This study evaluated the effects of irrigation management and chitosan application in a field grown grapevine (Vitis vinifera L., cv ‘Primitivo’ N.) on physiological and productive responses. Factors were compared following a factorial experimental design (2x2n). Irrigation management (factor A) significantly affected stomatal conductance (gs), with irrigated (I) vines exhibiting approximately 30% higher gs than drought-stressed (D) vines and significantly reduced cluster fresh mass (- 18% g in D), yield (- 52% g in D), berry (- 15% g in D) and skin (- 9% mg in D) fresh mass. Chitosan application (factor B) did not significantly affect gs, yield, or berry ripening parameters. The interactions of factors showed a reduction of gs but only in D vines. The study showed that water restrictions could impact on gs and yield components without compromising berry quality. The preliminary outcomes about chitosan spray on grapevines at veraison, suggest that it could act as a short-term anti-transpirant without affecting vine yield and berry quality. Further in-field research is needed to assess chitosan’s role in mitigating water stress under severe water restriction restriction.
Nuzzo et al. (Wed,) studied this question.