2 August 2002

Time to deal with problem of take-all in first wheats

By Tom Allen-Stevens

TAKE-ALL in first wheat crops is on the increase because growers are failing to control oilseed rape volunteers, warns an independent crop consultant.

The consequences for second wheats could be disastrous, says Glos-based AICC agronomist Jonathan Olver.

"The low levels are not sufficient to have caused significant yield loss or have justified an expensive take-all seed treatment.

Volunteer cereals

"But the real value of rape as a break crop is being seriously undermined if growers dont control even relatively low populations of volunteer cereals and grass weeds."

Take-all has also been seen after set-aside, but not following peas or beans, where volunteer cereal control has been better, says Mr Olver.

The problem has been exacerbated by the wet autumn in 2000 restricting herbicide applications and growers reducing inputs, he believes.

Particularly troublesome are volunteer barley patches appearing where crops have lodged and rooks have fed, he notes. "Growers really need to concentrate on these areas which provide the critical root mass for take-all to develop and carry through the break crop year." &#42