Question

Brown heart rot of beet is due to deficiency of
(a)B
(b)P
(c)Mg
(d)Mo

Answer 1

Hint: The deficiency of this element can affect the vegetative growth and reproductive growth of plants by inhibiting the cell expansion and increasing the death rate of meristem tissue.

Complete answer:
Boron deficiency can be seen on leaves showing necrosis on the petiole. Brown heart rot of beet is due to the deficiency of boron where the young leaves turn brown and die at the early stage of growth. The appearance of black spots is due to internal and external black spots of necrotic tissue developing. Boron deficient beet show brown tops, rough root, and from the cut section shows black sunken spots on and in the roots.

Additional Information:
-Boron is an essential micronutrient for the plant.
-The boron in the plant is present in two forms either water-soluble or water-insoluble form.
-The main function of boron is to provide structural integrity to the cell wall, maintenance of the plasma membrane, and another metabolic pathway.
-The optimum requirement of boron in the crop is 20-100 ppm.
-Boron deficient beet show brown tops, rough root, and from the cut section shows black sunken spots on and in the roots.
-Applying boron to the soil with fertilizer or separately can overcome the deficiency of boron.
So, the correct answer is, ‘B- Boron.’

Note: -In soil, the boron is present in the most common form of boric acid.
-Boron toxicity in the soil leads to the death of plants due to being incapable of coping with the excess of boron.
-In mango, boron deficiency shows internal lesions and cracking in the fruit.