Question
Mention the sources of Gibberellin and Kinin. Discuss the practical application of plant hormones in agriculture.
Answer
Sources of Gibberellin and Kinin:
- Gibberellins are primarily synthesized in the shoot and root apical meristems, young leaves, and developing seeds.
- Cytokinins are synthesized in the root apical meristem, developing embryos, and young leaves.
Practical applications of plant hormones in agriculture:
- Rooting of stem cuttings: Auxin-containing rooting hormone powders or solutions are used to promote the formation of adventitious roots in stem cuttings, which can be then used for vegetative propagation of plants.
- Fruit thinning: Auxin sprays are used to reduce the number of fruit on a tree by inducing fruit drop. This helps in increasing the quality and size of the remaining fruit.
- Weed control: Auxin-like herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-D), are used to control broadleaf weeds in crops such as corn, soybeans, and wheat.
- Delaying fruit ripening: Synthetic auxins, such as 2,4-D, are used to delay the ripening of fruit such as apples and pears to extend their shelf life and improve their marketability.
- Controlling plant growth: Plant growth regulators, such as gibberellins, are used to regulate plant growth and development to improve crop yields and plant quality.
