In this PPT you will come to know about the different types of mosaic virus which is caused in BHENDU crop, its life cycle, epidemiology, and its management.
3. Introduction
•Okra (Abelmoschus esculentus (L) Moench), is widely grown all over tropical,
subtropical and warm temperature regions of the world.
•It is a popular crop in Bangladesh due to its ease of cultivation and adaptability
to varying moisture conditions.
•It is called lady’s finger in England, Gumbo in the USA and Okra in Bangladesh.
Okra appears to have originated in South Africa or Asia.
•The cultivated okra containing chromosome number 2n=130 is an amphidiploid
vegetable of Abelmoschus tuberculatus (2n=58) and an unknown species with
chromosome number 2n= 72.
4. What are Mosaic Viruses ?
•This virus infects more than 150 types of plants, including many
fruits, vegetables, and flowers.
•It is characterized by leaves mottled with yellow, white, and light
and dark green spots or streaks.
•Some of the most commonly infected plants include okra,
tomatoes, squashes, cauliflower, and cucumbers.
Vector of Yellow Vein Mosaic
Virus
The YVMV is neither sap transmissible nor seed transmissible. It is
mainly transmitted through most important sucking pest, white fly
during feeding.
5. Symptoms of Yellow Vein Mosaic
Virus Yellowing of the entire network of veins in the leaf blade is the
characteristic symptom.
In severe infections the younger leaves turn yellow, become reduced in size and
the plant is highly stunted.
The veins of the leaves will be cleared by the virus and inter venal area
becomes completely yellow or white.
In a field, most of the plants may be diseased and the infection may start at any
stage
of plant growth.
Infection restricts flowering and fruits, if formed, may be smaller and harder.
The affected plants produce fruits with yellow or white colour and they are not fit
for marketing.
The virus is spread by whitefly.
8. MANAGEMENT
Biological
Control Restrict the vector by spraying 5% neem seed kernel extract, or
ginger, garlic, and chili extracts.
Cut pieces of cactus, or milk bush, immerse in water (enough for
the pieces to float), allow it to ferment for 15 days.
Filter and spray on affected plants.
Apply neem and mustard oil, Rhizobacteria, Crozophera oil
followed by Palmarosa oil.
A mixture of oil @ 0.5% and 0.5% washing soap is also reported to
help.
9. Chemical Control
Two sprays of Acetamiprid 20SP @ 40g a.i/ha has been proven
effective in reducing the incidence of the mosaic virus and
subsequently increases the yield of Okra.
Imidacloprid 17.8% SL applied twice and one seed treatment
(Imidacloprid @ 5 gm/kg of seed) can significantly reduce the pest
population up to 90.2%.
10. Preventive Measures
Grow resistant varieties.
Maintain proper crop spacing.
Plant Maize or Marigold as a border crop to trap the vector insect.
Avoid summer season planting as this is the peak season of whiteflies.
Avoid sowing susceptible varieties during the summer season, when the
whitefly activity is high.
Place yellow sticky traps (12/acre) above the plant height to monitor
and catch
vector insects.
Destroy weeds and other wild hosts, especially Croton sparsiflora and
Ageralium spp., whenever possible.
Remove the affected plants from the field and burn them.