Aphicide resistance in UK is a timely warning
Crops were sown into lovely seedbeds this autumn, resulting in good plant establishment and plenty of optimism. That said, establishment of cereal volunteers has been phenomenal in fields which were not grubbed prior to sowing.
Volunteers have brought all the problems associated with the "green bridge" – aphids, mildew and rhyncosporium in barley.
Seeding rates should be increased from now on to allow for poorer seedbeds. Both wheat and oats should have a minimum seeding rate of 350 seeds/sqm.
Lower temperatures and wetter soil conditions will result in slow emergence of crops sown recently and will give a longer period for slug damage. Crops sown after oilseed rape or where a lot of trash was present in the field are particularity at risk.
Slug pellets will control mature slugs that are feeding but may miss juvenile slugs so repeat applications are likely to be necessary if moist mild conditions occur.
Cooler weather will slow down aphid migration but periods of milder weather will allow further invasions.
Continue to monitor crops carefully and spray if aphids are found.
In most years, a final aphicide application in early November will provide control for the remainder of the year. However, guidance on the need for later applications will be available from our monitoring of ITCA aphid traps.