Differences in growth and branch production by young plants of two provenances of Quercus robor L.

2000

S 271-281

2 Abb., 4 Tab., 36 Lit.

Unselbständiges Werk

200067658

Growth and branching of Q. robur was studied in young plants grown from acorns collected at two sites in Holland: one, at Ede-de-Klomp, was a registered seed stand having parents with good form; the other was poor phenotype at Wolfheze where parents had crooked trunks and epicormic branches. Observations were made after 6 months growth in the greenhouse and a further eight seasons in the field. In the greenhouse the plants flushed 2-5 times, with those from Wolfheze generally forming most growth units. Mean length of the growth units produced during the flushes of growth varied between 116 and 242 mm and where there were significant differences between provenances those of Ede-de-Klomp were longer. However, there were no significant differences in height between origins after 6 months growth. Branches were not produced on all trees or on all growth units, their occurrence declining on growth units formed during the later flushes of growth. Between 7 and 64 per cent of buds grew out on those growth units which produced branches, and plants from the Wolfheze origin were generally more branched. After 8 years in the field, the height of the plants varied between 1.3 and 4.2 m, those from Ed-de-Klomp were generally taller with smaller stem diameters than those from Wolfheze. There were significant relationships between shoot length and branch numbers, with the Wolfheze origin generally having more branches per unit length than Ede-de-Klomp. The results are discussed in relation to the phenotype of the parent and early selection of oak provenances.