SEEDBED CONDITIONS in many areas are likely to be good for effective pre-emergence weed control this autumn, experts have advised.

Warm and moist soil means crops and weeds are likely to ‘get away’ quickly and growers should consider using a pre-em herbicide to ease the pressure on timing and choice of post-emergence products, said The Arable Group’s Jim Orson.

Pre-ems are usually a better option in difficult blackgrass or ryegrass situations, he noted.

“The latest results from a Sustainable Arable LINK project show a lack of dormancy in blackgrass this year. This means there is more likelihood of an early flush of blackgrass which a pre-em can curb.”

But while the exact blackgrass emergence pattern is still unclear, it is likely that a higher proportion will germinate early, added ADAS’s James Clark.

He also suggests using a robust pre-em, which will be an important part of an anti-resistance strategy.

BASF’s Phil Brown highlights the need to remove weed competition at the earliest opportunity and recommends Crystal (flufenacet + pendimethalin).

“In BASF trials last year, around 70% of the yield response from a programme for blackgrass control came from a pre-emergence treatment of Crystal at 4.0 litres/ha.”

Ongoing concerns over diffuse pollution caused by isoproturon (IPU) mean growers should start bringing alternatives into their spray programme, added Bayer CropScience’s Ron Graham.

He suggests using Liberator (diflufenican + flufenacet) for pre-em control of blackgrass, annual meadow grass or broad leaved weeds.