Detecting phosphorus deficiency can take multiple forms. A preliminary detection method is a visual inspection of plants. Darker green leaves and purplish or red pigment can indicate a deficiency in phosphorus. This method however can be an unclear diagnosis because other plant environment factors can result in similar discoloration symptoms. In commercial or well monitored settings for plants, phosphorus deficiency is diagnosed by scientific testing. Additionally, discoloration in plant leaves only occurs under fairly severe phosphorus deficiency so it is beneficial to planters and farmers to scientifically check phosphorus levels before discoloration occurs. The most prominent method of checking phosphorus levels is by soil testing. The major soil testing methods are Bray 1-P, Mehlich 3, and Olsen methods. Each of these methods are viable but each method has tendencies to be more accurate in known geographical areas. These tests use chemical solutions to extract phosphorus from the soil. The extract must then be analyzed to determine the concentration of the phosphorus. Colorimetry is used to determine this concentration. With the addition of the phosphorus extract into a colorimeter, there is visual color change of the solution and the degree to this color change is an indicator of phosphorus concentration. To apply this testing method on phosphorus deficiency, the measured phosphorus concentration must be compared to known values. Most plants have established and thoroughly tested optimal soil conditions. If the concentration of phosphorus measured from the colorimeter test is significantly lower than the plant’s optimal soil levels, then it is likely the plant is phosphorus deficient. The soil testing with colorimetric analysis, while widely used, can be subject to diagnostic problems as a result of interference from other present compounds and elements. Additional phosphorus detection methods such as spectral radiance and inductively coupled plasma spectrometry (ICP) are also implemented with the goal of improving reading accuracy. According to the World Congress of Soil Scientists, the advantages of these light-based measurement methods are their quickness of evaluation, simultaneous measurements of plant nutrients, and their non-destructive testing nature. Although these methods have experimental based evidence, unanimous approval of the methods has not yet been achieved.

Calcium deficiency can sometimes be rectified by adding agricultural lime to acid soils, aiming at a pH of 6.5, unless the subject plants specifically prefer acidic soil. Organic matter should be added to the soil to improve its moisture-retaining capacity. However, because of the nature of the disorder (i.e. poor transport of calcium to low transpiring tissues), the problem cannot generally be cured by the addition of calcium to the roots. In some species, the problem can be reduced by prophylactic spraying with calcium chloride of tissues at risk.

Plant damage is difficult to reverse, so corrective action should be taken immediately, supplemental applications of calcium nitrate at 200 ppm nitrogen, for example. Soil pH should be tested, and corrected if needed, because calcium deficiency is often associated with low pH.

Early fruit will generally have the worst systems, with them typically lessening as the season progresses. Preventative measures, such as irrigating prior to especially high temperatures and stable irrigation will minimize the occurrence.

Fertilisers like ammonium phosphate, calcium ammonium nitrate, urea can be supplied. Foliar spray of urea can be a quick method.

Correction and prevention of phosphorus deficiency typically involves increasing the levels of available phosphorus into the soil. Planters introduce more phosphorus into the soil with bone meal, rock phosphate,manure, and phosphate-fertilizers. The introduction of these compounds into the soil however does not ensure the alleviation of phosphorus deficiency. There must be phosphorus in the soil, but the phosphorus must also be absorbed by the plant. The uptake of phosphorus is limited by the chemical form in which the phosphorus is available in the soil. A large percentage of phosphorus in soil is present in chemical compounds that plants are incapable of absorbing. Phosphorus must be present in soil in specific chemical arrangements to be usable as plant nutrients. Facilitation of usable phosphorus in soil can be optimized by maintaining soil within a specified pH range. Soil acidity, measured on the pH scale, partially dictates what chemical arrangements that phosphorus forms. Between pH 6 and 7, phosphorus makes the fewest number of bonds which render the nutrient unusable to plants. At this range of acidity the likeliness of phosphorus uptake is increased and the likeliness of phosphorus deficiency is decreased. Another component in the prevention and treatment of phosphorus is the plant’s disposition to absorb nutrients. Plant species and different plants within in the same species react differently to low levels of phosphorus in soil. Greater expansion of root systems generally correlate to greater nutrient uptake. Plants within a species that have larger roots are genetically advantaged and less prone to phosphorus deficiency. These plants can be cultivated and bred as a long term phosphorus deficiency prevention method. In conjunction to root size, other genetic root adaptations to low phosphorus conditions such as mycorrhizal symbioses have been found to increase nutrient intake. These biological adaptations to roots work to maintain the levels of vital nutrients. In larger commercial agriculture settings, variation of plants to adopt these desirable phosphorus intake adaptations may be a long-term phosphorus deficiency correction method.

The most widely used potassium fertilizer is potassium chloride (muriate of potash). Other inorganic potassium fertilizers include potassium nitrate, potassium sulfate, and monopotassium phosphate. Potassium-rich treatments suitable for organic farming include feeding with home-made comfrey liquid, adding seaweed meal, composted bracken, and compost rich in decayed banana peels. Wood ash also has high potassium content. Adequate moisture is necessary for effective potassium uptake; low soil water reduces K uptake by plant roots. Liming acidic soils can increase potassium retention in some soils by reducing leaching; practices that increase soil organic matter can also increase potassium retention.

The visual symptoms of nitrogen deficiency mean that it can be relatively easy to detect in some plant species. Symptoms include poor plant growth, and leaves that are pale green or yellow because they are unable to make sufficient chlorophyll. Leaves in this state are said to be chlorotic. Lower leaves (older leaves) show symptoms first, since the plant will move nitrogen from older tissues to more important younger ones. Nevertheless, plants are reported to show nitrogen deficiency symptoms at different parts. For example, Nitrogen deficiency of tea is identified by retarded shoot growth and yellowing of younger leaves.

However, these physical symptoms can also be caused by numerous other stresses, such as deficiencies in other nutrients, toxicity, herbicide injury, disease, insect damage or environmental conditions. Therefore, nitrogen deficiency is most reliably detected by conducting quantitative tests in addition to assessing the plants visual symptoms. These tests include soil tests and plant tissue test.

Plant tissue tests destructively sample the plant of interest. However, nitrogen deficiency can also be detected non-destructively by measuring chlorophyll content.

Chlorophyll content tests work because leaf nitrogen content and chlorophyll concentration are closely linked, which would be expected since the majority of leaf nitrogen is contained in chlorophyll molecules. Chlorophyll content can be detected with a Chlorophyll content meter; a portable instrument that measures the greenness of leaves to estimate their relative chlorophyll concentration.

Chlorophyll content can also be assessed with a chlorophyll fluorometer, which measures a chlorophyll fluorescence ratio to identify phenolic compounds that are produced in higher quantities when nitrogen is limited. These instruments can therefore be used to non-destructively test for nitrogen deficiency.

Calcium (Ca) deficiency is a plant disorder that can be caused by insufficient level of available calcium in the growing medium, but is more frequently a product of low transpiration of the whole plant or more commonly the affected tissue. Plants are susceptible to such localized calcium deficiencies in low or non-transpiring tissues because calcium is not transported in the phloem. This may be due to water shortages, which slow the transportation of calcium to the plant, poor uptake of calcium through the stem, or too much nitrogen in the soil.

Magnesium supplements are used to prevent the disease when ruminants, for obvious economic reasons, must have access to dangerous pastures.

Manganese deficiency is easy to cure and homeowners have several options when treating these symptoms. The first is to adjust the soil pH. Two materials commonly used for lowering the soil pH are aluminum sulfate and sulfur. Aluminum sulfate will change the soil pH instantly because the aluminum produces the acidity as soon as it dissolves in the soil. Sulfur, however, requires some time for the conversion to sulfuric acid with the aid of soil bacteria. If the soil pH is not a problem and there is no manganese actually in the soil then Foliar feeding for small plants and medicaps for large trees are both common ways for homeowners to get manganese into the plant.

The affected animal should be left in the pasture, and not forced to come back to stall because excitation can darken the prognosis, even after adequate treatment.

Intravenous mixed calcium and magnesium injection are used. Subcutaneous injection of magnesium sulfate (200 ml of 50% solution) is also recommended.

Novel zinc biomarkers, such as the erythrocyte LA:DGLA ratio, have shown promise in pre-clinical and clinical trials and are being developed to more accurately detect dietary zinc deficiency.

Several decades of research in several countries with many cultivars showed that moderate levels of bitter pit could be controlled with the spraying of the trees with calcium chloride or calcium nitrate during the growing season. However, in the southern hemisphere where highly susceptible fruit had to be harvested early for export to Europe, the problem remained. An attempt to increase the calcium content by applying calcium after harvest had resulted in severe injury to the fruit. Export of susceptible apples from New Zealand was under threat and new methods for controlling bitter pit were investigated. While it was shown that bitter pit was reduced as calcium levels rose, it was not possible to determine a minimum level of calcium that would ensure that the disorder was controlled. The most effective treatment found for closed calyx fruit was to submerge the fruit in the calcium chloride solution and to apply a vacuum and immediately rinsing in water. This overcame the injury problem and gave much better control of the disorder. The vacuum treatment was commercialized in New Zealand for the Cox's Orange Pippin cultivar in 1978 and was used for several years. However the treatment was expensive and could not be used for open calyx cultivars.

A simpler treatment was developed in Western Australia and was adopted in Australia and in New Zealand. This involved dipping the fruit in the calcium solution and rinsing in water after about 36 hours. This treatment has been confirmed by independent workers and has generally been adopted in Australia and New Zealand. Postharvest dipping in a calcium solution has been recommended in some other countries where bitter pit is severe. However the problem of fruit injury does not seem to have been addressed.

It appears that bitter pit can generally be reduced by using good horticultural practices. Usually spraying throughout the growing season with a calcium salt is also necessary for moderately susceptible cultivars. It is more difficult to control storage pit in highly susceptible cultivars as field spraying may not be able to apply sufficient calcium to the fruit. Improved control can be obtained by also dipping the fruit in a 2-3 per cent calcium chloride solution after harvest and rinsing the fruit in water after about 36 hours.

Boric acid (16.5%boron), borax (11.3% boron) or SoluBor (20.5% boron) can be applied to soils to correct boron deficiency. Typical applications of actual boron are about 1.1 kg/hectare or 1.0 lb/acre but optimum levels of boron vary with plant type. Borax, Boric Acid or Solubor can be dissolved in water and sprayed or applied to soil as a dust. Excess boron is toxic to plants so care must be taken to ensure correct application rate and even coverage. Leaves of many plants are damaged by boron; therefore, when in doubt, only apply to soil. Application of boron may not correct boron deficiency in alkaline soils because even with the addition of boron, it may remain unavailable for plant absorption. Continued application of boron may be necessary in soils that are susceptible to leaching such as sandy soils. Flushing soils containing toxic levels of boron with water can remove the boron through leaching.

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.

Manganese deficiency can be easy to spot in plants because, much like magnesium deficiency, the leaves start to turn yellow and undergo interveinal chlorosis. The difference between these two is that the younger leaves near the top of the plant show symptoms first because manganese is not mobile while in magnesium deficiency show symptoms in older leaves near the bottom of the plant.

Iron deficiency can be avoided by choosing appropriate soil for the growing conditions (e.g., avoid growing acid loving plants on lime soils), or by adding well-rotted manure or compost. If iron deficit chlorosis is suspected then check the pH of the soil with an appropriate test kit or instrument. Take a soil sample at surface and at depth. If the pH is over seven then consider soil remediation that will lower the pH toward the 6.5 - 7 range. Remediation includes: i) adding compost, manure, peat or similar organic matter (warning. Some retail blends of manure and compost have pH in the range 7 - 8 because of added lime. Read the MSDS if available. Beware of herbicide residues in manure. Source manure from a certified organic source.) ii) applying Ammonium Sulphate as a Nitrogen fertilizer (acidifying fertilizer due to decomposition of ammonium ion to nitrate in the soil and root zone) iii) applying elemental Sulphur to the soil (oxidizes over the course of months to produce sulphate/sulphite and lower pH). Note: adding acid directly e.g. sulphuric/hydrochloric/citric acid is dangerous as you may mobilize metal ions in the soil that are toxic and otherwise bound. Iron can be made available immediately to the plant by the use of iron sulphate or iron chelate compounds. Two common iron chelates are Fe EDTA and Fe EDDHA. Iron sulphate (Iron(II)_sulfate) and iron EDTA are only useful in soil up to PH 7.1 but they can be used as a foliar spray (Foliar_feeding). Iron EDDHA is useful up to PH 9 (highly alkaline) but must be applied to the soil and in the evening to avoid photodegradation. EDTA in the soil may mobilize Lead, EDDHA does not appear to.

Day to day requirements of vitamin d are set around 800-1000IU to maintain healthy levels which in most cases can be provided by sun exposure. Increased amounts are required for individuals who are previously diagnosed as deficient. For those of moderate deficiencies,oral supplementation can be implemented into the diet at levels of 3000-5000 IU per day for a 6- to 12-week period continued by an ongoing reduced dose of 1000- 2000 IU per day to maintain stores in the body.

Severe deficiency is treated through megadose therapy where patients are given doses around 100 000 IU to assist in raising stores faster to ensure physical health in restored to prevent further illness or disease.

Early reports indicated that the disorder was affected by climate and growing conditions. Dry weather before harvest seemed to increase the condition. Light crops, heavy use of fertilizers, large fruit and early harvesting increased the condition. Fruit that were free of bitter pit at harvest were often severely affected after a short period of storage. Bitter pit has been widely reviewed over many decades.

The disorder became a major problem for exports from the Southern Hemisphere to Europe. The breakthrough in control came with the discovery in North America that the mineral calcium was low in affected fruit. This was confirmed elsewhere.

Magnesium (Mg) deficiency is a detrimental plant disorder that occurs most often in strongly acidic, light, sandy soils, where magnesium can be easily leached away. Magnesium is an essential micro nutrient found from 0.2-0.4% dry matter and is necessary for normal plant growth. Excess potassium, generally due to fertilizers, further aggravates the stress from the magnesium deficiency, as does aluminium toxicity.

Magnesium has an important role in photosynthesis because it forms the central atom of chlorophyll. Therefore, without sufficient amounts of magnesium, plants begin to degrade the chlorophyll in the old leaves. This causes the main symptom of magnesium deficiency, chlorosis, or yellowing between leaf veins, which stay green, giving the leaves a marbled appearance. Due to magnesium’s mobile nature, the plant will first break down chlorophyll in older leaves and transport the Mg to younger leaves which have greater photosynthetic needs. Therefore, the first sign of magnesium deficiency is the chlorosis of old leaves which progresses to the young leaves as the deficiency continues. Magnesium also is a necessary activator for many critical enzymes, including ribulosbiphosphate carboxylase (RuBisCO) and phosphoenolpyruvate carboxylase (PEPC), both essential enzymes in carbon fixation. Thus low amounts of Mg lead to a decrease in photosynthetic and enzymatic activity within the plants. Magnesium is also crucial in stabilizing ribosome structures, hence, a lack of magnesium causes depolymerization of ribosomes leading to pre-mature aging of the plant. After prolonged magnesium deficiency, necrosis and dropping of older leaves occurs. Plants deficient in magnesium also produce smaller, woodier fruits.

Magnesium deficiency may be confused with zinc or chlorine deficiencies, viruses, or natural ageing since all have similar symptoms. Adding Epsom salts (as a solution of 25 grams per liter or 4 oz per gal) or crushed dolomitic limestone to the soil can rectify magnesium deficiencies. For a more organic solution, applying home-made compost mulch can prevent leaching during excessive rainfall and provide plants with sufficient amounts of nutrients, including magnesium.

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.

Vitamin D deficiency historically used to be identified through counting cases of rickets. The old theory was that if someone had enough vitamin D to prevent rickets and osteomalacia, two skeletal disorders, they were considered safe from a deficiency. Nowadays through technological advancements Vitamin D deficiencies are now identified and thus calculated through the measurement of the serum 25-OH. According to the Australian Bureau of Statistics National Health Measures Survey (NHMS), the recommend Vitamin D levels to determine deficiency are categorised as follows:

•Adequate levels: >50 nmol/L

•Mild deficiency: 30-49 nmol/L

•Moderate deficiency: 13 – 29nmol/L

•Severe deficiency: <13 nmol/L

Photosynthesis transforms sunlight energy into plant energy compounds such as sugars. For this

process to continue in plants, the sugars must be moved away from the site of their development,

and stored or used to make other compounds.

Boron increases the rate of transport of sugars (which are produced by photosynthesis in mature

plant leaves) to actively growing regions and also in developing fruits.

Boron is essential for providing sugars which are needed for root growth in all plants and also for

normal development of root nodules in legumes such as alfalfa, soybeans and peanuts.

Zinc deficiency can be classified as acute, as may occur during prolonged inappropriate zinc-free total parenteral nutrition; or chronic, as may occur in dietary deficiency or inadequate absorption.

The official recommendation from the United States Preventive Services Task Force is that for persons that do not fall within an at-risk population and are asymptomatic, there is not enough evidence to prove that there is any benefit in screening for vitamin D deficiency.

Supplemental zinc can prevent iron absorption, leading to iron deficiency and possible peripheral neuropathy, with loss of sensation in extremities. Zinc and iron should be taken at different times of the day.