Symptom starts as pale green discoloration in the tip of older leaves, gradually turning to light green.
At later stages, older leaves start yellowing and drooping.
Plant growth is stunted.
Leaves and fruits become smaller in size
Early maturity of fruits
In severe stage, symptom progresses to young leaves.
Management
For determining the severity of the deficiency, soil analysis has to be done
Application of quick releasing nitrogen fertilizer like urea, according to the results of the soil test.
Apply urea as a foliar spray (10 gram per litre of water) once every 15 days .
Frequent application of organic growth boosters is also beneficial.
Phosphorus (P)
Symptoms
Symptom first appears in young mature leaves. It turns into dark green than normal leaves.
The leaves later develop an opaque red, green, or purple discoloration.
Plants show stunted growth with reduced leaf area and premature falling of leaves.
Dieback, necrosis of leaf tips and premature abscission of leaves are visible in some branches.
Management
Ensure that recommended amount of fertilizer is applied on regular time.
For determining the severity of the deficiency, soil analysis is to be done
Use fertilizers such as single superphosphate for quick correction or bone meal or rock phosphate for long-term correction.
In the pH range of 6.5-7.5, phosphorus is readily absorbed by the roots.
Addition of biofertilizers including phosphorus solubilizing bacteria along with organic manure helps to increase the availability of phosphorus
Potassium (K)
Symptoms
Symptom appears both in young and older leaves.
Symptom starts as a pale-yellow discoloration in margin of older leaves (marginal chlorosis) followed by browning and necrosis of leaf margins.
Symptom gradually progresses to upper leaves.
Presence of purple spots on the under surface of leaves
Poor plant growth, reduced size and weight of nuts.
Management
In the pH range of above 6, Potassium is readily available.
Maintain pH by addition of lime/dolomite
Improve the soil fertility by adding organic matter and wood ash.
For determining the severity of the deficiency, soil analysis is to be done
Use Muriate of Potash (MOP) according to the results of the soil test. Split application is preferable.
Apply foliar sprays of sulphate of potash (SOP) (10 gm/litre of water) and wetting agents in the morning as an immediate remedy
Calcium (Ca)
Symptoms
Symptoms appears in young leaves and developing fruits
Ripples in new leaves
Leaves turn brittle and leathery with reduced internodal length
Marginal scorching and cupping of young leaves.
Severe deficiency results in the death of growing points.
Management
Analysis of pH in the soil
If the soil is acidic, add 500 g of lime per plant/year in two split doses
High phosphorus levels leads to calcium deficiency
In alkaline soil application of Gypsum is preferable
Magnesium (Mg)
Symptoms
Symptom first appears in the older leaves as interveinal chlorosis and progresses to young leaves.
Plants show reduced growth and premature leaf fall.
Calcium deficiency and high potassium application can result in Magnesium deficiency
Management
Do the soil analysis and confirm the deficiency.
Addition of Magnesium sulphate (32 kg/ acre) in bands near plants.
Long-term usage of dolomite will reduce magnesium deficiency
Magnesium and potassium fertilizers should not be applied together.
Sulphur(S)
Symptoms
Symptoms initially appears as chlorosis and yellowing in young leaves
Older leaves develop chlorosis and become rigid.
Leaf tip become necrotic and curled.
Plants show stunted growth.
Management
Application of sulphur-containing fertilisers, such as Factamfos, Ammonium sulphate, Single superphosphate, etc., reduces the deficiency.
In sulphur deficient soils, apply sulphur dust (10 kilogrammes per acre).
eficiency in alkaline soil can be reduced by application of gypsum
ddition of organic material improves sulphur availability in the soil.
urning of organic waste leads to sulphur deficiency
Boron (B)
Symptoms
Symptom is visible mainly in growing points.
Roots do not elongate, disorganize, lose natural colour and dies off.
Death of growing buds and young leaves.
Flower dropping and fruits splits.
Under developed and unfilled nuts.
Management
Analysis of soil to confirm the deficiency.
Application of borax (50 gram /plant or 4 kg/ acre) into the soil
Addition of borax (1 gram / litre of water) as foliar spray .
Avoid the combined application of Boron and calcium.
Application of borax with ammonium fertilizers should be avoided.
Iron (Fe)
Symptoms
Symptom first appears in growing points.
Interveinal chlorosis and gradual bleaching of young leaves.
Growth of the tree is severely hindered and deficiency symptom is visible as severe chlorosis in young leaves within one month.
The leaves become more translucent with increasing deficiency.
Management
Iron content in Kerala soils is often high. So, get a soil test to determine the reason for the problem
Low potassium levels leads to iron deficiency
Addition of Ferrous Sulphate (75 gram/plant or 6 kg/ acre) into the deficient soils.
Manganese (Mn)
Symptoms
Symptom initially appears in the young leaves as pale green discoloration later changing to greenish-yellow.
Reduced plant growth with more lateral branches
Rosette appearance of leaves followed by drying and premature leaf fall
Management
Soil Analysis
Application of Manganese Sulphate (5 gram per litre of water) as foliar spray
Zinc (Zn)
Symptoms
Plants have short internodes and few lateral branches.
In deficient plants, the youngest leaves appear small, elongated, and with a colour varying from green to pale green, but the veins remain green.
The lower mature leaves develop normally.
Necrotic spots sometimes develop on leaves.
Management
The optimal pH range for zinc availability is 5 to 7.5.
Confirm deficiencies by doing soil testing.
Avoid the application of Zinc and phosphate fertilizers at the same time
In severe cases, foliar spraying of Zinc sulphate (2 gram/litre of water) with Calcium carbonate (2.5 gram/litre of water) can be advocated in morning hours.
