Growth and Yield of Okra with Rock-Phosphate – Amended Organic Fertilizer

Phosphorous supply from organic manures for okra production can be insufficient for optimal fruit yield. The growth and yield of okra (Variety- NHAe 47-4) were assessed in field experiments with an organic fertilizer made from cowdung (CD), fortified with Ogun Rock Phosphate (ORP). The ORP was applied sole at 100 kg ha-1 and also with each of 2.5; 5.0; 7.5 and 10.0 t ha-1 cowdung. There was a standard check of NPK 20-10-10 applied 2 weeks after planting at 400 kg ha-1 and an unfertilized control., Average number of leaves per plant, stem diameter and plant height were all similar, with 4 weeks growth. Average plant leaf area was however higher with ORP added to either 7.5 or 10.0 t ha-1 CD, relative to either sole ORP or the unfertilized treatments. At 8 weeks after planting, plant height was highest with 10.0 t ha-1 CD + ORP and was comparable only with plants from 7.5 t ha-1 CD + ORP application. Plant stem girths were similar with all ORP applications. Number of leaves per plant and average leaf area were highest with 10.0 t ha-1 CD + ORP. Applications of 2.5; 5.0 and 7.5 t ha-1 CD + ORP had comparable leaf areas. Application of 10.0 t ha-1 CD + ORP gave the highest okra fruit yield which was comparable with yields from 2.5; 5.0 and 7.5 t ha-1 CD +ORP that ranged from 2.92 to 3.05 t ha-1. Pod length and pod circumference were significantly higher with ORP + 10.0 or 7.5 t ha-1 CD. Plants from the unfertilized control treatment had significantly shorter pods with lower circumference than all the fertilized plants. Okra fruit yield is significantly increased with organic fertilizer fortification with ORP.