Sustainable Agricultural Practices in Disease Defence of Traditional Crops in Southern Italy: The Case Study of Tomato Cherry Protected by Trichoderma harzianum T-22 Against Cucumber Mosaic Virus (CMV)

Nowadays, crop production is at risk due to global warming, especially in Mediterranean areas where the increase of air temperature and/or reduction of precipitation is relevant. Climate changes that are occurring can severely prejudice plant defensive mechanisms during host-pathogen interactions by modifying growth and physiology of the host plant. In particular, viral diseases cause serious economic losses destroying crops and reducing agronomic productivity, and, in some cases such as tomato crops, they become the limiting factor production of both open field and under greenhouse cultivation systems. This is because plant viruses are obligate parasites and require living tissue for their multiplication and spread. Therefore, they are able to interfere with plant metabolism and compete for host plant resources, so determining a decrease of plant growth and productivity. Severe outbreaks of Cucumber mosaic virus (CMV) and other viruses caused disruption of tomato plants in the Mediterranean region and in Southern Italy since the 1970s. In such a scenario, it is necessary to introduce new strategies for controlling plant pathogens and parasites in order to help maintain ecosystems and to boost sustainable agriculture. The aim of this work is to give an up-to-date overview on the recent breakthroughs in the use of microorganisms on plants for improving crop yields, quality and plant tolerance against pathogens. In particular, here we report a case study regarding an innovative strategy to control a viral disease (CMV) in tomato, based on the use of rhizosphere microorganism (Trichoderma harzianum, strain T-22) as an antagonist biocontrol agent (BCA).