BYDV threat to increase
Agronomy Issues
Threat of BYDV increases after reports of aphids (winged and wingless) being found in cereals from Nottinghamshire down to Dorset...
High numbers of aphids have come in following the recent warm, dry spell of weather where crops have established well and are at the 1 true leaf stage.
The main vectors for BYDV are Grain aphid and Bird Cherry-oat aphid.
- Once aphids have the virus, they will be able to transmit for the remainder of their lives.
- Plants can be infected ~30 minutes after the aphid has started feeding.
- Aphid population increase during warm autumns and the earlier the infection, the worse the impact on yield.
Insecticide seed treatments will have activity for up to 8 weeks, a follow-up spray will then be required if populations remain high. HALLMARK ZEON is the most persistent pyrethroid available. Applying 50 mls/ha will reduce the need for several follow-up sprays and help reduce the risk of resistance build-up.
Insect traps at Rothamsted are recording high numbers of Bird Cherry-oat aphid and Grain aphid this autumn, the highest in 5 years.
