Question

Dieback' of citrus and 'reclamation' of legumes and cereals is due to deficiency of
A. Copper
B. Zinc
C. Sodium
D. Molybdenum

Answer 1

Hint: Dieback is a disease commonly found in woody plants. It is characterized by death of twigs, branches, shoots, or roots, starting at the tips. In reclamation, seed maturity stops due to deficiency of some ions.

Complete answer:
In this question, we have asked about the ion, whose deficiency leads to diseases called Dieback' of citrus and 'reclamation' of legumes and cereals. As we know plants require mineral ions for growth and development. These mineral jobs are divided into two categories: macronutrient and micronutrients. Macronutrients are required in large amounts and micronutrients are required in low amounts. Copper is an important micronutrient, plants need it in very low amounts. It is required for lignification of plants and it is the main component of protein and enzymes, it is also important for metabolic activities of plants. If there is a deficiency of copper then lignification of plants will not occur or reduce. Due to reduction in lignification, the leaves of citrus plants wilt, become brown in color or even die. This condition is called 'Dieback' of citrus or 'reclamation' of legumes and cereals. So, Dieback' of citrus and 'reclamation' of legumes and cereals is due to deficiency of copper.

So, the correct option is A. Copper.

Note:
Deficiency of copper generally occurs in leaves as copper ion is immobile. Root and stem can take copper directly from the soil but this copper can't travel to leaves. So, deficiency of copper mainly affects leaves. It causes wilting, chlorosis and death of the leaves and copper deficiency also leads to poor growth, delayed flowering, and plant sterility.