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.

Cape gooseberry (Physalis peruviana L.) is one of the most exported Andean fruits in Colombia. Vascular wilt caused by Fusarium oxysporum f. sp. physali (FOph) has led to a reduction in crop areas in recent years. Therefore, the aim of this study was to select genotypes with resistance to vascular wilt that can be useful as rootstocks from a group of six Physalis genotypes (Physalis ixocarpa, Physalis floridana, and Physalis peruviana genotypes Colombia, Sudafrica, Peru, and Accession 62) using physiological variables such as maximum quantum efficiency of Photosystem II (Fv/Fm), leaf gas exchange properties [net photosynthesis rate (Pn) and stomatal conductance (g s)], and leaf water potential. An experiment was carried out under greenhouse conditions in which plants of the different Physalis materials were inoculated with the F. oxysporum f. sp. physali strain Map5 at a concentration of 1 × 10 6 conidia mL −1. Physiological and disease development variables were measured at 15, 23, and 31 days after inoculation (DAI). The results obtained showed that P. peruviana genotypes Colombia and Sudafrica showed greater susceptibility to the disease (disease severity index 3.8 and 3.6, respectively). Net photosynthesis rate (Pn), stomatal conductance (g s), water potential (fw), and Fv/Fm ratio were lower compared to non-inoculated plants. P. floridana and P. ixocarpa plants inoculated with F. oxysporum showed similar behavior to non-inoculated plants for the evaluated variables. In conclusion, the results obtained suggest that these two genotypes can be considered in breeding programs or as rootstock for the establishment of cape gooseberry crops in soils with the presence of the pathogen.

Vascular wilt caused by Fusarium oxysporum f. sp. physali is the most limiting disease in cape gooseberry crops. The use of natural products such as organic additives is a promising alternative for management of this disease. The present study sought to evaluate the physiological response of cape gooseberry plants infected with this pathogen and treated with the organic additives chitosan, burned rice husks, or their mixture. The test was conducted under greenhouse conditions and soil was inoculated with F. oxysporum f. sp. physali strain Map5. Chitosan was applied to seeds and seedlings at the time of transplantation, whereas burned rice husk was incorporated into the soil in a 1:3 ratio. Plants inoculated and not inoculated with the pathogen were used as controls. The following variables were evaluated: area under the disease progress curve (AUDPC), leaf water potential, stomatal conductance (gS), leaf area (LA), dry matter accumulation, photosynthetic pigment contents, proline synthesis, and lipid peroxidation estimation [malondialdehyde (MDA)]. The results showed that cape gooseberry plants with vascular wilt and treated with chitosan had higher gS, leaf water potential, LA, dry matter accumulation, and proline content values. In addition, the levels of vascular wilt severity decreased in comparison with pathogen-inoculated controls. The results suggest that chitosan applications on cape gooseberry plants may be considered as an alternative in the integrated management of the disease in producing areas, because they can mitigate the negative effect of the pathogen on plant physiology.

This study aimed to assess the soil application of mixtures of biological control agents (BCAs) (Trichoderma virens and Bacillus velezensis) and organic additives (chitosan and burnt rice husk) on the physiological and biochemical behavior of cape gooseberry plants exposed to Fusarium oxysporum f. sp. physali (Foph) inoculum. The treatments with inoculated and non-inoculated plants were: (i) T. virens + B. velezensis (Mix), (ii) T. virens + B. velezensis + burnt rice husk (MixRh), (iii) T. virens + B. velezensis + chitosan (MixChi), and (iv) controls (plants without any mixtures). Plants inoculated and treated with Mix or MixChi reduced the area under the disease progress curve (AUDPC) (57.1) and disease severity index (DSI) (2.97) compared to inoculated plants without any treatment (69.3 for AUDPC and 3.2 for DSI). Additionally, these groups of plants (Mix or MixChi) obtained greater leaf water potential (~−0.5 Mpa) and a lower MDA production (~12.5 µmol g−2 FW) than plants with Foph and without mixtures (−0.61 Mpa and 18.2 µmol g−2 FW, respectively). The results suggest that MixChi treatments may be a promising alternative for vascular wilt management in cape gooseberry crops affected by this disease.