Abstract: The present specification discloses a collection device comprising an elongate duct for conveying loose material towards a downstream region thereof from a collection mouth at an upstream end thereof. at least one air outlet is disposed adjacent the collection mouth and arranged to in use direct an air flow transversely to the longitudinal axis of the duct over a curved, generally convex flow control surface of the collection mouth such that at least a portion of said air flow follows said curved surface and is directed downstream within said duct.