Comparison of Agromorphological Performances of Onion Varieties (Allium cepa L.) Violet De Galmi and Ares in Rainy and Dry Seasons and Prediction of Bulb Yield

Abstract

Côte d'Ivoire still imports high onions volumes to fit national demand. One solution to this problem would be to provide farmers with appropriate varieties.  The aim of this study is to select a variety that is adapted to the different growing seasons from savanah agroclimate zones, namely in Korhogo, Northern country. In this study, the agromorphological performances of the onion varieties Ares and Violet De Galmi were compared in the dry and rainy seasons using the Student's T test at a significance level of 5%. A multiple linear regression analysis was performed to predict bulb yield as a function of vegetative characteristics. The results showed that the Ares variety performed best in both the wet and dry seasons. This performance was better expressed in the dry season with a bulb yield of 31.17 ± 5.94 kg/ 6m² compared with 12.97 ± 3.45 kg/ 6m² for Violet De Galmi. The Ares variety produced a higher yield of 25.20 ± 9.00 kg/ 6 m² in the rainy season than Violet De Galmi, which produced 8.21 kg of bulbs/ 6m². This performance by Ares can be explained by the development of its vegetative characteristics. Bulb yield can be estimated on the basis of vegetative characteristics such as plant height (PH), number of leaves (NL) and leaf length (MLL) according to the following equation: Yield = -33 + 7.90 PH + 2.26NL - 7.41 MLL. The Ares variety can be recommended for cultivation in all seasons.