determination of effective inputs on production and production-risk of onion in tabriz plain

usage of inputs is one of the most important factors affecting agricultural production variations. thus, in the evaluation of production function, it is reasonable to consider the effects of inputs usage on the production fluctuation. east azerbaijan province is one of the five major producing in iran and tabriz plain and the most important region of the province for onion production. the main objective of this study is determination of effective inputs on production and production risk of onion in tabriz plain. to this end, the general model of just and pope has been used. results show the generalized quadratic and leontief form is best functional form to onion production and production risk, respectively. the results of these functions estimations indicates that area, seeds, water and labor inputs have significant and positive effect on onion production and chemical fertilizer has significant and negative effect on it. results of estimation of risk function represent that increasing area, labor, water and seed consumption increase production risk and increasing chemical fertilizer and pesticide decrease it. total output variance elasticity is 1.48 that shows that production risk increases by every increase of one percent of consumption of inputs.