Mineral Nutrition — BIOLOGY STD 11 Science — Question

Essential elements are required in very low quantity by plants and this especially holds true for micronutrients. Even a slight deviation from this quantity can be detrimental to the plant. If the level of micronutrients increases even by 10%, this can produce toxicity in plants. Let us take an example of manganese which is an important micronutrient for plants. Manganese shows following properties:

1. It competes with iron and magnesium for uptake.
2. It competes with magnesium for binding to specific enzymes.
3. It inhibits translocation of calcium to shoot apex.

Thus, excess of manganese can hamper the uptake of iron and magnesium and plant may begin to suffer from deficiency of iron and magnesium. Excess of manganese can prevent magnesium from binding with certain enzymes. This can hamper many metabolic activities. Inhibition of translocation of calcium to shoot apex can result in stunted growth.