Emerging Ornamental Plant Diseases and Their Management Trends in Northern Italy

The ornamental plant sector is characterized by the production of a large variety of genera, species and cultivars that are much more numerous than those of other agricultural production sectors. Many countries throughout the world are involved in an intensive exchange of potted plants, cut flowers and propagation material. This intense trade exchange favors the introduction of the causal agents of new diseases on farms, in parks, along tree-lined avenues and in city gardens. Global warming can favor plant pathogens that thrive under high temperatures. Moreover, the interaction between the ongoing increase in temperature and in the CO2 concentration has caused a significant increase in the disease severity of many pathosystems. The numerous reports of new plant pathogens on ornamental plants in Italy in recent years fall into this context. In plant pathology research, living labs incorporate the complexities and variability of natural conditions, and they can thus be used to conduct experiments and test hypotheses. A private garden, located in the hamlet of Bariola (Piedmont, Biella province, northern Italy), has become an ideal living lab that is used to monitor the evolution of the phytosanitary situation of ornamental plants. The results obtained in this living lab are reported hereafter. Moreover, new trends in disease prevention and management, such as the adoption of appropriate prevention practices, water and fertilization management and use of environmentally friendly methods to reduce pesticide use as part of an integrated pest management approach, are also examined.