_____________________________________________________________________________________________________ *Corresponding author: Email: oyunjustina@gmail.com; South Asian Journal of Research in Microbiology 7(2): 19-33, 2020; Article no.SAJRM.58838 ISSN: 2582-1989 Assessment of the Preservative Efficacy of Azadirachta indica A. Juss. and Psidium guajava L. Leaf Extracts on Capsicum annuum L. (Bell Pepper) Justina Folashade Oyun 1* and Victor Olusegun Oyetayo 1 1 Department of Microbiology, Federal University of Technology, Akure, P.M.B. 704, Ondo State, Nigeria. Authors’ contributions This work was carried out in collaboration between both authors. Author JFO designed the study, managed the literature searches, performed the statistical analysis, wrote the protocol and wrote the first draft of the manuscript. Author VOO supervised the study. Both authors read and approved the final manuscript. Article Information DOI: 10.9734/SAJRM/2020/v7i230166 Editor(s): (1) Dr. Ana Claudia Coelho, University of Tras-os-Montes and Alto Douro, Portugal. Reviewers: (1) M. Kamalam, Bharathiar University, India. (2) S. Sreeremya, Academy of Science, India. Complete Peer review History: http://www.sdiarticle4.com/review-history/58838 Received 08 May 2020 Accepted 13 July 2020 Published 25 July 2020 ABSTRACT This study assessed the preservative efficacy of Azadirachta indica (Neem) and Psidium guajava (Guava) leaf extracts on Capsicum annuum (Bell pepper). The phytochemical compositions of A. indica and P. guajava leaf extracts were determined using standard methods. Phytochemical analysis revealed the presence of saponnin, anthraquinone tannin, steroid, terpenoid, flavonoid and glycosides in ethanol extracts of Azadirachta Indica A. Juss. and Psidium guajava L. leaves and tannin, terpenoid, flavonoid and glycosides are present in n-hexane extracts of the selected plants. Among the phytochemicals identified, Terpenoid was the highest in value (25.79mg/g) and saponnin has the least value (3.27 mg/g). The ethanolic extracts of Guava had the highest inhibition against the growth of Staphyloccoccus aureus (35.00±1.15 mm).The n-hexane extracts of Neem leaves had the lowest inhibition against the growth of Staphyloccoccus sp (8.00±0.57 mm). Ethanolic extract has the highest antifungal effect against Saccharomyces cerevisiae (58.66±0.90 mm). Based on the findings of this study, it can be concluded that the ethanol extracts of Azadirachta indica A. Juss. and Psidium guajava L. leaves are more effective than the n-hexane Original Research Article