Nitrate content in wild rocket cultivated in the province of Udine (Northern Italy) by employing different growing techniques

Known data related to nitrate levels in wild rocket can hardly be compared. Infact, results may be influenced by a large number of parameters (temperature, luminosity, types and amounts of fertilizers and/or manure employed in soils, characteristics and composition of irrigation water and/or of nutritive solutions used for hydroponic growing, variety of vegetable grown, etc.). All these parameters play animportant role as far as plant metabolism is concerned, and therefore may significantly influence nitrate accumulation. Our research was carried on by limiting as much as possible variability parameters as climatic conditions, luminosity, genetic factors. Wild rocket was cultivated for two consecutive years in four farms of the province of Udine (Northern Italy) operating with different growing techniques (namely, conventional, organic, biodynamic and hydroponic techniques). Nitratelevels were determined in the product ready for commercialization obtained from spring, summer and autumn cultivations, in order to minimize the influence of the growing period. The hydroponic system showed the highest nitrate values, sometimes higher than current legislation limits. In the case of conventional, organic and biodynamic methods, nitrate values were always far below current legislation limits.