The effects of innovative silicon applications on growth and powdery mildew control in soilless-grown cucumber (Cucumis sativus L.) and zucchini (Cucurbita pepo L.)

Silicon (Si) is one of the most beneficial microelements for several plants, in mediating the growth regulation in horticultural species. This research evaluated the effects of innovative Si-applications on. soilless-grown Cucumis sativus L. and Cucurbita pepo L. Crop growth, powdery mildew incidence and abiotic stress resistance were evaluated. Two experiments were carried out in a nonheated glasshouse on benches. Two new Si treatments (Si–Nanosponge complex, and one experimental fertilizer) were compared with the traditional K2SiO3. Topas EC 10 was used as control fungicide treatment. Biometric parameters, and incidence and severity of powdery mildew were measured. Cucumis sativus plants showed a severe powdery mildew infection, and no significant effect of the Si treatments was found. Cucurbita pepo plants were initially grown under lower disease pressure conditions, and the positive effect of Si treatments was found. The innovative use of Si–Nanosponge complex and the new experimental fertilizer can be considered a good alternative to traditional compounds for plant growth stimulation.