Understanding natural zeolite´s (clinoptilolite) mode of action on grapevines leaves under drought

The project aims to reveal the possible mechanisms of stress reduction in plants by zeolite clinoptilolite (the most abundant natural occurring zeolite) observed by empirical data. The central hypothesis of the project is that the fine zeolite clinoptilolite particles when sprayed onto the plant leaf surface form a light particle film, that is able to maintain leaves cooler (light colour reflecting radiation) and reduce heat stress, while aiding the plant's stomata to optimally gain carbon for photosynthesis (i.e., increased water use efficiency). By setting an experiment under controlled conditions, the project aim to fully understand the mode of action of the zeolite clinoptilolite in order to develop concrete application recommendations for farmers for the specific problem of heat and drought stress in viticulture. Considering all the above, the project will (i) generate an understanding of natural zeolite´s (clinoptilolite) mode of action on grapevines leaves under drought (ii) determine the clinoptilolite application impact on grapevine ecophysiology under environmental controlled conditions (iii) determine the clinoptilolite capacity to improve grapevine performance under drought (iv) clarify the possible mechanisms involved in the stress relief capacity of clinoptilolite when applied on grapevine leaves under drought (v) assess the eventual capacity of zeolite in aiding grapevine functionality recovery after drought To do so, the project will setup an experiment under greenhouse-controlled conditions on potted grapevines to impose drought on plants previously treated with clinoptilolite or not. The experiment will encompass the entire grapevine growing cycle (ca. 6 months) and a frequent monitoring of eco-physiology parameters such as the rate of gas exchange, PSII photochemistry efficiency, and plant water status.