On severity of deficiency, chlorosis result in death of the plant or dropping of the older 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.
Frequent application of organic growth boosters is also beneficial
Apply urea as a foliar spray (10 gram per litre of water) once every 15 days .
Phosphorus (P)
Symptoms
Phosphorous is very much needed for root growth.
The root growth will be affected. This results in poor uptake of needed nutrients.
The deficiency symptoms will be first noticed in older and lower leaves.
The leaves become small and narrow with purplish or bronze discoloration. Later the leaves develop necrotic areas and fall off.
The affected plants will show stunted growth.
Management
Phosphorus is best absorbed by the roots in the pH range 6.5-7.5
So adjust pH in acidic soils by adding lime/ dolomite.
Add bio fertilizers containing phosphorous solubilizing bacteria along with organic manure to increase phosphorous availability.
Check whether the recommended quantity of fertilizers is applied in time.
An excess of Iron and Zinc may also cause the symptoms of phosphorus deficiency.
Go for soil analysis and understand the extent of deficiency.
Apply fertilizers such as single superphosphate for immediate correction or bone meal or rock phosphate for long term correction as per the soil test report.
Potassium (K)
Symptoms
Potassium is a highly mobile element in plant. So the deficiency symptoms will be first noticed in older and lower leaves.
The symptom starts as white, yellow, or orange chlorotic spots or stripes on older leaves starting from the leaf tips and margins.
Upper surface of leaves show reddish purple discoloration. Young leaves remain dark green.
Leaves curl down and lose luster and turgidity.
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
Calcium is an immobile element in plant. Hence, calcium deficiency is seen mainly in growing points, younger leaves and developing fruits.
The initial symptom will be browning and necrosis of the growing tips of roots and leaves.
The internodal length becomes reduced and leaves become resetting.
The edges of the leaves will look ragged and often brittle. Leaves later turn to greenish pink or red colour.
Downward curl of leaf tips occurs near terminal bud. Fruit quality will be affected.
Management
Analysis of pH in the soil
Check the pH of the soil. If the soil is extremely acidic (pH between 3.5 and 4.5), apply lime (3.4 kg/cent in two split doses). And in areas of moderate acidity (pH between 5.5 and 6), apply lime (1 kg/cent).
High phosphorus levels lead to calcium deficiency.
In alkaline soil application of Gypsum is preferable
Boron is needed for calcium utilization.
So a boron deficiency can also lead to calcium deficiency.
Boron (B)
Symptoms
Deficiency is seen mainly in growing points, younger leaves and developing fruits.
Fruit necrosis - browning of inner most part of the mesocarpic tissues
Brownish black areas are developed on the fruit surfaces depending of the severity of the disorder
Dieback of buds
impaired root & shoot growth
Poor fruit set
Reduced sugar content in fruits
Cracking of fruitlets
Malformed fruit
Management
Analysis of soil to confirm the deficiency.
Application of borax (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.
Copper (Cu)
Symptoms
Both young and old leaves show deficiency symptoms
Droopy appearance of plants
Shortened intervals between petiole.
Reduced size of leaves
Management
Soil testing and analysis
Addition of organic matter
Apply copper sulphate as foliar spray ( 5 gram/litre of water)
Iron (Fe)
Symptoms
Symptoms are first seen in the youngest leaves.
The leaves eventually turn completely chlorotic.
Management
Iron content in Kerala soils is often high. So, get a soil test to determine the reason for the problem
Low potassium levels lead to iron deficiency
Addition of Ferrous Sulphate ( 60 gram/cent or 6 kg/ acre) into the deficient soils.
Zinc (Zn)
Symptoms
Deficiency symptoms first appear on young leaves
Inter-veinal chlorosis
Pale green or yellow colour observed on leaves while Midrib of leaf remains green
Stunted growth of plants
Narrowing of leaves.
Management
The optimal pH range for zinc availability is 5 to 7.5.
Confirm deficiencies by doing soil testing.
Apply zinc sulphate to deficient soils (8 kg/ acre)
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.
