Prediction of Climate Yield Production Functions for Rainfed Barley at Kohdasht and Poldokhtar and its Sensitive Analysis

Assessment of effective climate parameters and planning for their managing and or arranging agronomic activity with those trend changes, that result to improving production baseline and prediction for future. In order to determination of climate-yield production functions, analyzed eight crop seasons data (1998-2006) of 25 climate parameters and rainfed barley grain yields of four cold and semi-cold regions of Lorestan province.These regions were including Kohdasht and PoleDokhtar regions. By path analysis method, correlationcoefficient separated to direct and indirect effects. Results showed that in local and common models ofproduction functions, the role of crop season vapor pressure deficit is very important. The local models necessary small input data but common model need more input data (Tmin, RHmean, n, PWinter, PStart, Pend, Tmin-abs, PAzar, PDay, PFar., POrd., Tmax-azar). Rain water productivity of all regions determined for eight crop seasons, and amounts of maximum, minimum and average of rain water productivity were 0.422, 0.137 and 0.304 kg per cubic precipitation, which its average was 27.2 percent more than national average (0.239 kg.m-3). The sunshine,minimum temperature, average relative humidity, start rain and winter precipitation parameters, were the most sensitive parameters on barley grain yield prediction. We conducted the climate-yield models are useful tools to predict rainfed barley yield and so to assist managers and farmers for making decisions in rainfed agronomic activity under climate parameters changes.