Chilli Capsicum annuum L. is the most widely cultivated species all over the world for its pungent fruits. Chilli is cultivated for both green and red. It is also called as hot pepper. Chilli crop is vulnerable to deadly viral infections like Leaf curl virus [Gemini virus], Tobacco mosaic virus and TOSPO [tomato spotted wilt virus].
Chilli leaf curl - murda disease is a most destructive disease of chilli in India. The typical symptoms of the gemini viral infections in the chilli are leaf curling, leaf rolling, wrinkling, scorchings of interveinous areas, Thickening and swelling of interveins and petioles. Gathering oo crowding of leaves, stunted growth of the chilli plants. Moreover the infected leaves will be leathery to touch. This viral infection is known to be transmitted by white flies
Tobacco Mosaic Viral Infections
Leaf mottling with yellow green patches, Plants expresses the stunted growth, leaflets and flowers may be curled, sometimes distorted and smaller than normal size. Flowers which are opened have streaks on the petals, Yellow chlorotic spots will be observed on the leaves of the infected plant. This disease is sap transmissible and any sucking pest may be responsible for the spreading of the disease in between the plants.
Tospovirus infection in Chilli
Tospo is abbreviated as tomato spotted wilt virus, a deadly disease of tomato crop and now this infections are also observed on Chilli and capsicum. The typical symptoms are chlorotic to necrotic rings on leaves and yellow blotches on fruits with reduced size, apical necrosis and leaf distortion. The petioles, inflorescence will be spotted with brownish irregular shaped brown patches and inflorescence will be seen burnt like. Tospo viruses are said to be transmitted by sucking pest thrips.
Management of Viral Infections
Viral diseases are spread from plant to plant at young growing stages before the age of 25 days and this particular stage is most vulnerable stage for spreading and carrying the viral infections which may express at later stages.
So, raise the saplings under controlled conditions where the germinated saplings or seedlings will be protected from sucking pest vectors like whiteflies, thrips, aphids and other plant hoppers providing minimal chances of viral infections at later stages.
In the main field the management of the viral infections the vector management is foremost. In addition to the management of sucking pests like whiteflies, aphids and thrips the supplement of plant stimulants may help plants develop some kind of inhibition towards virus attack and also bind the active viruses in the plant sap, so that the multiplication and further damage may be reduced.
Following combinations may be sprayed to manage both sucking pests [Vectors] as well as bind or develop resistance of plants against viral infections in the plants. 7 days intervals is required in between the sprays.
Use of more and more nitrogen to the chilli crop leads to the susceptibility o chilli plants to the viral infections especially ammoniacal nitrogen present in the fertilisers and other inputs which are supplemented to the crops will increase the viral infections. Amides formed in the plant sap from ammoniacal nitrogen sources will help the virus to multiply at higher rates increasing the symptoms.
Avoid Poultry manure, because poultry manure contains large quantities of ammoniacal nitrogen which Poultry manure need to be decomposed for minimum 6 months and be mixed 50: 50 red soil and poultry manure respectively before application.
Urea and Ammonium Sulphate contains ammoniacal nitrogen, better to limit of avoid using these fertilisers
Amino acids supplements through sprays and soil drenchings may be avoided to suppress the viral multiplications in the plant system.
Supplementation of Manganese micronutrients through foliar sprays and soil application will help in managing the viral infections not only in chilli but also in vegetable crops.
Integrated nutrient management practices followed effectively may reduce the chances of viral infections in chilli crop.
K SANJEEVA REDDY,
Senior Agronomist, BigHaat.
For more information kindly call on 8050797979 or give missed call on 180030002434 during office hours 10 AM to 5 PM
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