transpiration and absorption ratio experiment

Object:

Demonstration of Relation between Transpiration and Absorption

Requirements:

A bottle with a side, tube, cork, a plant, oil, balance, etc.

Experiment:

Here, the apparatus must be completely filled up with water and air-tight. In the side marked tube of the apparatus some oil drops are being added so that the water may not evaporate. The cork is fitted in the wide mouth of the bottle in the way that the aerial part of a complete plant remains outside of it and the root system or the plant remains within the bottle.

Now the apparatus is weighed on a pan balance to note its weight and thereafter it is kept for few hours in such a place where sufficient transpiration from the aerial parts of the plant takes place. In the end the apparatus is weighed once again and the difference from that of the original weight may be calculated.

Observation:

This way the quantity of transpired water is known in grams. The oil drops present on the surface of water in the marked side tube travel somewhat downward and we know the actual quantity of absorbed water in ml by the roots. By comparison, it is noted that the quantity of absorbed water is always greater than the transpired water because some of the water is used in other metabolic activities.