19 October 2001

Former blackgrass levels force policy

CULTIVATION for wheat establishment, nearly all with a 6m Simba Freeflow drill, is driven by previous cropping and blackgrass levels.

"We have some patchy blackgrass confirmed as resistant," says Mr Knight. "Anything with bad blackgrass or going into second wheat gets ploughed and pressed. And we ploughed after oilseed rape which had an immense problem."

Everything after peas, potatoes and sugar beet, is Flat-lifted, Simba disced, pressed and rolled ahead of drilling.

Two sprays of 2 litres/ha of Roundup (glyphosate) pre-cultivation and pre-drilling are employed to hit blackgrass at every opportunity.

Mr Knight drew up detailed costings of each operation for his recent BASIS qualification (see box above). It shows the eco-till non-ploughing route is often more expensive because of a frequent need to sub-soil.

"Unfortunately we havent had a chance to roll anything after drilling." But all fields at slug risk had a full 5.5kg/ha rate of Draza at the same time as the pre-emergence herbicide from the front of our Sands 24m sprayer."

IPU/diflufenican mixes including an anti-BYDV pyrethroid are the main first strike. But for the worst blackgrass a 3 litres/ha (three-quarter) dose of Crystal (flufenacet + pendimethalin) is being tested. "I have seen its effect in a few trials, but at £12/litre we couldnt afford it everywhere.

"For post-em treatments its a matter of keeping our fingers crossed and waiting to see. For severe cases I may go for a Stomp/Lexus mix."