5 April 2002

Get trials low-down online

By Tom Allen-Stevens

GROWERS with web access can now get the low-down on this years latest herbicide trials from Velcourts Arable Event trials at the Cereals 2002 site near Sleaford, Lincs.

Initial results, available on farmers weekly Interactive (www.fwi.co.uk), show a good pre-emergence herbicide is key to grassweed control.

The internet service was started after Cereals 2001 was cancelled due to foot-and-mouth. Distrib-utors and farmers, who visited the site privately, said following plot progress on the web helped them get much more from the visit.

Since updating tiller counts in the grassweed plots some big differences have emerged (see table), says Velcourt technical director Keith Norman.

"The pre-em treatments have been the most important in getting a good foothold on control." That is especially true of the ryegrass plots, which are new this year. "Its becoming more of a problem weed across the UK."

In the untreated plot, the ryegrass – deliberately sown with the wheat – has completely taken over, leaving very little crop.

The most effective chemical control has been terbutryn and chlorotoluron, followed by a post-em. "It is a good example that old products still have a useful role to play," says Mr Norman.

The new BASF herbicide Crystal (flufenacet + pendimethalin) has also done well. "Crystals a rising star and has given good grassweed control, but we have seen some crop thinning."

That could be down to the trial being on a brashy soil, sown relatively late in October. "Crystal can reduce establishment in wet, waterlogged soils, and correct drilling depth is critical."

Other big differences already showing are in the variety plots, where some unknown players are pitched against NIAB recommended favourites. "Non-recommended wheat Caphorn is looking good and new varieties Brunnel and Christelle are very much more advanced than the others," says Mr Norman. &#42

Velcourt grassweed trial results to date

Pre-em (25 Oct) 1st post-em (12 Dec) Resistant bgrass counts (plants/m2)

Control Control 500

Lexus (flupyrsulfuron-methyl) 20g/ha + Hawk (clodinafop-propargyl + trifluralin 2.5 litres/ha + oil

Avadex (tri-allate) 15kg/ha Lexus 20g/ha + Hawk 2.5 litres/ha + oil 120

Crystal (flufenacet + pendimethalin) 3.0 litres/ha Lexus 20g/ha + Hawk 2.5 litres/ha + oil 20

terbutryn 5.0 litres/ha + trifuralin 2.0 litres/ha Lexus 20g/ha + Hawk 2.5 litres/ha + oil 10

Crystal 3.0 litres/ha + trifuralin 2.0 litres/ha Lexus 20g/ha + Hawk 2.5 litres/ha + oil 0