H. Haryani1*, A. Aswanimiyuni1, F. Norfadzrin1, S. A. Syed Hussein2,M. A. Abu Hassan2, A. Azman1
Generally, plants need major nutrients such as nitrogen, phosphorus and potassium in order to grow well. Minor nutrients are also essential for healthy plant growth but in much smaller quantities. While trace elements called micronutrients which are also essential for healthy plant growth but only in very small quantities, for the proper functioning of enzyme, hormones and vitamins. The micronutrients are Boron (B), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo), Zinc (Zn), and Chloride (Cl) (1). Micronutrients play important roles in physiological functions of plants. Fe, Mn and Cu catalyze principally redox processes by electron transfer while Zn and Fe from enzyme-substrate complexes. Zn also enhances enzyme reactions by influencing the molecular configuration of an enzyme or substrate (2). Micronutrients deficiency is widespread in many Asian countries due to the calcerous nature of soils, high pH, low organic matter, salt stress, continuous drought, high bicarbonate content in irrigation water and imbalanced application of fertilizers. Some of the adverse effects of micronutrient deficiency-induced stress in plants include low crop yield and quality, imperfect plant morphological structure (such as fewer xylem vessels of small size), widespread infestation of various diseases and pests, low activation of phytosiderophores and lower fertilizer use efficiency (3). Micronutrients also play key roles in the release of carbon dioxide and in optimizing the function of vitamin A and the immune systems (4). Several studies have reported the significant reduction in growth and yield of different plant species in soil deficient in Fe, Mn, Zn, Cu, B and other micronutrients. Micronutrient deficiency can greatly disturb plant yield and quality and the health of domestic animals and humans (5).