Onions are vegetables that contain plant potent compounds that have been shown to promote human health in several ways. The biological productivity in terms of growth, yield and bulb qualities have been shown to vary among varietal type. Hence a field experiment was carried out to compare the growth, yield and bulb quality of two onions varieties (Allium cepa L. cv Red and White creoles). The field layout followed complete randomized block design with three replications. The data on biological yield and biochemical parameters were subjected to student t-test at 0.05 level of significance. The results showed that White creole had higher growth than Red creole. However significantly (p≤ 0.05) higher bulb yield was recorded in Red creole (1126kg/ha) compared to White creole (600kg/ha). Parameters such as number of bulb per plant, length and diameter did not show statistical differences. Composition of the bulb in terms of percentage moisture, ash, crude protein, crude fat, crude fibre, carbohydrate and energy value showed values that ranged from 86.1 ± 0.40 - 86.4 ± 0.64%, 0.6 ± 0.00 - 0.7 ± 0.02%, 3.3 ± 0.01- 3.6 ± 0.18%, 0.8 ± 0.01- 0.9 ± 0.01%, 1.7 ± 0.18 - 2.6 ± 0.07%, 7.0 ± 0.47 - 6.1 ± 0.29%, 48.9 ± 1.97 - 47.1 ± 1.93 kcal respectively. The moisture, protein, ash, carbohydrate and energy value of the two varieties did not show statistical differences. The vitamin C and sulphur contents values which ranged from 5.1 ± 0.08 - 3.5 ± 0.28 mg/100g and 248.1 ± 8.10 - 194.7 ± 3.40 mg/kg respectively were found to be significantly higher in Red creole than White creole. The results of this study suggests that Red creole consumption is better in the maintenance of healthy living while, White creole on account of high fibre content could be recommended for non-obese patients with indigestion problem.
Keywords: Onion bulb, growth, proximate composition, vitamin C and sulphur