Conclusions
Recent scientific investigations have focused on improving sustainable farming practices that stabilise yield under optimal and suboptimal conditions and comply with changing legislation regarding the application of low-input agrochemicals. Microbial-based biostimulants (AMF and/or Trichoderma ) may sustainably enhance crop productivity. Our greenhouse experiment on pepper confirmed that inoculation with a combination of AMF and Trichoderma increased fruit yield by 23.7% relative to that of the untreated control. A metabolomics analysis revealed that the biostimulant treatment reprogrammed the plant metabolome. Hence, several biochemical processes underly the observed increase in fruit yield. Here, we disclosed that the biostimulant modulated the phytohormone profile and induced secondary metabolism. Specifically, the microbial-based biostimulant upregulated compounds such as carotenoids, saponins, and phenolics that participate in plant nutrition, defence and stress response. Thus, the results of the present study confirm that biostimulant amendments favour stable increases in fruit yield and lead the way towards future investigations into their effects on plants under challenging conditions such as abiotic and biotic stress, environmental perturbations, and physicochemical imbalances.