Describe: Transpiration Pull.

(N/A) $\Rightarrow$ In higher plants,the flow of water upward through the $xylem$ can achieve fairly high rates,up to $15 \ m/h$.
$\Rightarrow$ Water is either pushed or pulled through the plant. Most researchers agree that water is mainly pulled through the plant,and the driving force for this process is transpiration from the leaves.
$\Rightarrow$ This is referred to as the $cohesion-tension-transpiration$ pull model of water transport.
$\Rightarrow$ Water is transient in plants. Less than $1\%$ of the water reaching the leaves is used in photosynthesis and plant growth. Most of it is lost through the stomata in the leaves. This water loss is known as transpiration.
$\Rightarrow$ This pull is generated because the evaporation of water from the leaf surface creates a negative pressure (tension) in the xylem vessels,which pulls the water column upward due to the cohesive and adhesive properties of water molecules.