L'ombreggiamento per favorire la produzione florovivaistica di piante arbustive.

The current requirements of environmental conservation and biodiversity, and the need to find materials and biomass from renewable sources, led to the discovery and study of plant species undervalued, including numerous plants of the Mediterranean flora. However, the nursery production of several species of the Mediterranean faces significant difficulties due to poor rooting ability in the propagation by cuttings. In fact, if on one hand sexual propagation allows to diversify the products retaining a wealth of genetic, the other lengthens the time required to obtain a product that may not correspond to certain commercial standards. In this study we observed the effects of different levels of shading (70%, 60%, 50% and 30%) and of etiolation on an attitude of rooting of shoots of six wood species of the Mediterranean maquis considered recalcitrant (Arbutus unedo L., Ceratonia siliqua L., Phillyrea latifolia L., Pistacia lentiscus L., Quercus ilex L. and Quercus suber L.), while the other two species (Ilex aquifolium L. and Rhamnus alaternus L.) with good natural ability to rooting were used as a control. Every six months, it was determined the linear growth of the plants subjected to shading and linear growth of the shoots. Moreover, a part of the cuttings has been subjected to an etiolating treatment. For each thesis in question the rooting ability of cuttings was rated and the same steps were taken to carry out chemical analysis considered most important: macro and micro minerals, starch, polyphenols, chlorophyll a, chlorophyll b and carotenoids. The analysis showed that the techniques of shading studied are not advisable for a long stay (over 12-18 months) in plant nurseries. In fact, some species have shown adaptability to shading, as in the case holm oak, cork oak and buckthorn. Other species have proven tolerant of shade lower rates, such as mastic tree, phillyrea, carob tree and holly, and cannot be excluded that under such conditions the plants can persist for longer periods than the shading thesis to 60 and 70%.