Okra (Abelmoschus esculentus L. Moench) is a member of the family Malvaceae and a native to West and Central Africa but is now widely grown throughout the tropics (Kochhar, 1986; Schippers, 2000). The world production of common okra as fresh vegetable is estimated at 1.7 million tons year−1 (Schippers, 2000; Asare-Bediako et al., 2014). Ghana is the eighth largest producer of okra in the world (FAOSTAT, 2014).
Okra crop is the third most important vegetable in Ghana after pepper and tomato, with production of 80,000 tons estimated at $51, 189,000 USD (FAOSTAT, 2011; 2013).
It can be grown anywhere in Ghana but the major producing centers are Brong Ahafo, Ashanti, Northern, Volta, Greater Accra, and Central regions (NARP, 1993). Okra production provides livelihood, employment, and income to rural smallholder farmers and retailers in urban centers. Okra is an important fruit vegetable crop in Ghana, and a source of energy for human consumption (Babatunde, 2007). The crop is a rich source of protein, fat, carbohydrate, fiber, thiamine, riboflavin, nicotinamide, and ascorbic acid (Hamon, 1988; Schippers, 2000; Babatunde, 2007). It also contains significant amount of potassium, magnesium, calcium, and iron (Hamon and Charrier, 1997). Okra is a multipurpose fruit vegetable due to its diverse uses of the fruits (pods), fresh leaves, buds, flowers, stems, and seeds (Mihretu et al., 2014). Immature okra fruits and fresh leaves are usually consumed as vegetables while the dried fruits are ground into powder and used in stews and soups (Siemonsma, 1982a). Okra seeds can be used as substitutes or additives in feed preparation (Purseglove, 1974), in the preparation of okra seed meal (Martin and Roberts, 1990), in the confectionery industry (Adetuyi et al., 2011), and in blood plasma replacement or blood volume expander.
In spite of the significant contribution (75%) of the West and Central African region including Ghana to okra production in Africa, average productivity in the region (2.5 t ha−1) is far below that of East (6.2 t ha−1) and North Africa (8.2 t ha−1) (FAOSTAT, 2008). In Ghana, yield potential of up to 3.0 t ha−1 has been reported for Okra (MoFA,...