Agro-morphological characterization of Okra (Abelmoschus species) for biotic stress and yield contributing traits under rainfed conditions in South Western Nigeria

Seventy accessions of oOkra (Abelmoschus caillei and Abelmoschus esculentus) were evaluated using phenotypic observations, expression of traits, resistance to virus vectors and diseases by symptom expressions. The genotypes were laid out in alpha lattice design and characterized using nine qualitative and twelve quantitative traits. The results revealed considerable morphological variability among okra accessions for studied traits. Green smooth pods with smooth pigmented peduncle, pigmented petiole, pigmented leaf vein and stems were predominant among the A. caillei and A. esculentus accessions. Okra genotypes characterized by horizontal fruit orientation dominated the A. caillei group while erect fruit orientation was preponderance among the A. esculentus group. Nine out of the twelve quantitative traits were discriminatory and grouped the okra accessions into six main groups. Association between traits showed moderate to high significant correlation between average stem cross section and most yield component traits (increased fruit length, plant height at maturity, average number of seeds per plant, days to flowering and 1000 seed weight). The genotypes varied in their level of resistance to insect attack and virus disease with A. caillei exhibiting about 22% and 66% level of tolerance over A. esculentus species for Podagrica and whitefly resistance respectively. A. caillei group exhibited more resistance when we considered the damage caused by virus disease. The promising genotypes identified in this study will facilitate the selection of parents needed to develop promising resilient okra varieties adaptable to the diverse okra growing environments in the region.