| Popis: |
The hydropneumatic seeder developed by Gautz et al. (1989) was modified to singulate and meter primed, wet celery seeds. The seeds were transported from the hopper to the metering plate by water. They were held in the metering hole by vacuum and were singulated by jetting the recirculated water which was used to transport seeds onto the metering holes holding multiple seeds. The hydropneumatic seeder metered primed celery seeds (1.53 mm average diameter) with planting efficiency in the range of 89.4 to 107.2%. There were only a few doubles and misses as the linear speed of the metering hole, applied vacuum level, seed delivery air flow rate, and knock-off air pressure were varied over a wide range (linear speed: 100 to 500 mm/s; vacuum level: 300 to 600 mm; air flow rate: 170 to 230 L/min, and air knock-off pressure: 13.8 to 69 kPa). |
