Effects of EC-level and plant shading on N.F.T.-grown �Friariello� pepper.

We report the results of research carried out in Campania in 2002 and 2003, during winter-summer period, with the aim of determining the production of Capsicum annuum L. var. Longum, also known as “Friariello” (local cv Nocera) grown under double plastic film (IR-PE) polytunnels with the nutrient film technique. Comparisons were made of four nutritive solutions differing in electrical conductivity (EC) levels (3.5, 3.8, 4.1 and 4.4 mS•cm-1), in factorial combination with crops arranged in pairs on two vertical overlapping layers; a split-plot design was arranged and each randomised treatment included 12 plants with three replications. Plants were placed on gullies through a pierced white PE film which prevents algae diffusion. A pepper control crop was grown in the same tunnels with the current technique, i.e. with plants spaced 30 cm apart along the row and in double rows 40 cm apart (achieving the same density of 5.3 plants per m2 as with the NFT) on black PE mulched ridges (80 cm wide). Due to the shade, the crop placed on the lower level was negatively affected with regard to yield, where the reduced fruit number caused a 37% mean decrease. Of the salinity treatments examined, those based on nutrient solutions with 3.8 mS•cm-1 EC gave the highest yields, within the higher crop level, whereas the 4.1 mS•cm-1 EC gave the best results with regard to the lower layer; these two treatments, overall and in relation to the net unit surface area, exceeded the control by about 70%. Daily water and ionic absorptions attained the highest intensities in the second decade of June, corresponding to the maximum fructification rate; in this phase, the absorption of most of the analysed nutrients was higher with the 3.8-4.1 mS•cm-1 EC range for the upper layer and 4.1-4.4 for the lower one.