Cumbers of a parthenocarpic variety Marinda F₁ were grown in the field under protective shields, i.e. a perforated PE sheet and PP needled cloth (17 g·m^-2), during the years 2001–2003. Unshielded plots served as the control treatment. It was found that the concentrations of nitrogen, calcium and iron increased significantly in cucumber plants grown under PP needled cloth. The edible parts of cucumbers were characterized by widened K : Ca, K :  (Mg+Ca) and K :  Mg ratios, as well as by favorable Ca :  Mg ratios.

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