Abstract: A defoliator having a frame suitable for mounting to a vehicle supports an elongated main support arm which extends substantially horizontally, and which has a tine-bearing main shaft which rotates to have the tines knock at least some leaves (or portions thereof) from plants beneath. The main support arm rides on wheels, and may pivot and vertically translate with respect to the frame such that the main support arm (and the tined main shaft) will generally follow the elevation and contour of the ground beneath. To defoliate greater areas, one or both ends of the main shaft may be connected to a boom arm hearing a rotating tined arm shaft, which extends the effective length of the main support arm and tined main shaft. The boom arms are preferably capable of folding rearwardly to reduce the effective size of the defoliator for easier transport.