The effect of Trichoderma harzianum on the biochemical properties and ‎photosynthetic pigments of basil under drought stress ‎

To evaluate the effect of Trichoderma application under drought stress conditions on biochemical properties and photosynthetic pigments of basil, an experiment was conducted in a completely randomized design with three replications. The studied treatments included 3 levels of irrigation (50, 75, and 100 Percent of field capacity) as the first factor and inoculation with Trichoderma (concentration 108) and non-inoculation with Trichoderma as the second factor. The results showed that the highest fresh and dry weight of leaves was observed in the treatment of irrigation area of 100 Percent of field capacity without the use of Trichoderma (control). Wet weight (17.69 Percent) and dry stem (17.27 Percent), chlorophyll a (0.66 Percent), chlorophyll b (0.64 Percent), total chlorophyll (0.66 Percent), proline(52/25 Percent) and the relative content of leaf water (1.37 Percent) in the irrigation level treatment of 100 Percent of field capacity along with the application of Trichoderma increased compared to the control and the amount of electrolyte leakage (7.5 Percent) in the treatment of 100 Percent of field capacity Decreased with the use of Trichoderma compared to the control.. The amount of carotenoids (31.74 Percent) and antioxidant activity (17.22 Percent) in the irrigation surface treatment of 50 Percent of field capacity with the use of Trichoderma were observed more than the control. According to the results, the application of Trichoderma harzianum increased proline, soluble carbohydrates, photosynthetic pigments, and antioxidant activity of the plant under different irrigation levels.