Abstract: A single-seed dispenser of a pneumatic precision sower includes a seed supply container, a housing defining a suction chamber, and rotatable perforated dispenser disc interposed between the supply container and the housing. At least one partition member is disposed at the rear surface of the disc in the housing wherethrough air is aspirated for drawing the seeds onto the disc. The partition member(s) covers only portions of the perforations at least over the circumferential extent of the disc over which suction in the suction chamber acts through the perforations. Thus, elongate very narrow seeds are prevented from passing through the perforations. A drive disc for driving the dispenser disc includes pins projecting through bores in the dispenser disc not only to transmit rotation of the driver disc to the dispenser disc but also to agitate the seeds in the bottom of the seed supply container. A stripper for stripping excess seeds from the dispenser disc includes two spaced apart plates.

Abstract: A precision-type single-seed planter has seed distributor in the form of a disk provided with elongate perforations of a narrow width, which cooperate with a seed container and an air suction device. Because the perforations in the disk have an elongate shape and a small cross section even large seeds can be held on the disk by suction at each of the perforations whereas smaller seeds will also be held without being able to pass through the perforations. A selector element cooperates with the disk by throttling the suction effected on the seeds through the perforations so that only individual ones of the seeds, particularly the smaller seeds, are adhered at each perforation. An optimum seed separation and single-seed distribution effect is thus achieved, regardless of the size and shape of the seeds.