The Effects of Drought Stress and Super Absorbent Polymer on Morph-physiological Traits of Pear millet (Pennisetum glaucum)

ABSTRACT: The objective of this study was to determine the effect of different rates of Super Absorbent Polymer and drought stress on water use efficiency (WUE), yield and some morph-physiological traits in pear millet. Factors were considered as four levels of irrigation (I1to I4) and three levels of super absorbent polymer (S1to S3). Before planting, super absorbent polymer was added to the soil of pots in deepness of root development. Drought stress was applied in four leaf stage. For stress application, the pots were weighted every day, then, irrigated with the water content at field capacity (FC) at 100, 80, 60 and 40 (%), respectively. Analysis of variance showed that the effects of treatments were significant on all of the studied traits. The interaction effects of two mentioned factors were not significant. The results indicated that water stress significantly decreased the number of leaves per plant, chlorophyll content, dry weight, relative water content (RWC) and Water Use Efficiency (WUE) in pear millet, whereas the application of super absorbent polymer compensated the negative effect of drought stress, especially in high rates of polymer application [ 0.2 (%)and 0.4 (%)(g/kg)]. These mentioned rates of polymer had the best effect to all of the studied traits. These findings strongly suggested that the irrigation intervals of millet could be increased by application of super absorbent polymer.