Development of sustainable strawberry production in closed cultivation systems: Effects of bagasse biochar on morphological and physiological attributes, yield and autotoxic changes.

Strawberry is considered one of the most important small fruits with a high nutritional content. Nowadays, it is cultivated globally using various greenhouse cultivation techniques, adapting to different climatic conditions. Meanwhile, it is essential to address challenges in closed hydroponic systems and finding effective solutions to enhance the production and to lower the level of autotoxin materials in the root substrate. An experiment was conducted to examine the response of three commercial strawberry cultivars (Paros, Camarosa, and San Andreas) to the application of biochar (0 and 5%) under a closed hydroponic system. The parameters examined in this study included growth and yield, gas exchange indicators, photosynthetic pigments, some fruit biochemical attributes, and the level of benzoic acid in the runoff. The interaction effect of the cultivar and biochar revealed that the Paros cultivar cultivated in a biochar medium exhibited the highest values for total chlorophyll content (50.83 mg g FW), fruit number (11.66), fruit weight (17 g), yield (198.59 g plant), and antioxidant capacity (49.32%). Meanwhile, the San Andreas cultivar, cultivated in a biochar medium, displayed the highest firmness (7.11 N), TA (0.97 mg CA 100 g FW), TSS (10.83%), pH (4.11), and vitamin C (17.35 mg AA 100 g FW), while in the absence of biochar, it had the highest Zn content (0.50 mg kg). The Camarosa cultivar cultivated in biochar substrate presented the highest Fe (9 mg kg) level. Additionally, the application of biochar led to a reduction in benzoic acid concentration in the runoff water compared to non-biochar approach. Overall, selecting an appropriate cultivar and application of biochar in closed hydroponic systems can reduce autotoxicity, thus enhancing growth and yield.