This study investigated the mechanisms of seed potato management by potato growers of Freydunshahr County in Isfahan province. Survey research method was used in this study. A sample of 250 potato growers (N=725) was selected for data collection. Stratified random sampling method was used. The research instrument was a questionnaire that was validated for face validity by a panel of faculty members and agricultural experts of Agriculture Jihad Organization in Freydunshahr County. For determining the reliability, Cronbach's alpha was estimated which turned to be higher than 0.7. Results showed that "a part of tubers produced by farmers" was the first priority of farmers as seed tuber source. Results showed that 89.6 percent of potato growers store and keep seed tubers in inappropriate conditions. Majority of the farmers did not have sufficient information on seed potato management and there was a positive and significant relationship between the farmers’ education and potato yield per hectare, but a negative relationship was found for age. Based on logistic regression analysis, the predictive power of the model was 0.639 and the sensitivity of total model to determine the correct percentage was 86.0 percent. Among individual, professional and economic factors, variables of age, number of family labor, area of owned land, area of potato farming, potato yield per hectare, number of owned land parcels and knowledge and information level of respondents significantly impacted on the adoption and use of modern seed potato production systems. Manuscript profile

The implementation of Iran GAPs standards in tomato production can have a very important impact on reducing harmful contaminants to achieve a healthy and safe product. The present study investigates the factors affecting farmers' tendency to use Iran GAPs during tomato production operation in Ardabil province, Iran. So, based on Bartlett et al. (2001), 310 tomato farmers were selected from three counties of Parsabad, Kowsar, and Bilesvar using the multi-stage random sampling method. Iran GAPs standards were collected according to the list of standards of the National Standards Organization of Iran for tomatoes. The results show that the majority of farmers (61.3%) are at a low level of the tendency to apply Iran GAPs standards in the tomato production operation. In this regard, the activities of “using minimal chemical pesticides”, “using personal protective equipment”, and “not using empty cans and tanks of pesticides and fertilizers and their safe disposal” were among the last priorities for farmers. Also, the most important factors differentiating farmer groups are observability (0.271), GAPs training courses (0.269), complexity (0.219), farm size (0.198), and relative advantage (0.178), respectively. Establishing a marketing and sales unit in the agricultural centers of the studied counties, holding "farm day" programs and farmers' visits to successful farms, and creating a "Seed Bank" for tomatoes can increase the tendency of farmers to use Iran GAPs. Manuscript profile