Abstract:
Onions are crucial vegetable and cash crops in Ethiopia, but farmers struggle to optimize
bulb yield and shelf life due to unbalanced fertilizer use. Nitrogen and phosphorus are
commonly used, but potassium (K) is also important. This study evaluated the effect of
potassium fertilizer sources and rates on bulb yield and shelf life of onion varieties in Jimma
during 2023/2024. Two varieties (Bombay Red and Nafis), two potassium sources (potassium
nitrate and potassium chloride), and four application rates (0, 60, 120, 180 kg/ha) were
studied using 2*2*4 factorial arranged in Randomized Complete Block Design (RCBD) with
three replications. Data on growth, yield, and shelf life were analyzed using SAS. Results
showed significant the main effects of variety, potassium source, and rate on most
parameters. Nafis had a taller plant height (53.99cm) and better shelf life (a rotting number
for Nafis is approximately 23.21% less than that of Bombay Red), whereas, Bombay Red had
a higher yield (24.98 tons/ha. Potassium nitrate was more effective than potassium chloride
on plant height (54.06cm), sheath diameter (12.73mm), total bulb yield (24.47 ton/ha),
