Diseases of chilli and their management

Anthracnose/Fruit Rot/Die-back of Chilli 

Causal organism: Colletotrichum capsici. 

Symptoms 

The disease occur in two forms; Die­back and Ripe fruit rot.

Die­back 

1. The disease causes necrosis of tender twigs from the tip to backward. The entire branch or  the entire top of the plant may wither away.

2. Numerous black dots (acervuli of fungus) are found scattered all over the necrotic surface  of the affected twigs.

3. Only the top or few side branches may be killed or in severe attacks the entire plant is  withered. Partially affected plants bear fruit which are few and low quality.

Ripe fruit rot 

1. Although red ripe fruits are frequently affected, anthracnose symptoms appear even on well  developed green fruits.

2.  Small black circular spots are appeared on the skin of the fruit and spread along the long  axis of the fruit and thus becoming more or less elliptical.

3. The spots are usually sunken with black margin. Badly diseased fruit turn straw colour  from normal color. Sunken spots are covered with pinkish mass of fungal spores.

4. The fruits with many spots drop off prematurely, resulting heavy loss in yield. Seeds are  also infected by this fungus.

Symptoms of Anthracnose/Fruit Rot/Die-back of Chilli

Favourable condition  

▲ High temperature (28 C). 

▲ High relative humidity (92% or above). 

▲ Heavy and prolong dew deposition after rainy season.

Management/Control Measure 

A. Cultural control  

♦  Seeds should be collected from spotless fruits. 

♦  Disease crop debris should be collected and burnt.

B. Chemical control  

♦ Seed treatment with Vitavax­200, Brassical @ 2g/ kg of seed. 

♦ Spraying with Dithane­M 45 or Bavistin @ 0.2% solution, 3­4 times after 15 days interval   when fruit begin to ripe.

 

Mosaic of Chilli 

Causal organism: Tobacco mosaic virus.

Vector: Aphid (Aphis gossypii).

Symptoms 

1. The most characteristics symptom appearance of dark green and light green areas on the  leaf surface.

2.  Leaves are greatly in size and filamentous like.

3. The diseased plant produces less flower and fruits. The fruits are usually deformed and  rough in texture.

Symptoms of Mosaic of Chilli

Transmission 

The virus is sap transmissible. It is also transmitted by aphid.

Management/Control Measure 

♦  Field sanitation.

♦  Roughing and cultural practices.

♦  Use of optimum doses of nitrogenous fertilizer in the field.

♦  Destruction of lateral alternate host.

♦  Spraying  with  Malathion/Metasistox/Diazinon/Sumithion  @  0.1%  solution  at  10  days  interval, starting from early stage of plant growth and stopped at least 20 days before plucking  of fruits.

 

Leaf Curl disease of Chilli 

Causal organism: Leaf curl virus.

Vector: White fly (Bamici tabaci).

Symptoms 

1. The leaf curl is characterized by severe stunting of the plants with downward rolling and  wrinkling of leaves.

2. Leaves become small in size; internodes are shortened, giving the plant as witches broom  appearance.

3. Leaves are pale yellow coloured.

4. Fruiting is stopped or fruits that formed are small and deformed. Alternate Hosts Tobacco, Tomato, Papaya etc.

Symptoms of Leaf Curl disease of Chilli

Transmission 

The virus is not sap transmissible or not seed borne. It is transmitted by white fly.

Management/Control Measure 

♦  Field sanitation.

♦  Roughing and cultural practices.

♦  Use of optimum doses of nitrogenous fertilizer in the field.

♦  Destruction of lateral alternate host.

♦ Apply Carbofuran 3G @ 4­-5 Kg/acre in the mainfield to control sucking complex and  insect vectors selectively.

♦ If it is not possible spray the crop with systemic insecticides. Dimethoate 2 ml or Acephate  1g per litre of water.

♦  Collect and destroy infected virus plants as soon as they are noticed.