DETERMINATION OF PHYSICO-MECHANICAL PROPERTIES OF TOMATO SEEDLINGS FOR DESIGN OF A TOMATO TRANSPLANTER

Abstract

Transplanting operation is an important phase in the production of Tomato. The process is carried out manually in Nigeria accounting for over 40% of the total working hours in its production. To address these problems, several mechanical transplanting machines have been developed to transplant various plants or crops in the developed countries. However, these transplanters were designed considering prevailing conditions and the plant or crop under study. These transplanters are expensive to procure by farmers in the developing countries. Therefore, there is need for engineers in the developing nations to develop transplanting machines that will suit the farming methods and bearing in mind materials availability, cost and operability. Though, in designing such machines for transplanting Tomato, the physical and mechanical properties of the Tomato seedling are required. In this work the physical and mechanical properties (stem thickness, height, weight, spread diameter, angle of friction, frictional coefficient, impact properties, compressive properties and tensile properties) of the seedling of the most commonly grown Tomato variety (Roma VF) in Nigeria were determined. The height, weight, stem thickness and spread diameter of the seedlings were found to be 243.35 ± 50 mm, 6.28 ± 3.42 g, 3.53 ± 1.07 mm and 70.08 ± 8 mm respectively while the impact energy was found to be 1.32 ± 0.38 J. The frictional angles and coefficient of friction when the seedlings were laid vertically on Mild steel, Aluminum and Galvanized sheets are 44.43 ± 5^o and 0.99 ± 0.18, 42.96 ± 4.85^o and 0.94 ± 0.16 and 43.73 ± 5.10^o and 0.96 ± 0.17 respectively and when laid horizontally on Mild steel, Aluminum and Galvanized sheets the values are 40.63 ± 3.50^o and 0.86 ± 0.11, 40.08 ± 2.75^o and 0.84 ± 0.09 and 39.58 ± 6.10^o and 0.83 ± 0.20 respectively. The Tensile force, stain, stress and Young's Modulus in Tension for the seedlings were found to be 3.50 ± 1.00 N, 15.67 ± 5.13 %, 1.11 ± 0.32 N/mm2 and 7.36 ± 2.80 N/mm2. While the maximum applied force the seedling can withstand in compression is 11.64 ± 3.73 N with maximum deflection and strain of 0.69 ± 0.24 mm and 34.39 ± 12.23 % respectively.