SEED POTATO growers have been warned crops face an increased risk from aphids this year.
The most serious virus carriers, Peach-Potato Aphid (Myzus persicae) and Potato Aphid (Macrosiphum euphorbiae), have already been identified in aphid traps across England.
This elevates the virus risk index rating early in the season for Scottish producers, according to Scottish Agricultural College specialist Andy Evans.
“This year seed crops will be going through the most vulnerable early growth stages just when aphid migration is likely to be approaching its peak,” he warned.
“Vigorous aphid feeding activity will be concentrated on tender soft new vegetative growth and any virus infection will rapidly spread throughout small plants.”
Wait for the first signs of migration before applying an insecticide, he advised.
A dual-action approach, using a pyrethroid with pirimicarb, is best where an application is needed, and will offer rapid knock-down as well as repelling recolonisation.
“If there is any sign that the pyrethroid/pirimicarb mixture has failed to achieve complete control, revert to a pyrethroid/Plenum (pymetrozine) mixture in the next application to prevent resistant colonies multiplying,” said Dr Evans.