The Micronutrients & Plant Growth - Zinc's Role
It's a well-known fact that plants require Zinc (Zn) as it activates enzymes. The soil's natural reserves, some liming materials contribute even more zinc to the soil. Application of zinc containing fungicides and animal and poultry waste products can also add zinc to the soil.
The first obvious symptom of zinc deficiency is interveinal chlorosis of the upper (youngest) leaves. Afterwards, shoot growth slows down; giving the affected plant parts a rosette-like appearance. Zinc deficiencies in corn and sorghum are typified by a wide band of white tissue on each side of the leaf midrib. This symptom is known as "white bud." "Little leaf" in cotton is also due to zinc deficiency.