Some physical and hydrodynamic properties of two varieties of apple (Malus domestica Borkh L.)

Several physical and hydrodynamic properties of two apple varieties (Redspar and Delbarstival), newly planted varieties in Iran, were determined and compared. These properties are necessary for the design of equipments for harvesting, proces- sing, transporting, sorting, separating and packing. Some physical characteristics such as: average fruit length, width, thickness, the geometric, arithmetic and equivalent mean diameter, projected area, surface area, sphericity index, aspect ratio, fruit mass, volume and moisture content were studied. These values were different statistically at 1% level of significance for both cultivars. The terminal velocity, coming up time, bounce and drag forces for Red- spar variety were 0.47 m s -1 , 2.33 s, 2.69 and 0.46 N, respectively. But in the case of Delbarstival variety, 0.42 m s -1 , 2.52 s, 1.40 and 0.24 N were as terminal velocity, coming up time, bounce and drag forces, respectively. The packaging coefficient was 0.62 and 0.53 for Redspar and Delbarstival varieties. The published comparison of data, which might be useful to engineering equipment design for the apple varieties, was generally found to be statistically different.