Nitrogen, being highly mobile within plants, redistributes from lower leaves to growing points in response to soil nitrogen deficiency.
Consequently, initial signs of nitrogen deficiency manifest primarily in older and lower leaves.
These symptoms typically manifest as a change in leaf coloration, transitioning from pale green to light green.
The discoloration commonly initiates from the tips of older leaves.
The severity of deficiency determines whether older leaves eventually die off and drop from the plant.
Affected plants exhibit stunted growth as a result of nitrogen deficiency.
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
Phosphorus nutrition plays a pivotal role in shaping root growth.
In cases of deficiency, root development suffers, leading to compromised nutrient uptake.
Initially, deficiency symptoms manifest in older and lower leaves.
These symptoms are characterized by a shift in leaf coloration towards a dull, dark, grayish green hue.
Suppression of plant branching occurs, accompanied by the thinning of stalks.
Ultimately, necrosis and leaf shedding ensue due to phosphorus deficiency.
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
Potassium, being highly mobile within plants, exhibits deficiency symptoms primarily in older and lower leaves.
Initial signs manifest as chlorotic spots or stripes, appearing white, yellow, or orange, originating from leaf tips and margins.
Subsequently, leaf margins undergo browning and necrosis.
Overall plant vigor diminishes as a consequence of potassium deficiency.
The expression of symptoms intensifies during the flowering and maturity stages of the plant's growth cycle.
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 g/litre of water) and wetting agents in the morning as an immediate remedy
Calcium (Ca)
Symptoms
Calcium, being immobile within plants, primarily exhibits deficiency symptoms in growing points, younger leaves, and developing fruits.
Shortening of internodes and the development of leathery, brittle leaves occur.
Terminal bud mortality is observed alongside distortion at the tips and bases of young leaves.
Characteristic symptoms include downward hooking of young leaf tips, followed by twisting and puckering.
Stunted growth is evident in affected plants.
Increased susceptibility to pests and diseases is a common occurrence in plants suffering from calcium deficiency.
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 of 40 m2 in two split doses). And in areas of moderate acidity (pH between 5.5 and 6), apply lime (1 kg/cent of 40 m2).
High phosphorus levels leads 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.
Magnesium (Mg)
Symptoms
Initially, magnesium deficiency symptoms manifest primarily in the lower leaves.
These lower leaves exhibit interveinal chlorosis, starting as a light yellow hue which later turns orange.
Despite the discoloration, the green color remains prominent in the midrib and veins, creating a distinct pattern.
Management
Do the soil analysis and confirm the deficiency.
Addition of Magnesium sulphate (320 gram /cent or 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
sulphur, being relatively immobile within plants, first displays deficiency symptoms in upper and younger leaves.
Initial signs include chlorosis followed by overall yellowing, accompanied by stunted growth and reduced leaf size.
Newly emerged young leaves initially pale, gradually transitioning to a golden yellow hue.
Within individual leaves, paling initiates at the tip and extends towards the base of the leaf blade.
Prolonged severe deficiency leads to premature shedding of young leaves.
Reduced flower count and size are observed under sulphur deficiency, with severe cases resulting in premature flower loss, impacting pod yield.
Affected plants exhibit smaller stature and poor nodulation
Management
Application of sulphur-containing fertilisers, such as Factamfos, Ammonium sulphate, Single superphosphate, etc., reduces the deficiency.
In sulphur deficient soils , apply sulphur dust (100 gram per cent or 10 kilogrammes per acre).
Deficiency in alkaline soil can be reduced by application of gypsum
Addition of organic material improves sulphur availability.in the soil .
Burning of organic waste leads to sulphur deficiency
Boron (B)
Symptoms
Boron, as an immobile element within plants, primarily exhibits deficiency symptoms in growing points, younger leaves, and developing fruits.
Manifestations include yellowing in these regions and among the youngest leaves.
Younger leaves show a transition to a pale green or white coloration.
Upper leaves display a dark green hue, becoming leathery in texture, with downward-curled edges.
Boron deficiency hampers root elongation, ultimately resulting in the demise of root tips
Management
Analysis of soil to confirm the deficiency.
Application of borax (40 gram /cent 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
Iron, being immobile within plants, initially showcases deficiency symptoms in newly emerging growth.
Manifestations include yellowing of leaves with dark green veins, known as interveinal chlorosis, progressing to eventual bleaching of the new growth.
Severe cases may lead to the entire plant displaying a light green coloration
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 (60 gram/cent or 6 kg/ acre) into the deficient soils.
Manganese (Mn)
Symptoms
Manganese, with moderate mobility within plant tissues, initially manifests deficiency symptoms in leaves nearing full size.
Signs include interveinal chlorotic mottling appearing on the apical part of the second set of leaves.
The entire leaf blades exhibit severe mottling, with interveinal chlorotic areas developing light brown irregular necrotic patches.
Initially prominent near the leaf tips, these patches progressively spread across the entire leaf blades, leading to severe necrosis.
Symptoms gradually extend from the middle leaves to both younger and older foliage
Management
Soil Analysis
Application of Manganese Sulphate (5 gram per litre of water) as foliar spray
Zinc (Zn)
Symptoms
Initially, symptoms are more pronounced during the early growth stages.
Chlorosis appears in the interveinal areas of middle leaves, accompanied by necrosis along the apical margins.
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.
