In addition to major nutrients, plants also need Trace Elements for their effective growth albeit in minor amounts as compared to NPK. The important Trace Elements required for plants are: Zinc, Iron, Copper, Magnesium, Manganese, Calcium, Boron and Molybdenum.
The most common way of detecting a Trace Element deficiency is through symptoms on the leaves of the plant or through local knowledge of which trace elements in a particular area are not very abundant. Additionally knowledge of the soil pH will also indicate which Trace Elements are not being made available to the plant. For example in alkaline soil pH conditions deficiency of Zinc, Manganese and Iron are very common. Soil pH directly affects nutrient uptake. As depicted in the diagram below most of these Trace Elements are less available in alkaline conditions i.e., when pH is very high (more than 8). Under neutral pH range of 6-7, most nutrients are better and easily available for absorption.
Natural Trace Element deficiencies can only be fixed by regular and repetitive applications of the deficient trace element. Problems caused by the Soil pH can often be easily fixed by adjusting the pH to neutral or correct level, the plant will however take some time to fully recover. The best way to quickly solve the problem is to apply a soluble form of the Trace Element so that the plant can quickly absorb the deficient nutrient. In situations where deficiencies are severe, both soil and foliage applications are advisable for quick recovery. However follow the directions on the product label and do not overdose at once.
A good example of this is citrus trees which are very heavy feeders on the Trace Elements Zinc and Manganese (not to be confused with Magnesium). Manutec’s soluble Zinc and Manganese has been specially formulated to be sprayed onto the leaves of citrus trees. In this soluble form, it is very quickly absorbed into the leaves and the plant will start showing signs of recovery very quickly.
Another good example is rhododendrons which have a high Magnesium uptake. If not available in sufficient quantities (particularly in highly acid soils, as this become deficient) the leaves will develop a yellowing between the veins. This problem can be easily rectified by using Manutec Epsom salts. Further information on Manutec Trace element products have been detailed under products menu on this website.
Sometimes it is not easy to recognize the deficiency symptoms of particular trace element in the plant and in such cases a general application of Manutec soluble Trace Elements mix will provide a balanced quantity of all of the Trace Elements necessary to support healthy plant growth. This is particularly important in potted plants, sandy soils, organic and alkaline soils where often many of the elements will be deficient. All soluble Trace Element applications are best applied by either applying dissolved solution to the soil/potting mix around the plants or by foliar spray. For most foliar sprays, as a thumb rule use the dilution rate of 1 gram per litre which is a safe dilution. However keep in mind that foliar application only provides quick relief to plants and do not provide a long term solution, after some time, plants again look for nutrients from soil, so it is also important to keep the soil source fertile and supplemented.
Deficiencies and remedies
Symptoms : generally necrotic leaf margins and curling of young leaves, death of terminal buds and root tips.
Crop-specific symptoms include : In tomatoes and HPeppers H (Capsicums) : ‘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 in addition to calcium rapid growth from high-nitrogen fertilizers and irregular watering (over or under) may also cause blossom end rot.
- In Apple – develop bitter pits – fruit skins develop pits, brown spots appear on skin and/or in flesh and taste of those areas is bitter.
- In Cabbage and Brussels seen as Internal browning.
- In Carrot – develop Cavity spots – oval spots develop into craters which may be invaded by other diseases.
Cause : Very high acidic conditions (low pH) results in Calcium being less available and plants are unable to take it up. Excessive application of Ammonium and Potassium fertilisers can also results in deficiencies of Calcium.
- Firstly check the pH and make sure soil or potting mix is not highly acidic, maintain neutral pH condition (6-7)
- Application of Calcium rich products such as Calcium Sulphate (Gypsum), Calcium Nitrate or soluble fertilisers enriched with Calcium such as MANUTEC TOMATO MAGIC.
- Water plants in a regular pattern or schedule
- Balance use of Calcium, Magnesium and Potassium is also important as they complement and absorbed in preference to other when available in excessive.
Symptoms : Patchy yellowing between the leaf veins of older leaves, sometimes with reddish brown tints and early leaf fall. Magnesium deficiency is common in tomatoes, apples, grape vines, raspberries, roses and rhododendrons. Very common in fruits, vegetables and acid loving plants such as azalea, camellias and rhododendrons.
Cause: Deficiencies of Magnesium are more common on light, sandy soils. Over-use of high-Potassium fertilisers or Potash can cause Magnesium deficiency, as plants take up Potassium in preference to Magnesium. Deficiencies are also common in acidic soils with low pH and in soils that are too wet or too dry restricting root growth
Remedy : For immediate and short term remedy, apply Manutec Epsom salts by dissolving in water either as foliar spray or applying solution to plants surrounding roots. In the long term regular application of Manutec Epsom Salt or Manutec Trace element mixes containing Magnesium will maintain adequate levels of Magnesium in soils. In acid soils where Lime has to be used to raise the pH, use Manutec Dolomite lime (instead of Garden Lime) which also supplies adequate Magnesium to soils. However care should be taken to not use Dolomite or Lime around acid Loving plants such as azalea and camellia.
Symptoms : General yellowing of new leaves including veins, in some plants leaves will be small with rolled down edges.
Cause : Sulphur is important for formation of proteins. Cabbages, onions and Brussels sprouts are crops that really do requireSulphur (the characteristic smell in these plants is from Sulphur). Alkaline soils, sandy soils, high rain fall areas, and potting mixes are commonly deficient in Sulphur.
Remedy : Application of Manutec Sulphur containing fertilisers such as Super Phosphate or Elemental Sulphur (partially in alkaline soils) helps to maintain adequate levels of Sulphur. Use of some Sulphate based fertilisers also adds Sulphur content to soils.
Symptoms: symptoms start on young/fresh growth with yellowing between veins with veins remaining sharp green
Cause : High pH ( alkaline conditions) generally causes deficiencies as Iron is chemically locked up and unavailable for plants to absorb in soils. Acid loving plants are particularly vulnerable when growing in alkaline soils or potting composts.
Remedy : Application of Manutec Iron Chelate (EDTA) as a foliar sprays or applied to the soil around the plant roots is recommended. This provides effective results to overcome deficiencies. Maintaining and growing plants in optimum pH conditions helps to avoid severe deficiencies
Symptoms: Yellowing of young leaves, results in small leaves and bunching of young leaves.
Cause : Alkaline conditions (high pH), sandy soils, excessive Phosphorus content in soils.
Remedy : Regular application of Manutec Zinc Sulphate or Manutec Trace Element mixes containing Zinc will provide immediate remedy to overcome Zinc deficiency. In the long term, maintaining optimum pH conditions is important to avoid severe deficiencies.
Symptoms : death of tips, yellowing and distorted young growth
Cause: Alkaline conditions, sandy soils and sometimes high levels of Iron, Manganese, Zinc or Phosphorus fertilisers without the addition of Copper can cause deficiencies.
Remedy : Regular use of Manutec Trace Element mix containing Copper or Manutec Copper Sulphate will maintain adequate levels of Copper in soils. In addition, maintaining optimum soil pH is important as a long term remedy to enable availability of copper.
Symptoms : Stunted growth and tip dieback on lettuce, brown cracks in celery; rotten Swedes, turnips and celeriac; dimples in pears with brown patches underneath
Cause : Soil shortages are rare, but this nutrient can be less available to plant roots in alkaline and high rainfall conditions.
Remedy: Application of Manutec Trace Elements mix containing Boron or by applying Manutec Boron (Sodium Borate) to the soil before sowing vegetables or as a foliar spray feed applied to fruit trees.
Symptoms : mottling and cupping of leaves and distortion of stems. Molybdenum deficiency is common in cauliflowers and other brassicas (cabbage and Brusselsâ€™ sprouts) particularly when grown in acidic soil pH conditions. Whiptail symptom in cauliflower is a common deficiency.
Cause : Molybdenum is required for a variety of plant growth processes, but is needed only in very small quantities. Soil shortages of Molybdenum are rare, but it can be less available to plant roots in acid conditions.
Remedy: Treat with Manutec Trace Elements mix that contains Molybdenum. Liming the soil will help in the long term, as making the soil more alkaline will help to make the Molybdenum more available.