Plants are prone to be attacked by various pathogenic microorganisms, leading to significant crop yield losses. Pesticides are used to control agricultural pathogens; however, frequently, they are toxic synthetic products. This work evaluated the antibacterial and antifungal activity of Pernettya prostrata, and Rubus roseus plant extracts against three phytopathogens Ralstonia solanacearum, Phytophthora infestans, and Neopestalotiopsis javaensis responsible for causing banana bacterial wilt, late blight y scab diseases, respectively. The extracts were obtained in methanol. The phytopathogens were isolated from diseased plants grown in Ecuador, R. solanacearum was isolated from samples of Musa paradiasiaca, P. infestans from samples of Solanum lycopersicum and N. javaensis from diseased samples of Persea americana—morphological and molecular methods identified the isolated pathogens. The antibacterial activity was determined by the microtiter broth dilution method; six serial concentrations of the extracts were tested. The antifungal activity was determined based on the effects of the plant extracts on the inhibition of radial growth of fungi; five serial concentrations of the extracts were tested. The extracts of P. prostrata and R. roseus showed activity against R. solanacearum and P. infestans with a MIC of 22.5 and 31.25 mg/mL, respectively.

Meloidogyne incognita, a widely distributed plant parasite that is considered one of the most devastating species for various crops, has traditionally been controlled through the use of synthetic products. However, the risks associated with these products for human health and the environment have prompted a search for more sustainable alternatives. In this context, plant extracts rich in secondary metabolites, such as those of Tagetes zypaquirensis and Dysphania ambrosioides, have shown potential for nematode management, although their efficacy varies. This study aimed to evaluate the effect of extracts of T. zypaquirensis, Lonchocarpus urucu, D. ambrosioides, Urera laciniata, and Ricinus communis on the population of M. incognita in Selenicereus megalanthus under controlled greenhouse conditions. A completely randomized block experimental design was used with three replicates per treatment and six yellow pitahaya (or dragon fruit) plants per experimental unit. A total of 10 g of extract per plant was applied at two application times: 7 days before nematode inoculation and 7 days after. In addition, two controls were included: an absolute control, with no extract application and no nematode inoculation, and an inoculated control, consisting of plants exposed only to nematodes. The results showed that the preventive application of T. zypaquirensis and D. ambrosioides extracts 7 days before nematode inoculation significantly reduced M. incognita populations compared to the inoculated control. At 60 days, both extracts were able to reduce nematode populations and the number of nodules on roots, with reproductive factors close to 1 (1.47 and 1.50), indicating efficient control. Moreover, plants treated with these extracts showed superior growth compared to the other treatments and the inoculated control. In conclusion, the preventive application of T. zypaquirensis and D. ambrosioides extracts had a positive influence on the control of M. incognita and caused an improvement in plant growth variables. These results suggest that these botanical extracts could be adopted within integrated nematode management strategies in agriculture, contributing to sustainability and a reduction in the use of chemicals.