Effect of arbuscular mycorrhiza (Glomus mosseae) on growth of greenhouse cucumber (Cucumis sativus cv. Nahid) under different levels of sodium bicarbonate in irrigation waterte

To study the effect of arbuscular mycorrhiza (Glomus mosseae) on growth of greenhouse cucumber (Cucumis sativus cv. Nahid) under bicarbonate stress originated from irrigation water, a completely randomized design was adopted in an experiment with four levels of bicarbonate in irrigation water (0, 400, 800 and 1200 mg/L), two levels of mycorrhiza (inoculated and un-inoculated plants) with five replications. Results showed that vegetative growth parameters (dry weight of root, stem and leaf, stem height and diameter, leaf number and surface area) of plants were reduced with increasing bicarbonate concentration, especially at 1200 mg/L, where more than 50% reduction in root and leaf dry weight was observed. Bicarbonate concentration above 800 mg/L caused around 50% reduction in stem dry weight and leaf area. Arbuscular mycorrhizal fungi had a prominent effect on maintaining of vegetative growth under bicarbonate stress, especially at 1200 mg/L. It can be concluded that vegetative growth of cucumber plant is reduced by bicarbonate stress and mycorrhizal symbiosis can ameliorate the adverse effects of bicarbonate.