Effects of arbuscular mycorrhizal fungi and organic fertilization on growth, flowering, nutrient uptake, photosynthesis and transpiration of geranium (Pelargonium hortorum L.H.!Bailey 'Tango Orange')

Greenhouse experiment was conducted to evaluate the effect of arbuscular mycorrhizal fungi (AMF) and organic fertilization on growth, flowering, nutrient uptake and some physiological traits of geranium. The roots of inoculated plants were colonised by mycorrhizal fungi regardless of preplant organic fertilization. Mycorrhizal inoculation increased the height of plants, irrespectively of organic fertilization. In plants unfertilised organically mycorrhizal inoculation increased leaf number, fresh and dry weight of leaves and roots. Mycorrhizal inoculation did not affect the numbers of flower buds and flowers but delayed flowering of plants unfertilised before planting. N, P, and K concentrations in the plants were higher in the mycorrhizal plants compared to the non-mycorrhizal ones when plants were not fertilised before planting. Transpiration and stomatal conductance were higher in mycorrhizal plants grown under lower level of organic fertilizer. Increased photosynthetic activity of mycorrhizal plants was connected with the increased ratio of variable to maximum chlorophyll fluorescence (F-v/F-m), which is directly proportional to the maximum quantum yield of primary photochemistry of PS II.