DISEASE OF FIELD AND HORTICULTURAL CROPS – I

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DISEASE OF FIELD AND

HORTICULTURAL CROPS – II

SESSION 25

CHILLY DISEASES

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Important Diseases

 Major Diseases

1. Anthracnose - Colletotrichum capsici 2. Bacterial wilt - Ralstonia solanacearum 3. Leaf curl - Chilly leaf curl virus

 Minor Diseases

1. Damping off - Pythium spp.

2. Powdery mildew - Levilula taurica

3. Cercospora leaf spot - Cercospora capsici

4. Mosaic - Cucumber mosaic virus

5. Spotted wilt - Tomato spotted wilt virus

Dr. Aravind.T, Asst. Professor, MSSSOA

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Anthracnose/Fruit Rot

Symptoms

 On Leaves and Stem

 Small, circular to irregular, brownish black scattered spots appear on leaves

 Severely infected leaves defoliate

 Infection of growing tips leads die back

 Lesions are grayish white with black dot like acervuli in the center

 On fruit

 Small, circular, yellowish to pinkish sunken spots appear on fruits

 Spots become elliptical in shape and fruits shrivel and dry.

 The lesions contain black ‘acervuli’ in concentric rings and fruits appear straw coloured

Colletotrichum capsici

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Black circular lesions on leaves – Upper surface

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Black circular lesions on leaves – Lower surface

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Greyish white lesions (Shot hole symptom)

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Acervuli

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Die back

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Sunken lesions on Fruits

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Lesions become eliptical

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Fruits dry up with black acervuli

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Etiology

Hyaline septate mycelium

Black acervuli – sickle shaped conidia

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Disease Cycle

Primary inoculum – Infected seeds and crop debris

Secondary Inoculum – Air borne conidia

Favourable Conditions

Susceptible stages - All stages are susceptible

Monocropping

Close planting

High temperature and high humidity

Cloudy weather with frequent rains

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Management

1. Resistant varieties: G3, G4, B61, Lorai 2. Collect and destroy all infected plant parts

3. Collect seeds only form fruits without infection

4. Removal and destruction of Solanaceous weed hosts and infected plant debris

5. Seed treatment with Captan or Thiram 3g/kg

6. Foliar spray thrice with propiconazole/ azoxystrobin (@0.1%) just before flowering, at fruit formation stage and 15 days after second spray.

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Leaf Curl

Symptoms

• Leaves curl towards midrib and become deformed.

• leaves greatly reduced in size.

• Stunted plant growth due to shortened internodes

• Flower buds abcise before attaining full size and anthers do not contain pollen grains

• Poor yield if plant is infected at early stage

Chilly leaf curl virus

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Deformation and Cupping of Leaves

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Leaf curling

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Severe Leaf Curling

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Stunting

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Etiology

Begomovirus (Geminiviridae)

Isometric; ssDNA virus

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Disease Cycle

Primary inoculum - Collateral hosts; volunteer plants

Secondary spread - Bemisia tabaci (Whitefly)

Management 1. Crop rotation

2. Field sanitation – Remove weeds, voluteer plants 3. Rouging

4. Use of yellow sticky traps

5. Foliar spray with NSKE @ 5%

6. Vector control – Imidachloprid @ 3ml/10L

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Bacterial Wilt

Ralstonia solanacearum

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Damping off

Pythium spp.

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Cercospora leaf spot

Cercospora capsici

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Chilly Mosaic

Cucumber mosaic virus

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Spotted wilt

Tomato spotted wilt virus