Evaluation of the Production and Preservation Ability of Four Varieties of Onions (Allium cepa L., Alliaceae) in Korhogo, Northern Côte d’Ivoire

Aims: The study was investigated the ability of producing and preserving fresh onion bulbs from various varieties to fit sustainable onion culture in Ivorian agroclimatic conditions.

Study Design: Four onion varieties, namely Dayo, Safari, Red Star and Red Jewel, were cultivated, and their fresh bulbs harvested and stored for the investigation of both physical and environmental parameters during the storage.

Place and Duration of Study: The onion culture and the physical and environmental measures were carried out from the experimental field and at the laboratory of Peleforo GON COULIBALY University, Korhogo, Côte d’Ivoire, over a period from December 2021 to September 2022.

Methodology: Onion bulbs of different varieties were cultivated on the experimental site. Thus, 10 kg of onion fresh bulbs per variety were collected in bags and stored in the store under ambient conditions, and then environmental (temperature and humidity) and physical (sprouting, rotting and loss rate, physiological weight loss and dry matter) parameters were determined at 30 days intervals stages for four months storage period. The statistical processing consisted of the comparison of means according to the ANOVA test, the study of correlation between parameters and the multivariate PCA analysis.

Results: The production yield varies between 17.16 and 23.69 t/Ha with the best production rates observed from Red Jewel and Red Star varieties. The average temperature was recorded between 26°C and 27.9°C while the average humidity increases from 77% (June) to 85% (September). Red Star and Red Jewel varieties assumed the highest bulbs loss rates with respective values of 81.58% and 90.38%, while Dayo and Safari varieties displayed losses of 19.88% and 14.29% over the four months storage. Sprouting represents the main causes of the losses of both red onion varieties. Furthermore, the weight loss and the dry matter vary according to the onion variety and the storage duration. After 4 months storage, the physiological weight loss of preserved onion bulbs remains minimal for Dayo and Safari varieties, while it’s more significant from red onions reaching 14.83% for Red Jewel. The dry matter content of the onion bulbs decreases with the storage during with Dayo and Safari provided higher values.

Conclusion: The red onion varieties Red Jewel and Red Star display more production potential for onion bulbs. But Dayo and Safari onion bulbs seem to have good preservation abilities compared to the red varieties under the storage conditions studied.