Integrated Pest Management

Alternaria blight

Causal Organism

Alternaria carthami

Damage

• It is the most destructive disease.

• Dark necrotic lesions 2-5 mm in diameter are formed first on hypocotyls and cotyledons.

• In mature plants, small brown to dark brown concentric spots of 1-2 mm appear on leaves.

•  Symptoms also appear on stem and 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.

Survival & Favourable Conditions

• Severe in irrigated crop and in warmer areas particularly under frequent showers or cyclonic cloudy weather.

• The pathogen survives through seeds. Primary  infection develops from infested seeds obtained from affected plants.

Cultural Control

• Use resistant varieties.

• Practice field sanitation.

• Sow the crop at the recommended time.

• 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.

Mechanical Control

• Destroy plant debris.

Chemical Control

• Seed treatment with carbendzim with 1.5g/kg of seed.

• Spray Mancozeb (0.25%) immediately after disease is noticed and repeat the spray 15 days later depending on the intensity of disease.

Leaf spot

Causal Organism

Cercospora carthami

Damage

• Safflower plants few weeks after planting or at 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.

Survival & Favourable Conditions

• The fungus survives in seed and affected plant debris and spreads through wind borne spores.
• Warm humid weather favours the disease development.

Cultural Control

• Use resistant varieties
• Follow field sanitation.
• Sow the crop at the recommended time.
• Remove and destroy the diseased plants.
• Deep summer ploughing,
• Avoid growing in low-lying areas and flooding under irrigation.
• Remove and destroy the diseased plants.

Chemical Control

• Seed treatment with thiram 3 g/kg and spraying of mancozeb 2.5 g ; or
  carbendazim 1 g per litre of water.

Powdery mildew

Causal Organism

Erysiphe cichoracearum

Damage

• The disease is characterized by whitish powdery growth on leaves.
• Later the fungus spreads over the entire leaf. Leaves turn yellow and dry up.

Cultural Control

• Use resistant varieties.
• Follow field sanitation.
• Seed the crop at the recommended time.
• Spineless genotypes are more susceptible.

Chemical Control

• Spray wettable sulphur 3 g/l or Carbendazim 0.05% for the control of the disease.

Mosaic

Causal Organism

Cucumber mosaic virus (CMV)

Damage

• 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.

Survival & Favourable Conditions

• It is transmitted by aphids.

Cultural Control

• Destruction of weeds.
• Control of insects and other pests.
• The disease can be controlled by roguing and destruction of the  infected plants.
• Sow the crop at the recommended time.
• Remove and destroy the diseased plants.
• Do not delay irrigation until the crop exhibits moisture stress symptoms.

Chemical Control

• Spraying of systemic insecticides, monocrotophos 1.5 ml
  OR
  Dimethoate 2ml, for the control of aphid vectors.

Rust

Causal Organism

Puccinia carthami

Damage

• Seeding infection causes twisting towards one side. Chestnut brown pustules are formed on hypocotyl leading to 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 uredopustules 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.

Survival & Favourable Conditions

• The pathogen mainly perpetuates through teliospores present on the seed or on the crop residues.

• Some of the Carthamus species act as collateral hosts of the pathogen.

Cultural Control

• Use disease free seeds.
• Seed treatment is must.
• The disease can be managed by growing resistant varieties like  Sagaramuthyalu, Manjeera.
• Control method by agronomic management:
• Seed the crop at the recommended time.
• 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.

Mechanical Control

• Destruction of plant debris.

Chemical Control

• One or two sprays of Hexaconazole/propiconazolw 1 ml/litre 0.05%) or mancozeb (0.25%) at 15 days interval.
• Seed treatment with thiram or captan 3g/kg.

Wilt

Causal Organism

Fusarium oxysporum f.sp.carthami

Damage

• 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.

• Symptoms develop in acropetal succession. In older plants the lateral branches on one side may be killed while the remainder of the plant remains free from the disease.

• Infected plants produce small sized flower heads which are partially blossomed.

• In seedling stage cotyledonary leaves show small brown spots either scattered or arranged in a ring on the inner surface and they may be shriveled or rolled or curved.

• Number of ovaries fail to develop seeds or they may form blackish, small, distorted chaffy seeds.

Survival & Favourable Conditions

• The fungus survives in seed, soil and in infected debris.
• The disease is severe in acidic soils with high nitrogen and warm moist weather.

Cultural Control

• Use tolerant varieties.
• Crop rotation
• Seed the crop at the recommended time.
• Avoid growing in low-lying areas and flooding under irrigation.
• Water stress should be avoided.

Biological Control

• Seed treatment Pseudomonas fluorescence 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.

Chemical Control

• 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.