Influence of cover type and training method on yield and quality of "organic" muskmelon

Research was carried out in 2002 and 2003 in the province of Salerno on muskmelon (Cucumis melo L. var. reticulatus) grown organically with the aim of identifying the most effective environment for yield and quality. Six treatments, obtained by factorial combination of three cover types (polytunnels covered only with COPEVA film, as the control, or equipped, in addition, with 25% or 35% white shading nets) and two training methods (traditional or vertical) were compared. A split-plot design with three replicates was arranged and the subplots, in which training methods were placed, covered a 48.0 m2 (4.0 x 12.0 m) surface area on which 48 plants were spaced 1.0 x 1.0 m (1.0 plant per m2). The cover type did not have significant effects on mean yield components. The traditional training method was more effective than the vertical one, giving higher values of both the number of fruits per plant and their mean weight. In comparison with the fruits obtained from the 35% shaded environment, those harvested from the control tunnels displayed higher values of the residues (dry and optical) and the analysed organic substances as well as the cation concentrations and a more intense colour; similarly, most of quality characteristics showed higher values when the vertical training was adopted. The exceptions are represented by vitamin C, within the organic compounds, which did not vary in relation to the factors tested, and the nitrates, which reached the maximum accumulation in the most shaded conditions and with the traditional training method, but at very low levels.