Aphid numbers soaring in cereal and potato crops

Aphid numbers have been soaring in cereal and potato crops in southern and eastern regions due to favourable conditions, according to a joint HGCA/Rothamsted Research report.

“The big increase has been boosted by the very warm spring and early summer and limited natural enemy success in the early part of the season,” the report said.

In cereals, the rose-grain aphid is thriving in the greener late-sown spring barley and peach-potato aphid numbers have been increasing in potato crops.

Suffolk-based Prime Agriculture agronomist Marion Self says pest numbers are currently below spray thresholds in most cereal crops in her region, but there are some heavy localised populations, especially in drought-stressed second wheats.

But this year she says there are many predators which should help mop up aphid populations. “I have been recommending Aphox (pirimicarb) in cereals where infestations have been heavy in the hope that it will reduce numbers without affecting the predators,” she adds.

Scottish Agricultural College‘s Andy Evans advises growers to spray potato crops for peach-potato aphids (Myzus persicae) as soon as the pest is found in traps or crops.

But products based on pirimicarb should not be used due to problems with resistance, he warns.

He suggests using products with alternative chemistry, such as Actara (thiamethoxam), Plenum (pymetrozine), Teppeki (flonicamid) or Insyst (acetamiprid).