Varietal performance and correlation of okra pod yield and yield components
Abstract Field irrigation experiments were conducted to assess the varietal performance and correlation of pod yield and yield attributes under irrigation at the Teaching and Research Farm, University of Maiduguri, Nigeria, during the 2015 and 2016 dry seasons. The results revealed that the most outstanding for fresh pod yield per plant were okra cultivar Kwadag Y’ar gagure Salkade, and Kwadam, in descending order, with yield ranging from 580.38 to 622.67 g, while the Composite cultivar had the lowest value of pod yield of 428.62 g over the two years. The greatest average values for the number of pods per plant and the number of primary branches per plant were observed for Salkade and Y’ar gagure, respectively. Highest fresh pod length and fresh pod diameter were also exhibited for Salkade and Kwadag. The genotypic coefficient of variation was higher than the phenotypic variation for the entire yield-contributing characters. Days to 50% flowering were positive and highly significant differences associated with plant height, number of pods per plant, and fresh weight per pod could be observed. Path coefficient analysis showed that the number of pods per plant exhibited positive and direct influence on the pod yield across the studied years. Indirect influence of other yield components through this character also contributed mainly towards pod yield. Therefore, days to 50% flowering, plant height, pod length, number of pods per plant, pod diameter, number of primary branches per plant, and fresh weight per pod could be taken into consideration for the selection and development of high pod-yielding varieties in okra.
Interactive Effects of Genotype and Nitrogen on the Phenology and Yield Determination of Okra [Abelmoschus esculentus (L.)]
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.
Seed yield and quality of okra as influenced by sowing dates
Field trials were conducted at the Gangetic Alluvium of eastern India to find out the most suitable sowing time to achieve higher yield, comparatively less incidence of yellow vein mosaic virus (YVMV) and quality seed of okra over four consecutive years having seven sowing times at fortnight interval (1st February, 16th February, 1st March, 16th March, 1st April, 16th April and 1st May). The seed yield attributing characters differed significantly with different sowing dates. The maximum matured pods per plant (14.57) and the longest matured pod (18.00 cm) was observed from 1st April sowing which was statistically similar with that of number and length recorded between16th February and 1st May sowing dates. However, seeds sown in 16th February significantly produced the highest mean seed yield (6.84 q/ha) followed by 1st March (6.18 q/ha) sowing over the years. Seeds sown in either 16th February or 1st March produced the best quality seed (85.30 and 80.0% germination; 45.0 and 44.0 g test weight 29.75; 11.79 and 11.64 vigour index, respectively). Correlation study clearly revealed that seeds per pod and test weight significantly contributed to the seed yield. Rainfall was found to be the major contributor with a significant negative effect on yield over the year. The seed yield of okra was highly influenced by the incidence of YVMV and higher yield was obtained during disease free period, particularly between February and March. The income per rupee investment of okra seed crop was found to be the maximum (2.40) when sown at 2nd fortnight of February. Key words : Okra, seed yield, seed quality, economics.