During 2021 and 2022 seasons, Flame seedless grapevines were treated three times with chitosan at 100 to 400 ppm and / or seaweed extracts at 0.05 to 0.2% . The merit of this study was examining the effect of single and combined application of chitosan and seaweed extracts at different concentration on growth, vine nutritional status, yield as well as physical and chemical characters of Flame seedless grapes.
Spraying the vines with chitosan at 100 to 400 ppm and / or seaweed extracts at 0.05 to 0.2% three times during season was very effective in enhancing growth aspects, leaf pigments and nutrients, yield and both physical and chemical characteristics of the berries over the control treatment. The promotion was associated with increasing the concentrations. Negligible promotion on these parameters was observed among the higher two concentration. Using chitosan was greatly superior than using seaweed extract in all parameters.