Effects of Planting Time and Mother Bulb Size on Onion ( Allium cepa L.) Seed Yield and Quality at Kobo Woreda, Northern Ethiopia

摘要

A field experiment was conducted at Sirinka Agricultural Research centre Kobo sub center research field during the 2012/2013 under irrigation condition with the objective of assessing the effect of different planting time (October 25, November 5 and November 15) and mother bulb sizes (2-3, 3.1-4 and 4.1-5 cm) on onion seed yield and quality. The study was conducted by using 3x3 factorial design with three replications. Data was collected on growth, yield and quality parameters and analyzed using SAS version 9.2 statistical software. The results of the study showed significant interactions between mother bulb size and planting time on days to 50% flowering, scape diameter (cm), seed yield per plant (g), seed yield per hectare (kg) and germination index. The maximum seed yield (1155.73 kg ha-1) was obtained from large bulbs planted on October 25 while the least (75.15 kg ha-1) from small bulbs planted on November 15. In terms of germination index, the highest (6.03) was obtained from the large bulbs planted on October 25, whereas the lowest germination index (3.37) was from small bulbs planted on November 15. Early planting on October 25 increased germination percentage by 39% than the last planting 15 November. Regarding mother bulb size, large bulbs increased germination percentage by 13.32% than the small bulbs. Correlation coefficient indicated that umbel diameter, seed number per umbel, seed weight per umbel and seed yield per plant were found to have positively and highly significantly correlated with seed yield per hectare. Therefore, based on the findings of the current study, early planting (October 25) of large bulbs (4.1-5 cm) can be used for high yield and better quality of onion seeds. Considering the above mentioned results, it would be advisable to further investgated the seed production potential of different onion types at different locations over years so as to come up with best recommendation. In addition, plant spacing, fertilizer rate and storage methods of onion seed could also be considered. Furthermore, the seed quality performance of imported and locally produced onion seeds could be investigated to promote the onion seed industry.