Valutazione economica del ruolo del triciclazolo nella risicoltura italiana

Rice is a highly valuable national product but in the Northern Italian areas dedicated to its production it is seriously affected by rice blast, a disease induced by the pathogenic fungus Magnaporthe oryzae. The main way to control the disease is by using fungicides. Since the early 90’s in Italy fungicides containing tricyclazole and azoxystrobin were authorized. If fungicides against the rice blast were not used there would be an estimated average reductions in yield of 40%. The negative outcome of the European review of tricyclazole resulted in the withdrawal of national authorizations. Thanks to the Italian rice growers’action, in 2010 and 2011 the emergency use of tricyclazole was authorized, waiting that a new European evaluation process is initialized. The present study, starting from analyzing the importance of rice in Italy, describes rice blast spread and damages on different rice varieties, analyses the possible defense strategies and their adoption by the rice-growers. From such information, through a scenarios simulation, we outlined the potential impact on rice cultivation in case of eventual tryciclazole exit from the market and in case of possible complete lack of agrochemicals effective on rice blast if azoxytrobin remaining the only fungicide applied on the entire surface and leading to resistance in the pathogen population.