Effect of Humic acid, Mycorrhizal Fungi and Madder Residue on Some Growth Characteristics and Nutrient Uptake of Evening Primrose (Oenothera biennis L.) Under Salt Stress

In this study, effects of humic acid, mycorrhizal fungi and madder residue on some growth characteristics and nutrients uptake of evening primrose (Oenothera biennis L.) were investigated under soil salinity stress. The experiment was conducted as factorial based on a completely randomized design. Six levels of fertilizers including control (without soil amendments), 1.5 and 3 g L-1 mycorrhizal fungi, 16 and 32 mg L-1 humic acid, and 25% v/v madder residue were used in the presence ofthree levels of soil salinity (4, 7, and 12 dS m-1) with three replications. Results showed that in salinity of 4 dS m-1 the maximum number of flowers, flowering duration and dry weight of flowers were obtained in 32 mg L-1 humic acid. In salinity level of 7 dS m-1 the treated plants with 1.5 mg kg-1 mycorrhizal fungi showed the maximum number of flowers, flowering duration, and the highest uptake of Na, K and P. In salinity level of 12 dS m-1 the maximum number of flowers, dry weight of flower, total protein, peroxidase activity, and the lowest Na uptake were observed in plants treated with madder residue. Using organic and biological fertilizers induced flowering in salinity of 12 dS m-1. Generally, all organic and biological fertilizers treatments in all salinity levels caused increasing growth and yield of plant.