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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.
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.
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.
Fertilisers like ammonium phosphate, calcium ammonium nitrate, urea can be supplied. Foliar spray of urea can be a quick method.
Magnesium supplements are used to prevent the disease when ruminants, for obvious economic reasons, must have access to dangerous pastures.
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.
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.
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.
Five interventional strategies can be used:
- Adding zinc to soil, called agronomic biofortification, which both increases crop yields and provides more dietary zinc.
- Adding zinc to food, called fortification.
- Adding zinc rich foods to diet. The foods with the highest concentration of zinc are proteins, especially animal meats, the highest being oysters. Per ounce, beef, pork, and lamb contain more zinc than fish. The dark meat of a chicken has more zinc than the light meat. Other good sources of zinc are nuts, whole grains, legumes, and yeast. Although whole grains and cereals are high in zinc, they also contain chelating phytates which bind zinc and reduce its bioavailability.
- Oral repletion via tablets (e.g. zinc gluconate) or liquid (e.g. zinc acetate). Oral zinc supplementation in healthy infants more than six months old has been shown to reduce the duration of any subsequent diarrheal episodes by about 11 hours.
- Oral repletion via multivitamin/mineral supplements containing zinc gluconate, sulfate, or acetate. It is not clear whether one form is better than another. Zinc is also found in some cold lozenges, nasal sprays, and nasal gels.
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.
This disease is hard to control because plants can carry the pathogen prior to showing any symptoms. It is important to be aware of where new plants are being planted so that they aren't exposed to disease.
The most effective method to avoid disease is to plant resistant cultivars that are specific to the location of planting. Some examples of resistant cultivars include Allstar, Cardinal, Delite, Honeoye, Jewel and Tennessee Beauty. Examples of susceptible cultivars that should be avoided include Sparkle, Sunrise, Raritan and Catskill.
Amongst the many different management strategies, cultural control practices play a significant role in prevention or reduction of disease. Some common cultural practices that have been used are as follows. In order to have more successful yields, strawberry plants should be planted in well-drained soil, in an area exposed to lots of available sunlight and air circulation. Presence of weeds may reduce air circulation for strawberry plants and create a shaded, moist environment, which would make the plants more wet and susceptible to disease. Therefore, weed growth needs to be prevented, either by chemical or cultural control methods. Immediately after harvest, any severely infected plants and plant debris should be raked, removed and burned completely to get rid of any remaining spores and reduce inoculum of the pathogen.
At the beginning of renovation, which occurs after harvest, one application of nitrogen fertilizers should be applied to help with canopy regrowth. About 4–6 weeks later, it is generally a good time to apply another application of nitrogen fertilization to the developing strawberry plants. This will allow for the plants to absorb nutrients provided by the fertilizer. However, applying too much nitrogen fertilizer throughout the spring, may result in an abundance of young foliage tissues that could be susceptible to disease.
Fungicides are not necessarily required, however if the strawberry grower decides to use fungicides, they should be applied during early in the spring and immediately after renovation. A fungicide spray schedule may also be put into place. It is recommended to spray in intervals of about 2 weeks. Examples of some recommended fungicides are Bulletin 506-B2, Midwest Commercial Small Fruit and Grape Spray Guide for commercial growers and Bulletin 780, Controlling Disease and Insects in Home Fruit Plantings for backyard home growers.
Once boron has been absorbed by the plant and incorporated into the various structures that require boron, it is unable to disassemble these structures and re-transport boron through the plant resulting in boron being a non-mobile nutrient. Due to translocation difficulties the youngest leaves often show deficiency symptoms first.
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.
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.
Calcium deficiency symptoms appear initially as localized tissue necrosis leading to stunted plant growth, necrotic leaf margins on young leaves or curling of the leaves, and eventual death of terminal buds and root tips. Generally, the new growth and rapidly growing tissues of the plant are affected first. The mature leaves are rarely if ever affected because calcium accumulates to high concentrations in older leaves.
Crop-specific symptoms include:
- Apple : 'Bitter pit' – fruit skins develop pits, brown spots appear on skin and/or in flesh and taste of those areas is bitter. This usually occurs when fruit is in storage, and Bramley apples are particularly susceptible. Related to boron deficiency, "water cored" apples seldom display bitter pit effects.
- Cabbage and Brussels sprouts : Internal browning and "tip burn"
- Carrot : 'Cavity spot' – oval spots develop into craters which may be invaded by other disease-causing organisms.
- Celery : Stunted growth, central leaves stunted.
- Tomatoes and peppers: 'Blossom end rot' – Symptoms start as sunken, dry decaying areas at the blossom end of the fruit, furthest away from the stem, not all fruit on a truss is necessarily affected. Sometimes rapid growth from high-nitrogen fertilizers may exacerbate blossom end rot. Water management and preventing water stress is key to minimizing its occurrence.
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.
"F. oxysporum" is a major wilt pathogen of many economically important crop plants. It is a soil-borne pathogen, which can live in the soil for long periods of time, so rotational cropping is not a useful control method. It can also spread through infected dead plant material, so cleaning up at the end of the season is important.
One control method is to improve soil conditions because "F. oxysporum" spreads faster through soils that have high moisture and bad drainage. Other control methods include planting resistant varieties, removing infected plant tissue to prevent overwintering of the disease, using soil and systemic fungicides to eradicate the disease from the soil, flood fallowing, and using clean seeds each year. Applying fungicides depends on the field environment. It is difficult to find a biological control method because research in a greenhouse can have different effects than testing in the field. The best control method found for "F. oxysporum" is planting resistant varieties, although not all have been bred for every forma specialis.
"F. oxysporum" f. sp. "batatas" can be controlled by using clean seed, cleaning up infected leaf and plant material and breeding for resistance. Fungicides can also be used, but are not as effective as the other two because of field conditions during application. Fungicides can be used effectively by dip treating propagation material.
Different races of "F. oxysporum" f. sp. "cubense", Panama disease on banana, can be susceptible, resistant and partially resistant. It can be controlled by breeding for resistance and through eradication and quarantine of the pathogen by improving soil conditions and using clean plant material. Biological control can work using antagonists. Systemic and soil fungicides can also be used.
The main control method for "F. oxysporum" f. sp. "lycopersici", vascular wilt on tomato, is resistance. Other effective control methods are fumigating the infected soil and raising the soil pH to 6.5-7.
The most effective way to control "F. oxysporum" f. sp. "melonis" is to graft a susceptible variety of melon to a resistant root-stock. Resistant cultivars, liming the soil to change soil pH to 6-7, and reducing soil nitrogen levels also help control "F. oxysporum" f. sp. "melonis".
The fungus "Trichoderma viride" is a proven biocontrol agent to control this disease in an environment friendly way.
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.
All plants require sufficient supplies of macronutrients for healthy growth, and nitrogen (N) is a nutrient that is commonly in limited supply. Nitrogen deficiency in plants can occur when organic matter with high carbon content, such as sawdust, is added to soil. Soil organisms use any nitrogen to break down carbon sources, making N unavailable to plants. This is known as "robbing" the soil of nitrogen. All vegetables apart from nitrogen fixing legumes are prone to this disorder.
Nitrogen deficiency can be prevented in the short term by using grass mowings as a mulch, or foliar feeding with manure, and in the longer term by building up levels of organic matter in the soil. Sowing green manure crops such as grazing rye to cover soil over the winter will help to prevent nitrogen leaching, while leguminous green manures such as winter tares will fix additional nitrogen from the atmosphere.
Strawberry foliar nematodes are difficult to manage due to their robust life cycle. While dormant, they are quite difficult to kill, and they remain viable in dry debris for more than one year. Adult nematodes can survive desiccation and lie dormant for several years. Eggs can stay dormant until survival conditions are optimal for growth. Once eggs or nematodes are present in the soil, they are nearly impossible to eradicate because they can move laterally in the soil to escape non-optimal conditions. They are found in most foliar tissue, including the leaves, stems, buds, and crowns, making it difficult to control the disease on the plant itself once it has been infected
Many plant diseases are managed chemically, but due to a ban of nematicides there are currently no nematicides available for any type of foliar nematode. Some insecticides, pesticides, and plant product extracts from plants such as Ficus and Coffee (of which many pesticides and nematicides are neem-based ) can be used to reduce the numbers of strawberry foliar nematode (a reduction of 67-85%), but none of these chemicals can completely eradicate the nematodes once they are present in the soil. These chemicals affect all stages of the life cycle because they target the nervous system. One chemical, ZeroTol, a broad-spectrum fungicide and algaecide, was shown be to 100% potent against nematodes living in a water suspension, but the study does not show how nematodes are affected in soil or outside of a laboratory environment.
An alternative method of control is a hot water treatment, which affects all stages of the life cycle and can be used on whole plants. This treatment has been used for 60 years with some effect in greenhouse plants, but not on a widespread agricultural level. The difficulty in this treatment is that exposure times to hot water and the temperature of the water must be optimized so that the nematodes are killed, but the cultivar remains undamaged. One study, which researched five California strawberry cultivars including Chandler, Douglas, Fern, Pajaro, and Selva, demonstrated that the minimum-maximum exposure times and temperatures that killed the nematodes but did not harm the cultivars were: 20–30 minutes at 44.4⁰C, 10–15 minutes at 46.1⁰C, and 8–10 minutes at 47.7⁰. The study also found that fruit production was more sensitive to the treatment than mere survival of the plant, so the minimum exposure times are recommended when using plants for fruit production, and the maximum time is recommended when using plants for propagation.
One of the best and most practiced forms of management to reduce the local and geographical spread of the disease is sanitation. Removing the infected leaves of the plant can reduce spread in the individual plant, but because the nematode is found in most foliar tissue the nematodes may already be present in other tissues before the leaf symptoms appear. The nematodes can also move on the outside of the plant surface when water is present, so the nematodes can move around the outside surface of the plant and infect new tissues. Therefore, once plants show any signs of infection, they should be removed and destroyed. Reducing or eliminating overhead irrigation can prevent dispersal of the nematode through water splashing, and keeping the foliage dry prevents the nematodes from moving on the outside of the plant. Plants should be placed further apart to allow water to dry quickly after irrigation. In the greenhouse or nursery, soils, containers, and tools should be sterilized on a regular basis, and the floor and storage areas should be free from plant debris.
The most important form of management is prevention of introduction of the nematode to the environment. One should avoid planting infected plants, and it is recommended that new plants (especially in a personal lawn or greenhouse) be planted in an isolated area to monitor the plant for the development of symptoms before transplanting the plant near established plants. This will prevent the established plants from getting infected from a new, infected plant. All symptomatic plants should be destroyed immediately. Dead plant material should also be handled with caution. Vermiform nematodes can survive and reproduce in compost piles of dead plant material by feeding on fungi that are commonly found in compost. As a result, infected plants should be burned and sterilized to prevent the nematodes from infecting soil (which results directly from burying the material), or other plants (from allowing the plant to remain rooted in the soil near other plants as it dies).
Poor growth and a variety of disorders such as leaf discolouration (chlorosis) can be caused by a shortage of one or more plant nutrients. Poor plant uptake of a nutrient from the soil (or other growing medium) may be due to an absolute shortage of that element in the growing medium, or because that element is present in a form that is not available to the plant. The latter can be caused by incorrect pH, shortage of water, poor root growth or an excess of another nutrient. Plant nutrient deficiencies can be avoided or corrected using a variety of approaches including the consultation of experts on-site, the use of soil and plant-tissue testing services, the application of prescription-blend fertilizers, the application of fresh or well-decomposed organic matter, and the use of biological systems such as cover crops, intercropping, improved fallows, ley cropping, permaculture, or crop rotation.
Nutrient (or mineral) deficiencies include:
- Boron deficiency
- Calcium deficiency
- Iron deficiency
- Magnesium deficiency
- Manganese deficiency
- Molybdenum deficiency
- Nitrogen deficiency
- Phosphorus deficiency
- Potassium deficiency
- Zinc deficiency
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.
The goal of therapy is to treat the hypercalcaemia first and subsequently effort is directed to treat the underlying cause.
Initial therapy:
- hydration, increasing salt intake, and forced diuresis.
- hydration is needed because many patients are dehydrated due to vomiting or kidney defects in concentrating urine.
- increased salt intake also can increase body fluid volume as well as increasing urine sodium excretion, which further increases urinary potassium excretion.
- after rehydration, a loop diuretic such as furosemide can be given to permit continued large volume intravenous salt and water replacement while minimizing the risk of blood volume overload and pulmonary oedema. In addition, loop diuretics tend to depress calcium reabsorption by the kidney thereby helping to lower blood calcium levels
- can usually decrease serum calcium by 1–3 mg/dL within 24 hours
- caution must be taken to prevent potassium or magnesium depletion