Friday, 24 October 2014

Aphids in Ukraine and Russian winter wheat

Current weather conditions in Ukraine and Russia has been dry and unseasonably warm which will favour cold blooded aphids.

In warm weather aphids migrate into winter cereal crops and reproduce.

The issue with aphids this time of year is not injury from direct feeding but as they feed they introduce plant viruses much in the same way intravenous drug users do when sharing a needle.

They transmit barley yellow dwarf luteovirus (BYDV) and very low populations, which may go unnoticed, can cause economic damage.

The two aphids in question are Grain Aphid (sitobion avenae) and Bird Cherry-Oat Aphid (rhopalosiphum padi) both of which I have seen in Ukraine and Russian.

As yet have never met a local agronomist who knows what they are or could identify one.

These two aphids and the problem they cause have been well documented in Western Europe but I haven't seen any research data or information on control or thresholds in Ukraine or Russia.

I'm not saying it’s not there I just haven’t seen it or have been shown anything by local agronomists.

In the UK losses up to 2.5mt/ha have been recorded, losses in Ukraine and Russia might be low but they could be significant.

Control is based around imidacloprid seed treatment and autumn applications of pyrethroids, neither of which are currently done so if they are causing a problem they are not being controlled.