Question

The disease-related with deficiency of molybdenum is?
A) Whiptail disease of cauliflower
B) Little leaf disease
C) Reclamation disease of cereals
D) Brown heart disease

Answer 1

Hint: Molybdenum has an important role to play in the metabolism of nitrogen. It affects the synthesis of ascorbic acid. It activates the enzymes involved in nitrogen metabolism.

Complete answer:
The correct answer is option (A). The reason is cauliflower deformation a disease in cauliflower occurs due to the lack of molybdenum and is named as whiptail disorder. This disease causes disordered leaves with reduced areas of the leaves in cauliflower. The symptoms usually begin in younger leaves. Whiptail disease in cauliflower also leads to mottling and wilting of leaves at the margins which further causes yellow spot disease of citrus. Leaf-blades are narrowed in this disease and there is a rugged appearance due to distortion.

Zinc is an essential micronutrient for plants. Its deficiency leads to little leaf disease, leaf rosette formation, short internodes, interveinal chlorosis appearing first marginally on older leaves, followed by necrosis, white bud, and stunted growth. Therefore, option (b) is wrong. The reason why option (c) is wrong is that reclamation disease or ‘yellow tip’ is a deficiency symptom of copper in plants. It affects oat cereals plants, sugar beet, and leguminous crops. It is caused in plants growing on newly reclaimed land where seed formation is affected.
The reason why option (D) is wrong is Brown heart disease is caused in Rutabaga and Turnip by the deficiency of microelement Boron. It appears as firm, dark, water-soaked patches which later transform into brown, spongy structure affecting mainly the storage area. This disease is considered to be a physiological disturbance occurring in the tissues.

Hence, we considered option (a) as correct.

Note: Plant nutrition is the study of the chemical elements and compounds necessary for plant growth, plant metabolism, and external supply. Plants absorb nutrients and water through their root system, as well as carbon dioxide from the atmosphere. The deficiency of various minerals leads to many diseases as discussed.