Effect of density control and undercutting on root morphology of 1+0 bareroot hardwood seedlings: five-year field performance of root-graded stock in the central USA

• Published in: New forests 1997-05, Vol.13 (1-3), p.301-301
• Main Authors: Schultz, R.C. (Iowa State Univ., Ames, IA (USA). Dept. of Forestry), Thompson, J.R
• Format: Article
• Language: English
• Subjects: CORTA DE LAS RAICES; CROP PERFORMANCE; DESEMPENO DE CULTIVOS; ESPACEMENT; ESPACIAMIENTO; ETATS UNIS; EUA; FOREST NURSERIES; Forestry; GROWTH RATE; INDICE DE CRECIMIENTO; Juglans; JUGLANS NIGRA; Morphology; Nurseries; PEPINIERE FORESTIERE; PERFORMANCE DE CULTURE; Plant growth; PLANTULAS; PLANTULE; QUERCUS RUBRA; ROOT PRUNING; ROOT SYSTEMS; Roots; SEEDLINGS; Seeds; SISTEMA RADICULAR; SPACING; Stems; SUPERVIVENCIA; SURVIE; SURVIVAL; SYSTEME RACINAIRE; TAILLE DES RACINES; TAUX DE CROISSANCE; USA; VIVEROS FORESTALES
• ISSN: 0169-4286; 1573-5095
• DOI: 10.1023/A:1006594510503

The Hardwood Quality Nursery Cooperative (bareroot forest nurseries in 5 midwestern states) initiated a series of studies in 1987 to evaluate red oak (Quercus rubra L.), and black walnut (Juglans nigra L.) seedling performance as a function of cultural treatments and seedling root system morphology. Seedlings were grown at three densities (32, 64, and 128 stems m^sup -2^for red oak; 32, 64, and 96 stems m^sup -2^for black walnut), and half of the density plots were undercut. Seedlings received fertilizer, weeding, and irrigation treatments customary to their respective nurseries. Seedlings were lifted, measured, and outplanted in their respective states as completely random individual tree plots during spring 1988. Survival, height, and diameter were evaluated annually through 1992. Seedling height, diameter, and number of permanent first-order lateral roots (FOLR) decreased with increasing bed density. At a given density, undercutting produced smaller seedlings (for both height and diameter) that had greater numbers of FOLR. Numbers of FOLR influenced seedling performance after outplanting. Red oak seedlings with at least 5 FOLR and black walnut with at least 7 FOLR had better survival and growth than seedlings with fewer roots.[PUBLICATION ABSTRACT]