Effects of zeolite on Aloe barbadensis Miller. grown under water stress conditions

Aloe barbadensis Miller. is one of the most economically important medicinal plants in many countries of the world. This investigation aimed at evaluating the effects of water stress and zeolite on growth, yield and chemical compositions of A. barbadensis. The study was conducted in the research greenhouse of Faculty of Agriculture, Tarbiat Modares University. The plants were harvested 90, 180 and 270 days after imposing the treatments. Water deficit stress decreased growth, leaf fresh and gel fresh weight and increased biochemical compounds. The results showed that the greatest number of new leaves and pup were produced by the plants irrigated 20% and 40% FC with 8 g zeolite, respectively. Generally, the highest leaf fresh and gel fresh weight were observed 270 days after imposing the treatments when plants were irrigated after depleting 40% of the FC and amendment with 8 g zeolite (624.13 and 397.17 g), respectively. The water use efficiency increased with less water and more zeolite availability. The highest water use efficiency of leaf and gel was obtained from the plants irrigated after depleting 60% of field capacity and treated with 8 g zeolite. In addition, the results indicated that the maximum aloin concentration (23.48%) and proline accumulation (0.85 (mg [g FW]-1) were obtained 90 days after imposing the treatments when the plants were irrigated after depleting 80% and 60% of FC where no zeolite was applied, respectively. Irrigation after 80% depletion of FC without zeolite application resulted in the highest fructose and glucose content, respectively (234.71 and 79.83 mg g DW−1). In general, application of zeolite could alleviate water stress adverse effects, and improved plant growth and yield. Severe water stress decreased leaf yield and plant growth, while caused an increase in biochemical compounds.