The present invention relates to a process of forming a sprayable pesticide or herbicide formulation having improved spray drift properties comprising the steps of, i) providing an aqueous concentrate containing pesticide or herbicide, ii) providing an aqueous concentrate containing pesticidal or herbicidal adjuvant or fertiliser, iii) forming the sprayable pesticide or herbicide formulation by combining water, the pesticide or herbicide and the pesticidal or herbicidal adjuvant or fertiliser, wherein the aqueous concentrate of pesticide or herbicide and the aqueous concentrates of the pesticidal or herbicidal adjuvant or fertiliser both contain one or more polymers capable of enhancing spray drift control. The sprayable formulation may be prepared in a spray tank into which is metered water, the concentrate containing herbicide or pesticide and the concentrate containing the pesticidal or herbicidal adjuvant or fertiliser. The process brings about significant improvements in spray drift control without the risk of overdosing with either adjuvant/fertiliser or pesticide/herbicide.
