Question

In a girdled plant, when water is supplied to the leaves above the girdle, leaves may remain green for sometime then wilt and ultimately die. What does it indicate?

Answer 1

Girdling:

Girdling is the complete removal of a bark strip around the entire circumference of a trunk of a tree. The tissue that is removed in girdling is the phloem (the tissue that translocates food in a bidirectional manner). The xylem that transports water upwards is retained.

Condition of the leaves :

• Initially since the xylem is present the water is transported upwards to the leaves, the leaves remain turgid and green performing photosynthesis.
• The food prepared by the leaves are not able to reach the roots as phloem is missing at the girdled region.
• After some time the roots start dying, finally resulting in the withering of the leaves and the death of the plant.

Significance:

This experiment indicates the importance of phloem in the translocation of food.