Regression Models For Saffron Yields in Iran
Saffron is an important crop in social and economical aspects in Khorassan Province (Northeast of Iran). In this research wetried to evaluate trends of saffron yield in recent years and to study the relationship between saffron yield and the climate change. A regression analysis was used to predict saffron yield based on 20 years of yield data in Birjand, Ghaen and Ferdows cities.Climatologically data for the same periods was provided by database of Khorassan Climatology Center. Climatologically data includedtemperature, rainfall, relative humidity and sunshine hours for ModelI, and temperature and rainfall for Model II. The results showed the coefficients of determination for Birjand, Ferdows and Ghaen for Model I were 0.69, 0.50 and 0.81 respectively. Also coefficients of determination for the same cities for model II were 0.53, 0.50 and 0.72 respectively. Multiple regression analysisindicated that among weather variables, temperature was the key parameter for variation ofsaffron yield. It was concluded that increasing temperature at spring was the main cause of declined saffron yield during recent years across the province. Finally, yield trend was predicted for the last 5 years using time series analysis.
KeywordsTime Series Analysis Weather Factor Weather Index Yield Trend Weather Variability
- Behdani, M., A. M. Nassiri, and A. A. Koocheki. 2003. Modeling Saffron Flowering Time Across a Temperature Gradient. In proceedings of 2nd International Symposium on Saffron Biology and Technology. 22–25 October. Albacete, Spain.Google Scholar
- Hosseini, M., and A. Mollafilabi, 2006. Spatial and temporal patterns of saffron (Crocus sativus) yield in Khorasan Province and their relationship with long-term weather variation. In proceedings of 2nd International Symposium on Saffron Biology and Technology. 28–30 October, Mashhad, Iran.Google Scholar
- Mashayekhi, K., B. Kamkar, and A. Soltani, 2006. The Effect of Corm Weight and Environmental Temperature on Flowering Behavior of Saffron (Crocus Sativus). In proceedings of 2nd International Symposium on Saffron Biology and Technology. 28–30 October, Mashhad, Iran.Google Scholar