FOLIAR APPLICATION OF MICRONUTRIENTS PROMOTES GROWTH AND YIELD-RELATED ATTRIBUTES OF OKRA (Abelmoschus esculentus L.) IN A SLIGHTLY SALINIZED AREA

Background: Micronutrients are required in trace amounts, but are importantly associated with plant growth and development. While soil salinity causes a frequent micronutrient deficiency in soil, the condition withholds plant growth, development, and eventually crop production. Since foliar application of micronutrient provides rapid nutrient absorption compared to soil amendments, it may confer straightforward mitigation of salinity stress. However, micronutrients availability to plants under saline conditions has drawn limited attention. Objective: To study the role of four micronutrients namely boron (B), zinc (Zn), chlorine (Cl), and silicon (Si) as well as their combinations as foliar application on growth, development, and yield responses of ‘okra cv. Nulok F₁’ in a naturally very slightly salinized soil. Methodology: The research site belongs to Young Meghna Estuarine Flood Plain under the soil of Agro-ecological Zones (AEZ)-18. The area of EC dsm^-1 2.39 is used for the cultivation of horticultural and cereal crops. The one-factor experiment was designed in a randomized complete block design with three replications and six treatments. The factor having six different micronutrients and their combinations under saline soil viz. T₁ = control (untreated), T₂ = 0.2 % B as solubor^®, T₃ = 0.2 % ZnSO₄, T₄ = 0.2 % KCl, T₅ = 0.2% SiO₂, and T₆ = 0.2% solubor^® B + 0.2% ZnSO₄ + 0.2% SiO₂ + 0.2% KCl. Result: A number of foliar treatments of micronutrients substantially improved plant height, stem diameter, leaf number, depth of root, fruit length, number of fruits, single fruit weight, yield plot^-1, and total yield. Implication: Among the treatments, Si, and a mixture of solubor^® B, Zn, Cl, and Si significantly uphold growth and yield-related attributes of okra indicating them as suitable micronutrients for okra production in salt-affected areas. Conclusion: The foliar application of Si and the mixtures of the four aforementioned micronutrients might enhance the growth and yield attributes of ‘okra cv. Nulok F₁’ under salinity stress.