Integrated Pest Management

Potassium Deficiency

Symptoms

• Symptoms appear as yellowish white mottling often starting from the leaf margins.
•   Affected leaves become light yellowish green with yellow specks appearing between leaf veins and the bronzed leaf margins.
• The specks become necrotic, causing the leaves to appear rusted or dotted with brown specks at leaf tips, margins and inter-veinal areas.
• Late-season deficiency results in foliar symptoms that differ from early-season deficiency.
• After peak bloom, K deficiency symptoms first appear on the younger mature leaves in the upper third of the canopy.
• Premature shredding of leaves prevents boll development, resulting in small immature bolls.
• Symptom traverses from the bottom to top of plant often ultimately leading to death of plant.

Remedies

• Apply K2O(Potassium peroxide) as potassium fertilizer @ 40-50 kg/ha.
• Use foliar spray with potassium-bearing inorganic fertilizer.
• Apply potassium in 3 equal split dose at 30, 60 and 90 DAS through either muriate of potash or 
  potassium sulphate at the rate indicated by soil test.

Resources

• POTASSIUM CONTENT OF VARIOUS FERTILIZERS (%)
  Muriate of Potash 60%
  Growmore 14%

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Nitrogen Deficiency

Symptoms

• Plants deficient in nitrogen produces small, pale yellow leaves, reduced stalk height, and lesser number of vegetative branches.
• Bolls shed in the first 10-12 days after flowering.
• When occurs later, it results in yellowing, premature reddening and early shedding of leaf.
  

Remedies

• Grow leguminous crop as intercrop to correct edaphic conditions and to augment biological nitrogen fixation process.
• Top dressing with inorganic nitrogen fertilizer @10-20 Kg N/ha.
• Foliar spray of nitrogen fertilizers @ 0.5% N.
• Hand weeding and hoeing at 3, 6 and 9 WAS will augment N availability to the crop.

Resources

• Urea contains 46% Nitrogen.

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Phosphorus Deficiency

Symptoms

• Phosphorus deficiency symptoms are not strongly 
  expressed. 
• However, it adversely affects growth rate which ultimately results in stunted plants with dark leaves. 
• Other symptoms include delayed fruiting, reduced 
  flowering, boll setting and delayed maturity of set bolls.
• In certain severe cases, the foliage becomes reddish to purple in colour.
  

Remedies

• Correct soil pH by adding adjuvants.
• Apply p 205 @ 40-50 kg/ha as single or tripl ( phosphate.
• Spray with 1-2% solutiol) of triple super phosph;
  

Magnesium Deficiency

Symptoms

• Magnesium deficiency can be expected in calcareous soils, specially when high amounts of single super phosphate and potassium are applied.
• Reddening of older and middle leaves is an indication for magnesium deficiency.
• Lower leaves become purplish-red with distinct green veins.
• Upper leaves develop symptoms as the older leaves start senesce and shed prematurely.
  

Remedies

• Spray 25-50 kg MgSO{-4} or spraying of 2 percent MgSO{-4} during reproductive stage. 
• Spray 20g MgSO{-4} + 10 g urea per litre at the interval of 15 days.

Resources

• Application of magnesium containing fertilizers and chelates.
•  Magnesium Chelate 5.5%

Zinc Deficiency

Symptoms

• Deficiency of zinc is found in heavy calcareous soils having high clay content.
• Symptoms are exhibited after 3 weeks of sowing.
• Young plants are most susceptible and show abnormally small, thickened, brittle with inter-veinal chlorotic leaves.
• Upward cupping of the leaf edges is common.
• Red pigmentation mixed with rusted iron colour appear on older and new leaves.
• These leaves lose their normal green colour and the inter-veinal portions turn to golden yellow colouration.
• Small dots of tissues in the chlorotic area become necrotic often producing a bronzing effect.
• Leaves and inter nodal stem portions of zinc deficient plants do not grow properly, get shortened, and present "rosette' appearance.
• Flowers often fall before the bolls are formed.
• In case of mild deficiency, the maturity gets delayed and fiber quality deteriorates.
  

Remedies

• Use zinc sulphate @ 15-25 kg/ha in soil application.
• Spray Zinc sulphate @ 4-5 kg along with lime @2-2.5 kg/ha.

Resources

• ZINC CONTENT OF VARIOUS FERTILIZERS (%)
  Zinc Sulphate 22 - 35%
  Zinc Chelate NaZnGHEDTA 09%

Boron Deficiency

Symptoms

• Boron deficiency occurs in lime rich heavy clay soils under rain fed conditions.
• The growth of the growing young buds and leaves is generally affected.
• Growth of side shoots is encouraged profusely due to stoppage of growth of apical parts and hence the shoot portion of the top appears
  crowded.
• The young leaves and stem portions lose their normal shape and colour, become thick, brittle, with water spots and the buds drop from the
  plants.
  

Remedies

• Spray 0.1 % borox solution twice at 60 and 90th DAS.

Resources

• BORAX CONTENT OF VARIOUS FERTILIZERS (%)
  Sodium Borate 10.5%

Sulfur Deficiency

Symptoms

• Characteristic symptoms include pale green to yellow leaves in the upper part of plant. 
• In case of severe deficiency, plants have only few vegetative and fruiting branches. 
• The most consistent symptom is the irregular-thickening of young petioles, accompanied by dark bands and necrotic pith. 
• In case of deficiency becoming more severe, stunting, shorter internodes, splitting of petioles and possibly main stems, deformation of leaves, abnormal terminals and excessive branching, have been observed. 
• Discolouration of flowers and early bolls are common. New leaves are smaller than the normal ones, with margins and main vein showing
  chlorotic symptoms and get cupped upwards.