Correct Answer - B
Moderate increase in the amount of microutrients causes toxicity. Toxicity levels for any element also vary for different plants. Many times, excessof an element may inhibit the uptake of another element. For example, the promient sympton of manganess toxicity is the apperarance of brown spots surrounded by chlorotic veins. Manganese competes with iron and magnesium for uptake and with magnesium with for binding with enzymes. manganese also of manganese may induce deficiencies of iron, magnesium and calcuim.
