Aphid numbers are low this October. Recent frosty mornings have no doubt contributed to this.
Counts from unsprayed winter barley in Teagasc Oak Park have been ongoing since the first week of October.
While aphid counts remain low, the advice will still be to spray at the two to three leaf stage with an aphicide, where Redigo Deter seed dressing was not used at planting.
Where Redigo Deter was used, it provides protection for at least six weeks. It is only after this time the crop should be sprayed and only if conditions warrant an aphicide application at the time.
Cold conditions and low aphid numbers may rule out an application after the six week period is up. Ground conditions will also play a role in application.
While all farmers should look out for these conditions, the time-frame should be watched particularly carefully on early sown crops.
It should be noted that no winged aphids were collected in samples so far. Winged aphids increase the likelihood of Barley Yellow Dwarf Virus (BYDV) being spread.