Question

Plant growth substances (PGS) have innumerable practical applications. Name the PGS you should use to
a.Increase yield of sugar cane.
b.Promote lateral shoot growth.
c.Cause of the sprouting of potato tubers.
d.Inhibit seed germination.

Answer 1

Phytohormone increasing yield of sugar cane:

Carbohydrate is stored as sugar in the stems of sugarcane. Gibberellin, when sprayed on sugarcane, results in an increase in the length of the stem thus increasing the yield by as much as 20 tonnes per acre. This results in an increase in sugar content.

Final answer: Gibberellins.

Phytohormone promoting lateral shoot growth:

Cytokinins promote lateral growth. They also help in adventitious shoot formation. This helps to overcome apical dominance.

Final answer: Cytokinin.

Phytohormone causing sprouting of potato tubers:

Ethylene is a gaseous phytohormone. It helps to break seed dormancy, initiates germination and promotes sprouting of tubers like potatoes.

Final answer: Ethylene.

Phytohormone inhibiting seed germination:

Abscisic acid, also called the stress hormone, acts as a plant growth inhibitor. It is an inhibitor of plant metabolism and promotes seed dormancy, closure of stomata at the time of stress. Seed germination is prevented due to the action of ABA that helps overcome the unfavorable weather conditions.

Final answer: Abscisic acid.