Water scarcity condition decreases the yield production of most important crops which leads alarming situation for food security worldwide. Drought stress reduces the growth and development up to 70% in different plants. Exogenously applied thiourea protected the plants by improving growth and yield in different plants. A pot experiment was conducted to estimate the role of thiourea as rooting medium treatment on different aspects of growth, yield, gas exchange, photosynthetic pigments, and availability of mineral nutrients under moisture stress condition in two varieties (FH-114 and FH-118) of cotton (Gossypium hirsutum L.) plant. After 49 days of sowing, the plants were applied with two drought stress treatments (normal watering and 60% field capacity) and three level of thiourea (water, 10 mM and 20 mM) applied after two weeks of drought stress (after 63 days of sowing) as root growing medium for this experiment. The completely randomizes design was used with each treatment replicated four times. In this research, water scarcity condition considerably decreased the growth parameters (such as shoot length, shoot fresh and dry weight), gas exchange parameters [such as net CO₂ assimilation rate (A), transpiration rate (E), stomatal conductance (g_s) and water use efficiency (A/E)], photosynthetic pigments (such as chlorophyll a, total chlorophyll and carotenoid contents), mineral ions (like potassium, calcium and sodium  of shoot) and yield attributes (such as number of bolls and seeds, weight of bolls and seeds and number of sympodial branches). Among different level of thiourea, 10 mM as root growing medium significantly improved the rate of CO₂ assimilation (A), conductance of stomata (g_s), water use efficiency (A/E) and yield attributes. While application of 20 mM thiourea increased the fresh and dry weight of shoot, stomatal conductance, chlorophyll a contents, total chlorophyll contents, mineral ions uptake of shoot and yield attributes. Among different levels of thiourea, 20 mM was better than other levels in enhancing the growth, photosynthetic pigments and yield attributes. Variety FH-142 performed better as compared to FH-942.

Keywords: Cotton, drought, thiourea, ions, yield