Abstrakt

Effects of different levels of potassium fertilization on yield, quality and storage life of onion (Allium cepa L.) at Jimma, Southwestern Ethiopia.

Muluneh Bekele

In Ethiopia the yield of Onion (Allium cepa L.) is far below the national standards owing to several factors; absence of location specific fertilizer recommendation being the major among others. Thus, field and laboratory experiments were undertaken at Jimma in collaboration with Jimma University, Department of Post-harvest Management. Potassium sulphate fertilizer as TSP was used at 0, 40, 80 and 120 kg ha-1 levels with three replications. GenStat 12.1 version computer software packages were employed to analyze the data. From the results potassium fertilizer application at different levels showed significant effects on growth, yield and quality parameters i.e. Plant height, leaf length, leaf number, sheath length, bolters percentage, days to maturity, harvest index, mean bulb weight, bulb length, bulb diameter, TSS (oBrix), DMC (%) and bulb shape index. Similarly, keeping quality of the onion bulbs including bulb sprouts (%), weight loss (%), weeks to 50% bulb sprouts and storage rots (%) were highly influenced by application of K at different levels. Maximum (120 kgha-1) application of potassium significantly decreased bulb rots (%), bulb sprouts (%), weight loss (%) and prolonged weeks to 50% bulb sprout during the two month storage time at ambient storage temperature and humidity. This could be recommended for the uses by potential onion investors or farmers in the study area. Nevertheless, more researches are needed in different locations and on different soils in various season to come up with specific soil test based fertilizer recommendation.