Studies on the Physico-mechanical Properties of Okra (Abelmoschus esculentus L) Pods, in Relation to its Automated Harvesting

Abstract

This study evaluated the effect of farming method (organic and inorganic), on some physical characteristics and mechanical properties of okra pod. Two commonly cultivated okra varieties (Kirikou and Clemson) in Nigeria were used for this study. The two okra varieties were cultivated both under the organic and inorganic farming method. Under the organic farming, the soil was treated with organic manure at the rate of 2,000 kg/ha; while under the inorganic farming method, the soil was treated with NPK 15:15:15 fertilizer, at the rate of 200 kg/ha. The okra pods were harvested at the mature green maturity stage, and their physical characteristics and mechanical properties tested. The mechanical properties of the okra pods were determined through compression and shear tests, using standard recommended procedures. Results obtained revealed that the soil treatment significantly (p ≤0.05) affected the physical characteristics and mechanical properties of the okra pods. Irrespective of the okra variety, the okra cultivated with organic manure recorded highest physical characteristics values; when compared with the okra cultivated with NPK 15:15:15 fertilizer and the control okra pod. Furthermore, the study revealed that the okra pod cultivated with organic manure recorded higher failure force and failure energy, when compared with the compared with the okra pods cultivated with NPK 15:15:15 fertilizer and the control okra pods. Regardless of the okra variety, the maximum shear force and energy were recorded in the control okra pod stalk; while the shear force and energy of the Kirikou okra pod was higher than the values obtained in the Clemson okra pod. Results obtained from this study will be useful in the design and optimization of automated okra pods harvesting and handling machines.