HORTICULTURE

Detailed explanation-1: -What causes water to fill the xylem pipeline completely, from the roots to the leaves, and to resist any separation? Transpiration creates a pushing effect, which forces a column of water up from the roots to the leaves.

Detailed explanation-2: -The tension created by transpiration “pulls” water in the plant xylem, drawing the water upward in much the same way that you draw water upward when you suck on a straw. Cohesion (water sticking to each other) causes more water molecules to fill the gap in the xylem as the top-most water is pulled toward the stomata.

Detailed explanation-3: -The suction force (negative pressure) created by transpiration from the leaves’ surface draws water from the soil and roots through the xylem. Water is sucked up as a result of the xylem vessel. Due to the appearance of capillary action, transpirational pull moves water from roots to leaves.

Detailed explanation-4: -According to the cohesion-tension theory, transpiration is the main driver of water movement in the xylem. It creates negative pressure (tension) equivalent to –2 MPa at the leaf surface. Water from the roots is ultimately pulled up by this tension.

Detailed explanation-5: -Root pressure is the force that pulls water into the xylem from the roots. Root pressure forces water into the cell walls of the phloem to be transported around the plant. Root pressure is the bonding of water molecules to the walls of the root hair cells.