Translocation:

Translocation is a vital process in plants involving the movement of sucrose (and other organic compounds such as amino acids) through the phloem from areas of production, known as sources, to areas of storage or utilization, known as sinks. Sucrose is the primary form in which carbohydrates are transported in the phloem.

Translocation in Different Seasons:

Spring:

• During spring, when plants are emerging from dormancy, translocation primarily involves the movement of sucrose from storage organs, such as roots, to active growing regions, particularly the leaves.
• Stored carbohydrates, accumulated during the previous growing season, are mobilized from the roots and transported to developing leaves to support early growth and photosynthesis.
• This translocation of sucrose from roots to leaves ensures an adequate supply of energy for leaf expansion, chlorophyll synthesis, and the initiation of new growth.

Summer & Early Autumn:

• In the peak growing season of summer and early autumn, translocation shifts as photosynthetic activity in leaves increases.
• Sucrose produced during photosynthesis in the leaves is transported through the phloem to various sink tissues throughout the plant, including roots, stems, flowers, and developing fruits.
• In addition to supporting growth and metabolic processes, sucrose may also be stored in the form of starch or other carbohydrates in sink tissues, such as roots, for future use during periods of reduced photosynthetic activity or dormancy.
• This movement of sucrose from photosynthesizing leaves to storage organs ensures a continuous supply of energy and nutrients to support plant growth, development, and survival.

Girdling in a Tree Trunk:

A girdle in a tree trunk refers to the removal or interruption of the phloem tissue encircling the trunk. This process disrupts the flow of carbohydrates, including sucrose, through the phloem, leading to significant consequences for the plant:

• Reduced Translocation: Girdling prevents the movement of sucrose and other nutrients from the leaves to the roots and other sink tissues. This disruption impairs the plant’s ability to transport essential resources, resulting in stunted growth, wilting, and eventually, the death of affected tissues.

• Impact on Fruit Development: In fruit trees, girdling is sometimes used as a horticultural technique to increase fruit size and quality. By preventing the downward flow of carbohydrates from the leaves, girdling leads to an accumulation of sugars in the fruit, enhancing its flavor, size, and market value.