International Journal of Plant Production

, Volume 13, Issue 1, pp 73–90 | Cite as

Interactive Effects of Genotype and Nitrogen on the Phenology and Yield Determination of Okra [Abelmoschus esculentus (L.)]

  • Saba Fatima
  • Muhammad Sohail KhanEmail author
  • Muhammad Nadeem
  • Ilham Khan
  • Kashif Waseem
  • Muhammad Nisar
  • Muhammad Iqbal


Limited studies have been conducted to assess key yield-determining processes and their inter-relationships in okra under both nitrogen (N) poor as well as optimum growing environments on a set of contrasting genotypes. Therefore, in this study, we analyze the yield formation in two diverse genotypes of okra (Sabz Pari ‘SP’ and Arka Anamika ‘AA’) across seven contrasting N environments (0–300 kg ha−1) and to determine effects of genetic (G), environmental (E) and their interaction (G × E) on a set of traits relevant to vegetative growth, onset of reproductive cycle, pod characteristics, and yield. The effects of G, E, and G × E were significant for majority of traits. Ranking of genotypes changed across the environments for most of the traits indicating a cross-over type G × E interactions. Majority of traits showed differential response to varied N availability. Mean values of plant height, canopy diameter, leaves plant−1, leaf area plant−1, stem girth, internodes plant−1, length of internode, pod length, pod diameter, and pod yield enhanced with rising N (50–300 kg ha−1). However, pod fresh weight and number of pods plant−1 declined with N availability above 150 kg ha−1. The onset of first flowering delayed with decline in N availability and vice versa. Late maturing genotype AA indicated a better yield potential across N environments by producing 50.96% more yield over early maturing genotype SP. There existed significant inter-relationships among most of the traits. Four traits including leaf area plant−1, pod diameter, pod fresh weight and number of pods plant−1 explained most of the variance (97.4%) in pod yield. It was concluded that gain in these parameters may lead to an increase in pod yield. Our approach could be useful in developing an indirect selection criterion for yield improvement in okra and could provide a theoretical framework for breeding programmes in developing an ideal genotype.


Abelmoschus esculentus Component traits Genotype-by-environment (G × E) interaction Key traits Plant phenology Yield 



We thank the staff of Department of Soil and Environmental Sciences, the University of Agriculture, Peshawar, Pakistan for performing the soil analysis.

Compliance with ethical standards

Conflict of interest

The authors declare no conflict of interest.


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Authors and Affiliations

  1. 1.Department of Horticulture, Faculty of AgricultureGomal UniversityDera Ismail KhanPakistan
  2. 2.Institute of Chemical SciencesGomal UniversityDera Ismail KhanPakistan

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