Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2006.2281.2286BozdoganAli Musa 102006610Three vacuum precision seeders` performance was investigated in laboratory studies. Trials were conducted to quantify seed spacing distribution on within-row. In trials, seed spacings uniformity was determined in three within-row distances which were at 14, 7 and 20 cm. The seeders were operated at 1.8, .6 and 5.4 km h-1 ground speed. Seed spacing distances on the greased belt were measured by hand. MISS, MULT, QFI and PREC index values were used for determining of seed spacing uniformity of seeders. Results showed that there were significantly difference among machines in MULT and QFI index values in p<0.01. Operating speed affected MISS index values which changed from 0.96 to 4.51% and seed spacing on within-row affected PREC index values which changed from 13.36 to 17.36%. According to operating speed, the best QFI value obtained at 1.8 km h-1 operating speed (96.72%). In QFI values, this operating speed was statistically difference from others in p<0.10. At 1.8 km h-1 operating speed, the lowest MISS, MULT, PREC values and the highest QFI value were determined as 0.96, .32, 4.44 and 96.72%, respectively. After 3.6 km h-1, MISS index value changed statistically. The best within-row distance was 20 cm because of the lowest PREC index values (13.36%).]]>Ball, B.C.,1986357195Bauer, P.J., J.R. Frederick and W.J. Busscher,200266175182Bracy, R.P. and R.L. Parish,19988182185Brown, F.R., S.J. Miles and J. Butler,199458261270Culpin, C.,198711th Edn.,pp: 451pp: 451Danfors, B.,198738167172Garcia, L.C. and S.G. Barron,19961996pp: 243244Gil, E. and R. Carnasa,19961996pp: 5758Ivancan, S., S. Sito and G. Fabijanic,200489373376Jindal, V.K. and J.T. Walker,1987301517Kachman, S.D. and J.A. Smith,199538379387Liu, W., M. Tollenaar, G. Stewart and W. Deen,200444847854Mohammed, A. and F.A. Gumbs,1982Zea mays L.) on a steep slope of an ultisol in Trinidad.]]>27481488Nielsen, R.L.,19911991Nielsen, R.L.,19941994Ozmerzi, A., D. Karayel and M. Topakci,200282227230Parish, R.L., P.E. Bergeron and R.P. Bracy,19917537540Parish, R.L. and R.P. Bracy,200313100102Picanco, M., G.L.D. Leite, R.N.C. Guedes, E.A. Silva,199817447452Whitehead, W.F. and B.P. Singh,2000Clemson Spineless` okra are affected by within-row spacing.]]>35849852Wilkins, D.E., J.M. Kraft and B.L. Klepper,19913419571961