Journal of Materials Science Research and Reviews

The knowledge of the mechanical properties of agricultural products plays an essential role during the design, development, programming and utilization of their automated harvesting, handling and processing machines. The aim of this study was to investigate the influence of field practices (pre-harvest treatments) on some mechanical properties of eggplant (Solanum aethiopicum L.) fruits, necessary for the automation of agricultural production. Eggplant (cv. Djamba) was cultivated in the field trial, in four different treatments mediums, which were: Zero amendment (also referred to as the control), organic manure, potassium nitrate (KNO₃) and combination of organic manure and KNO₃. The eggplant fruits were harvested at peak maturity (35 days after flowering), and their mechanical properties tested, according to standard procedures. Results obtained revealed that field practices had a significant (p ≤0.05) effect on all the mechanical properties investigated. The fruits produced by using the combination of organic manure and KNO₃ had superior mass, when compared with other treatments options. The control fruits exhibited the poorest failure force (305.58 N) and failure energy (3.895 Nm); while the fruits cultivated with the combination of organic manure and KNO₃ had the highest failure force and failure energy of 636.6 N and 5.312 Nm respectively. The study revealed that the fruits produced with organic manure exhibited superior failure force and failure energy, compared to the fruits produced with KNO₃. Additionally, the fruits produced by using organic manure, exhibited the highest deformation (24.01 mm) at failure point; while the control fruits recorded the lowest deformation (18.8 mm). Regarding the puncture properties, the tissues of the fruits produced with organic manure had the least resistivity to puncture force (50.30 N); which was lower than the puncture force of 65.73 N recorded by the control fruits. The highest resistance to puncture force (89.17 N) was observed in the fruits cultivated with KNO₃. These results will help to optimize the efficiency of eggplant fruits harvesting and handling machines; thereby reducing the rate of mechanical damage being done to the harvested products.