by: Kanika SohaneyPosted on:

Safflower diseases

Major Safflower diseases are given below:-

1.Alternaria blight: Alternaria carthami

safflower alternaria blight
Symptom:
  • It is the most destructive disease.
  • Dark necrotic lesions 2-5 mm in diameter are formed first on hypocotyls and cotyledons.
  • Symptoms also appear on the stem and the severely infected plant gets blighted.
  • Brown discolouration appears on the stem, dark brown spots with concentric rings up to 1 cm in diameter appear on the leaves which later develop into large lesions.
  • Seeds also may be affected. Dark sunken lesions are produced on the testa. It may rot and damping off of seedlings occur.
Management:
  • Avoid growing in low-lying areas and flooding under irrigation.
  • Remove and destroy the diseased plants.
  • Seed treatment with Carbendazim with 1.5g/kg of seed.
  • Spray Mancozeb (0.25%) immediately after the disease is noticed and repeat the spray 15 days later depending on the intensity the of disease.

 

2.Leaf spot: Cercospora carthami

safflower leaf spot

Symptom:
  • Safflower plants few weeks after planting or at the flowering stage are commonly attacked.
  • Circular to irregular brown sunken spots of 3-10 mm diameter are formed on leaves.
  • Spots are surrounded by yellow halos.
  • Symptoms first appear on lower leaves and spread to upper leaves.
  • Stems and nodes may also be affected.
  • In severe infections, bracts are also affected with reddish brown spots.
  • Affected flower buds turn brown and die.
Management:
  • Remove and destroy the diseased plants.
  • Deep summer ploughing,
  • Avoid growing in low-lying areas and flooding under irrigation.
  • Seed treatment with thiram 3 g/kg and spraying of mancozeb 2.5 g; or carbendazim 1 g per litre of water.

 

3.Powdery mildew: Erysiphe cichoracearum

safflower powdery mildew

Symptom:
  • The disease is characterised by whitish powdery growth on leaves.
  • Later the fungus spreads over the entire leaf. Leaves turn yellow and dry up.
Management:
  • Use resistant varieties.
  • Follow field sanitation.
  • Seed the crop at the recommended time.
  • Spineless genotypes are more susceptible.
  • Spray wettable sulphur 3 g/l or Carbendazim 0.05% for the control of the disease

 

4.Safflower Mosaic: Cucumber mosaic virus (CMV)

safflower mosaicSymptom:
  • In CMV infected safflower plants young leaves show irregular yellow or light patches alternating with normal green areas.
  • Leaves may become blistered and distorted and infected plants are stunted.
  • In few plants, primary leaves are produced, forming a rosette of leaves exhibiting mosaic mottling and from the centre of this, the axis bearing secondary leaves is produced.
  • It is transmitted by aphids.
Management:
  • The disease can be controlled by roguing and destruction of the infected plants.
  • Remove and destroy the diseased plants.
  • Do not delay irrigation until the crop exhibits moisture stress symptoms.
  • Spraying of systemic insecticides, monocrotophos 1.5 ml or Dimethoate 2ml, for the control of aphid vectors.

 

5.Rust: Puccinia carthami

safflower rust

Symptom:
  • Seeding infection causes twisting towards one side. Chestnut brown pustules are formed on hypocotyl leading to the collapse of seeding.
  • On older plants girdling and hypertrophy of the stem base may occur.
  • Small, powdery chestnut brown pustules of 1-2 mm in size develop on leaf surface which later turn black.
  • Rust symptoms appear on leaves, flowers and fruits in the form of uredo-pustules which are brown in colour.
  • In seedling stage initially, orange yellow spots appear, later turn to brown to black on cotyledons resulting in drooping and wilting of the seedlings.
Management:
  • Avoid growing in low-lying areas and flooding under irrigation.
  • Remove and destroy the diseased plants.
  • Do not delay irrigation until the crop exhibits moisture stress symptoms.
  • Destruction of plant debris.
  • One or two sprays of Hexaconazole/propiconazole 1 ml/litre 0.05%) or mancozeb (0.25%) at 15 days interval.
  • Seed treatment with Thiram or captan 3g/kg.

 

6.Wilt: Fusarium oxysporum f.sp.carthami

safflower wilt

Symptom:
  • Lesion at soil line is the first symptom noticed which extends inside and affects the vascular system.
  • Symptoms become distinct when plants are in 6-10 leaf stage as yellowing of leaves followed by wilting, epinasty and vascular browning.
  • Infected plants produce small sized flower heads which are partially blossomed.
  • The fungus survives in seed, soil and in infected debris.
  • The disease is severe in acidic soils with high nitrogen and warm moist weather.
Management:
  • Crop rotation
  • Water stress should be avoided.
  • Seed treatment Pseudomonas fluorescens recorded the least wilt-disease incidence.
  • Soil application of Trichoderma harzianum @2.5 kg/ha. T. harzianum and T. viride seed treatment @ 10 g/kg seed.
  • Seed treatment with Carbendazim (ST)
  • Seed treatment with Captan or Carbendazim @0.1-0.2% 3 g/kg.
  • Seed treatment with Trichoderma viride mutant and Carbendazim (0.01% a.i.) and soil.
  • Application of potash (15 kg/ha) at the recommended dose reduced wilt incidence besides giving higher yields of safflower.

 

Source-

  • TamilNadu Agritech Portal
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