Zinc deficiency occurs when plant growth is limited because the plant cannot take up sufficient quantities of this essential micronutrient from its growing medium. Zinc is one of the most important micronutrients. [2]
Zinc deficiency occurs when plant growth is limited because the plant cannot take up sufficient quantities of this essential micronutrient from its growing medium. Zinc is one of the most important micronutrients. [2]
Visible deficiency symptoms include: [3]
Zinc deficiency is common in many different types of soil; some soils (sandy soils, histosols and soils developed from highly weathered parent material) have low total zinc concentrations, and others have low plant-available zinc due to strong zinc sorption (calcareous soils, highly weathered soils, vertisols, hydromorphic soils, saline soils). Soils low in organic matter (such as where topsoils have been removed), and compacted soils that restrict root proliferation also have a high risk of zinc deficiency. Application of phosphorus fertilizers has frequently been associated with zinc deficiency; this may be due to enhanced sorption by clay minerals (especially iron oxides), suppression of vesicular arbuscular mycorrhizae and/or immobilization of zinc in plant tissues. Liming of soils also frequently induces zinc deficiency by increasing zinc sorption. [3]
Zinc is an essential micronutrient which means it is essential for plant growth and development, but is required in very small quantities. Although zinc requirements vary among crops, zinc leaf concentrations (on a dry matter basis) in the range 20 to 100 mg/kg are adequate for most crops.
Zinc sulphate or zinc oxide can be applied to soils to correct zinc deficiency. Recommended applications of actual zinc range from 5 to 100 kg/hectare but optimum levels of zinc vary with plant type and the severity of the deficiency. [5] [6] Application of zinc may not correct zinc deficiency in alkaline soils because even with the addition of zinc, it may remain unavailable for plant absorption.
Foliar applications of zinc as zinc sulphate or as zinc chelate (or other organic complexes) are also widely used, especially with fruit trees and grape vines. Zinc can also be supplied as a seed treatment, or by root-dipping of transplant seedlings. [3]
Zinc is a cofactor in a number of enzymes.
Zinc deficiency increases membrane leakiness as zinc-containing enzymes are involved in the detoxification of membrane-damaging oxygen radicals. Zinc may be involved in the control of gene expression; it appears important in stabilizing RNA and DNA structure, in maintaining the activity of DNA-synthesizing enzymes and in controlling the activity of RNA-degrading enzymes. [7]
Almost half of the world's cereal crops are grown on zinc-deficient soils; as a result, zinc deficiency in humans is a widespread problem. [3]
Physiological plant disorders are caused by non-pathological conditions such as poor light, adverse weather, water-logging, phytotoxic compounds or a lack of nutrients, and affect the functioning of the plant system. Physiological disorders are distinguished from plant diseases caused by pathogens, such as a virus or fungus. While the symptoms of physiological disorders may appear disease-like, they can usually be prevented by altering environmental conditions. However, once a plant shows symptoms of a physiological disorder, it is likely that that season's growth or yield will be reduced.
Boron deficiency is a common deficiency of the micronutrient boron in plants. It is the most widespread micronutrient deficiency around the world and causes large losses in crop production and crop quality. Boron deficiency affects vegetative and reproductive growth of plants, resulting in inhibition of cell expansion, death of meristem, and reduced fertility.
Iron (Fe) deficiency is a plant disorder also known as "lime-induced chlorosis". It can be confused with manganese deficiency. Soil iron concentration is high, but can become unavailable for absorption if soil pH is higher than 6.5. Excess of elements such as manganese in the soil can interfere with plant iron uptake triggering iron deficiency.
Manganese (Mn) deficiency is a plant disorder that is often confused with, and occurs with, iron deficiency. Most common in poorly drained soils, also where organic matter levels are high. Manganese may be unavailable to plants where pH is high.
Nitrogen deficiency is a deficiency of nitrogen in plants. This can occur when organic matter with high carbon content, such as sawdust, is added to soil. Soil organisms use any nitrogen available to break down carbon sources, making nitrogen unavailable to plants. This is known as "robbing" the soil of nitrogen. All vegetables apart from nitrogen fixing legumes are prone to this disorder.
Potassium deficiency, also known as potash deficiency, is a plant disorder that is most common on light, sandy soils, because potassium ions (K+) are highly soluble and will easily leach from soils without colloids. Potassium deficiency is also common in chalky or peaty soils with a low clay content. It is also found on heavy clays with a poor structure.
Plant nutrition is the study of the chemical elements and compounds necessary for plant growth and reproduction, plant metabolism and their external supply. In its absence the plant is unable to complete a normal life cycle, or that the element is part of some essential plant constituent or metabolite. This is in accordance with Justus von Liebig’s law of the minimum. The total essential plant nutrients include seventeen different elements: carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil.
Micronutrients are essential dietary elements required by organisms in varying quantities throughout life to orchestrate a range of physiological functions to maintain health. Micronutrient requirements vary among organisms. Humans and other animals require numerous vitamins and dietary minerals. Plants tend not to require vitamins, but minerals are required still. For human nutrition, micronutrient requirements are in amounts generally less than 100 milligrams per day, whereas macronutrients are required in gram quantities daily.
In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to manufacture carbohydrates through photosynthesis and may die unless the cause of its chlorophyll insufficiency is treated and this may lead to a plant diseases called rusts, although some chlorotic plants, such as the albino Arabidopsis thaliana mutant ppi2, are viable if supplied with exogenous sucrose.
Mycosphaerella coffeicola is a sexually reproducing fungal plant pathogen. It is most commonly referred to as the asexual organism Cercospora coffeicola.
Zinc deficiency is defined either as insufficient zinc to meet the needs of the body, or as a serum zinc level below the normal range. However, since a decrease in the serum concentration is only detectable after long-term or severe depletion, serum zinc is not a reliable biomarker for zinc status. Common symptoms include increased rates of diarrhea. Zinc deficiency affects the skin and gastrointestinal tract; brain and central nervous system, immune, skeletal, and reproductive systems.
Micronutrient deficiency is defined as the sustained insufficient supply of vitamins and minerals needed for growth and development, as well as to maintain optimal health. Since some of these compounds are considered essentials, micronutrient deficiencies are often the result of an inadequate intake. However, it can also be associated to poor intestinal absorption, presence of certain chronic illnesses and elevated requirements.
Phosphorus deficiency is a plant disorder associated with insufficient supply of phosphorus. Phosphorus refers here to salts of phosphates (PO43−), monohydrogen phosphate (HPO42−), and dihydrogen phosphate (H2PO4−). These anions readily interconvert, and the predominant species is determined by the pH of the solution or soil. Phosphates are required for the biosynthesis of genetic material as well as ATP, essential for life. Phosphorus deficiency can be controlled by applying sources of phosphorus such as bone meal, rock phosphate, manure, and phosphate-fertilizers.
Sugarcane grassy shoot disease (SCGS), is associated with 'Candidatus Phytoplasma sacchari' which are small, pleomorphic, pathogenic mycoplasma that contributes to yield losses from 5% up to 20% in sugarcane. These losses are higher in the ratoon crop. A higher incidence of SCGS has been recorded in some parts of Southeast Asia and India, resulting in 100% loss in cane yield and sugar production.
Abdul Rashid, is a Pakistani agricultural scientist, who has served as a Member (Bio-sciences) of the Pakistan Atomic Energy Commission (PAEC) from 2008 to 2011 and Director General of Pakistan's National Agricultural Research Center (NARC) from 2006 to 2008. He received a Ph.D. from the University of Hawaii at Manoa, Hawaii, in the United States.
Haifa Group is a private international corporation which primarily manufactures Potassium Nitrate for agriculture and industry, specialty plant nutrients and food phosphates. Haifa Group (Haifa) is the world pioneer in developing and supplying Potassium Nitrate and Specialty Plant Nutrients for advanced agriculture in various climates, weather, and soil conditions. Haifa also manufactures Controlled Release Fertilizers (CRF) for agriculture, horticulture, ornamentals, and turf. Many of Haifa's fertilizers can be used as a fertilizer solution that is applied through drip irrigation. This latter application is the principal driver of demand today, now that more countries are turning to controlled irrigation systems that make more efficient use of water.
Melon necrotic spot virus (MNSV) is a virus that belongs to the genus Gammacarmovirus of the family Tombusviridae. It has been observed in several countries of the Americas, Africa, Asia, and Europe. It is considered to be an endemic virus in greenhouses and field productions of Cucurbitaceae crops, including melon, cucumber, and watermelon. MNSV is mainly spread through infected soil, seedlings, insects, and by the root-inhabiting fungus vector Olpidium bornovanus. Symptoms vary between Curbitaceae crops, but generally consist of chlorosis, brown necrotic lesions, leaf wilt, fruit decay, and plant death. Management of the disease consists of preventing infection by rotating fields and crops, steam sterilization, and disposal of infected plants. Also, treated seeds with heat or chemicals are efficient in preventing infection. MNSV is important in melon plants as it causes vast economical damage worldwide reducing significant yields.
Molybdenum (Mo) deficiency occurs when plant growth is limited because the plant cannot take up sufficient quantities of this essential micronutrient from its growing medium. For crops growing in soil, this may be a result of low concentrations of Mo in the soil as a whole, or because the soil Mo is held in forms that are not available to plants – sorption of Mo is strongest in acid soils.
Seventeen elements or nutrients are essential for plant growth and reproduction. They are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg), iron (Fe), boron (B), manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo), nickel (Ni) and chlorine (Cl). Nutrients required for plants to complete their life cycle are considered essential nutrients. Nutrients that enhance the growth of plants but are not necessary to complete the plant's life cycle are considered non-essential. With the exception of carbon, hydrogen and oxygen, which are supplied by carbon dioxide and water, and nitrogen, provided through nitrogen fixation, the nutrients derive originally from the mineral component of the soil. The Law of the Minimum expresses that when the available form of a nutrient is not in enough proportion in the soil solution, then other nutrients cannot be taken up at an optimum rate by a plant. A particular nutrient ratio of the soil solution is thus mandatory for optimizing plant growth, a value which might differ from nutrient ratios calculated from plant composition.
Zinc is an essential trace element for humans and other animals, for plants and for microorganisms. Zinc is required for the function of over 300 enzymes and 1000 transcription factors, and is stored and transferred in metallothioneins. It is the second most abundant trace metal in humans after iron and it is the only metal which appears in all enzyme classes.
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