Uses of Plant Hormones

Auxins, Gibberellin and Ethene have many COMMERCIAL USES in agriculture and horticulture:

1. GIBBERELLINS are important in initiating SEED GERMINATION (process where a seed turns into a plant).

2. ETHENE is a gas produced by AGING parts of a plant, and it controls CELL DIVISION and RIPENING OF FRUITS.

AUXINS

1. KILLING WEEDS — Auxins are used to kill WEEDS in crops, specifically targeting BROAD-LEAVED WEEDS without affecting GRASSES and CEREALS which have NARROW LEAVES.

2. ROOTING POWDER — When a CUTTING is taken from a plant and treated with ROOTING POWDER containing auxins, it rapidly develops ROOTS, which allows the growth of new plants.

3. GROWING CELLS IN TISSUE CULTURE — Auxins are used in TISSUE CULTURE to grow CLONES of a plant by stimulating cells in a GROWTH MEDIUM to DIVIDE, forming roots and shoots.

GIBBERELLIN

1. CONTROLLING DORMANCY — Dormancy is a period when the seed of a plant is NOT actively growing. Seeds need specifc conditions in order to germinate (warm and sunny conditions). Gibberellin helps seeds overcome DORMANCY, by allowing them to GERMINATE under less than ideal conditions.

2. INDUCING FLOWERING — It triggers plants to grow FLOWERS in conditions where they normally would not. They can also be used to produce BIGGER flowers than usual.

3. GROWING LARGER FRUIT — Gibberellin is applied to certain fruit plants to produce LARGER FRUIT without seeds.

ETHENE

CONTROLLING RIPENING OF FRUIT: Fruit are picked from plants when UNRIPE so they are less easily damaged when stored. The ETHENE is then added to the fruits when they are being transported to the supermarkets so that they become RIPE when they reach the supermarkets.