Avaliação da ação bioestimulante e antagonista de Penicillium citrinum no desenvolvimento inicial de Zea mays L.

Abstract

The search for sustainable alternatives in agriculture has encouraged the use of microorganisms with bio-stimulant and biocontrol potential. In this context, Penicillium citrinum stands out for producing metabolites capable of modulating plant growth and inhibiting phytopathogens. This study aimed to evaluate the potential of the P. citrinum MO2 isolate as a growth promoter in maize (Zea mays L.) and as an antagonistic agent against fungal phytopathogens. Three experimental systems were used: exposure to volatile organic compounds (VOCs) in glass jars; exposure to VOCs combined with direct inoculation in desiccators; and direct inoculation in trays containing autoclaved substrate. Shoot and root length, fresh biomass, and antagonistic activity against Fusarium sp. and Colletotrichum falcatum were evaluated through dual culture assays and discs containing fungal extract. In the glass jar system, VOCs did not promote significant differences in plant growth, although a qualitative increase in root branching was observed. In desiccators, high VOC concentration reduced shoot and root development, whereas direct inoculation resulted in growth comparable to the control. In tray assays, inoculated plants showed a tendency toward greater vigor, with higher mean values of length and biomass, although not statistically significant. In antagonism assays, P. citrinum inhibited the growth of Fusarium sp. and C. falcatum under direct confrontation, but the filtered extract did not produce inhibition halos, suggesting that antifungal activity depends on direct interaction or on metabolites with low diffusion in agar. The results indicate that P. citrinum MO2 shows potential as a plant bio-stimulant primarily through direct inoculation, and demonstrates relevant antagonistic activity under direct-contact conditions. These findings reinforce the potential of this fungus as a promising component in sustainable agricultural management strategies.