Effect of Pre-Harvest Treatment on the Tensile and Biochemical Properties of Okra (Abelmoschus Esculentus L) Fibre

Abstract

The improvement in the mechanical properties of plant fibres, to enhance high quality composites production, is still a great concern to the scientific world. This study was done to evaluate the effect of pre-harvest treatment on the tensile properties of okra (cv.kirikou) fibre. The okra plants were pre-harvest treated with five concentrations (0 mg/l, 100 mg/l, 200 mg/l, 300 mg/l and 400 mg/l) of calcium nitrate. All the treated okra plants were harvested at 80 days after planting, and their fibre extracted through the retting method. The tensile properties of the fibre, obtained from each treatment were determined using the ASTM C1557:03 recommended procedures. In addition, the calcium and cellulose content of the fibres were determined using approved standard methods. Results obtained revealed that the pre-harvest treatment significantly (p ≤0.05) affected the tensile properties, by increasing the tensile strength and Young’s modulus. The tensile strength increased from 214.8 MPa to 311 MPa, while Young’s modulus increased from 5.84 GPa to 10.76 GPa; as the treatment concentration increased from 0 mg/l to 400 mg/l. Furthermore, the results have shown that pre-harvest treatment significantly increased the calcium and cellulose content of the fibre. The fibre calcium content increased from content 6.37 mg/100g DW to 11.40 mg/100g DW; while the cellulose concentration increased from 54% to 78.33%, as the treatment concentration increased from 0 mg/l to 400 mg/l. This study had shown that okra fibre can be improved b pre-harvest treatment. This study is not only beneficial to the fibre/composite industry but to plant breeders, as calcium is one of the essential nutrients required by plants.