Investigating Effect of Water-superabsorbent Polymer on Growth and Leaf Relative Water Content in Foxtail Millet (Setaria italica) under Drought Condition

Drought is one of the most important environmental stresses in agroecosystems. In order to determine the optimum level of water-superabsorbent that can reduce drought effect on growth traits in foxtail millet, an experiment was conducted as a factorial based on completely randomized design at Research Greenhouse, College of Agricultural Science and Engineering, Razi University. Different levels of drought included non-drought (short-term irrigation interval) and drought (long-term irrigation interval). Different rates of superabsorbent included 0, 0.2, 0.4 and 0.8 g per kg of soil. Results showed that non-drought with water-superabsorbent rate of 0.8 g per kg of soil produced the highest leaf dry weight, stem dry weight and seedling dry weight. Drought with non-application of water-superabsorbent produced the lowest leaf dry weight, stem dry weight and seedling dry weight. Application of water-superabsorbent increased leaf relative water content in foxtail millet. Drought increased chlorophyll index in foxtail millet, but application of water-superabsorbent decreased this index. In conclusion, the results show positive effect of water-superabsorbent on growth and dry matter production in foxtail millet under drought condition.