Effect of Fertilizer and Drying Methods on Seed Germination of Okra (Abelmoschus esculentus L.) Cultivars at Different Harvesting Times

摘要

Okra hardseedness results in slow and uneven germination. This study determined the effects of fertilizer application and drying methods on hardseedness breakdown of okra (Abelmoschus esculentus L.) cultivars (cv. Boyiatiou’, ‘Veloudo’, ‘Clemson’ and ‘Pylias’). Three fertilizer level (150, 300 and 450 mg L-1 N) and two different drying methods (seeds and pods) were applied. The results showed that by increasing N application from 150 to 450 mg L-1 N increased seed germination regardless of drying method, whereas the application of 450 mg L-1 N resulted in the higher seed germination percentage, regardless of cultivar and drying method. In addition, harvesting seeds at 40 days after flowering (DAF) resulted in an increase of germination rate, especially when 450 mg L-1 N were applied. Seed germination of seeds harvested at 40 to 50 days after flowering (DAF) was reduced, especially when seed drying instead of pod drying was applied. However, for cv. ‘Boyiatiou’ the application of 150 mg L-1 N resulted in higher percentage of hard seeds and lower seed germination rate, whereas pod drying reduced the occurrence of hardseedness. For all cultivars, seeds from the middle part of the plant had a higher seed germination percentage at 450 mg L-1 N level, regardless of drying methods. In conclusion, increasing the N application rate up to 450 mg L-1, harvesting seeds at 40 DAF and collecting seeds from the middle part of the plant could be a useful means for reducing the occurrence of hardseedness and increasing germination percentage of okra seeds.