School Papers

One attempts are being madeto develop an automatic

One of the important components of the vegetabletransplanter is the seedling extraction mechanism,which extracts the plug seedling from the pro – traycell and transfers them to the transplanting device, whichplaces them into the soil.Yanmar Agricultural Equipment Co.and Kubota Cooperation, leading agricultural machinerymanufacturers in Japan, have developed two of the mostcommon seedling pick – up devices for the vegetabletransplanters widely used in Korea and Japan. The Yanmar -type moves the pick- up pins toward the lower part of the cellsurface and extracts the seedling from the cell while movingalong a path in an open, counter – clockwise loop. The Kubota- type generates a crossed path when picking up seedlings byusing a more sophisticated mechanism comprising of a slider,cam, and links. Although these two pick – up devices performwell, their structural complexity have made them difficult touse for various types of vegetable transplanters. In addition,these pick – up devices are not economically feasible forindigenously made vegetable transplanters because of theirhigh manufacturing costs (Choi et al., 2000).The demand for mechanization of vegetable productionin India has increased every year, so attempts are being madeto develop an automatic transplanter for vegetables. Seedlingpick – up mechanisms that are simple, accurate andeconomically feasible are to be developed for vegetabletransplanters in India. This study was one of these attempts.The articles authored by Brewer (1994), Choi et al. (2001)and Choi et al. (2002) were reviewed to develop a concept ofseedling ejection device that will satisfy our requirement. Notmuch of literature is available in this context. The objectiveof this study was to develop a seedling pick – up mechanismfor vegetable transplanters suitable to Indian conditions andevaluate its work performance in a laboratory.METHODOLOGYDevelopment of seedling ejection mechanism:To obtain the best performance of the pick – upmechanism, it needs to satisfy the following requirements.The pick – up claw enters into the pro tray cell with thedepth of penetration not to be more than half the depth of thepro – tray cell.The pick – up claw should release the seedlingimmediately after coming out from the tray cell.The mechanism should be simple and easy to fabricate.Extracting and discharging of seedling should be doneat predetermined points on the locus of the claw.The stem and leaves of the seedling should not be