Bud necrosis: Groundnut bud necrosis virus (GBNV)

Symptoms:

• Chlorotic spots or rings on young leaflets
• Necrosis of terminal bud

Bud necrosis

Identification of pathogen:

Favourable Conditions:

• Temperature: 30ºC
• Wind speed: 10 km/h favour migration of thrips

Mode of Spread and Survival:

• Thrips palmiand other species transmits GBNV in circulative and propagative manner
• The virus survives on ornamentals (Zinnia, cosmos and sunflower), weeds (Ageratum conyzoides, Cassia tora, Acanthospermum hispidum, Desmodium triflorum) and crop plants (tomato, brinjal, green gram, black gram, beans, pea etc)

Management:

• Remove infected plants up to 6 weeks of sowing and spray systemic insecticide 30 days after sowing
• Antiviral principle application @ 500 litre/ha. Two sprays at 10 and 20 days after sowing
• Antiviral principles (AVP) from sorghum or coconut leaves are extracted as follows to use: Sorghum or coconut leaves are collected, dried, cut into small bits and powdered. To one kg of leaf powder, two litres of water is added and heated to 60°C for one hour, filtered through muslin cloth and diluted to 10 litres and sprayed
• Spray any one of the following insecticides at fifteen days interval: imidacloprid 17.8 SL 125ml/ ha, quinalphos 25 EC @ 1400 ml/ha, quinalphos 1.5 DP @ 25 kg/ha