Physiological Response of Cape Gooseberry Seedlings to Three Biological Control Agents Under Fusarium oxysporum f. sp. physali Infection.

Cape gooseberry (Physalis peruviana) fruit has gained recognition owing to its nutritional value and versatility to be consumed processed or as a fresh product. These characteristics have made it an important product in both national and international markets. One of the main limitations for this crop is Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. physalis, for which biological control is emerging as an alternative to conventional management with chemical synthesis products. However, information on the effect that biological control agents have on the growth and development of plants is scarce. In this research, the physiological response of cape gooseberry plants (stomatal conductance, leaf water potential, growth parameters, total chlorophyll, carotenoid, and proline and malondialdehyde contents) to the treatment with three potential biocontrol agents (BCAs) Trichoderma koningiopsis, Trichoderma virens, and Bacillus velezensis was determined. The study was conducted under greenhouse conditions; F. oxysporum was inoculated in the soil, and BCAs were soil drenched in the germination and transplanting stages. Plants inoculated with the pathogen and plants without inoculation were used as controls. It was found that the plants inoculated and treated with T. virens showed the lowest disease levels (area under the disease progress curve of 48.5 and disease severity index of 2.1). Additionally, they showed a lower water potential (-0.317 Mpa), a greater leaf area (694.7 cm²), and a higher stomatal conductance (110.3 mmol m^-2 s^-1) compared with the control. Consequently, it can be concluded that T. virens can be a good candidate for the management of Fusarium wilt in the cape gooseberry crop.