An opener for mounting on a shank of an agricultural implement features a central body to be mounted on the shank, furrowing portions carried on the central body to form a seed bed as the central body is pulled through ground on the shank in a forward working direction, a seed delivery passage operable to deliver seed onto the seed bed from a seed outlet on a first side of the central body, and a fertilizer delivery passage operable to deliver fertilizer onto the seed bed from a second side of the central body. In use, the opener delivers the seed and the fertilizer onto the same seed bed on opposite sides of the central body. A rubber cover seals closed an upper end of the central body to prevent moisture from anhydrous ammonia tubes from dripping into the body, and is adaptable to accommodate seed tubes of different diameters.