Effect of salinity stress on NPK partitioning, growth, yield and proximate composition of Okra (Abelmoschus esculentus)

Abstract

This experiment was conducted to determine the effects of salinity on growth, yield, NPK partitioning and proximate composition of okra. To achieve this objective, four levels of salinity (0, 50, 75 and 100mM sodium chloride) were tested on 17Lucky19 okra variety in a pot experiment. The experiment was laid out in randomized complete block design (RCBD) with three replications. Parameters used to determine the effects of salinity on the crop were nitrogen, phosphorus and potassium contents of stem and leaves. Also, plant height, number of branches, number of leaves, number of fruits, fresh fruit mass, dry straw mass, chlorophyll content and proximate parameters (crude fat, crude fibre, crude protein and ash contents of the plant leaves) were used. It was found that all the growth and yield parameters tested reduced with increase in salinity levels. Similarly, all proximate parameters decreased with increase in salinity levels with the exception of crude fibre which increased with increase in salinity level. In the same vein, nitrogen and potassium levels decreased with increase in salinity level in both leaves and stems. However, phosphorus levels in stems and leaves decreased with increase in salinity level. It is, therefore, concluded that 17Lucky19 okra variety is susceptible to salinity stress. This implies that salinity tolerant or resistant varieties should be used instead of 17Lucky19 whenever saline soil is to be used for cultivating okra. KEY WORDS: salinity stress, okra, NPK partitioning, proximate composition, growth and yield