Influence of Genotype, Fruit Maturity and Post-Harvest Ripening On Germination and Early Seedling Performance in Pepper (Capsicum Sp.)

Abstract

An experiment to evaluate the influence of fruit maturity and after ripening on germination and early seedling performance in Pepper (Capsicum spp.) was conducted at the research field of the department of Crop Science, University of Ghana, Legon between November 2016 and May 2017. Five pepper genotypes were grown on the field in a Randomized Complete Block Design and seeds extracted at two maturity stages namely, physiologically matured and full red ripe stages. Seeds were extracted from fuits at physiological maturity and at fully ripe stage. Number of seeds per fruit, seed dry weight, food reserves (carbohydrate, protein, fat) content in seeds, total phenols and total flavonoids content in seeds were determined in the laboratory. A second experiment arranged in a completely randomized design to evaluate germination of seeds harvested from pepper fruits at the different maturity stages was conducted on a Jacobsen germination table in the laboratory. The genotype Shito Adope obtained the highest germination percentage of 88.5%, which was significantly higher than Bird beak (83.5%), Legon 18 (68.5%), Ojemma (47.25%) and Red Scotch Bonnet (13%) for seeds harvested at full ripe stage whiles for seeds from physiologically mature fruits that had gone through after ripening, Shito Adope had a germination percentage of 68% which was significantly different from Bird beak (46%), Legon 18 (28.5%), Ojemma (23.5%) and Red Scotch Bonnet (3.75%). A third experiment arranged in a completely randomized design was conducted to evaluate early seedling performance of seeds of the genotypes harvested at the different maturity stages. From the results obtained, it was observed that harvesting stage significantly affected seed yield (number of seeds / fruit), seed quality and early seedling performance in all the genotypes studied. Seeds from fully ripe fruits showed higher germination and early seedling performance for all five genotypes studied. Seeds from fully ripe fruits performed significantly better than those taken from physiologically mature fruits that had gone through after ripening in terms of emergence percentage and early seedling performance as well as food reserve composition. Correlation analysis showed positive associations in all food reserve components and percentage germination and emergence as well as seedling vigour. However, there were negative correlations between phytochemicals present in seeds and percentage germination, percentage emergence as well as seedling vigour. For better germination and vigour, extraction of pepper seeds from half ripe fruits should be avoided.