Symptoms of Deficiency In Essential Minerals

May 8, 2008

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

Iron Deficiency

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 Deficiency

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 Deificiency

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.

Written by admin · Filed Under Hydroponics Articles