Growth and bulb yield of some onion (Allium cepa L.) varieties as influenced by NPS fertilizer at Dambi Dollo University Research site, Western Ethiopia

Abstract

Onions are the main crops in Ethiopian regular nutrition, cultivated year round under rain-fed and irrigated conditions. The low production and productivity of onion crops in Ethiopia as compared to other onion producing countries were due to disease, insect pest, lack of improved varieties, low level use improved varieties of onion and improper agronomic practices used by farmers. A field experiment was conducted at Dambi Dollo University research site for 2 consecutive years (2020 and 2021 cropping season) under rain-fed to evaluate effect of NPS fertilizer rates on performance of onion varieties (Allium cepa L.). The experiment was laid out using Randomized Complete Block Design with three replications in a factorial mixture of four levels of NPS fertilizer (0, 50, 100, and 150 kg ha⁻¹) and three varieties (Adama red, Monarch, and Nafis). Variance Analysis indicated that NPS fertilizer and varieties were expressively affected days to 90% physiological maturity, marketable and unmarketable yield, and total bulb yield of onion crop but not significantly influenced by their interaction. The number of leaves per plant and plant height was significantly influenced by the main effect of varieties, NPS fertilizer rates and their interaction. The highest values for the number of leaves per plant (16.08) recorded at 150 kg ha⁻¹ and monarch variety. Moreover, days to 90% physiological maturity (134.8 days) and total bulb yield (29.35 t ha⁻¹) were noted from the highest NPS application rate of 200 kg ha⁻¹. Similarly, the maximum plant height (16.08 cm) and marketable onion bulb yield (26.41 t ha⁻¹) were obtained from 150 kg ha⁻¹ NPS rate. Hence, based on the highest marketable onion bulb yield gained, Nafis variety of onion crop and 150 kg ha⁻¹ of NPS fertilizer rates should be advised for production in the study area and other areas with similar agro-ecological condition.

Keywords:

• Growth
• NPS fertilizer
• onion
• bulb yield

Public Interest Statement

Onions, being a main vegetable crop, have a massive potential in developing the Ethiopian economy through improving smallholder farmers, creation of employment opportunities, and source of income. The country has a diverse agro climatic condition, abundant cultivable and irrigable land and favorable policy environment for growing a wide variety of onions. However, due to due to limited knowledge about the NPS on the vegetative growth and yield of onion, many farmers still custom the same amount of NPS fertilizer of all varieties of onion in the study area. Research-based recommendations on the level of NPS fertilizer can increase onion crop production and increase the benefits of local farmers.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors received no direct funding for this research.

Notes on contributors

Chala Kitila

Chala Kitila (MSc in Horticulture) is a Lecturer, Researcher and Reviewer at the Department of Plant Sciences, Dambi Dollo University. His main research interest is on Developing Improved Production Technologies and Management of Horticultural Crops.

Abdisa Abraham is a Lecturer, Researcher, and Reviewer at the Department of Natural Resources Management program, Dambi Dollo University. He specializes in Soil Sciences from Jimma University. His research interest is on Integrated Soil Fertility management.

Soressa Shuma is a Lecturer, Researcher, and Reviewer at Animal Science Department, Dambi Dollo University. He is specialized in Animal Production from Wollega University. His research interest is on Dairy Production, Poultry and Fisheries.