Question

Discuss the practical applications of auxins in Agriculture and Horticulture.

OR

What are auxins? Explain briefly uses of Auxins.

Answer 1

Auxins are a group of plant growth substances, acidic in nature and bring about over-all growth.

• Apical dominance:
• As long as the apical bud is present growth of lateral buds is pre-vented which is used in the long term storage of potato tubers.
• Rooting:
• In low concentrations, auxins stimulate root formation which is used to propagate cuttings. When dipped in a dilute solution of auxins the root formation is initiated.
• Flower initiation:
• Low Concentration of 2, 4-D and NAA are used to initiate flowering in a pineapple so that harvesting becomes easy.
• Abscission:
• Application of auxins increase the concentration and thereby delays the development of abscission which prevents ***** leaf and fruitful. This is used in orchards and prevention of defoliation in cabbages and cauliflower.
• Parthenocarpy:
• This is the process of obtaining fruits without fertilization and gives rise to seedless varieties which is successfully used in citrus, dates.
• Sex expression:
• Use of auxins on cucurbit plants increases the production of female flower.
• Weedicide / Herbicide:
• 2-4-D is widely used as a herbicide on broad-leaved forms because of its non-toxic nature. Widely used in crop plant cultivation or lawns.
• Tissue culture (organogenesis):
• In tissue culture where micropropagation is carried out the auxins are used to bring about organogenesis.