Question

‘Little leaf disease’ is developed due to deficiency of
A) Copper
B) Sodium
C) Molybdenum
D) Zinc

Answer 1

Hint: It is an element which has an atomic number 30. It is the first element of a periodic table in group 12. Deficiency of this mineral leads to short internodes, interveinal chlorosis appearing first marginally on older leaves, followed by necrosis and stunted growth.

Complete Answer:
- Various mineral elements have their unique roles within the plant body. It cannot be substituted with some other element.
- Deficiency symptoms are chronic disorders which are externally visible due to the deficiency of certain basic mineral elements. A plant body element deficiency hampers development, growth, and metabolism.

Now, let us find the solution from the options-
1) Zinc is essential for tryptophan synthesis and protein synthesis. It functions as a multiple enzyme activator too.
- Little leaf and white bud diseases are caused by a zinc deficiency.
- The most distinguishing symptom of sweetpotato zinc deficiency is a decrease in the size of young leaves.
- The leaves are thickened, but not necessarily twisted, and may be as small as 1-3 cm long.
- Zinc deficiency creates malformations and rosettes to the leaf.
2) Copper deficiency causes die-back disease, and potato tuber blackening.
3) Deficiency of molybdenum causes mottled chlorosis with marginal necrosis, cabbage whiptail disease and also cauliflower inflorescence loosening.

Thus, the correct answer is option (D) Zinc.

Note: Sodium deficiency tends to have no effects, because it is not an important element. Sodium is not a nutrient for plants, but it plays a part in soil quality. High sodium levels suggest problems with salinity, such as poor soil quality.