Iran has a dry and semi-arid climate and lack of water is one of the main problems of Iran's agriculture. Therefore, the occurrence of drought stress during the growth period of plants is inevitable. One of the solutions to reduce the harmful effects of drought stress is to add organic compounds to the soil, which improves the soil and improves the soil
structure. One of these compounds that can be called organic matter is biochar. This research was conducted in order to investigate the effect of using biochar on plant tolerance and overcoming drought stress and their effect on the growth characteristics of Ahar flower in open space in the suburbs of Bushehr city. This research was conducted in
a factorial manner and in the form of a completely randomized design, and the effect of using biochar prepared from Sargassum sp. was evaluated in two separate experiments under irrigation conditions of 50% and 100% of the agricultural capacity and also with the use of vermicompost organic fertilizer. were compared under similar conditions. Test
factors including biochar prepared from Sargassum algae were applied in four mass ratios (B4) 4, (B6) 6, (B8) 8 and (B12) 12 g/kg agricultural soil in three replicates. The treatment of 100% of agricultural soil as a control and the mixture of agricultural soil and vermicompost with ratios of (V20) 20, (V25) 25, (V30) 30 and (V40) 40 grams in one
kilogram of soil is also considered as a comparative treatment. and in order to apply irrigation stress, each of the treatments will be irrigated at two levels of 100% and 50% of the agricultural capacity. According to the obtained results, there was a significant difference in all the measured traits except for the number of nodes and leaves, and the
highest yield was related to the application of vermicompost fertilizer at the rate of 40
grams per kilogram. And the lowest amount related to the control treatment. According to
the obtained results, the characteristics of the number of days of