determining the best variety of rice for cultivation using kataoka's and telser's risky-linear programming methods-case study of gilan province 2000-2006

gilan province is among the most important regions of iran for rice production. the general aim of this research is to determine the best variety of rice for planting, so that the minimum level for farmer's expected living gross margin can be provided. on the other hand, determining the best variety with regard to the risk in price is another aim of this research. to this end two risk models based on telser and kataoka linear programming were used. data needed for seven understudy varieties in this research during 2000-2006 were connected from 7 representative farms at the gilan province level. taking the related risk-rows to gross margin per hectare of the 7 varieties under study during the aforesaid years, and using the kataoka model, the highest amount of living gross margin per hectare at different probability levels was calculated. on the other hand, through the telser model the area under planting of optimized varieties over different probability levels, showing that the probability of the gross margin per hectare of rice farming is less than the highest amount of living gross margin, was calculated. the results showed that at different levels the gross margin of the aim, considering the probability constraints, the two items hashemi and ali kazemi were the best ones for achieving the aforesaid goals.