Ragi (Eleusine coracana)

Nitrogen(N)

Symptoms

  • Deficiency symptoms will be first noticed in older and lower leaves.
  • The initial symptoms will be pale green to light green colour change on leaves.
  • The deficient leaves are narrow, short, erect, and lemon yellowish.
  • The affected field will show stunted growth and general yellowing.

Management

  • Add organic matter to the soil at the time of planting.
  • Treat the planting materials with bio fertilizers like Azotobacter, Azospirillum etc.
  • Check whether the recommended quantity of fertilizers is applied in time.
  • Go for soil analysis and understand the extent of deficiency.
  • Apply quick release nitrogen fertilizers like urea as per soil test result in split doses.
  • As an immediate solution applies urea as foliar spray (10 gram /liter of water) once in 15 days till the deficiency is over.

Phosphorus(P)

Symptoms

  • The deficiency symptoms will be first noticed in older and lower leaves.
  • The older leaves will have a purple coloration, particularly on the underside.
  • In severe cases, the plants show stunting, reduced tillering, poor root development and early flowering.

Management

  • Phosphorus is best absorbed by the roots in the pH range 6.5-7.5.
  • Add bio fertilizers containing phosphorous solubilizing bacteria along with organic manure to increase phosphorous availability.
  • An excess of Iron and Zinc may also cause the symptoms of phosphorus 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.
  • Incorporate ragi straw into the soil to overcome deficiency in the next crop.

Potassium(K)

Symptoms

  • Deficiency symptoms first appear as pale to lemon-yellow margins on older leaves.
  • This is followed by browning and necrosis of leaf margins.
  • Purple spots may also appear on the leaf undersides.
  • The deficiency also influences tillering or branching of plant and size and weight of grain.
  • The general health of the plant will be weak.

Management

  • Optimum availability of potassium is at soil pH above 6.0. So correct soil pH in acidic soils by adding lime/ dolomite.
  • Add organic matter and wood ash to the soil.
  • Add bio fertilizers containing potash mobilizing bacteria to release non exchangable potassium from soil.
  • Apply Muriate of Potash (MOP) as per soil test report.
  • Split application is more beneficial.
  • As an immediate solution apply Sulphate of Potash (SOP) as foliar spray (10 gm /liter of water) during morning hours along with wetting agents.

Calcium(Ca)

Symptoms

  • Calcium deficiency is seen mainly in growing points, younger leaves and developing fruits.
  • The initial symptom will be browning and necrosis along the lateral margins of leaves.
  • Stunting and death of growing points are the characteristic symptom.
  • Old leaves turn brown and die. The leaf lamina will be leathery in texture.

Management

  • 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 levels of phosphorous can also induce calcium deficiency.
  • In alkaline soil go for application of Gypsum.
  • Boron deficiency can also lead to calcium deficiency.

Magnesium(Mg)

Symptoms

  • The magnesium deficient leaves show advanced interveinal chlorosis, with necrosis developing in the highly chlorotic tissue.

Management

  • Go for soil analysis and confirm the deficiency.
  • Apply Magnesium sulphate (32 kg/acre) in bands near plants.
  • Application of dolomite will also reduce magnesium deficiency in long run.
  • However, magnesium and potassium fertilizers should not be used together.

Sulphur(S)

Symptoms

  • Deficiency symptoms first appear in the upper and younger leaves.
  • The symptoms are chlorosis followed by general yellowing.
  • An acute sulfur deficiency causes the entire plant to turn yellow.
  • The tips of the young leaves may show necrotic symptoms.
  • The affected plants show stunted growth.

Management

  • Apply organic matter to increase sulphur availability.
  • Avoid burning of organic wastes.
  • Application of fertilizers like Factamfos, Ammonium sulphate, Single superphosphate etc. that contain sulphur reduces the deficiency.
  • Apply sulfur dust (10 kg/acre) in the soil.
  • The application of gypsum will also correct the deficiency in alkaline soil.
  • Go for tillage after harvest.

Boron(B)

Symptoms

  • Boron deficiency is seen mainly in growing points, younger leaves and developing fruits.
  • The leaves show as zig zag appearance and plant height is reduced.
  • Those plants affected with boron deficiency at panicle initiation stage fails to produce panicles.
  • The yield will be reduced due to poor grain setting.

Management

  • Boron deficiency is seen more in dry soils.
  • High available phosphorous in soil also hinders boron absorption.
  • Apply Borax (4 kg/acre) into the soil.
  • For immediate result spray Borax (1 g/litre of water) as foliar spray. Excess concentration may result in toxicity.
  • Borax should not be applied with ammonium fertilizers.

Iron(Fe)

Symptoms

  • Deficiency symptoms appear on the new growth first.
  • The symptoms will be yellow leaves with dark green veins (interveinal chlorosis) with eventual bleaching of the new growth.
  • When severe, the entire plant may be light green in color.

Management

  • Good drainage and soil aeration favors iron availability.
  • Low levels of potassium can increase Iron deficiency.
  • In deficient soils, apply Ferrous Sulphate (6 kg/acre) into the soil.

Manganese(Mn)

Symptoms

  • The leaves develop interveinal chlorosis.
  • They begin with a light chlorosis of the young leaves and netted veins of the mature leaves especially when they are viewed through transmitted light.

Management

  • Kerala soils in general have high levels of manganese.
  • High amount of iron may induce manganese deficiency.
  • So go for soil testing to understand the real reason for the problem.
  • In deficient soils, apply Manganese Sulphate (5 g/litre of water) as foliar spray.

Zinc(Zn)

Symptoms

  • Younger leaves become chlorotic.
  • The affected plants will show stunted growth.

Management

  • The ideal pH range for zinc availability is 5 to 7.5.
  • Undertake soil testing to confirm deficiency. In deficient soils, apply Zinc sulphate (8 kg/acre) in the soil.
  • Zinc fertilizers and phosphate fertilizers should not be used simultaneously
  • In severe cases, foliar spraying of Zinc sulphate (2 g/litre of water) with Calcium carbonate (2.5 g/litre of water) can be advocated in morning hours.