc is not present in the nutrient solution, the chlorosis can appear to be identical to that of iron and manganese deficiency.

Excess zinc toxicity often looks like copper deficiency because it interferes with uptake of copper. Symptoms of some fungal and viral diseases can resemble symptoms of excess zinc, which can manifest as upward-curling leaves.

Excess zinc can cause iron deficiencies and in extreme cases it can cause plant death, but it is uncommon to have excess zinc. One way that excess zinc can be generated is when growers use a farm feed tank or metal garbage can for nutrient water. These are often zinc coated, and the coating can come off easily and poison your plants with toxic zinc buildup.

Also be advised that some types of manufactured lava rock root zone media contain high zinc levels.

Zinc is essential for growth regulation and regulating carbohydrate consumption. Zinc improves chlorophyll function. It’s a component in many enzymes and is important in enzyme systems, particularly for water absorption and usage. It’s essential for plant hormone balance, especially auxin (IAA) activity and electron transport.

Zinc is absorbed through roots. After it reaches the xylem it is transported as a free Zn+ ion. Plants depend on several zinc-containing enzymes, including alcohol dehydrogenase. In Super Oxide Dismutase (SOD), zinc is complexed with copper by means of a nitrogen atom from histidine. Carbonic anhydrase binds carbon dioxide, which makes it possible to reversibly store CO2 as HCO3-. This enzyme, found in the chloroplast and in the cytoplasm, consists of six subunits each of which binds a zinc atom.

Zinc is essential for protein synthesis and for the activity of RNA polymerase. Zinc also plays a role in the synthesis of tryptophan from indol thus affecting the formation of indol acteic acid by the plant.

Zinc is a critical miconutrient and must be properly provided to plants in a form that is bioavailable to them.

Symptoms of Deficiency In Essential Minerals -part 4

Cobalt – (Co) (immobile in plant/immobile in soil)

Deficiencies are rare, but express themselves as chlorosis of younger leaves.

Cobalt is a chelation “bridge” that assists uptake of other metals and nitrogen fixation. It assists enzymes related to manufacture of aromatic compounds. It is also required for a few bacteria and algae.

Cobalt is essential to proper use of nitrogen Three enzyme systems of Rhizobium bacteria are known to contain cobalamin. There’s correlation between cobalt concentration, nitrogen fixation and root nodule development.

Cobalt is required for methionine synthesis, ribonucleotide synthesis and synthesis of methylmalonyl-coenzyme A mutase. The latter is necessary for the synthesis of leghemoglobin, which plays a major role in protection of nitrogenase against oxygen, which is able to irreversibly damage the enzyme.

Copper – (Cu) (immobile in plants/mobile in soil)

Deficiencies show up first on youngest leaves, young tips, buds and shoots. Older leaves develop chlorosis, growing tips die and bud development is small. Copper deficiencies cause irregular growth and pale green leaves that wither at leaf margins.

Leaves at top of the plant wilt first, followed by chlorotic and necrotic areas on leaves, and necrosis of the apical meristem (the center stem of the plant).

Leaves on top half of plant show unusual puckering with veinal chlorosis. Copper deficiencies also show on the leaf, where the petiole joins the main stem of the plant beginning about 10 or more leaves below the growing point.

Excess copper is extremely dangerous to plants. Plants can develop iron chlorosis, stunted growth and stunted root development. Toxic buildup of copper occurs quicker in acidic soils.

Copper activates several enzymes, is needed for photosynthesis, and assists metabolism of carbohydrates and proteins. It intensifies color and flavor. It is essential in several enzyme systems and in plant respiration.

Copper is a divalent cation and is taken up by the plant as Cu+ or as a copper chelate complex and transported via xylem and phloem.

Copper deficiency immediately harms activity of copper-containing enzymes, but remember, an excess of copper is toxic to plant cells.

Chlorine – (CL) (immobile in plants, mobile in soil)

Believe it or not, chlorine is essential for plant growth. It’s needed for photosynthesis. It’s an enzyme activator that assists production of oxygen from water and in water transport regulation.

Plants use chlorine as chloride ion. Chlorine is useful as a charge balancing ion and for turgidity regulation, keeping plant cells free of infection by disease. It helps open and close stomata by increasing osmotic pressure in cells.

Excess chlorine causes burnt tips and margins on young leaves. If chlorine levels are too high, cuttings will not root well, and seeds may not germinate.

High chlorine levels also cause leaves to take on a yellowish bronze color, and they are slow to develop. Chlorine is commonly used to treat drinking water, so you are far more likely to see an excess of chlorine in your garden rather than a deficiency.

If you determine that chlorine is at toxic levels in your garden, get a reverse osmosis unit or distiller to remove chlorine from the water you use for your plants.

Molybdenum – (Mb) (mobile in plant, immobile in low pH soils)

Deficiencies show up in older and middle-aged leaves first, and then show up in younger leaves.

Molybdenum is rarely deficient in most plants, but chlorosis symptoms similar to nitrogen deficiency are typical of molybdenum deficiency, along with scorching and strapping of leaf margins.

Molybdenum deficiency often occurs when sulfur and phosphorus are deficient. It can reveal itself as interveinal yellow spotting and mottling of older leaves. Deficiency also shows as pale leaves (similar to nitrogen deficiency), with some marginal leaf chlorosis. New leaves may twist and leaves may cup and thicken.

Excessive molybdenum looks like iron or copper deficiency.

Molybdenum is needed for the reduction of absorbed nitrates into ammonia prior to incorporation into amino acids. It performs this function as part of the enzyme nitrate reductase.

In addition to direct plant functions, molybdenum is used for nitrogen fixation by nitrogen-fixing bacteria.

Molybdenum is primarily present in the form of MoO4. Depending on the environmental conditions a molybdate ion can accept one or two protons. Polyanions such as tri- and hexamolybdate can be formed under certain physiological conditions. Molybdenum (Mo) has limited mobility in plants and is apparently transported through the xylem and phloem.

Several enzymes are known to use Mo as a co-factor. The two most important molybdenum-containing enzymes are nitrogenase and nitrate reductase.

Molybdenum is directly involved in the reduction of nitrogen. Nitrogen molecules bind to molybdenum atoms in the nitrogenase complex. After activation of the nitrogenase complex, the iron-molybdenum complex changes its structure and as a result reduction of nitrogen occurs. The electrons required for this reduction are supplied by an iron-sulfur protein which is part of the nitrogenase complex. This is an energy-intensive reaction.

Nitrate reductase reduces nitrate into nitrite in the nitrogen assimilation process of the plant. Nitrate reductase contains a heme-iron molecule and two molybdenum atoms. FAD, cytochromes [Fe2/Fe3] and molybdenum [Mo(V)/(VI)] are functional parts of the nitrate reductase complex and the electron transport chain. Electrons derived from NADPH are used to reduce nitrate to nitrite. The activity of nitrate reductase is reduced during molybdenum deficiency but can be restored by adding molybdenum.

As you can see, this hard to pronounce micronutrient is important to plant functions.

Types of Hydroponics – Wick

The Wick system is by far the simplest type of hydroponic system.
This is a passive system, which means there are no moving parts. The nutrient solution is
drawn into the growing medium from the reservoir with a wick.
This system can use a variety of growing medium. Perlite, Vermiculite, Pro-Mix and Coconut
Fiber are among the most popular.

The biggest draw back of this system is that plants that are large or use large amounts of
water may use up the nutrient solution faster than the wick(s) can supply it.

We have created a Custom animated application in flash to better illustrate exactly how these systems work. We encourage you to place these on your site to better inform your customers and visitors. If you would like to use this application on your webpage, all you need to do is place the code below between the <body></body> tags on your site.

<script type="text/javascript" src="http://www.hydroponicsdictionary.com/type.js"></script>

Symptoms of Deficiency In Essential Minerals -part 3

Potassium (K)

Potassium deficiencies show first in older leaves and are displayed as: yellowing; singed or scorching of leaf margins with small necrotic areas that start small and get bigger; brittle stems accompanied by withering leaf tips; interveinal chlorosis starting at the base of young leaves; reddening and upwards leaf curl in older leaves.

In vegetative stage, plants develop too slow and are stunted. In bloom phase, flowers develop slowly and fail to achieve normal size. Deficiencies of potassium are a major cause of small harvests.

Excess potassium interferes with calcium and magnesium uptake.

Potassium is essential in function and formation of enzymes and proteins. It is also essential in regulation of osmotic pressure and in most metabolic cellular processes.

Calcium (Ca)- (immobile in plant, immobile in soil)

Deficiencies show first in new, young growth. Calcium moves slowly within plants and concentrated in roots and older growth. That’s why young growth shows deficiency signs first.

Calcium deficiency symptoms include: leaf tips, leaf edges and new growth turn brown and die; chlorosis, necrosis, & distorted leaf margins; leaf tips hooking, turning brown and black, and dieing off.

Deficiency is not the only problem associated with calcium. If too much calcium is present early in a plant’s life cycle, growth is stunted. In other phases of growth, calcium excess interferes with magnesium and potassium uptake.

Calcium is transported via water to plant tissues, but if calcium levels in root zone media are too low, calcium deficiency can occur regardless of what levels are in the plant aboveground.

Because calcium is immobile, it cannot be easily translocated to the region of active growth in the shoot tip. Thus, calcium deficiency can cause severe reduction in new growth.

Although calcium may be adequate in the lowest leaves, levels in the meristematic upper plant region can still be low, causing defective upper leaf growth followed by necrotic patches in young leaves.

During early blooming phase, calcium deficiency can affect shoot growth, resulting in abortion of flower and bud structures.

Moderate calcium deficiency results in bended or twisted leaves, along with white streaks or white leaf margins in new leaf growth.

Calcium deficiencies make roots stubby and twisted and can cause root death.

Severe calcium deficiency can destroy all new growth and cause leaf mutations.

Calcium is crucial to cell elongation and is an important component in cell walls. It acts as a binding agent between cells and enhances uptake of negatively charged ions such as nitrate, sulfate, borate and molybdate.

Calcium is important for uptake of most macro and micro nutrients. Calcium is responsible for strong growth and very important in bud set and water uptake.

Calcium is a major constituent of cell walls, is critical to root and leaf development, seed production, pollen germination, cell mitosis, cell division and floral maturity.

Calcium binds primarily to cell walls and cell membranes. The high concentration of calcium in the cell wall and cell membranes provides rigidity to the plant cell wall structure. The absence of calcium causes degradation of the cell wall and lead to a softening of the plant tissue.

Adequate calcium helps plants resist fungal infections, which are often a big problem in hydroponics grow rooms.

Calcium plays a vital role in cell and root replication.

Magnesium – (Mg) (mobile in plant, immobile in soil)

Magnesium deficiencies show first in older, lower leaves. The symptoms start from the margin inwards. The leaf mid-rib and veins remain green while leaf margins are yellow or whitish, sometimes leaving a green arrowhead shape in the centre of the blade.

Interveinal chlorotic mottling or marbling of older leaves proceeds toward younger leaves as magnesium deficiency becomes more severe. This is sometimes accompanied by leaf tips curling upwards.

Chlorotic interveinal yellow patches can occur near leaf centers. In these cases, leaf margins are the last to turn yellow.

Interveinal yellow patches then progress to necrotic spots or patches and scorching of the leaf margins. In some cases, leaves die and drop off.

Magnesium shortages result in defective bud production and inadequate bud development.

Excess magnesium interferes with calcium and potassium uptake.

Plants use magnesium to: produce chlorophyll; regulate enzymes for transport of nutrients and carbohydrates in the plant; cell replication; seed production.

Magnesium is an important co-factor in production of ATP, the compound that helps plants transfer energy. It is also a bridge between ATP and enzyme activity.

Flowering and fruiting plants use more and more magnesium as they progress towards maturation and harvest.

Magnesium helps plants generate energy through photosynthesis and is also crucial to protein synthesis.

Sulfur – (S) (moderately mobile in plant, immobile in soil)

Deficiencies show up on older leaves first. Then they show up on younger leaves, turning them light green, then yellow. These symptoms are accompanied by slow growth. Leaves lose color, but veins remain green.

Sulfur deficiency symptoms are easily recognizable and are frequently confused with the nitrogen deficiency symptoms.

Sulfur deficiency causes small and spindly plants with short, slender stalks and reduced growth rate with delayed maturity.

An overdose of sulfur can cause premature dropping of leaves.

Some plants require as much sulfur as they do phosphorus. Sulfur is a component of cystine and methionine (amino acids that make up plant proteins). Sulfur is therefore a component of plant proteins.

It also has a major role in root growth and chlorophyll production. Sulfur is essential to seed production and overall plant hardiness. It is an enzyme activator and coenzyme compound. Sulfur enhances flavor and odor; it also is a formative part of chloroplasts and nucleic acid proteins. Sulfur deficiency decreases protein synthesis and causes significant reduction in leaf chlorophyll levels.

Please note that augmentation of sulfur is NOT achieved by the use of sulfur burners.

Boron – (B) (immobile in plant, mobile in soil)

Deficiencies show up first in younger leaves; they turn yellow. Boron deficiencies resemble calcium deficiencies. Symptoms include stunting, discoloration, death of growing tips, and floral abortion.

Boron deficiencies stunt roots, mutate leaves, and create brittle leaves that appear bronzed or scorched.

Boron deficiency symptoms first appear at growing points. This results in a stunted appearance and short internodes (rosetting). Both the pith and epidermis of stems may develop hollow, roughened or cracked stems.

Leaf margins discolor and die backs. Necrotic spots develop between leaf veins. Deficient leaves become thick and they may wilt with necrotic and chlorotic spotting.

If you have a potassium deficiency, plants have a hard time absorbing boron.

Excessive boron can cause the same kinds of problems as calcium deficiency cause. To complicate matters, the symptoms of excess boron can resemble the symptoms of deficient boron.

Boron is used for sugar transport within the plant. It helps with cell replication, production of amino acids, pollination, seed production, carbohydrate synthesis and transport, cell division, differentiation, maturation, respiration and growth, and water uptake.

Boron is essential for plant growth but its mode of action is poorly understood. Boron is taken in by roots and transported via xylem to other parts of the plant. In the cell membrane it is mainly present as a borate ester. Boron is involved in lignification of cell walls and in differentiation of xylem.

Boron plays a regulating role in synthesis of cell walls. as well as in stabilization of constituents of the cell wall and cell membranes. Boron deficiency immediately results in inhibition of primary and secondary root growth.

Boron regulates phenol metabolism and synthesis of lignins by forming a stable borate ester with phenolic acids.

Symptoms of Deficiency In Essential Minerals -part 2

Definition Of Plant Terms: Plant Science Vocabulary

Following are terms commonly used to name plant parts or to describe how nutrient problems look on plants.

Note that plant leaves are the part of the plant where the effects of deficiencies are most easily seen.

Here are the terms:

Mottling – Patches of green and light, non-green areas on leaves.

Firing – Yellowing, followed by rapid death of lower leaves, moving up the plant and giving the same appearance as if someone torched the bottom of the plants.

Necrosis – Severe deficiencies result in the death of the entire plant or parts of the plant first affected by the deficiency. Plant tissue browns and dies. Tissue which has already died on a still living plant is called necrotic.

Necrotic – dead spots on leaves.

Chlorosis – Yellowing of leaf tissue. A common deficiency symptom because many nutrients affect the photosynthesis process directly or indirectly. If leaves are yellow, this is a sure sign that something is seriously wrong in your garden.

Interveinal Chlorosis – Yellowing between leaf veins but the veins themselves are still green. In grasses, this is called “striping.”

Rosetting – Very short internodes.

Stippling – Small spots or dots on leaves.

Axil – The angle between the upper side of the stem and a leaf, branch, or petiole.

Axillary bud – A bud that develops in the axil.

Flower – The reproductive unit of a female plant.

Flower stalk – Structure that supports the flower. Internode – The area of the stem between any two adjacent nodes.

Internode – The area of the stem between any two adjacent nodes.

Lateral Shoot (branch) – An offshoot of the stem of a plant.

Leaf – an outgrowth of a plant that grows from a node in the stem. Most leaves are flat and contain chloroplasts; their main function is to convert energy from sunlight into chemical energy (food) through photosynthesis. Healthy leaves are lime green.

Node – The part of the stem of a plant from which a leaf, branch, or aerial root grows; each plant has many nodes.

Petiole – The leaf stalk that attaches a leaf to the plant.

Root – A root is a plant structure that obtains food and water from the soil, stores energy, and provides support for the plant. Most roots grow underground.

Root cap – A structure at the ends (tips) of the roots. It covers and protects the apical meristem (the actively growing region) of the root.

Stem (also called the axis) – The main support of the plant.

Tap root – The main root of some plants. The tap root extends straight down under the plant.

Terminal bud – Located at the apex (tip) of the stem. Terminal buds have special tissue, called the apical meristem, consisting of cells that can divide indefinitely.

Symptom Descriptions

It is unusual to find any one leaf or even one plant that displays the full array of symptoms that are characteristic of a given deficiency. It is thus highly desirable to know how individual symptoms look, for it is possible for them to occur in many possible combinations on a single plant. Most of the terms used below in the description of deficiency symptoms are reasonably self evident; a few however have a distinct meaning in the nutrient deficiency field. For example, the term chlorotic, which is a general term for yellowing of leaves through the loss of chlorophyll, cannot be used without further qualification because there may be an overall chlorosis as in nitrogen deficiency, interveinal, as in iron deficiency, or marginal, as in calcium deficiency. Another term used frequently in the description of deficiency symptoms is necrotic, a general term for brown, dead tissue. This symptom can also appear in many varied forms, as is the case with chlorotic symptoms.

Nutrient deficiency symptoms for many plants are similar, but because of the large diversity found in plants and their environments there is a range of expression of symptoms. Because of their parallel veins, grasses and other monocots generally display the affects of chlorosis as a series of stripes rather than the netted interveinal chlorosis commonly found in dicots. The other major difference is that the marginal necrosis or chlorosis found in dicots is often expressed as tip burn in monocots.

Nitrogen – (N) (mobile in plant, mobile in soil)

Nitrogen deficiencies often appear first in older leaves, and will manifest as a light green overall appearance.

As symptoms progress, the leaves turn a yellow color and stems become weak and lower leaves drop off. Necrosis develops in older leaves. New growth becomes weak and spindly. Tops and roots grow poorly.

When plants are in the mid to later growth or flowering stages, older growth and large fan leaves may show nitrogen deficiency.

This is normal during the late stage of floral development because plants near the end of their lives are using up their nutrient and carbohydrate reserves. As leaves turn completely yellow, remove them from the plant.

Nitrogen excess turns foliage very dark green and can make plants susceptible to drought, disease and insect predation.

Nitrogen is crucial to photosynthesis and reproductive function. Nitrogen makes proteins and is essential to new cell growth. Nitrogen is mainly utilized for leaf and stem growth, as well as overall plant size and vigor.

Nitrogen moves easily to active young shoots and leaves and moves more slowly to older leaves. Nitrogen is involved in the structuring of amino acids, enzymes (specialized proteins that perform duties inside plants), proteins and nucleic acids. All of these are essential for cell division and most other plant functions. Obviously, nitrogen is essential to plant growth.

The “salts” commonly used as a source of nitrogen are: potassium nitrate (KNO3), ammonium nitrate (NH4N03) and calcium nitrate (Ca (N03)2.4H2O).

Nitrate is transported via xylem to all parts of the plant, where it participates in nitrogen assimilation. Nitrate is stored in cell vacuoles and fulfills important functions in the osmo-regulation and anion-cation balance in plant cells.

Inorganic nitrogen is reduced to ammonia and incorporated in organic molecules. Ammonium in the roots is most commonly stored as organic nitrogen.

This reaction is carried out by two enzymes, nitrate and nitrite reductases. Nitrate is first converted into nitrite by nitrate reductase; then, nitrite is reduced into ammonia by nitrite reductase.

Conversion of nitrate into nitrite occurs in the cytoplasm. Nitrate reductase consists of FAD, cytochromes [Fe2/Fe3] and molybdenum [Mo(V)/(VI)].

These components form integral parts of the electron transport chain through which electrons are used to reduce nitrate to nitrite. If high nitrate concentrations are present it can also be transported to the leaves where it is then reduced.

Glutamine synthetase and glutamate synthase are key enzymes in conversion of ammonium into glutamine. It is then converted into asparagine, arginine and allantoin act as basic sources of nitrogen for all macromolecules biosynthesis.

You should daily monitor your plants, focusing on their leaves. If you see pale leaves with a yellow tinge like the picture, you may have a nitrogen deficiency. Such deficiency can slow growth, decrease harvest size and damage the overall health of your plants.

The best ways to avoid nitrogen deficiency are to use quality products, and to keep your root zone pH in the ideal 5.8 to 6.3 range.

Phosphorus – (P) (mobile in plant, immobile in soil)

Phosphorus deficiencies show up in older growth first. You will see leaf tips curling downwards.

When phosphorus is deficient, slow and spindly plants with reduced growth will result.

Phosphorus deficiency leaf damage often shows itself as patches that are dull dark green to bluish green. In severe cases, older leaf and petioles turn reddish purple.

Younger leaves appear yellowish green with purplish veins when nitrogen is deficient, but will have dark green veins when phosphorus is deficient.

Necrotic spots occur on leaf margins in advanced stages of phosphorus deficiency. Leaf tips look like they have been burnt.

Phosphorus deficiency is most common when ph is above 7 or below 5.5. Phosphorus will bind with soil very easily and this can cause excess phosphorus. Excess phosphorus can create deficiencies of zinc and iron.

Plants use phosphorus for photosynthesis, respiration, storing carbohydrates, cell division, energy transport (ATP, ADP), nucleic acids, enzymes and phospholipids.

Phosphorus builds strong roots and is vital for seed and flower production. Highest levels of phosphorus are needed during germination, early seedling growth and flowering.

Some crops require lots of phosphorus, but most require more potassium and nitrogen and magnesium than phosphorus. Several types of hydroponics plants need far more phosphorus during flowering than during vegetative growth phase.

Excess phosphorus causes decrease in the uptake of zinc, iron and copper- which starts a chain reaction of other macro and micro nutrient deficiencies.

When temperatures drop below 55 degrees Fahrenheit (12 degrees Celsius), plants have a hard time uptaking phosphorus.

Phosphorus is present in the plant as inorganic phosphate (Pi), or bound to a carbon atom. Phospholipids in bio-membranes contain a large amount of phosphorus. In these molecules phosphorus makes a connection between a diglyceride and an amino acid, amine or alcohol via a phosphate- ester bond.

Phospholipids consist of a hydrophobic tail, the diglyceride, and a hydrophilic head containing PO4. Membranes consist of two monolayers of phospholipids known as a lipid bilayer. The hydrophilic end of the phospholipids are oriented towards water (outward) while the hydrophobic ends are orientated inwards.

Phosphorous plays a very central role in determining the total energy metabolism of the plant because it forms energy-rich phosphate esters (C-P) such as glucose-6-phosphate.

Energy released during the glycolysis, oxidative phosphorylation or photosynthesis is used to synthesize ATP and this energy is liberated during the hydrolysis of ATP in ADP and inorganic phosphate. ATP is unstable and therefore turns over rapidly.

Plant cells contain two different forms of phosphate storage. Within the metabolic storage, phosphate is primarily stored as phosphate esters which can be found in the cytoplasm and mitochondria of the cell.

With non-metabolic storage, phosphate is stored as inorganic phosphate (Pi) in vacuoles.

Phosphorus regulates starch production in chloroplasts. ADP-glucose-pyrophosphorylase, an enzyme involved in the synthesis of starch, is inhibited by Pi and stimulated by triose-phosphates.

Phosphorous availability has a direct affect on the energy balance in the cell and nucleic acid biosynthesis.

Phosphorus deficiency can cause reduction in growth rate and show up as dark-green coloration of leaves, caused by accumulation of chlorophyll in leaves.

How to Make a Simple Homemade Aeroponics System

The main problem I have always had with building a homemade aeroponics system is the clogging spray nozzles. I was in a hydroponics supply store
the other day when it occurred to me the aeroponics system I was looking at
did not use any spray heads. As I looked over the new hydroponic gardening
system, I marveled at how simple the design really was. With the right pump
and correct assembly, the following homemade aeroponics system is relatively
problem free.

There are four main parts to this simple system. There is a 20 gallon (75
liter) reservoir. There are several channels 4 or 6 inches in diameter and
several feet long. Every 6 or 8 inches there is a hole drilled into the
channel to accomodate a plant. The channels are pitched to allow drainage
back to the reservoir. Next is a 1/2 inch line, run down the center of each
channel and capped at the end. All the lines are connected at the other end
by a manifold. Finally, the manifold attaches to a pump. At any point along
the 1/2 line where spray is desired a 1/16 inch drill bit is used to cleanly
make a small hole (usually one between each plant site).

First, 1/2 inch PVC is cut to length and capped at one end. Spray locations
are marked and drilled into the 1/2 inch PVC. A 1/2 inch line is run through
the length of each channel, which is made from 4 or 6 inch PVC. The line is
held in place by drilling two small holes and fastening a zip tie every few
feet.

One end of each channel will have to be sealed with an end cap. The other
end may be sealed or left open, depending on how drainage back to the
reservoir is to be accomplished. 2 1/2 or 3 inch holes are cut every 6 to 8
inches in the channel to accomodate netted pots (or other planting
containers).

At one end of the homemade aeroponics system, the 1/2 inch lines elbow out
of their channels and are joined together by a series of “T” fittings. This
is known as the manifold. One end of the manifold is left open to connect to
the pump. Your pump may be an external pump or you may use a submersible
pump. Either way, the pump needs to be able to deliver a water pressure of
45 to 60 psi to each of the 1/2 inch lines coming from the manifold.

Finally, any large, cheap, plastic storage tote may be used for the nutrient
reservoir. A homemade aeroponics system with 24 to 36 plant sites would
require a 20 gallon (75 liter) reservoir. It is always best to choose a dark
tote, to keep as much light from the nutrient reservoir as possible. This
will prevent algae growth and therefore help prevent fungus gnats. Whenever
constructing a homemade hydroponics system you should always use PVC, and
not CPVC. CPVC is known to slowly leach harmful chemicals. To prevent leaks,
be sure to use PVC cleaner on all parts BEFORE you apply PVC glue and join
the parts.

With systems becoming this simple, it is no surprise many people are
interested in the faster growth rates aeroponics has to offer.

Bonus- learn how to make an aeroponics cloner
http://www.jasons-indoor-guide-to-organic-and-hydroponics-gardening.com/homemade-aeroponics.html

Article Source:
http://EzineArticles.com/?expert=Jason_Willkomm

Symptoms of Deficiency In Essential Minerals -part 1

Symptoms of Deficiency In Essential Minerals

Introduction

Visual nutrient deficiency symptoms can be a very powerful diagnostic tool for evaluating the nutrient status of plants. One should keep in mind, however, that a given individual visual symptom is seldom sufficient to make a definitive diagnosis of a plant’s nutrient status. Many of the classic deficiency symptoms such as tip burn, chlorosis and necrosis are characteristically associated with more than one mineral deficiency and also with other stresses that by themselves are not diagnostic for any specific nutrient stress. However, their detection is extremely useful in making an evaluation of nutrient status. In addition to the actual observations of morphological and spectral symptoms, knowing the location and timing of these symptoms is a critical aspect of any nutrient status evaluation. Plants do not grow in isolation, they are part of the overall environment and as such they respond to environmental changes as that affect nutrient availability. Also, plants do influence their environment and can contribute to environmental changes, which in turn can affect the nutrient status of the plant.

Sources of Visual Symptoms

Stresses such as salinity, pathogens, and air pollution induce their own characteristic set of visual symptoms. Often, these symptoms closely resemble those of nutrient deficiency. Pathogens often produce an interveinal chlorosis, and air pollution and salinity stress can cause tip burn. Although at first these symptoms might seem similar in their general appearance to nutrient deficiency symptoms, they do differ in detail and/or in their overall developmental pattern. Pathological symptoms can often be separated from nutritional symptoms by their distribution in a population of affected plants. If the plants are under a nutrient stress, all plants of a given type and age in the same environment tend to develop similar symptoms at the same time. However if the stress is the result of pathology, the development of symptoms will have a tendency to vary between plants until a relatively advanced stage of the pathology is reached.

Environmental Associations

Plants remove substantial amounts of nutrients from the soil during their normal growth cycle and many long-term environmental changes occur as a result of this process. Effects on the soil go considerably beyond the straight removal or depletion of nutrients. Charge balance must be maintained in the plant-soil system during nutrient uptake. Charge balance is usually achieved by the excretion of proton and/or hydroxyl ions by the plant to replace the absorbed nutrient cations or anions. For example when plants are fertilized with ammonia, they acquire most of their nitrogen in the form of the ammonium cation, rather than from the usual nitrate anion. Because nitrate is the only anion used by the plant in large amounts, the net result of this change is that during normal nutrient uptake the proton excretion will far exceed that of hydroxyl ions. In the case of vigorously growing plants, the amount of excreted protons can be sufficiently large as to decrease the pH of the soil by several pH units. Changes in soil pH of such magnitude can have large implications for a number of soil processes such as soil structure, nutrient availability and leaching of nutrients. The immediate effect on the soil may be favorable for some plants, especially acid-loving plants, in that it tends to make iron more available. However, in the long run, lowering the soil pH can be deleterious to plants in that the availability of nutrients will change. A lower soil pH will allow micronutrients to be more readily leached from the soil profile, eventually resulting in deficiencies of nutrients such as Cu and Zn. Additionally, when the pH of the soil drops much below pH 5, the solubility of Al and Mn can increase to such an extent as to become toxic to most plant growth (see textbook Figure 5.4).

Plants are often thought of as passive in relation to the environment. However this is not always a valid assumption; for there are many plants that clearly manipulate their environment in a fashion that tends to makes certain nutrients more readily available. For example, iron is a limiting nutrient in many agricultural areas, but it comprises about 3% of the average soil which, if available, would be far in excess of the needs of the average plant. Some plants actively excrete protons, and the resulting decrease in pH increases the solubility of iron in their environment. In addition, other plants excrete phytosiderophores that chelate the soil iron rendering it a more available form for the plants (see p. 277 of the textbook).

Pathways of Symptom Development

At first glance, it would appear that the distinction of deficiency symptoms for the 13 known essential mineral nutrients should be relatively simple. But such an assumption is incorrect. In fact, the deficiency symptoms are quite complex because each nutrient has a number of different biological functions and each function may have an independent set of interactions with a wide range of environmental parameters. In addition, the expression of these symptoms varies for acute or chronic deficiency conditions. Acute deficiency occurs when a nutrient is suddenly no longer available to a rapidly growing plant. Chronic deficiency occurs when there is a limited but continuous supply of a nutrient, at a rate that is insufficient to meet the growth demands of the plant.

Most of the classic deficiency symptoms described in textbooks are characteristic of acute deficiencies. The most common symptoms of low-grade, chronic deficiencies are a tendency towards darker green leaves and stunted or slow growth. Typically most published descriptions of deficiency symptoms arise from experiments conducted in greenhouses or growth chambers where the plants are grown in hydroponics or in media where the nutrients are fully available. In these conditions, nutrients are readily available while present, but when a nutrient is depleted, the plant suddenly faces an acute deficiency. Thus, hydroponic studies favor the development of acute deficiencies.

In experiments designed to study micronutrient deficiency symptoms, micronutrients are usually omitted from the nutrient solution. Micronutrients are often present in the seed or as contaminants in the environment, so a plant of adequate size will exhaust these trace amounts of micronutrient and develop characteristic acute deficiency systems. When deficiency symptoms of macronutrients are sought, the macronutrient is removed suddenly from a suitable sized rapidly growing plant. Alternatively the plant can initially be given a one-time supply of the nutrient that is sufficient for a limited amount of growth. Because macronutrients are continuously required in relatively large amounts by rapidly growing plants, the available nutrients will be rapidly depleted, resulting in an acute deficiency.

In natural systems, the plant encounters many degrees and types of stresses that result in different types of symptoms occurring over time. Perhaps the most common nutrient deficiency in natural environments is the case of a limited nutrient supply that is continuously renewed at a low rate from soil weathering processes. In such cases, the limited nutrient availability results in chronic nutrient deficiency symptoms.

Effect of Nutrient Mobility on Symptom Development

The interaction between nutrient mobility in the plant, and plant growth rate can be a major factor influencing the type and location of deficiency symptoms that develop. For very mobile nutrients such as nitrogen and potassium, deficiency symptoms develop predominantly in the older and mature leaves. This is a result of these nutrients being preferentially mobilized during times of nutrient stress from the older leaves to the newer leaves near the growing regions of the plant. Additionally, mobile nutrients newly acquired by the roots are also preferentially translocated to new leaves and the growing regions. Thus old and mature leaves are depleted of mobile nutrients during times of stress while the new leaves are maintained at a more favorable nutrient status.

The typical localization of deficiency symptoms of very weakly mobile nutrients such as calcium, boron, and iron is the opposite to that of the mobile nutrients; these deficiency symptoms are first displayed in the growing regions and new leaves while the old leaves remain in a favorable nutrient status. (This assumes that these plants started with sufficient nutrient, but ran out of nutrient as they developed). In plants growing very slowly for reasons other than nutrition (such as low light) a normally limiting supply of a nutrient could, under these conditions, be sufficient for the plant to slowly develop, maybe even without symptoms. This type of development is likely to occur in the case of weakly mobile nutrients because excess nutrients in the older leaves will eventually be mobilized to supply newly developing tissues. In contrast, a plant with a similar supply that is growing rapidly will develop severe deficiencies in the actively growing tissue such as leaf edges and the growing region of the plant. A classic example of this is calcium deficiency in vegetables such as lettuce where symptoms develop on the leaf margins (tip burn) and the growing region near the meristems. The maximal growth rate of lettuce is often limited by the internal translocation rate of calcium to the growing tissue rather than from a limited nutrient supply in the soil.

When moderately mobile nutrients such as sulfur and magnesium are the limiting nutrients of the system, deficiency symptoms are normally seen over the entire plant. However the growth rate and rate of nutrient availability can make a considerable difference on the locations at which the symptoms develop. If the nutrient supply is marginal compared to the growth rate, symptoms will appear on the older tissue, but if the nutrient supply is very low compared to the growth rate, or the nutrient is totally depleted, the younger tissue will become deficient first.

Plant Competition and Induced Deficiencies

When the observed symptoms are the direct result of a nutrient deficiency, the actions needed for correction are relatively straight-forward. However symptoms are often the result of interactions with other environmental factors limiting the availability of the nutrient whose symptoms are expressed. The classic instance is that of iron deficiency induced by an excess of heavy metals in the environment. Transition metals such as Cu, Zn Cr and Ni compete with Fe and each other for plant uptake. Competition for uptake is not specific to Fe and heavy metals but is true for all mineral nutrients that are chemically similar and have similar uptake mechanisms. For example if the availability of Cu or Zn is relatively less than that of Fe, then excessive concentrations of some other metal such as Ni or Cr will induce a deficiency of one of these nutrients rather than Fe. In the case of the macronutrients, excessive amounts of Mg will compete with K for uptake and can possibly induce a K deficiency. The barrenness of serpentine soils is the result of such competition, with the high Mg of these soils inducing a Ca deficiency. The toxicity of a low pH soil is another example of a basic nutrient deficiency. Low pH has a two-fold effect on soil nutrients: It enhances the leaching of cations, reducing their availability in the soil, and the relatively abundant protons in the soil compete with Ca and other cations for uptake. Thus, nutrient deficiencies can be induced by a number of different mechanisms often working in concert to limit the availability of a nutrient.

Nutrient Demand and Use Efficiency

Although all plants of the same species respond similarly to nutrient stress, plants of similar species will often show significant differences in their nutrient use efficiency. This results from differences in growth rate, root distribution, phase of development, and efficiency of nutrient uptake and utilization. This implies that in any given location, plants from one species may become nutrient-deficient, while those from another species growing in the same environment right next to them, may not show any deficiency symptoms.

Growth rate also affects nutrient status. When the nutrient supply is barely inadequate for growth under existing environmental conditions, many plants adjust their growth rate to match that supported by the available nutrient supply without displaying typical visual deficiency symptoms.

Agricultural systems differ from natural systems in that crop plants have been selected primarily for rapid growth under low stress conditions. This rapid growth rate results in a high nutrient demand by these plants and a higher incidence of nutrient deficiency unless supplemental fertilizers are supplied. It is not uncommon to find agricultural crops showing severe signs of nutrient stress, with native plants growing in the same area showing little or no indication of nutrient stress. In agriculture systems chronic deficiency symptoms develop mostly in crops with little or limited fertilization. Acute nutrient deficiency symptoms most often occur when new crops with a higher nutrient demand are introduced, or less productive lands are brought under cultivation for the production of rapidly growing crop plants.

Uniformity of Nutrient Status

Not all tissues of a plant are at the same nutrient status during times of stress. Leaves on the same plant that are exposed to different environmental conditions, (such as light), or those of different ages may have considerable differences in nutrient status. Mineral nutrients are for the most part acquired by the roots and translocated throughout the plant. The distance of any part of the plant to the roots will influence nutrient availability, particularly in the case of the less mobile nutrients. In plants recovering from nutrient deficiency, the root and conductive tissues recover first. For example, in the case of recovery from Fe deficiency, it is common to see the veins re-green while the interveinal tissue remains chlorotic and Fe-deficient.

In order to maintain rapid, optimal growth, all plant tissues must have a favorable nutrient status. Although a plant may be marginally low in a number of nutrients, only one nutrient at a time will limit overall growth. However, if the supply of that limiting nutrient is increased even slightly, the resulting increase in growth will increase the demand for all other nutrients and another nutrient, the next lowest in availability, will become limiting.

Other Diagnostic Tools

Although visual diagnostic symptoms are an extremely valuable tool for the rapid evaluation of the nutrient status of a plant, they are only some of the tools available. Other major tools include microscopic studies, spectral analysis, and tissue and soil analysis. These methods all vary in their precision, rapidity and their ability to predict future nutrient status. Because of the close interaction between plant growth and the environment, all predictions of future nutrient status must make assumptions about how the environment will change in that time frame.

The principle advantage of visual diagnostic symptoms is that they are readily obtained and provide an immediate evaluation of nutrient status. Their main drawback is that the visual symptoms do not develop until after there has been a major effect on yield, growth and development.

Tissue analysis is nutrient-specific but relatively slow; tissues must be sampled, processed and analyzed before the nutrient status can be determined. An analysis of the mineral nutrient content of selected plants tissues, when compared against Critical Level values (which are available for most crop plants, see textbook Figure 5.3), can be used to evaluate the plant nutrient status at the time of sampling with a relatively high degree of confidence and can be extrapolated to project nutrient status at harvest. Soil analysis is similar to tissue analysis but evaluates the potential supplying power of the soil instead of plant nutrient status. Plant analysis provides information as to what the plant needs, while soil analysis provides information about the status of the nutrient supply.

Spectral analysis of nutrient status is still in its infancy and is presently used primarily in the inventory of global resources and in specialized studies. Microscopic studies are most valuable in looking at the physiological aspects of nutrient stress rather than the evaluation of plant nutrient status on a whole plant or crop basis.

How To Use This Guide

Nutrient problems can be caused by a variety of factors, including undersupply or oversupply of nutrients. But problems are never as simple as they seem, so you should read and use this guide carefully- or you could do more harm than good.

Plant nutrients are classified into two categories: macronutrients and micronutrients.

Macronutrients are elements that plants most need. Macronutrients are nitrogen, phosphorus, potassium, calcium, magnesium and sulfur, with nitrogen, phosphorus and potassium being most commonly recognized as macronutrients.

Micronutrients are elements that plants need in smaller amounts; they are sometimes called trace elements. These include iron, manganese, copper, zinc, molybdenum, cobalt, boron and chlorine. Calcium, magnesium and sulfur and sometimes classified as micronutrients.

The following information focuses on nutrient deficiencies, excesses and interactions. You will be able to read information and view photos that illustrate or describe what your plants will look like, and/or how they will be affected by specific deficiencies.

Note that the most common deficiencies involve iron, manganese, zinc, calcium or nitrogen.

Research shows that interactions between nutrients can affect deficiency syndromes. For example, the correct ratio of iron and sulfur uptake is very important for optimal nitrogen uptake.

When you are trying to understand if a plant problem is caused by a nutrient deficiency, it is important to note not just what the deficiency looks like, but where it appears on the plant.

Indeed, the location on the plant that a deficiency symptom shows up is a critical factor that will help you ascertain the cause of the deficiency.

That’s because macro and micronutrients fall into two categories: mobile and immobile. Mobile nutrient deficiencies will show up in older growth first. Immobile nutrient deficiencies will show up in new growth first.

Mobile elements are nitrogen, phosphorus, potassium, molybdenum, magnesium and zinc. Immobile elements are iron, copper, manganese, chlorine, cobalt, boron, calcium and sulfur.

Sulfur deficiency is difficult to identify, but it most often appears on older growth first. Sulfur is considered a semi-mobile element.

If you believe that you have identified a particular deficiency issue, be sure to do other troubleshooting before you start augmenting an allegedly deficient nutrient.

Perhaps it’s not a nutrient deficiency at all. It could be that something is wrong in your garden environment.

For example, if a plant is yellow at the top with some browning, and the rest of the plant is healthy down below, it could be that your light is too close to the plant and is burning it.

And before you begin adding extra nutrients to correct an alleged deficiency, flush the root zone. It sounds counterintuitive, but sometimes too much nutrients can cause a chemical reaction that makes some nutrients unavailable to plants.

H2O Hang-ups?

WHETHER STILL PLANNING or in the midst of a hydroponic grow, there are a few things worth spending time familiarizing yourself with in a bid to guarantee your investment in time and money.

Essentially, you can put a plant in a pot full of high-quality compost and keep it watered regularly, and the plant will do the rest — often carrying itself right through until harvest with no need for nutrients at all. With an automated irrigation system you can simply plant and forget. If you have confidence in your compost mix, this is a fine way to grow great-tasting produce.

When growing hydroponically there are a few diff erences the grower needs to take into account to ensure the plant gets everything it needs to not only survive, but thrive and prosper its way to a happy, healthy harvest.

An indoor grower takes over as God in the eyes of the plant, supplying absolutely everything necessary, and in just the right amounts to ensure success. But like everything in life, too much of a good thing soon turns bad and eventually the plants can die as a result of all the kindness bestowed upon them. This is often made worse when things go awry, and the novice grower ends up hurling lotions and potions at the plant in a bid to cure an unknown ailment, instead of dumping the reservoir and refi lling with plain, pH-adjusted water (pH 5.5).

This buys you time when using a method such as NFT, in which things can go seriously wrong very quickly. There’s no more frustrating a time for a grower than when he or she knows that everything the plant could possibly need has been provided, and yet it simply refuses to feed, leaving the plant displaying defi ciencies galore. Even worse if the plant runs into a wilt even though water and nutrients are available!

OSMOSIS
Before getting to grips with our theoretical situation there are a couple of things worth knowing regarding how roots do their stuff , and all will become crystal clear. The fi rst thing to suggest would be fi ring up Google and doing a search for “Osmosis” (with the quotation marks). Roots take up water and nutrients via the process of osmosis. In short, osmosis is the ability of a fl uid or solution to translocate through a semi-permeable membrane, thus equalizing the concentration of the fl uids on either side of the membrane.

If one side of the membrane has a higher concentration of solution than the other, osmosis sorts it out and maintains the status quo by driving the solution from the highest concentration toward the lowest. Science rocks, huh? Just think about the next time you put on your Goretex™ jacket, (Goretex – a semi-permeable membrane that allows sweat and condensation to pass through while keeping the rain out). Your roots work in much the same manner. O kay, that all sounds pretty straightforward, until you run into nutrient lockout.

LOCKED OUT
The passage of nutrients through the semi-permeable membrane is controlled by the relative concentrations of individual nutrient elements on either side of the membrane. In layman’s terms, if you are feeding an excessively higher concentration of magnesium (for example) than that already existing within the roots, osmosis can work against you by “shocking” the roots into thinking the levels of magnesium are too high.

This can cause the plant to attempt to “shed” magnesium by slipping into reverse gear and drawing magnesium away from the roots and into the root mass. Magnesium will be transported the wrong way, out of the roots and into the cubes/slabs (EC/pH rising at runoff?). This condition will quickly manifest itself as a magnesium deficiency. Once the concentration in the solution is lower than that in the roots, the tide changes and the magnesium deficiency is soon cured. But what happens if it isn’t cured?

The passage of water through the semi- permeable membrane is controlled by either the TDS (total dissolved solids) or EC (electrical conductivity) of the nutrient solution. So, if the EC of the solution you’re feeding is excessively higher than the EC currently in the roots, the plant can dehydrate by drawing water out of the roots and into the medium via osmotic action. If using NFT and this proves to be the case, you can run your irrigation pumps 24/7, but the end is nigh through a “dry” wilt unless fast countermeasures are taken.

TAKING THE PLUNGE
But it’s not all doom and gloom, and if NFT was that easy, everyone would be doing it, right?

It’s no accident that the growers who constantly succeed where others fail are generally the ones who take the time to constantly monitor their water quality. By taking regular readings of your pH/EC values from the reservoir, as well as within the cubes/slabs and at runoff , it’s easy to keep track of how your plant is health-wise and you can counteract these readings before any signs of ailing have manifested on the leaves.

Once the system is dialled, there’s not a lot will get close to NFT yield-wise, but initially it can seem like you’re in at the deep end. Keep treading water and hang in there.

Essential Micronutrients Required by Plants; Part 1

IN MY PREVIOUS ARTICLE (see Maximum Yield, November / December 2006), the roles for the major elements – carbon (C), calcium (Ca), hydrogen (H), magnesium, (Mg), nitrogen (N), oxygen (0), phosphorus (P), potassium (K), and sulfur (S) – on the nutrition of plants were discussed. The major elements are found in the plant dry weight in per cent concentrations. For the micro-nutrients boron (B), chlorine (CI), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn), plants require considerably smaller concentrations
(less than 0.01 per cent of the dry weight) to sustain sufficiency.

The commonly used unit of concentration for the micronutrients is parts per million (ppm), avoiding the confusion that would come with decimals if the concentration in the plant’s dry weight were in per cent. In metric units, micronutrient concentration is expressed in milligrams per kilogram (mg/kg). One ppm is equal to 1 mg/kg. Another equivalence for solution concentration used in this article is milligram per liter (mg/L) equal to parts per million (ppm).
Interestingly, all but one of the micronutrients, Fe (iron), have been established as “essential” between the years 1922 and 1954. Essentiality for Mn was established in 1922, B and Zn in 1926, Cu in 1931, Mo in 1939, and Cl, the last to be identified as essential, in 1954. For all the major elements and Fe, their essentiality has been known since the 1800s. So, what we know today about the micronutrients is of more recent history.

Another change that has taken place recently has been the use of the word “micronutrient” as the proper term, rather than the words “trace element” or “minor element,” terms that are found in the older literature and, unfortunately, are still occasionally used to identify the micronutrients. Today, “trace element” is used to designate those non-essential elements found in plants in low concentrations, at the parts per million (ppm) level, in the dry weight of plants.

In the case of several of the micronutrients, the range of plant content sufficiency is quite narrow. Departure from this narrow range results in either a deficiency or toxicity when below or above, respectively. In addition, deficiency or toxicity symptoms can be difficult to evaluate visually and, therefore , require an analysis of a specified plant part for confirmation by means of a plant analysis.

The micronutrients, as a group, are far more critical in terms their control and management than most of the major element particularly in soilless culture systems. Most micronutrient deficiencies can usually be corrected easily and quickly, but when dealing with excesses or toxicities, correction can be difficult, if not impossible. If toxicity Occurs, the grower may well have to start over. Therefore, great care Must be taken to ensure that an excess concentration of a micronutrient be not introduced into the rooting media, either initially or during the growing season.
The availability of some of the micronutrients, particularly Fe Mn, and Zn, are significantly affected by the pH of the rooting medium, particularly in organic soilless mixes. A pH greater than 5.5 can result in a micronutrient deficiency, though a recommended quantity of that micronutrient had been added to the mix. The level of a major element, particularly high P, in a rooting medium will affect the uptake of Cu, Fe, Mn, and Zn. Therefore, proper control of the pH and concentration of major elements in a rooting medium are important to ensure “available” sufficiency.

Since the requirements for some of the micronutrients are relatively low, there may be sufficient concentration in the natural environment (i.e., in the water used to make a nutrient solution, in the inorganic or organic rooting media substance, as a contaminate in a major element supplying reagent or fertilizer or from contact with piping, storage tanks, etc.) to preclude the necessity to add micronutrient. Therefore, it is best to analyze a prepared nutrient solution after constituting it and after contact with the environment to determine its micronutrient content. In addition, careful monitoring of the rooting media and plants will ensure that the plant’s micronutrient requirement is being satisfied but not exceeded.

Article source: Maximum yield magazine February 2007

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Hydro-organics and the use of biological recyclers

by Todd Salemi

Organic soil gardening has always been known to be the best way to grow for earth friendly reasons and a more natural tasting crop, but hydroponics can deliver larger yields at faster growth rates with an almost incomparable taste. Hydroponics and the goal to achieve organic recognition have been long overdue. The goal of this article is to show that in a hydroponic application, microbial activity, biological recyclers and bio-diversity can lead to organic certification, increased yields, flavors and harvests. The use of synthetic fertilizers prevents the hydroponics industry from supplying the rapidly increasing demand for “organic” fruits and vegetables. Until the hydroponics industry can provide the nutrients from all organic forms this growing market is not attainable.

In current conventional methods, synthetic fertilizers and mineral salts provide the plant nutrients. When these synthetic fertilizers become aqueous in the reservoir, the plants are able to access the nutrients directly without the facilitation of microbial activity. The advantage to this is faster growth than standard soil applications and a more sterile gardening practice. The downside is the increased salts level that is produced by the chemical base of fertilizers. These mineral salts build up, cause pH deficiencies, root lock, pathogenic buildups, and cause negative environmental impacts.

Bio-technology and the use of microbial rich solution can change the way hydroponic gardeners produce crops. (Note: this solution is not a compost tea; the NOP, National Organic Program, does not allow “compost teas” to be used for food crops within 120 days of harvest). This biological approach will take the hydroponic industry in a huge step in the right direction towards organic recognition. Hydro-organics are a basic concept of bio-diversity, balanced biology, and an increased concentration of chitin and cellulose recycling organisms.

Full range biology and Bio-diversity

Significant academic research has shown that healthy, biological growing environments include both beneficial bacteria and fungi in a wide diversity. The beneficial bacteria provide the highest concentration of biological nitrogen. Each bacterial organism is comprised of seven carbons and one nitrogen. The beneficial fungus is comprised of 30 carbons and one nitrogen, which is the second highest nitrogen source. Bacteria and fungi are consumed by the microbial biology contained within the hydroponic solution, and are releasing needed sources of nutrients into the root web system. A full-range of biology significantly reduces the amount of fertilizer required.

Bio-diversity is also very important. In order to prevent any one specific set of organisms from predominating and causing imbalance in the hydroponics system, a wide set of beneficial organisms are needed. A healthy soil or hydroponic system must have diversity of at least 10,000. When bio-diversity reaches an excess of 30,000, the optimal health and growth rate of the plant increases and the rate of nutrient absorption and mineral control becomes augmented through symbiotic plant and microbial relationships.

Chitin and cellulose recycling biology

Both refined chemical nutrients and unrefined organic nutrient approaches can breed unbeneficial competitors. Most beneficial and pathogenic competitors are predominantly made of chitin, although the Pythium and Phytophthora fungi groups are cellulose based. Chitinase and cellulase producing organisms consume and recycle both beneficial and pathogenic competitors exuding nutrients as a result of the recycling process. If the unbeneficial competitors surround the root zone of the plants they will deprive the plants’ ability to absorb the necessary nutrients for robust and vigorous growth. If the unbeneficial competitors overwhelm the root zone the plant will virtually starve. Dr. Garn Wallace of Wallace Labs states that unbeneficial competitors are not strong and only thrive when beneficial organisms are not present. By increasing chitinase and cellulase producing organisms, the rate at which nutrients is supplied to the plant is dramatically increased.

A healthy organic hydroponic system needs a balanced concentration of bacterial and fungal organisms with a wide diversity. The levels of bacterial and fungal for healthy systems should be:

Total mcg/gm Active mcg/gm
Bacteria 15-30+ 150-300+
Fungal 2-10+ 150-200+
Tests and Research

Tests have shown phenomenal results with microbial rich solution.

The 150,000sf Ohtani Hydroponics facility provides 90% of the restaurants in Tokyo with table lettuce, Chinese cabbage and other green vegetables.

The test was performed under the guidance of Japanese Agriculture with the five ministers of agriculture observing the results. Two separate systems were assembled to determine the effect of adding biologically active solution compared to the standard protocol.

Iceberg lettuce and Chinese cabbage were grown from seed for this test. In 12 days, the plant mass of the treated plants had grown 387% greater than the standard protocol. At the end of the second year Ohtani found that harvests have increased from four to seven harvests a year with an average of 30% yield increase for each harvest.

Dr. Joe Bradford, the director of ARS-USDA, at Texas has been using this same solution on pecans. The application is not hydro, but the results are significant. Texas A&M gives the max yield of 23 pounds/tree for the Pawnee variety. The yield increased to 32 pounds the first year. Many other pecan growers felt the yield would drop the following year. 2005 was the second growing season and the yield on the Pawnee pecan trees increased to 43 pounds/tree. The taste improvement is best described by Dr. Bradford’s statement that even a blind man will be able to tell the improved taste and will not choose to eat the pecans that did not have this advantage.

The rate and amount of biological build up and balance that old grove trees require are unnecessary for hydroponic applications. The non soil media results in a balanced biology that can be acquired within five minutes of adding microbial rich solution.

The same yield increase and taste improvement was seen in onion production testing. The standard protocol onions from eight different farms are the size of a cue ball. Production in a side-by-side field with only organic nutrients and microbial rich solution with high levels of biological recyclers produced grapefruit size onions. In the case of many fruits and vegetables, improved taste can be directly determined by Brix level. This is a measurement of the sugar content. In tested onions, the standard protocol onions produced a Brix level of 2-3. The “solution” produced onions at a brix level of 10. This level of sweetness means the onion is so good it can be sliced and eaten like an apple.

An additional advantage of balanced biology and increased biological recyclers is extended shelf life. The average shelf life for the large sweet onions is less than six (6) weeks at room temperature. Onions tested with “solution” lasted well past six months. Similar long shelf life periods have been seen across the board in a wide range of applications.

This includes lettuce that lasts longer, and flowers that hold their blooms longer.

More research and application results will be presented in future articles, but the following can be applied by the hydroponic industry.

• Supplying the needed plant nutrients in organic form is possible when the hydroponic systems are inoculated with the right biology.
• This biology must have a balance of the bacterial and fungal with diversity in excess of 10,000+.
• Optimal growth is possible if sufficient recycling organisms are present to digest the biology and provide it as a food source for the plants.
• Chitin and cellulose degrading organisms should be increased to the range 200 and 400 cfu/gwd.
• Quality growth can be achieved by a simple inoculation of quality solution every time the reservoir is refilled.

Article Source: http://www.maximumyield.com/article285.htm

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