Cultural technique influences on post-harvest quality of rocket (Eruca sativa Mill.)

Soilless culture system is a good technique of plant growth offering guarantees of quality to the current rocket (Eruca sativa Mill.) market. This leafy vegetable is often commercialized fresh, cut, washed, conditioned in packages as ready-to-eat food, giving added-value to the fresh products. They have a high commercial potential deriving from market opportunities based on meals on air crafts, trains and boats and on school- and elderly-meals. However, fresh cut sliced vegetables not only maintain their metabolic activities, but also show a higher respiration rate than whole vegetables. The aim of the research was to obtain rocket plants with good food characteristics and the best post-harvest shelf life optimizing different cultural techniques. The rocket was sown on 29 November 1999 and harvested on 7 February 2000. Trays of 40 and 160 cells were used, filled with two media made by different proportions of peat and perlite. Two irrigation systems were used (Ebb-and-Flow and Flotation) with two nutrient solutions containing 30 and 60 mmol L-1 N, respectively. The statistical design was a split-plot design with randomized blocks, with irrigation as main-plot factor and media x cell-tray x N as sub-plot factor. During post-harvest, leaf shelf life was assessed by fresh weight, and nitrate content was measured. The fresh mass was significantly influenced by the growing medium and by the interaction irrigation x cell number and N x irrigation. The best production was obtained using flotation and 40-cell trays. During post-harvest shelf life, the leaf loss of weight was significantly affected by the interaction growing medium x cell tray x N. The greatest loss of weight was found using 160-cell trays and 30 mmol L-1 N with both the tested media. Soilless culture resulted to be an efficient cultivation system to grow homogeneous, clean, marketable and of high quality rocket plants.