The behavior of agricultural seeds under compression loads was studied and reveald that their useful properties such as Poisson’s ratio and elastic modulus which can be applied in design of their processing equipment. The feasibility of using different elasticity theories including Hook's theory, Hertz theory and Boussinesq's theory for evaluation of the modulus of elasticity of agricultural produce was investigated in this research. Two major commercial Iranian varieties of pumpkin seed namely Zaria and Gaboor were used as a case study. Their general behavior under compressive loads was also reported. These values ranged from 61.15 × 10 5 to 91.6 Mpa and 89.43 × 105 to 119.88 Mpa for Zaria and Gaboor varieties, respectively. The Hertz theory was found more applicable due to good agreement between its theoretical and experimental results. Also, among the four investigated methods of loading the highest values in elastic modulus of pumpkin seed belonged to parallel plate method in Hertz theory while cylindrical indenter in Boussinesq's theory showed the lowest values. Then, the obtained forcedeformation curves for pumpkin seed were interpreted in several different ways to select the best theory. The methods of interpretation of the force-deformation curves were based on the Hertz theory and utilized the complete curve were preferred to those methods which "linearize" the initial part of the curve.

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