MATERIAL AND CURVATURE OF THE OIL PALM HARVESTING KNIFE AND THEIR EFFECTS ON FORCE AND ENERGY REQUIREMENTS

Oil palm is an economically important crop, and the process of harvesting its fruit constitutes a major proportion of the production cost.Using an efficient harvesting knife can reduce the cultivation cost and ensure a high yield.In this study, the effect of the material and curvature of the knife for cutting fronds and fresh fruit bunches (FFB) was investigated.Three different materials, namely, and Hardened and Tempered (H&T) steel and five different curvatures namely, Malaysian model, Andhra model, Kerala model, FMD-1 and FMD-3 were examined.A total of 15 harvesting knives were developed and evaluated in the field using a load cell indicator attached between the pole and the harvesting knife.The parameters of maximum cutting force (CFc) , maximum specific cutting force (SCFc), and maximum specific cutting energy (SCE) were calculated.The findings indicated that the material of the knife exhibited a negligible effect, but the curvature had a significant effect.Of the various models tested, the values of the CFc (30.56, 54.50 kgf), SCFc (0.26, 0.95 kg cm -2 ), and SCE (5.08, 4.78 kg cm cm -2 ) were the least for the Malaysian model followed by FMD-3 model for cutting the frond and FFB.