Effect of Different Parent Materials on Growth and Yield of Okra (Abelmoschus esculentus) in Unwana-Afikpo, South East Nigeria

The study was conducted to assess the effect of different parent materials on growth and yield of okra (Abelmoschus esculentus) in Unwana South East, Nigeria. Four parent materials were selected: sandstone, coastal plain sand, shale and alluvium. Three farms were randomly selected in each parent material and composite samples collected from each farm at two different depths (0-20 and 20-40cm) using soil Auger. The soil samples were analyzed in the laboratory for selected physical and chemical properties following standard methods. Pot experiment was laid out as 4×2 factorial experiment in completely randomized design where three seeds of Okra (Abelmoschus esculentus) var. otukwuru omia obtained from local farmers were sown in each bucket and later thinned down to two after germination. Plant height, number of leaves, number of flowers, number of fruits and weight of fruits were measured. Data collected from the study were subjected to two-way Analysis of variance (ANOVA) using Genstat 12 and the significant means separated using Fishers Least Significant Difference (F-LSD). Results revealed that soils generally showed moderate (pH = 5.6-6.0) to strongly acidic (pH <5.5). Soils also differed significantly in their Available P, Calcuim, Magnessium, potassium, Sodium, EA and BS contents. Alluvium soil recorded the highest values of Organic matter (2.64 %), AP (14 mg/kg), total nitrogen (0.13 %) Calcium (4.87 cmol/kg), Magnessium (2.0 cmol/kg), potassium (0.26 cmol/kg) and BS (80.59 cmol/kg) and the least values were recorded in sandstone. Tallest plants (42.45cm), heaviest fruits (22.56g), greater number of leaves (6.78) and flowers (4.89) were also observed in soil developed from alluvium. This study revealed that soil developed from alluvium consistently showed higher values of OM, Ca, Mg, K, Na, EA and BS contents which significantly differed from soil developed from other parent materials. This meant better nutrient availability, resulting in observed higher okra growth and productivity. The study recommends regular soil testing to ascertain soil fertility status, sustainable maintenance of alluvium soils and proper management of coastal plain sand, shale and particularly sandstone for greater crop productivity.