Contamination of tomatoes with coliforms and Escherichia coli on farms and in markets of northwest Nigeria

Although recent reports indicated that produce contamination with foodborne pathogens is widespread in Nigeria, the sources and magnitude of microbial contamination of fruits and vegetables on farms and in markets have not been thoroughly identified. To ascertain possible pathways of contamination, the frequency and magnitude of coliform and Escherichia coli contamination of tomatoes produced in northwest Nigeria was assessed on farms and in markets. Eight hundred twenty-six tomato fruit samples and 36 irrigation water samples were collected and assessed for fecal indicator organisms. In addition, the awareness and use of food safety practices by tomato farmers and marketers were determined. Median concentration of coliforms on all field- and market-sourced tomato fruit samples, as well as in irrigation water sources, in Kaduna, Kano, and Katsina states exceeded 1,000 most probable number (MPN) per g. Median E. coli counts from 73 (17%) of 420 field samples and 231 (57%) of 406 market tomato fruit samples exceeded 100 MPN/g. Median E. coli concentrations on tomato fruits were higher (P < 0.01) in the rainy season (2.45 Log MPN/g), when irrigation was not practiced than in the dry (1.10 Log MPN/g) and early dry (0.92 Log MPN/g) seasons. Eighteen (50%) of 36 irrigation water samples had E. coli counts higher than 126 MPN/100 ml. Median E. coli contamination on market tomato fruit samples (2.66 Log MPN/g) were higher (P < 0.001) than those from tomatoes collected on farms (0.92 Log MPN/g). Farmers and marketers were generally unaware of the relationship between food safety practices and microbial contamination on fresh produce. Good agricultural practices pertaining to food safety on farms and in local markets were seldom used. Adoption of food safety practices on-farm, during transport, and during marketing could improve the microbial quality of tomatoes available to the public in this region of the world.

Potential of extension workshops to change farmers' knowledge and awareness of IPM

Farmers' knowledge of IPM has been considered, as prerequisites to IPM adoption. In Iran the most prevalent extension method for training farmers in different fields like IPM is extension workshops. The main purpose of this study was to investigate workshop effectiveness to change farmer's knowledge of IPM through assessing and comparing farmer's knowledge of IPM. A survey was conducted among 90 farmers in Karaj City in 2007--08 that included 30 workshop participants, 30 farmers who had exposed to workshop participants, and 30 randomly selected farmers, which were outside of this community. A questionnaire including open and close ended questions was designed. Data was collected through personal structured interviews with respondents at their farms. The study found that workshop participants (10.38) had significantly higher knowledge scores than their non workshop counterparts (5.90). Data also showed very little diffusion of workshop-acquired knowledge from workshop participants to other community members.