Abstract: A plurality of pivotable spray chambers are mounted on an elongated beam extending from a boom secured to a three-point trailer hitch of a tractor. Controlled herbicide spraying of the unwanted growth which occurs in the furrows between dikes in fields of strawberries, lettuce, corn, tomatoes, onions, and other crops is achieved. Each furrow is sprayed by at least two spray chambers pivotally mounted from a beam. Each spray chamber includes an open bottomed box, with each of the two spray chambers being movable towards and away from each other against the bias of springs so that varying widths of furrows between adjacent dikes are accommodated.