_____________________________________________________________________________________________________ *Corresponding author: E-mail: mmgoss7@gmail.com, mmgoss@agric.uz.ac.zw; International Journal of Plant & Soil Science 18(2): 1-11, 2017; Article no.IJPSS.29850 ISSN: 2320-7035 Black Rot (Xanthomonas campestris pv. campestris) Control in Field Grown Cabbage (Brassica oleracea var. Sugar Loaf) with Moringa oleifera Extracts M. Goss 1,2* , P. Mafongoya 1 , A. Gubba 1 and Tesfay Sam 1 1 School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa. 2 Faculty of Agriculture, University of Zimbabwe, P.O. Box MP167, Mt Pleasant, Harare, Zimbabwe. Authors’ contributions This work was carried out in collaboration between all authors. Author MG designed the study, carried out the field work, collected field data, performed the statistical analysis and wrote the first draft of the manuscript. Author PM managed the literature searches and the whole experimental process, and finalized the experimental design. Author AG identified the species of plant pathogens, managed the culturing of the test organisms and edited the final draft manuscript. Author TS carried out the phytochemical analysis of all the plant extracts. All authors read and approved the final manuscript. Article Information DOI: 10.9734/IJPSS/2017/29850 Editor(s): (1) Marco Trevisan, Institute of Agricultural Chemistry and Environmental Research Centre BIOMASS, Faculty of Agriculture, Catholic University of the Sacred Heart, Italy. Reviewers: (1) Andell Edwards, University of Trinidad and Tobago, Trinidad and Tobago. (2) Isaac Kojo Arah, Ho Polytechnic, Ghana. (3) Marshall McCue, St. Mary’s University, USA. Complete Peer review History: http://www.sciencedomain.org/review-history/20592 Received 30 th September 2016 Accepted 11 th November 2016 Published 21 st August 2017 ABSTRACT Aims: To evaluate if the antibacterial compounds present in Moringa were significant enough to effect suppressive effect on Xanthomonas campestris pv campestris (black rot) in field grown cabbages (Brassica oleracea), in an open field experiment. Study Design: The experimental design was a 3 x 3 factorial laid out in a split plot in two blocks with three replicates. Place and Duration of Study: Field experiments were carried out for 6 months during the October 2015 to April 2016 season at Victory Farm in Beatrice, Zimbabwe Methodology: Three aqueous Moringa extracts (leaf, bark, and seed) at 3 concentration levels of 60, 100 and 140% were sprayed as foliar applications weekly from 5 weeks after crop emergence Original Research Article