Effect of N Fertilization on Pod and Seed Characteristics of Okra in Relation to Plant Part

Four cultivars of okra (Abelmoschus esculentus [L.] Moench. cv. ‘Boyiatiou’, ‘Veloudo’, ‘Pylaias’ and ‘Clemson’) were sown on 1st of May (Experiment 1) and 20th of May, 2011 (Experiment 2) and fertilized with three nitrogen levels (150, 300 and 450 mg N l-1). The pods were harvested from three plant parts (upper, middle and lower part) and the seeds were extracted from the pods either immediately after harvest or after storage for 15 days at room temperature. The present study provides new information on the seed quality of four cultivars of okra in relation to N level and the region (upper, lower and middle) of the plant from which harvest took place. N application generally increased flowering, but pod set increased only in ‘Boyiatiou’. Pod dimensions (length and diameter) were largely unaffected by N level, irrespective of the position of the pods on the plant, as was the 100-seed weight and seed germination. The slight (insignificant) increase in seed germination of ‘Boyiatiou’ in response to N is worthy of further study in view of the susceptibility of this cultivar to seed hardness. There was no benefit of pod after-ripening, but seed storage for 18 months at room temperature proved to be a positive way to improve seed quality, especially in ‘Boyiatiou’.