Abstract: The efficient way to apply foliar active herbicides is to cover foliage with herbicide as completely as possible. Spray in suitable drop under low application pressure is the trend to prevent application from drift using ground sprayer. There is only a highly-mounted boom which can reach high-growing foliage of hardwood under low application pressure. This design makes a boom flexible and keeps it always pointing to the centre of the earth to supply spray pattern consistently in rough areas and guarantees its safety because of its ability to keep obstructions away automaticly in space.