TNAU Agritech Portal
  Home | About Us | Success Stories | Farmers Association | Farmers' Innovation | Publications | Contact

Horticultural crops :: Vegetables:: Chilli

  1. Damping off: Pythium aphanidermatum
  2. Fruit Rot and Die Back: Colletotrichum capsici
  3. Powdery mildew: Leveillula taurica
  4. Bacterial leaf spot: Xanthomonas campestris pv. vesicatoria
  5. Cercospora leaf spotCercospora capsici
  6. Fusarium wilt: Fusarium oxysporum f.sp.capsici
  7. Leaf curl virus

1. Damping off: Pythium aphanidermatum                                 

Symptoms:

  • Seedlings killed before emergence
  • Water soaking and shrivelling of stem
  • Factors favouring infection:Moist soils poordrainage 90-100% R.H soil temperature 20°C

Management

  • Soil drenching with Copper oxychloride 0.25%

2. Fruit Rot and Die Back- Colletotrichum capsici

Symptoms:

  • As the fungus causes necrosis of tender twigs from the tip backwards the disease is called die-back Infection usually begins when the crop is in flower. Flowers drop and dry up.
  • There is profuse shedding of flowers. The flower stalk shrivel and dry up. This drying up spreads from the flower stalks to the stem and subsequently causes die-back of the branches and stem and the branches wither. Partia1lly affected plants bear fruits which are few and of low quality.
  • On the surface of the soil the necrotic areas are found separated from the healthy area by a dark brown to black band.

 

Management

  • Use of disease-free seeds is important in preventing the disease. Seed treatment with Thiram or Captan 4g/kg is found to be -effective in eliminating the seed-borne inoculum.
  • Good control of the disease has been reported by three sprayings with Ziram O. 25% Captan 0.2% or miltox 0.2%. Chemicals like wettable sulphur 0.2%, copper oxychloride 0.25% and Zineb 0.15% not only reduced the disease incidence but also increased the yield of fruits.
  • The first spraying should be given just before flowering and the second at the time of fruit formation.
  • Third spraying may be given a fortnight after second spraying.

3. Powdery mildew: Leveillula taurica

Symptoms

  • Shedding of foliage
  • white powdery growth on lower side of leaves

Management

  • Spray Wettable sulphur 0.25% or Dinocap (Karathane) 0.05%

4. Bacterial leaf spot: Xanthomonas campestris pv. vesicatoria

 

Symptoms

  • The leaves exhibit small circular or irregular, dark brown or black greasy spots. As the spots enlarge in size, the centre becomes lighter Surrounded by a dark band of tissue.
  • The spot coalesce to form irregular lesions. Severely affected leaves become chlorotic and fall off.
  • Petioles and stems are also affected. Stem infection leads to formation of cankerous growth and wilting of branches.
  • On the fruits round, raised water soaked spots with a pale yellow border and produced.
  • The spots turn brown developing a depression in the centre wherein shining droplets of Bacterial cozen may be observed.   

 

Management

  • Seed treatment with 0.1% mercuric chloride solution for 2 to 5 minutes is effective.
  • Seedlings may be sprayed with Bordeaux mixture 1. Per cent or copper oxychloride 0.25%.
  • Spraying with streptomycin should not be done after fruits begin to form.
  • Field sanitation is important. Also seeds must be obtained from disease free plants.

5. Cercospora leaf spot :Cercospora capsici

 

Symptoms

  • Leaf lesions typically are brown and circular with small to large light grey centres and dark brown margins. The lesions may enlarge to 1cm or more in diameter and some times coalesce.
  • Stem, petiole and pod lesions also have light grey centres with dark borders, but they are typically elliptical.
  • Severely infected leaves drop off prematurely resulting in reduced yield.

Management

  • Spray twice at 10-15 days interval with Mancozeb 0.25% or Chlorothalonil (Kavach) 0.1%.

6. Fusarium wilt :Fusarium oxysporum f.sp.capsici

Symptoms 

  • Fusarium wilt is characterised by wilting of the plant and upward and inward rolling of the leaves. The leaves turn yellow and die.
  • Generally appear localised areas of the field where a high percentage of the plants wilt and die, although scattered wilted plants may also occur.
  • Disease symptoms are characterised by an initial slight yellowing of the foliage and wilting of the upper leaves that progress in a few days into a permanent wilt with the leaves still attached.
  • By the time above - ground symptoms are evident, the vascular system of the plant is discoloured, particularly in the lower stem and roots.

Management

  • Use of wilt resistant varieties.
  • Drenching with 1% Bordeaux mixture or Blue copper or Fytolan 0.25% may give protection.· Seed treatment with 4g Trichoderma viride formulation or 2g Carbendazim per kg seed is effective. Mix 2kg T.viride formulation mixed with 50kg FYM, sprinkle water and cover with a thin polythene sheet. When mycelia growth is visible on the heap after 15 days, apply the mixture in rows of chilli in an area of one acre.

Viral diseases

Leaf curl

  • Leaves curl towards midrib and become deformed.
  • Stunted plant growth due to shortened internodes and leaves greatly reduced in size.
  • Flower buds abcise before attaining full size and anthers do not contain pollen grains.
  • The virus is generally transmitted by whitefly. So control measures of whitefly in this regard would be helpful.

Mosaic Viruses

  • Light green and dark green patches on the leaves.
  • Stunted plant growth during early stages.
  • Yellowing, chlorotic ring spots on leaves and fruits.
 
Tobacco Mosaic Virus
Cucumber mosaic virus
   

 

Tomato spotted wilt virus at different stages of crop growth
Potato viruses

Management of viral diseases

  • Control measures are not known for majority of viral diseases.
  • Hence, mechanical, cultural methods are mostly recommended.
  • The infected plants should be uprooted and burnt or buried to avoid further infection.
  • Avoid monoculture of chilli crop.
  • Selection of healthy and disease - free seed.
  • Suitable insecticidal sprays reduce the incidence of viral diseases, since majority of viral diseases are transmitted by insect vectors.
  • Soaking seeds in a solution containing 150 g Trisodium orthriphosphate per litre of water for 30 minutes inhibits seed - borne inoculum.
  • Treated seed should be washed with fresh water and dried before sowing.
  • Nursery beds should be covered with nylon net or straw to protect the seedlings from viral infection.
  • Raise 2-3 rows of maize or sorghum as border crop to restrict the spread of aphid vectors.
  • 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. Like Monocrotophos 1.5 ml or Dimethoate 2ml of Acephate 1g per litre of water.
  • Collect and destroy infected virus plants as soon as they are noticed.

Home | About Us | Success Stories | Farmers Association | Publications | Site Map | Disclaimer | Contact Us

© 2014 TNAU. All Rights Reserved.