EFFECT OF DEFICIT IRRIGATION ON THE ELASTIC PROPERTIES OF TOMATO FRUITS

The aim of this research work was to determine the physical and elastic properties of tomato fruits (Lycopersicon esculentum) cv under four water regimes (ET_100, ET_90, ET_80 and ET_70 of water requirements) to develop a technique that can predict the packing height to protect fruits from mechanical damage. The physical properties of tomato include mass, volume, dimensions, bulk density, soild density and geometric mean diameter. The elastic properties of tomato fruit include Young s modulus of elasticity (E), firmness coefficient (FC), bioyield stress (σb), bioyield strain (εb), rupture stress (σr), rupture strain (εr) and rupture energy (RE). The results showed that the different water regimes have a significant effect on physical and elasticity properties. The values of E, FC, σb and RE were increased with decreasing water level, while, σr was increased with increasing water level. Accordingly, the maximum heights of packing box were 177.4, 353.6, 456.5 and 526.4 mm for ET_100, ET_90, ET_80 and ET_70, respectively.