Alternatives to methyl bromide in strawberry production in the United States of America and the Mediterranean region [Fragaria x ananassa Duch.]

Methyl bromide (MB) is a broad-spectrum soil fumigant, which has been critical in strawberry production for forty years. Strawberry and other high-value cash crops benefit from pre-plant soil fumigation with MB and chloropicrin (Pic). Mixtures of these two fumigants work synergistically in controlling a wide range of plant pathogens and pests, including fungi, nematodes, insects, mites, rodents, weeds and some bacteria. Methyl bromide was listed in 1993 by the Parties of the Montreal Protocol as an ozone-depleting compound. According to the Montreal Protocol, the import and manufacture of MB in the United States of America (USA) and other developed Countries will be banned by 2005, after stepwise reductions in 1999, 2001, and 2003. Currently, there is no single registered alternative fumigant for all of the MB uses and there is a need for environmentally sound and economically feasible alternatives. The fumigants 1,3-dichloropropene (l,3-D) and Pic in combination with methyl isothiocyanate (MITC) generators have shown to be the most promising alternatives to methyl bromide for strawberry production. Studies with the experimental fumigants methyl iodide and propargyl bromide suggested that these compounds have higher reactivity than MB as stand-alone fumigants. This review evaluates the commercially available and experimental alternatives to MB soil fumigation for strawberry production based on relevant scientific publications, proceedings and personal communications [Il bromuro di metile (MB) e' un fumigante ad ampio spettro del terreno, che e' stato fondamentale nella fragolicoltura per quaranta anni. La fragola e altre colture ad alto reddito traggono beneficio dalla fumigazione del terreno, prima dell'impianto, con MB o cloropicrina (Pic). Miscele di questi due fumiganti operano in modo sinergico nel controllo di un'ampia gamma di patogeni e parassiti delle piante, compresi funghi, nematodi, insetti, acari, roditori, piante infestanti e alcuni batteri. Il bromuro di metile e' stato inserito nel 1993, da parte dei firmatari del Protocollo di Montreal, nella lista dei composti che riducono l'ozono. Secondo il Protocollo di Montreal, l'importazione e la fabbricazione del MB negli Stati Uniti e in altri Paesi industrializzati verranno proibite a partire dal 2005, dopo riduzioni progressive nel 1999, 2001 e 2003. Attualmente non esiste un singolo fumigante registrato per tutte le utilizzazioni proprie del MB e vi e' quindi la necessita' di alternative sicure