Design of a low-cost pneumatic seeder for nursery plug trays

Manual indenting and sowing of small vegetable seeds in plug trays is a slow and labour-intensive operation, which limits the production capacities of vegetable nurseries in India. High-capacity imported seeders have not been adopted by nursery growers due to their high costs. The objective of this study was to develop a precision plug tray seeder, using indigenous materials and off-the-shelf available standard components. Based on the design parameters obtained in laboratory experiments, a prototype pneumatic seeder was fabricated and tested for its performance for sowing capsicum and tomato seeds in plug trays. The seeder could make indents in one row of cells in a plug tray and simultaneously place single seeds in the indented cells. The seeder worked satisfactorily at suction pressures of 4.91 and 3.92 kPa and nozzle diameters of 0.46 and 0.49 mm to achieve more than 90% single seed sowing in the case of capsicum and tomato, respectively. The capacity of seeder, depending on the tray size used, ranged between 38,000 and 60,000 cells h(-1). The total cost of sowing 1000 cells using a prototype precision plug seeder was found to be Rs. 1.56 (US$0.034) which was only 15.27% of the estimated cost of manual sowing. (C) 2007 IAgrE. Published by Elsevier Ltd. All rights reserved.