Silicon fertilization of plants improves yields and increases plant resistance to various stress factors. The use of silicon in plant fertilization is particularly justified in soilless culture. The aim of the present study, conducted in 2009-2010, was to determine the effect of root application of silicon in the form of silica sol and two growing media with a different content of silica on the yield and chemical composition of fruit and leaves of greenhouse cucumber cv. Unicum F1. Plants were grown in 10 dm3 cylinders filled with sphagnum peat (I) or peat mixed with large-grained river sand at a ratio of 3:1 (v/v) (II). Different rates of silicon were applied in the study: 0, 250, 500 or 750 mg dm-3 Si. The study demonstrated a significant increase in cucumber fruit yield when plants were fertilized with silicon by root application at the rates of 500 and 750 mg dm-3 Si, compared to control plants. Cucumber grown in peat with the addition of sand (v/v 3:1) produced significantly fewer fruits compared to its culture in peat alone, but these fruits contained more total soluble solids. Significantly more silicon and less calcium were found in leaves of cucumber root fertilized with silicon compared to control plants. Fruits of cucumber plants fed with silicon by root application contained more dry matter, total soluble solids, and silicon as well as less zinc and copper compared to fruits of control plants.

18.3.2013