Three separate experiments were conducted during the growing season 2013. The first experiment was applied to estimate the leaf area of buckwheat Fagopyrum esculentum Moench Var. Hruszowska via a simple model derived from triangle area. Buckwheat leaf parameters; height (h) and the baseline (b) were combined as an equation of triangle area then adjusted. Two models were compared with the conventional method (Millimeter graph paper) using simple linear regression. Regression analysis showed that the two models could be used for determining leaf area of buckwheat. The model equation of (((1/2BC.AG)-(1/2EF.DG)).(1/2EF.DG) /(1/2BC.AG)-(1/2EF.DG)) gave the most accurate estimate (r2=0.989, with linear equation of y=0.707x+0.596). The second experiment was conducted to evaluate buckwheat growth performance under various sowing dates. Results showed that the buckwheat seed sowing at 6th September was significantly improved number of leaves per plant11.83, inflorescences per plant19.33 and seeds per plant 47.67. As well as, plants were sown in this date were taken the lowest period from sowing to germinate. The third experiment was applied to evaluate growth performance of buckwheat under two growing locations. Al-Fallujah location was more suitable to buckwheat plants as compared with Al-Ramadi location wherein most of the growth parameters were increased. As a result, the proposed linear equation could be replaced with the derived model equation above
(x= calculated area, y= adjusted area) to estimate buckwheat leaf area. Furthermore, al - Fallujah location was fitted to establish buckwheat and this plant could be sown at 6th September. Thus, it could be recommended that multi-environment test it is very important to evaluate proposed leaf area model.