Vigorouslygrowing volunteer beans and oilseed rape are threatening the effectiveness ofblack-grass control programmes this autumn and Dow AgroSciences recommends thatspraying the volunteers is a priority right now.
Theproblem is especially severe where farmers experienced a difficult beanharvest. High numbers of volunteers are likely to be emerging this autumn.
Thevolunteer beans and oilseed rape will shade black-grass and reduce theeffectiveness of contact graminicides. Removing these will increase theeffectiveness of black-grass control.
StuartJackson, Dow AgroSciences cereal herbicide specialist, says: Its vital to actnow on volunteer control to ensure there is still time to apply post-emergenceblack-grass applications before temperatures drop and growth slows down.
Wherethere are large populations of volunteer beans in particular, farmers will needto wait around two weeks for the leaves to curl up sufficiently before treatingblack-grass.
Inwinter wheat and barley crops, from GS13, Dow AgroSciences recommend applyingSPITFIRE (florasulam and fluroxypyr) for the control of volunteer beans atrates from 0.5 litre/ha plus approved adjuvant (volunteer beans up to 4 true leaves). Larger weeds up to 6 true leaves should receive an increased doseof 0.75 litre/ha plus approved adjuvant.
Wherevolunteer oilseed rape is the target the adjuvant is not required and theserates will control volunteer oilseed rape up to 4 or 6 true leavesrespectively.
Inaddition to volunteer beans and oilseed rape, SPITFIRE also offers effectivecontrol of a range of broad leaf weeds, including mayweed, chickweed and anumber of other brassica weeds.