Question

Heart rot of marigold is caused by the deficiency of
A. Chlorine
B. Copper
C. Boron
D. Zinc

Answer 1

Hint: Heart rot is a fungal infection that begins the deterioration of timber at the heart of the trunk and parts. Fungi invade the tree by wounds in the bark and weaken the heartwood. The infected heartwood melts, causing trees structurally more vulnerable and inclined to breakage.

Complete Answer:
Let us examine the given options to find the correct answer.

Option A: Scorched leaf might be the outcome of chlorine deficiency. Therefore this is an incorrect answer.

Option B: Excess chlorine,phosphorus, potassium or other micronutrients can obliquely produce copper insufficiency. Also if the pH of the developing medium is high, this can cause a copper deficiency as it is limited access for plant uptake. Therefore this is an incorrect option.

Option C: Heart rot of marigold is produced by the lack of Boron. Heart rot of marigold can be prevented by the utilisation of a small dose of sodium tetraborate in the loam. Therefore, this is the correct answer.

Option D: Utilization of phosphorus manure has generally been linked with zinc insufficiency; this may be due to improved sorption by clay ores (particularly iron oxides), destruction of vesicular-arbuscular mycorrhizae and im-mobilization of zinc in plant cells. Therefore, this is an incorrect answer.

Thus option C is the correct answer.

Note: Plants need Boron for the following functions,
- It has an important role in the cell wall formation.
- It is required for maintenance of structural and functional integrity of biological membranes.
- It is needed for movement of sugar, energy into the growing parts of the plants.