Abstract
Abstract Greenhouse tomato cultivation faces challenges such as nutrient imbalance and declining soil health, requiring sustainable biostimulant strategies. Objective: This study aimed to evaluate the synergistic effects of humic acid (HA) and arbuscular mycorrhizal fungi (AMF) on tomato growth, yield, and nutritional quality. Tomato plants were subjected to four treatments: control, HA alone, AMF alone, and combined HA+AMF. Growth parameters, biochemical composition, and mineral content were analyzed. Results: The combined HA+AMF treatment significantly enhanced shoot length (+50.4%), root length (+32.1%), fruit yield (+415.2%), and lycopene content (+395.3%) compared to the control. Increases in proteins, sugars, flavonoids, and key minerals (K, P, Mg) were also observed. Molecular analysis confirmed upregulation of stress-related and nutrient transporter genes. The HA+AMF synergy markedly improves tomato productivity and fruit quality, offering an eco-efficient solution for sustainable agriculture in semi-arid conditions..