Journal of Plant Process and Function

The present investigation was designed and carried in order to study the effects of nitrogen and phosphorus biofertilizers on some morphophysiological and reproductive characteristics, of two pea (Pisum sativum L.) varieties under different irrigation regimes, for two years. This experiment was conducted as a split-split plot based on a randomized complete block design with three replications. The main plots were allocated to irrigation treatments including: irrigation after 50, 75 and 100 mm (I1, I2 and I3, respectively) cumulative evaporation from class A evaporation pan and the sub plots were allocated to different source of biofertilizers treatments including: control (no biofertilizer), Azotobarvar-1, Phosphatebarvar-2 and Azotobarvar-1 + Phosphatebarvar-2. Sub-sub plots were allocated to two varieties of peas (Majarestani and Wolfholland). Drought stress led to a significant decrease in biological yield in two mentioned varieties (especially in Wolfholland variety), through reducing the shoot dry weight, leaf relative water content, and also increasing the malondialdehyde concentration and leaf electrolyte leakage. Majarestani variety was more tolerant to drought stress with more effective use of defense systems Such as: higher level of proline content and antioxidant enzyme activities. Biofertilizers played an effective role in reducing the adverse effects of drought stress. Biofertilizers improved biological yield by increasing the shoot dry weight, leaf relative water content, proline content and antioxidant enzyme activities in both varieties, especially in Majarestani variety. Generally, Majarestani variety due to its more tolerant to drought stress conditions is recommended for cultivation in areas with the terminal drought stress. The application of biofertilizers (especially the integration of nitrogen and phosphorus biofertilizers under mild and severe drought stress conditions) is also a promising approach to adapt to drought stress conditions in such areas.