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Plant Abuse Chart and Photos by Nietzsche


Heat Stress :

Examine the image below carefully, and you'll notice the brown-tipped leaves, which signal heat stress. This type of harm is similar to nutrient burn, but it is only present on the uppermost parts of the plants nearest to the light sources. There's a single solution to this issue: distance the heat from the plants by either repositioning the lamps or relocating the plants themselves.

Plant abuse chart and photos by nietzsche

Figure 1

Nutrient Solution Burn:

It is likely that this leaf experienced nutrient solution scorching. Such indications are observed when the electrical conductivity (EC) of hydroponic solutions is excessively high. Additionally, these symptoms can occur when a potent nutrient solution inadvertently splashes onto the leaves beneath intense HID lamps, leading to the leaves being scorched by the solution.


Figure 2
Numerous hydroponic gardeners encounter this issue, which is the onset of nutrient burn. It signifies that the plants have reached their maximum nutrient absorption capacity, with a minor surplus remaining. To resolve this, slightly reduce the concentration of the nutrient solution, and the issue should vanish. Keep in mind that if the plants' condition does not worsen beyond this point (figure 3), they are likely just fine. However, figure 4 clearly illustrates a nutrient oversupply issue. Excessive nutrient levels accumulate in the leaves, causing them to dehydrate and exhibit signs of burn, as depicted here. It is crucial to flush the system with clean, clear water right away to allow the roots to recuperate and prevent further damage. Subsequently, identify the source of the elevated nutrient levels.


Figure 3 (left) and Figure 4 (right)
Over Watering:

In Figure 5, the plants are subjected to a continuous drip system, where the nutrient solution is persistently pumped into the medium. This method can often lead to the entire root system being overly saturated. A more effective approach would involve periodically feeding the plants, for instance, for 30 minutes every 2-3 hours, allowing the roots to acquire necessary oxygen and averting issues such as root rot.

Although the plants in Figure 5 appear to be sitting in stagnant water, it is essential to note that this is an H2O2 solution employed to address the issue. Incorporating an airstone into the tub can further enhance oxygen supply to the solution.


pH Fluctuation:
In both Figure 6 and Figure 7, the leaves originate from the same plant. While over-fertilization could be a factor, it is more probable that an imbalanced pH is the primary cause. An excessively high or low pH can cause nutrients to become trapped as insoluble salts and compounds, some of which can be toxic to plants. This often leads the grower to introduce additional fertilizers in an attempt to address the issue, further disrupting the pH balance and causing more nutrient lockout. Such problems are more prevalent in soil mixes, where uneven mixing of the medium's components can result in concentrated areas, known as "hot" spots.


Ozone Damage:
Damage from ozone is usually observed close to the generator. While it's an infrequent issue, the signs often resemble a magnesium deficiency. However, these symptoms tend to be concentrated in the area directly surrounding the generator.


Root Stunting:

Root stunting is a common sign of calcium deficiency, acidic conditions, aluminum toxicity, and copper toxicity. Some plant species may exhibit this when facing a shortage of boron. The affected roots become shorter and thicker, while the lateral roots transform into short, peg-like structures. Additionally, the entire root system may change color, turning brown or gray.

Symptoms primarily appear at the shoot growth points.

Copper deficiency: New shoots remain unopened; young leaves become distorted; leaf tips die; plant exhibits a pale green hue.

Calcium deficiency: New shoots wither or die; petiole or stem collapse; shoots appear stunted; plant maintains a green color.

Boron deficiency: Young leaves turn pale green or yellow; rosetting or dead tips occur; dieback is observed; plant displays a dark green shade.

Mobile elements tend to show visible deficiencies in older leaves, as they are transported to new growth during periods of high demand.

Nitrogen (N):
Nitrogen, found in both organic and inorganic forms, combines with carbon, hydrogen, oxygen, and occasionally sulfur to create amino acids, amino enzymes, nucleic acids, chlorophyll, alkaloids, and purine bases. In plant tissues, nitrogen is highly present in molecular weight proteins.

During the vegetative stage, plants require ample nitrogen, but it is easy to over-apply. If you've added too much, flush the soil with plain water. Soluble nitrogen, particularly nitrate, is the most readily available form for roots, while insoluble nitrogen, such as urea, must first be broken down by soil microbes before roots can absorb it. Be cautious of excessive ammonium nitrogen, as it can negatively affect the absorption of other nutrients.

Excessive nitrogen can delay flowering. For optimal flavor, allow plants to become nitrogen-deficient in the late flowering stage.

Nitrogen Deficiencies:
Deficient plants may display poor vigor, slow growth, and stunted, weak development. Both quality and yield are significantly reduced. Older leaves turn yellow (chlorotic) due to insufficient chlorophyll. These leaves may eventually die and fall off. A uniform light green to yellow color appears on older leaves without noticeable curling of leaf margins. Chlorosis gradually spreads across the plant. Stems, petioles, and lower leaf surfaces might turn purple.


Figure 9

As depicted in Figure 10, it is entirely normal for nitrogen (N) to be consumed from the fan leaves during the final stage of flowering.


Figure 10

Nitrogen Overload:

Leaves typically appear dark green during the initial phase, with an abundance of foliage. In cases of extreme excess, leaves may dry out and eventually drop. The root system will either be poorly developed or degrade over time. Fruit and flower formation may be hindered or malformed.

The breakdown of vascular tissue limits water absorption, significantly reducing the plant's resistance to stress.

Phosphorus (P)

Phosphorus is an essential component of certain enzymes and proteins, adenosine triphosphate (ATP), ribonucleic acids (RNA), deoxyribonucleic acids (DNA), and phytin. ATP plays a crucial role in various energy transfer reactions, while RNA and DNA are vital components of genetic information.

Phosphorus (P) Deficiency:

Figure 11 demonstrates severe phosphorus (P) deficiency during the flowering stage. Fan leaves may appear dark green or red/purple, eventually turning yellow. Leaves may curl inward, turn brown, and die. The formation of small buds is another primary symptom.

Phosphorus deficiencies result in slow-growing, weak, and stunted plants, with dark green or purple pigmentation in older leaves and stems.

A certain degree of deficiency during flowering is normal, but excessive deficiency should not be allowed. Red petioles and stems are a standard genetic trait for many plant varieties and can also be a co-symptom of N, K, and Mg deficiencies. Therefore, red stems are not an accurate indicator of P deficiency. Excessive P can lead to iron deficiency.

Purpling: The accumulation of anthocyanin pigments causes an overall dark green color with a purple, red, or blue hue, which is the most common sign of phosphate deficiency. Some plant species and varieties may exhibit yellowing in response to phosphate deficiency rather than purpling. Purpling is a natural characteristic of some healthy ornamental plants.


Figure 11

Figure 12 illustrates phosphorus (P) deficiency during vegetative growth. Often, this deficiency is misidentified as a fungal issue. However, one can distinguish it by observing the damage that appears close to the leaf ends, leaving them with a dull, grayish hue and an extremely brittle texture.


Figure 12

Phosphorus (P) Toxicity:

Phosphorus toxicity is an uncommon issue, typically mitigated by pH constraints. An excess of phosphorus might disrupt the availability and stability of copper and zinc in plants.

Potassium (K)
Potassium plays a crucial role in managing a plant's water balance, cell turgor pressure, and the opening and closing of stomata. It is essential for the accumulation and transportation of carbohydrates within plants. Insufficient potassium results in reduced yield and diminished quality.

Potassium Deficiency:
In the early stages, older leaves display chlorosis, which soon develops into dark necrotic lesions (dead tissue), predominantly on the tips and margins of the leaves. Plant stems and branches may weaken and become prone to breaking, while the plant itself might stretch. This deficiency can make the plant more susceptible to diseases and toxicities. Besides resembling iron deficiency, potassium-deficient leaves tend to curl, and their edges may burn and wither.

Potassium Imbalance
High sodium (Na) levels can displace potassium, leading to a deficiency. Elevated salinity can arise from sodium bicarbonate ("pH-up") in baking soda, excessive manure, or the use of water-softening filters (which should be avoided). If sodium is the issue, flush the soil. Potassium can also become locked up due to an abundance of calcium, ammonium nitrogen, or potentially cold temperatures.



Figure 14

Potassium (K) Toxicity:

Potassium is typically not taken up excessively by plants. However, an excess of potassium can hinder the absorption of magnesium, manganese, zinc, and iron, and affect the availability of calcium.

Magnesium (Mg)
Magnesium plays a vital role as a component of the chlorophyll molecule and acts as a cofactor in many enzymes.

Magnesium (Mg) Deficiency:
A deficiency in magnesium can result in a yellowing (which may eventually turn brown) and interveinal chlorosis, beginning in the older leaves. The first symptoms of this deficiency can be observed in the form of interveinal chlorosis, starting at the leaf margins or tips and progressing inward between the veins. The veins, however, tend to remain somewhat green, as illustrated in Figure 15.

In Figures 16 and 17, notice how the leaves curl upwards, resembling a praying gesture? This indicates a need for magnesium. The leaf tips may also twist. To remedy this situation quickly, water the plants with a solution containing 1 tablespoon of Epsom salts per gallon of water. Until nutrient lockout is corrected, consider foliar feeding to ensure the plants receive adequate nitrogen and magnesium. Plants can be foliar-fed with a solution of 1 teaspoon of Epsom salts per quart of water (first dissolve the salts in hot water). When preparing soil, add 2 teaspoons of dolomite lime per gallon of soil.

If the initial water ppm is above 200, it is considered hard water, which can cause magnesium lockout due to high calcium content. To address this, either add 1/4 teaspoon of Epsom salts or lime per gallon of water (both can effectively reduce lockout) or invest in a reverse osmosis water filter.

Magnesium can become locked up by excessive amounts of calcium, chloride, or ammonium nitrogen. Avoid overusing magnesium to prevent the lockout of other nutrients.


Figure 15

Figure 16


Figure 17

Magnesium (Mg) Overload:

Magnesium excess is uncommon and typically does not manifest in visible signs. Extremely high concentrations can interfere with other ions in the nutrient solution.

Zinc (Zn)
Zinc is involved in similar enzymatic functions as manganese and magnesium. Over eighty enzymes require tightly bound zinc for proper functioning. Zinc contributes to chlorophyll formation and aids in preventing its degradation. Zinc is specifically known to activate carbonic anhydrase.

Zinc Deficiencies:
Deficiency symptoms include interveinal chlorosis on new leaves, resulting in a banded appearance as shown in figure 18. This may coincide with reduced leaf size and shorter internodes. Leaf edges can be misshapen or crinkled. In severe cases, the branch terminals of fruit-bearing plants may die back.

Zinc can also become locked out due to a high pH. Deficiencies in zinc, iron, and manganese often occur simultaneously, typically resulting from high pH levels. Avoid overusing micronutrients; instead, lower the pH to make the nutrients more accessible. Apply a foliar spray if the plant appears severely affected, and use chelated zinc. Zinc deficiency can lead to "little leaf" in various species, particularly woody plants, causing younger leaves to be noticeably smaller than normal. Additionally, zinc deficiency may result in "rosetting," where the stem does not elongate behind the growing tip, leading to tightly clustered terminal leaves.


Figure 18

Zinc Toxicity:

An excessive amount of zinc can be highly toxic, leading to a swift demise. Too much zinc can disrupt the absorption of iron, resulting in chlorosis from iron deficiency. Sensitive plants may become chlorotic due to zinc excess.


Non-movable elements first display symptoms on younger leaves, eventually affecting the entire plant.

Sulfur (S)
Sulfate plays a key role in protein synthesis and constitutes the amino acids cystine and thiamine, which serve as protein building blocks. It is vital for plant structure, metabolism, respiration, and the creation and breakdown of fatty acids.

Sulfur (S) Deficiency:
The primary sign of sulfur deficiency is the yellowing of the entire leaf, including veins, typically beginning with younger leaves. Leaf tips may turn yellow and curl downwards. Sulfur deficiency can lead to light green fruit or younger leaves lacking succulence, elongated roots, and a woody stem. In Figure 19, it is challenging to discern, but the plant's upper stems are purple. While many cannabis varieties exhibit purplish stems, this characteristic generally spans the entire stem length and not just near the top, as seen in this particular specimen.


Figure 19

Sulfur Toxicity:

Reduced leaf size and stunted overall growth are common symptoms. Leaves may exhibit yellowing or scorching at their edges, and excess sulfur can lead to early senescence.

Calcium (Ca)
Calcium is crucial for maintaining cell integrity and ensuring proper membrane permeability.

Calcium Deficiency:
Younger leaves are the first to be affected, showing symptoms such as chlorosis, irregular margins, spotting, necrotic areas, or distortion. Bud development may be inhibited, leading to blossom end rot, internal decay, and underdeveloped or dying roots. Leaf tip die-back, curling, and marginal necrosis primarily appear in younger leaves. Symptoms include chlorosis, distortion like crinkling, dwarfing, and developing a strap-like shape, as well as halted and thickened shoot growth.

Calcium Toxicity:
It is challenging to identify visually. Calcium may react with sulfur in a solution, resulting in cloudiness or residue within the tank. Excessive calcium can cause magnesium and potassium deficiencies.

Iron (Fe)
Iron is a vital component of plant enzyme systems that facilitate electron transport during photosynthesis and terminal respiration. It acts as a catalyst for chlorophyll production and is necessary for nitrate and sulfate reduction and assimilation.

Iron Deficiency:
  • Noticeable interveinal chlorosis, similar to magnesium deficiency, but occurs on younger leaves.
  • Leaves display chlorosis (yellowing) mainly between the veins, starting with lower and middle leaves.
Caused by factors that obstruct root iron absorption: overwatering, excessive soluble salts, poor drainage, pests, high substrate pH, or nematodes. This can be easily corrected by adding an iron supplement during the next watering.

Fe becomes unavailable to plants when the water or soil pH is too high. To resolve deficiency, lower the pH to approximately 6.5 (5.7 for rockwool) and ensure that you are not adding excessive amounts of P, which can lock up Fe. Use chelated iron for maximum availability. Check your fertilizer's ingredients - chelated iron may be listed as "iron EDTA". Excessive Fe without sufficient P can result in a P-deficiency.

Note: When adding iron to the solution, it might be necessary to avoid using fertilizer for that particular watering. Iron tends to react with many fertilizer solution components, causing nutrient lockup. Read the labels of both your iron supplement and fertilizer before attempting to combine them.


Figure 20

Iron Toxicity:

Though uncommon, excessive iron buildup may lead to bronzing or minuscule brown spots on the leaf surface.

Manganese (Mn)
Manganese participates in the oxidation-reduction process within the photosynthetic electron transport system. Scientific research indicates that manganese has a structural function in the chloroplast membrane system and also activates numerous enzymes.

Manganese Deficiency:
Symptoms include interveinal chlorosis of younger leaves, necrotic lesions, and leaf shredding. Elevated levels can result in an uneven distribution of chlorophyll, causing a blotchy appearance. Hindered growth and abnormal maturation may also occur.

-Mn becomes unavailable when the pH is too high or when iron levels are excessive. Use chelated Mn.

Manganese Toxicity:
Toxicity symptoms include chlorosis or blotchy leaf tissue due to inadequate chlorophyll synthesis. Plant growth rate and vigor will decline.

Chlorine (Cl)
Chloride is involved in oxygen evolution during photosynthesis and is vital for cell division in roots and leaves. Chlorine increases cell osmotic pressure, influences stomata regulation, and enhances plant tissue hydration. Levels below 140 ppm are safe for most plants. Chloride-sensitive plants may experience tip or marginal leaf burn at concentrations above 20 ppm.

Chlorine Deficiency:
Leaves become wilted, chlorotic, and bronze-colored. Roots appear stunted and thickened near the tips. Chlorine-deficient plants will exhibit paleness and wilting.

Chlorine Toxicity:
Symptoms include leaf tip or margin burning, bronzing, yellowing, and leaf splitting. Leaf size and growth rate will decrease.

Boron (B)
Though boron's precise biochemical functions remain uncertain, it is believed to play a role in the synthesis of one of the bases for RNA (uracil) formation. Boron may also participate in cellular processes such as division, differentiation, maturation, and respiration and is associated with pollen germination.

Boron Deficiency:
Boron-deficient plants display brittle, abnormal growth at shoot tips, and one of the first symptoms is the failure of root tips to elongate normally. Stem and root apical meristems may die, and root tips can become swollen and discolored. Internal tissues could rot and become susceptible to fungal infections. Leaves demonstrate various symptoms, including drying, thickening, distortion, wilting, and chlorotic or necrotic spotting.

Boron Toxicity:
Leaf tips turn yellow, followed by necrosis of the leaves, starting at the tips or margins and progressing inward before the leaves die and fall off prematurely. Some plants are particularly sensitive to boron accumulation.

Copper (Cu)
Copper is an essential component of many enzymes and proteins. It aids in carbohydrate metabolism, nitrogen fixation, and oxygen reduction processes.

Copper Deficiency:
Deficiency symptoms include stunted growth, distortion of younger leaves, and dieback of the growth tip. Young leaves may become dark green and twisted, potentially dying back or developing necrotic spots. Growth and yield will be insufficient.

Copper Toxicity:
Copper is needed in minuscule amounts and can easily become toxic in solution culture if not carefully managed. Excessive copper can induce iron deficiency. Root growth will be inhibited, followed by symptoms of iron chlorosis, stunted growth, reduced branching, and abnormal darkening and thickening of roots.

Molybdenum (Mo)
Molybdenum plays a vital role in two primary enzyme systems that facilitate the conversion of nitrate to ammonium, known as nitrate reductase.

Molybdenum Deficiencies:
Deficiencies often manifest as interveinal chlorosis, initially affecting older leaves before spreading to the entire plant. Younger leaves may become severely twisted and eventually die. Molybdenum deficiencies often resemble nitrogen deficiencies, with older leaves appearing chlorotic, exhibiting rolled margins, and stunted growth.

Molybdenum Toxicity:
Excess molybdenum might cause leaf discoloration, depending on the plant species. Although rare, toxicity can result from continuous accumulation. Plants use molybdenum in small quantities, and excess typically does not affect the plant. However, high levels consumed by grazing animals may pose problems, potentially making the plant unsuitable for consumption.

Sodium (Na)
Sodium can promote crop yields and, in certain cases, counteract the effects of toxic salts. It may also partially compensate for potassium deficiencies. Excess sodium can lead to plant toxicity or cause deficiencies in other elements. Overabundance of sodium in the solution may impact calcium and magnesium levels.

Silicon (Si)
Silicon is typically present in solution as silicic acid and is absorbed in this form. It accumulates most abundantly as hydrated amorphous silica in the walls of epidermal cells, as well as in primary and secondary walls of other cells. Silicon is widely available in soils and water. Insufficient silicon can decrease tomato yields by up to 50%, cause deformation in new leaves, and inhibit fruit set. Toxicity symptoms are currently undetermined.

Cobalt (Co)
Cobalt is crucial for many beneficial bacteria involved in nitrogen fixation in legumes. It is a component of vitamin B12, which is essential for most animals and possibly plants. Some reports suggest its involvement with enzymes necessary for forming aromatic compounds. Although the full extent of cobalt's benefits for plant growth is not yet understood, it is considered essential for addressing certain animal health issues.
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