Determination of appropriate planting time for better seed yield of onion (Allium cepa) varieties at selected districts of Gamo Zone, Southern Ethiopia

Onion is among the important vegetable crops commercially grown both by large and small scale farmers in Ethiopia as well as Arba Minch area. Its seed production (high seed yield and quality) depends on a number of factors such as planting date, bulb size, varieties, soil fertility, growing environments, plant population and adequate plant protection measures. Among these factors, planting time, varieties and growing environment are believed to have a remarkable influence on seed production of onion. The main objective of this study is to determine appropriate planting time for onion seed production and to select high seed yielder onion variety. Mother bulb was produced during June to August and the bulbs are stored in diffused light storage (DLS) about 3o days. Field experiment was conducted in Gamo Zone, Mirab Abaya woreda for two successive years (2021 - 2022) using spacing of 40cm x 20cm in Plot size of 3m x 2m.The experiment consisted of two varieties (Bombay red & Nafis) and four planting times (Mid September, Early October, Late October & Early November) in completely randomized block design in factorial arrangement replicated three times. ANOVA revealed that highly significant differences among treatments (P<0.01) were observed for most characters studied. Mean performance of combined result indicated that variety Bombay red planted in mid October gave highest seed yield (1178.3 kg/ha) whereas the lowest seed yield was recorded from the same variety planted at early October (415.0 kg/ha). Therefore, variety mid October is recommended as a suitable planting time of seed production for variety Bombay red and to be popularized in the study area for better onion seed yield production.