Response of micronutrients on qualitative and quantitative parameters of onion (Allium cepa L.)

A field experiment was conducted to determine the response of micronutrients on qualitative and quantitative parameters of onion (Allium cepa L.) Cv. Pusa Red. The experiment was laid out in Randomized Block Design with three replications. Treatments consists of five micronutrients viz., Cu, Zn, B, Fe, and Mn each in two concentrations and their combinations (Cu @ 2, 4 mg L⁻¹), (Zn @ 4, 6 mg L⁻¹), (B @ 1, 2 mg L⁻¹), (Fe @ 100, 200 mg L⁻¹), (Mn @ 1, 2 mg L⁻¹) along with control. Results were found to be significant in most of the yield contributing parameters of onion. The number of leaves per plant (12.4), plant height (64.9 cm), leaf width (3.9 cm), leaf length (58.9 cm), neck length (9.2 cm), neck diameter (2.0 cm), roots length (8.1 cm), number of roots per plant (160.3), number of scales (12.0), soluble sugar (6.1%), TSS (13.9%), volume of bulbs (162.9ml), specific gravity (1.2), dry weight of bulbs (12.3 gm), dry weight of leaves (19.6 gm), dry weight of roots (1.5 gm), total weight of plants (213.9 gm), fresh weight of bulbs (162.9 gm), fresh weight of leaves (55.3 gm), fresh weight of roots (3.6 gm), bulb diameter (7.2 cm), and yield ha⁻¹ (379.6 q) were maximum found in treatment T₃ (Zn @ 4mg L⁻¹) and T₁₁ (Cu @ 2 mgL⁻¹ + Zn @ 4 mgL⁻¹ + B @ 1 mgL⁻¹ + Fe @ 100 mgL⁻¹ + Mn @ 1mgL⁻¹) while treatment T₄ (Zn @ 6 mgL⁻¹) show maximum ascorbic acid content (17.4 mg). The obtained results clearly indicated that using the foliar application of T₃ (Zn @ 4 mgL⁻¹) and T₁₁ (Cu @ 2 mgL⁻¹ + Zn @ 4 mgL⁻¹ + B @ 1 mgL⁻¹ + Fe @ 100 mgL⁻¹ + Mn @ 1mgL⁻¹) significantly increased plant vegetative growth parameters, total yield and quality contents in bulb tissues compared to other micronutrients and control. foliar application of zinc sulphate (Zn @ 4 mgL⁻¹) was found to show best effect on growth and quality parameters, and combination of micronutrients viz, treatment T₁₁ (Cu @ 2 mgL⁻¹ + Zn @ 4 mgL⁻¹ + B @ 1 mgL⁻¹ + Fe @ 100 mgL⁻¹ + Mn @ 1 mgL⁻¹), was found most effective with regards yield and quality parameters.