Prevention of drought damage through zeolite treatments on Vitis vinifera: A promising sustainable solution for soil management

Viticultural activity is intrinsically interlocked with climatic fluctuations and awful subjected to soil management. Increasing temperatures and reduced precipitation originate several alterations in the metabolic plant pathway and a depletion in grapes quality. The main aspiration of soil management is to keep and retain a microenvironment that considers all vine requirements to upgrade the balance between vegetative growth and cluster quality intensifying its resilience towards abiotic stress. Aiming to establish match and dissimilar drought stress responses among Sangiovese grapevines, we scouted ecophysiological and biochemical alterations after zeolite and irrigation soil application (combined and/or alone), using as control plants naturally exposed to abiotic stress in a Chianti Classico vineyard. When grapevines were exposed to water stress alone, the main reactions encompassed dwindled leaf midday water potential (Ψleaf) and increased proline content. These were accompanied by augments in zeaxanthin and lutein leaf contents, symptomatic of oxidative stress. Positive metabolic alterations in grapes triggered by zeolite and/or water showed some influence on the ripening of the berry differently depending on the year. They created a situation of resilience in berry avoiding arrest in the anthocyanin synthesis pathway during the warmest season and produced a more balanced maturation, closer to the objectives of the modern producer of classic Chianti (i.e. fresher and less alcoholic wines) during the fresher one. Under severe drought, it was activated the shikimic acid pathway and in stressed vines treatment, (WS) a reduction in malic acid content was found. Sugar and phenolic compounds were enhanced by zeolitic and undrought treatments. A negative effect enkindled by the drought and high temperatures combined with stress was the accumulation of quercetin-3- O-rutinoside (Qrut), quercetin-3-O-galactoside (Qgala), quercetin-3-O-glucoside (Qgluc) and quercetin-3-O-glucoronide (Qgluco) in WS treatment. These results summarize that clinoptilolite applied to the soil, both combined with water as well in purity, noteworthy protectorship from more detrimental repercussions of drought-stressed grapevines, suggesting that new sustainable approaches in soil management are useful for the wellness of vines.