influenced the seed placement. The large, rounded 

 seeds were more evenly spaced by the Summit 

 Seeder. The Oyjord plots tended to have more blank 

 spaces and more clumping of seeds. This was not 

 the case at the J. W. Toumey Nursery where the 

 seeds were smaller and the Summit Seeder placed 

 seeds inconsistently. 



When seed was small like white spruce, or angled 

 on one end like coastal Douglas-fir, the Summit 

 Seeder's vacuum system had problems picking up 

 and placing just one seed at a time. This explains 

 why several species showed little difference between 

 the two seeders. The Summit Seeder also had diffi- 

 culty sowing the resinous and sticky noble fir seed at 

 Wind River Nursery. The plots that were oversown 

 and hand thinned produced fewer seedlings per unit 

 area, fewer blank spaces, less clumping of seedlings, 

 and generally, more well-spaced seedlings than the 

 other two treatments. 



Seedbed density and spacing did not affect the 

 percentage of total trees that met grading specifica- 

 tions. In fact, Oyjord plots, which often had the 

 poorest seedling spacing, produced as many or more 

 shippable seedlings per unit area as the other two 

 treatments in all of the tests lifted. Since the Oyjord 

 and hand-thinned cull rates were only slightly dif- 

 ferent and had more total seedlings, the Oyjord plots 

 surpassed the hand-thinned plots in shippable seed- 

 ling production. 



Seedling spacing is a function of seed placement 

 and seedlot germination. This complex problem and 

 the way it influences seedling growth and morphol- 

 ogy depends on many factors. Many of these factors 

 were not measured in this study. It appears that 

 the differences in seedling spacings were not great 

 enough to change the seedling morphology. Even 

 when we hand-thinned plots to specified seedling 

 spacings, we did not greatly reduce the cull rates or 

 increase the total shippable seedling production per 

 unit area. 



The results of this study emphasize some of the 

 major underlying problems which must be solved if 

 we desire evenly spaced and morphologically consis- 

 tent seedlings. A machine that can place seed ex- 

 actly loses its value very quickly if the germination 

 rate of our seed goes down. Even a very precise and 

 consistent seeder using a high germination seedlot 

 is of little value if we have not determined the opti- 

 mum morphological characteristics of the seedlings 

 we want to grow and the spacing and culture that 

 will produce those results. 



REFERENCES 



Boyer, J. N.; South, D. B.; Muller, C. A.; Vanderveer, 

 H. 1985. A comparison of nursery sowers. Tree 

 Planters' Notes. 36(3): 20-24. 



Boyer, J. N.; South, D. B. 1986. Loblolly pine seed- 

 ling morphology and production at 53 southern 

 forest nurseries. Tree Planters' Notes. 39(3): 13-16. 



Boyer, James N.; South, David B. 1987. The influ- 

 ence of seedbed density on loblolly and slash pine 

 seedling grade distributions. In: Proceedings, 

 fourth biennial southern silvicultural research 

 conference; 1986 November 4-6; Atlanta, GA. Gen. 

 Tech. Rep. SE-42. Asheville, NO: U.S. Department 

 of Agriculture, Forest Service, Southeastern For- 

 est Experiment Station: 189-197. 



Brissette, John C; Carlson, William C. 1987. Effects 

 of nursery bed density and fertilization on the 

 morphology, nutrient status, and root growth po- 

 tential of shortleaf pine seedlings. In: Proceedings, 

 fourth biennial southern silvicultural research 

 conference; 1986 November 4-6; Atlanta, GA. Gen. 

 Tech. Rep. SE-42. Asheville, NC: U.S. Department 

 of Agriculture, Forest Service, Southeastern For- 

 est Experiment Station: 198-204. 



Burns, R. M.; Brendemuehl, R. H. 1971. Nursery 

 bed density affects slash pine seedling grade and 

 grade indicates field performance. Res. Pap. SE-77. 

 Asheville, NC: U.S. Department of Agriculture, 

 Forest Service, Southeastern Forest Experiment 

 Station. 7 p. 



Caulfield, Jon P.; South, David B.; Boyer, James N. 

 1987. Nursery seedbed density is determined by 

 short-term or long-term objectives. Southern Jour- 

 nal of Applied Forestry. 11(1): 9-14. 



Mulhn, R. E.; Bowdery, L. 1977. Effects of seedbed 

 density and nursery fertilization on survival and 

 growth of white spruce. Forestry Chronicle. 53: 

 83-86. 



Richards, N. A.; Leaf, A. L.; Bickelhaupt. 1973. 

 Growth and nutrient uptake of coniferous seed- 

 lings: comparison among 10 species at seedbed 

 densities. Plant & Soil. 38: 125-143. 



Scarborough, N. M.; Allen, R. M. 1954. Better long- 

 leaf seedlings from low density nursery beds. Tree 

 Planters' Notes. 18: 29-32. 



Shoulders, E. 1961. Effect of nursery bed density on 

 loblolly and slash pine seedlings. Journal of For- 

 estry. 59(8): 576-579. 



Sloan, John P. 1990. Comparison of the Summit Pre- 

 cision Seeder with the Oyjord Seeder. In: Rose, 

 Robin; Campbell, Sally; Landis, Thomas D., eds. 

 Target seedling symposium: Proceedings, com- 

 bined meeting of the Western Forest Nursery 

 Associations; 1990 August 13-17; Roseburg, OR. 

 Gen. Tech. Rep. RM-200. Fort Colhns, CO: U.S. 

 Department of Agriculture, Forest Service, Rocky 

 Mountain Forest and Range Experiment Station: 

 167-173. 



van den Driessche, R. 1984. Seedling spacing in the 

 nursery in relation to growth, yield and perfor- 

 mance of stock. Forestry Chronicle. 60(6): 345-355. 



24 



6U.S. GOVERNMENT PRINTING OFFICE: 1992-673-041/61012 



