Caratterizzazione morfologica di differenti tipi di postime di Juglans regia L. destinati a piantagioni di arboricoltura da legno

Good results in plantations are strictly related to the fitness of the nursery stock. Plant fitness, or quality, depends on inherent genetic characters and on physiological and physical (dimensional, morphological and nutritional) characteristics. In arboriculture for wood production the role of stock quality is essential for a prompt expression of plant growth potential. So the necessity to define stock quality standards is widely recognized, though is still discussed how to assess stock cultural value by characteristics easy to measure. First step in such activities is to individuate in the above-ground part of the plantlets some traits related to the root system development. The study was carried out in two public forest nurseries (property of Regione Piemonte) on 163 Juglans regia seedlings and transplants produced for wood plantations. In order to evaluate Walnut nursery stock production, different kinds of bare-root seedlings and transplants have been compared. For each kind, shoot and root system dimensional and morphological traits have been investigated after assignment of plants in 3 dimensional (height) categories. Relations between shoots and roots traits have been studied to allow a visual evaluation of nursery plants based on data easy to collect. This study is to be considered a preliminary survey in the evaluation of stock quality based on field performance.