The flush of Black-grass germination expected in areas where rain has fallen recently will present cereal growers who have already drilled their wheat with a major challenge when it comes to post-emergence control this autumn.
This is the warning from Agronomist Libby Powell, of Morley Research Centre and Agronomy Manager Clare Tucker, of BASF, following evidence from around the country that there was little germination of Black-grass prior to drilling.
"There was very little germination before the recent rain, so the delayed emergence will put more pressure on the performance of the post-emergence herbicides this autumn," says Libby Powell.
Commenting on two of the main post-emergence options (Lexus + Stomp and Lexus + Hawk) she says Lexus + Stomp would be preferred where growers can get on at the 1-2 leaf stage of the weed, and also where target site or enhanced metabolism resistance is present.
However, she does warn growers that the residual effect of the Stomp could be reduced if sprayed onto a cloddy seedbed, as the clods may break open if a frost or exceptionally high rainfall follows application resulting in unsprayed soil.
"A firm and consolidated seedbed is therefore important for optimum performance," she says.
Clare Tucker, of BASF, also urges cereal growers to go early this autumn with post-emergence sprays by targeting leaf 1 of the Black-grass plant. "It's better to get what's first to show rather than wait and risk poor control of the older plants."
