Studying The Interaction between Drought Stress and Ascorbic Acid on Growth Analysis and Biochemical Responses of Tagetes erecta Plants Grown under Various Growing Media

: The goal of this study was to assess the effect of the interaction between ascorbic acid application as a foliar spray, growing media, and irrigation rates on the development, flowering, and chemical constituents (chlorophyll, carotenoids, and proline) of Tagetes erecta , L. plants. Three replicates in a split-split plot experimental design were employed during both seasons. The main plot was the various growth media [75% calcareous soil + 25% peatmoss (v/v) or 75% sand + 25% peatmoss (v/v), or 25% sand soil + 25% calcareous soil + 50% peatmoss (v/v)]. Three irrigation intervals were utilized in the subplot (daily as normal stress, three days as mild stress, and six days as severe stress). The sub sub-plot displayed Ascorbic Acid (As.A) solution as foliar spray three times per season at T 0 (tap water), T 1 (100 mg l -1 ), and T 2 (200 mg l -1 ).Results revealed a substantial interaction between varied potting media, irrigation intervals, and ascorbic acid applications. The most beneficial growth (plant height, leaves and branches numbers, and leaves dry weight/plant) and flower quality (flower number, diameter, as well as dry weight) resulted from using growing media of (75% sandy soil + 25% peatmoss (v/v) or 25% sandy soil + 25% calcareous + 50% peatmoss (v/v) in addition to irrigating every three days as moderate stress. The chemical components of leaves also increased significantly, such as proline, total chlorophyll and carotenoids content. The findings of this investigation also showed that ascorbic acid increased plant resistance to water stress and decreased the harmful effects of stress.