Effect of zeolite on biochemical and physiological properties of coriander (Coriandrum sativum L.) under water deficit stress

The aim of this experiment was to investigate the effect of zeolite on biochemical and physiological properties of coriander under drought stress in factorial form in a randomized complete block design with 4 replications during the two cropping years of 2017-2018 and 2018-2019. Drought stress at 3 levels (including: 100% water requirement (no stress), 75% water requirement (mild stress) and 50% water requirement (severe stress)) and zeolite consumption at 5 levels (no use, 2, 4, 6 and 8 t. ha-1 of zeolite) were applied. The results showed that the water deficit stress decreased plant height drought, fresh and dry weight of shoots significantly; However, with the application of zeolite, the effects of stress were somewhat reduced. The highest and lowest shoot dry weight was obtained, in normal irrigation (without stress) with the use of six tons of zeolite per hectare (2.99 g. plant-1) and in drought conditions (50% water requirement) without the use of zeolite (1.22 g. plant-1), respectively. Reduction of irrigation also increased proline, while application of zeolite reduced drought effects slightly. Normal irrigation and consumption of six tons per hectare of zeolite showed the lowest amount of proline and severe stress (irrigation 50% of water requirement) and non-consumption of zeolite showed the highest amount of proline. In general, it was gained an acceptable economic yield in the coriander plants by applying mild stress (75% of water requirement) and using six tons per hectare of zeolite, as well as reduces the effects of stress.