In-vitro Activity of Selected Plant Extracts on Post-Harvest Pathogens Causing Tomato Fruit Rot

Most researchers have majored on research to improve tomato production whileneglecting post-harvest issues. Control of the post-harvest diseases in tomato is by useof synthetic pesticides. However, current research shows that pesticides are toxic withlong residue effect. Some of the products are rejected in the market due to highchemical residue levels resulting to losses. A sustainable solution to this problem canbe obtained from bio-controls that are environmental friendly. In this study, threedifferent crude plant extracts (ginger rhizomes, neem leaves and garlic bulbs) wereevaluated in-vitro at different concentrations for the control of pathogens causingtomato post-harvest rots. The used concentrations were: 1, 2, and 3mg/ml. The isolatedand identified pathogen species used in this study were Fusarium, Rhizopus, andGeotrichum. Pathogen growth media (Potato Dextrose Agar) were amended with the differentconcentrations of the selected crude plant extracts and the pathogens introduced intothe media. Radial growth of the fungal pathogens was measured at an interval of twentyfour hours after the second day for seven days and was compared with the control.Results showed that all extracts’ concentrations had antimicrobial effect against thetest pathogens with garlic having the highest bio-control activity. However, theantimicrobial effect varied with the concentration and the plant species. From the studyit is evident that plant extracts can be used as safe alternatives for management ofpost-harvest rot causing pathogens in tomato fruits thus safeguarding the human healthand the environment