IDENTIFICATION AND PATHOGENICITY OF FUNGI CAUSING POSTHARVEST DECAY OF TOMATO (SOLANUM LYCOPERSICUM L.) FRUITS IN MAKURDI

Spoilage of tomato fruits is the major threat to its storability after harvest. This spoilage is caused by biotic and abiotic factors. The study was carried out at the Botany Laboratory of the Benue State University Makurdi to isolate and identify fungal organisms causing post- harvest decay of tomato fruits in Makurdi and to test their pathogenicity. Tomato fruits showing symptoms of decay were obtained from four markets namely; Wurukum, High Level, Railway and Wadata markets. Small sizes were cut from decaying portions of the fruits. They were surface sterilized in 5% sodium hypochlorite (NaOCl) solution and rinsed in three changes of sterile distilled water. The direct plating method was used for fungal isolation and the Potato Dextrose Agar was used as the culture media. The disease causing potential of the isolates were carried out on healthy tomato fruits. Data collected on occurrence of fungi was presented in percentages and Chi Square (2) was used to show relationship in fungi occurrence to the location. Analysis of Variance was used to analyze data collected on disease causing potential (pathogenicity) of these organisms. The mean was separated using Fisher's Least Significant Difference. The result revealed that five fungi were isolated namely; Aspergillus flavus, Aspergillus niger, Mucor sp., Fusarium sp. and Aspergillus sp. There was significant relationship in fungi occurrence in respect to the locations (x* = 8.480, df = 12, P = 0.037). Wurukum had significantly higher fungi occurrence 17 (34.00%) followed by Wadata 15 (30.00%), Railway 10(20.00%) and High level 8 (16.00%). There was no significant fungal occurrence on tomato fruits x* = 1.600, df = 4, P = 0.809). Aspergillus flavus, Fusarim sp. and Mucor sp had higher occurrence each with 11 (22.00%) followed by A. niger 9 (18.00%) and Aspergillus sp with 8 (16.00%). The area of rot induced by Fusarium sp (7.05+5.50)em' was significantly higher compared with A. niger (7.02+2.74)em', A. flavus (5.55+3.97)em', Aspergillus sp (5.23+4.92)cm', Mucor sp (4.28÷0.29)cmª and the control (0.58=0.19)em'. Consumption of tomatoes with symptoms of decay poses a health risk to humans. Therefore, farmers should engage in proper agronomic practices right from field after harvest and sellers should also engage in hygienic practice to ensure disease free tomatoes.