Evaluation of growth slowdown nursery treatments on Prunus avium seedlings by means of allometric relationships and relative growth rates

Abstract

To evaluate the effects of carbonic fertilization and apical brushing (brushing of shoot apices to induce a negative thigmonastic response) on Prunus avium growth under nursery, carbon dioxide (CO₂) was fed to cherry trees. Later, carbonic fertilization was withdrawn and apical brushing was applied. Finally, the original conditions were reinstated. Height and trunk diameter, allometric relations with plant biomass and relative growth rate were followed. Contrary to expectations, apical brushing resulted in increased trunk diameter and, hence, growth rate. Carbonic fertilization did not produce differences in the initial growth, probably owing to the deciduous characteristics of the species. Continuous application of carbonic fertilization maintained growth rate, whereas no fertilization or its withdrawal reduced the growth rate, but acclimation of the CO₂-fed plants appeared by the end of the growing period. No differences in root growth potential at the end of the assay were observed between treatments. In conclusion, owing to the observed acclimation, carbonic fertilization is not advised throughout the complete period of growth. The tested treatments did not help to adapt supply of plant material of this species to the demand for revegetation. However, growth-slowing treatments may be applied to P. avium without any negative effects on potential root growth.

Keywords:

• apical brushing
• carbonic fertilization
• growth slowdown
• nursery
• potential root growth
• Prunus avium

Acknowledgements

This work has been possible thanks to a grant from INIA to Ms Carolina Miguel linked to the project RTA-04-028-C2 and SUM2006-00020-C02, in which this work is included. We also thank Carburos Metalicos SA (Air Products) for providing facilities to apply CO₂ in the experimental nursery.