Trattamenti fogliari con Arthrospira platensis in viticoltura: primi risultati da esperimenti in campo

Abstract

Biostimulants are increasingly assuming a key role in viticulture, thanks to the well-known ability to influence the physiological behavior of plants, promoting the quality of the grapes and improving vine response to abiotic stress. Seaweed extracts are among the most used and studied biostimulants, while there are very few cyanobacterial-based biostimulants currently available on the market. This work had the purpose of investigating the effects of an extract of Arthrospira platensis on eco-physiology, water potential, yield and quality of grapes in Vitis vinifera Experiments were conducted in open field (seasons 2017 and 2018) in Tuscany, carrying out foliar treatments with the A. platensis extract 20 days and ten days before the expected harvest. Following the treatments, gas exchanges and water potential were monitored, and berry samples were collected to evaluate the technological and phenolic quality of the grapes. In general, the treatments only marginally influenced gas exchanges and water potential, with diversified results in relation to the seasonal climatic trend (2017 season, hot and drought; 2018 milder season), indicating a more conservative behavior of the treated vines compared to the control vines. In addition, A. platensis always increased the berry weight, maintaining unchanged or improving the technological and phenolic quality of the grapes at harvest compared to the control. Although no univocal response to treatment emerges, the results globally suggest a positive impact of the leaf distribution of A. platensis on the eco-physiology and quanti-qualitative characteristics in V. vinifera candidating cyanobacteria for the formulation of new biostimulants.