Enhancing Secondary Compounds in Strawberry Fruit Through Optimized Irrigation and Seaweed Application

This study aimed to assess the influence of seaweed application in combination with different irrigation water levels on secondary compounds in strawberry fruits. To achieve this, four irrigation water levels (1-IR125: 125 % of the control treatment; 2-IR100: the control treatment; 3-IR75: 75 % of the control treatment and 4-IR50: 50 % of the control treatment) were used. These levels were tested in plots both with and without the application of a seaweed-based biostimulant. This research focused on evaluating the variations in individual sugars and acids, total monomeric anthocyanin (TMA), total phenol (TP), total antioxidant activity (TAA), and important individual phenolic compounds contents in strawberry fruits subjected to different treatments. Biostimulant application had no significant effect on the levels of fructose, glucose, ferulic acid, TMA, TP, and TA (p>0.05). However, under water stress conditions, the application of biostimulant led to a significant decrease in ellagic acid, sinapic acid, caffeic acid, (+) catechin, (-) epigallocatechin gallate and quercetin, resulting in an increase in syringic acid, chlorogenic acid, p-coumaric acid, (-) epicatechin, rutin, cyanidin-3- glucoside, pelargonidin 3glucoside and pelargonidin- 3- rutinoside content. These results are expected not only to assist in optimizing the cultivation process but also to prove to be beneficial in obtaining high-quality strawberry fruits under water stress conditions when combined with biostimulant application.