The appearance of plant micronutrient deficiency symptoms raises immediate concerns that something critical was overlooked in the planning stage and that crop yields will likely be reduced. Deficiency symptoms appear in the plant after the internal metabolism has been sufficiently disrupted to show visible problems. Even if no micronutrient deficiency symptoms are observed in the field, many farmers are now conducting their own simple trials to see if a certain micronutrient might be holding back their push for ever-increasing yields.
When a specific micronutrient is lacking, remember that not all fertilizer sources are equivalent in meeting crop needs. Selecting a form of micronutrient that will provide a soluble form of the nutrient requires careful attention. Very little micronutrient is actually needed by plants, but supplying it in an available form is a challenge.