Studio di metodi non invasivi, a basso impatto ambientale, per la somministrazione di fungicidi su piante arboree ornamentali.

The phytosanitary defense has become necessary for the safeguard of urban green areas because the plants are more and more susceptible to biotic adversities potentially compromising their survival, the stability and the esthetic value. The most commonly used in urban environments are plane trees, limes, hackberry, maples, horse-chestnuts and pines. The presence of these species in crowded areas, such as parks and public gardens, is the main obstacle in the application of phytosanitary treatments. In fact, the traditional methods of pesticides administration (such as foliage treatment ), are often difficult to apply in these contexts. Instead, the endotherapic treatments have a greater effectiveness and persistence of action with a lower environmental impact. However, they are very costly and limited to a small number of specific products, and the methods of application must be further tested. In this study, therefore, an innovative method of administration based on the absorption of pesticides through the trunk, using a cortical carrier (Pentra-bark®), was tested. This carrier is a superior nonionic wetting agent, designed for decreasing the surface tension and improving the traslocation of systemic fungicides through the vascular system of plant, and allowing to reduce the amount and dispersion of active principle into environment. The efficiency of this carrier has been tested through trunk application with the following preventive treatments : Tetraconazolo against Guignardia aesculi on horse-chestnuts, Thiabendazole against Apiognomonia platani on plane trees, Thiophanate methyl against Ceratocystis fimbriata on plane trees and against Sphaeropsis sapinea on black pine. The preliminary results obtained are not encouraging. In fact, the plants inoculated with pathogens and treated with fungicides combined with the carrier have shown an evolution of disease symptoms similar to that of the untreated plants.