impact of information obtain from interpersonal communication channels on using optimum amount of fertilizers by grape farmers in the khoramdareh township

farmers' behavior can be affected by different socio-economic factors. the purpose of this study is to analyze the impact of interpersonal information sources on grape farmers’ behavior in terms of optimum use of fertilizers in their vineyards. the data for this survey were collected using a questionnaire through structured interviews. a sample of 260 out of 3942 grape farmers of the khoramdareh township was selected using a stratified sampling technique. the content validity of the questionnaire was obtained through a panel of expert discussion and the questionnaire constructs were validated using the convergence analysis technique. the instrument reliability was also analyzed by a pilot test and measuring the cronbach’s alpha coefficient (0.71-0.91). results showed the highest percentage of optimum use of fertilizers belonged to micro element fertilizers and livestock manures, while the lowest optimum use of fertilizers was related to the boric acid, vermi-compost and green fertilizers. less than half of the farmers used appropriate amount of other fertilizers. farmers’ behavior regarding the use of optimum amount of fertilizers can be explained by variables such as farmer age, government interventions for improving orchards, and information obtain from the township jihad-e- agriculture directorate specialists, particularly the horticulture office, from visiting the vineyards outside their village, from pesticide and input sellers, and from model and experienced farmers. thus, farmers' behavior can be affected by both formal and informal interpersonal information sources.