The effects of seaweed extract and amino acid fertilizers on growth and productivity of two grape (Vitis vinifera L.) cultivars.

The effects of two concentrations of seaweed extract (15, 30 ml L−1) and amino acid fertilizer (10, 20 ml L−1) were tested on some growth, productivity and sustainability traits of Thompson Seedless and Olivette Noire grape vines with five years old in a RCBD experiment with three replicates in Which treatments were evaluated independently to assess their individual effects on grapevine performance. No significant difference was observed between cultivars for studied traits. The fertilizer levels (seaweed and amino acid), especially 20 ml L−1 amino acid positively influenced the yield, chlorophyll content, and vegetative and reproductive attributes except number of leaves, 100 berry volume and weight, as well as TSS content. Application of 20 ml L−1 amino acid significantly were increased number of leaves vine, leaf area, vine leaf area, dry weight of leaves, number of clusters per vine, cluster length, cluster width, cluster weight, and number of berries in the cluster, as well as volume of 100 berries, total yield per vine, total chlorophyll in leaves, and TSS value in the Olivetti Noire cultivar as well as Thompson Seedless compared to control. PC analysis confirmed the results of mean comparisons. The results of correlation estimation and regression, revealed a tightly coordinated structure among vegetative and yield-related traits under the applied treatments. According to the results, the use of amino acid 20 ml L−1 is recommended as a superior treatment and a proper stimulant to improve the grape growth and fruit yield of these two grape cultivars. Overall, the results highlight amino acid application as the most effective factor under the conditions of this study.