You probably don’t want to miss this session if you have ever found yourself wondering about whether you really need to apply micronutrients in your field. Over half of the elements present in the Periodic Table have been observed in plant tissues. However, presently only 17 elements are considered essential for plants. These nutrients are broadly divided into nine macronutrients: carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) and seven micronutrients: boron (B), chloride (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn). In addition, cobalt (Co) is considered essential for symbiotic N fixation in legumes and other species. There are other elements that have been defined as beneficial or functional (metabolic) nutrients: aluminum (Al), cerium (Ce), lanthanum (La), nickel (Ni), silicon (Si), and sodium (Na). While we will touch on all these different elements, the main focus of the discussion will be on the first seven. We will start off by talking about what makes these nutrients essential and how knowing some of their functions in plants can help us visually diagnose problems in the field. We will continue on by talking about where micronutrient deficiency or toxicity problems are most likely to occur due to environmental and soil factors. We will then dive into a discussion on the value of soil and plant tissue analysis as a diagnostic tool and how to properly interpret those analytical results.  We will conclude by discussing micronutrient fertilizer technology and fertilization methods to correct micronutrient problems.