Physiological growth, yield and quality responses of okra to sole and combined soil application of green biomass, poultry manure and inorganic fertilizers

Agronomic practices using different organic materials helps in improving soil fertility and quality of produce. Experiments were conducted to determine the effects of different sole and combined application of organic manures and inorganic fertilizers on the physiological growth, yield and quality of okra. Treatments consisted two green biomass viz- Gliricidia sepium leaves (5 and 10 t ha−1 Gs), Chromolaena odorata leaves (5 and 10 t ha−1 Co), poultry manure (5 and 10 t ha−1 Pm), zinc sulphate (0 and 10 kg ha−1 Zn) and NPK fertilizer (200 kg ha−1 NPK) in a Randomized Complete Block Design (RCBD) with four replications. Application of 5 t ha−1 Co + 5 t ha−1 Pm (T2), 10 t ha−1 Pm + 0 kg ha−1 Zn (T8) and 10 t ha−1 Pm + 10 kg ha−1 Zn (T9) increased vegetative growth, number of fruits and quality of okra fruits similar to application of NPK except fruit weight per hectare while 5 t ha−1 Gs + 5 t ha−1 Pm (T1) improved all the parameters including fruit weight. Effects of treatments had significant influences on the proximate composition. The average concentrations of the heavy metals (Pb, Zn, Cu and Fe) detected in the samples were all below the safe limit. Incorporation of 5 t ha−1 Gs + 5 t ha−1 Pm (T1) will be adequate for growth, yield and quality characteristics of okra without the addition zinc sulphate fertilizer. Further increase in the amendments may therefore not be economical.