ABSTRACT

Yield losses can be the result of abiotic or biotic stressors during the development of crop plants. A large share of these yield losses in sweet potato is caused by fungal plant pathogens. Fungicide-resistance, health hazards and the endophytic life-style of fungi within their host makes traditional chemical control difficult and unsustainable. Using biological control agents like endophytic bacteria as a means to combat these pathogens could be viable method to secure future food production on a safe and sustainable way. In this experiment we test the biological control potential of some potato endosphere- derived bacteria against some strains of fungal plant pathogens. Pathogenicity test carried out on the fungal isolates; Aspergillus niger, Rhizopus stolonifer, Aspergilius flavus and Fusarium oxysporum using fresh and healthy potato tubers shows that they are able to cause spoilage in healthy potato tubers. Biocontrol assays conducted shows that bacterial strains Bacillus species and Pseudomonas species isolated form root of potato has the ability to prevent fungal strains Aspergillus niger, Rhizopus stolonifer, Aspergillus  flavus and Fusariurm oxysporum from causing storage rot. Most Bacillus species also produces auxins, making it also a plant growth promoting bacteria as well as a biological control agent of plant pathogenic fungi.