CALCIUM

For Strong Plants

The main function of calcium in the plants is the stabilization of the cell membranes. Calcium has an important role for being a component of the cell membranes. It facilitates the cell cohesion by the action of the calcium pectate which fixes the cell in the intermediate lamina keeping it together. It is known that calcium stabilizes the pH of the cellular solution to maintain the equilibrium with other ions and organic acids. The role of calcium in the carbohydrates translocation and in the root growing is also significant.

Calcium is mobile in the xylem, but not it the phloem. Therefore, it is accumulated more in the organs which occur in great dimension. A limited movement happens between the organs.

Calcium has three main functions in the plant:

It is essentials for the cell walls and structures of the plant. Approximately 90% of calcium is found in the cell walls. It acts as a cohesion factor that joints the cells together and supports its structure in the plant tissues. Without calcium, the new tissue development (cellular division and extension) of roots and sprouts is detained. As a result, the crop yield is seriously affected. Calcium is a key factor responsible for the fruit firmness; an example is the tomato. It retards the senescence resulting in durable leaves being able to continue the photosynthesis process.

It maintains the integrity of the cell membranes. This is important for the appropriate functioning of the absorption mechanism, and for preventing the escape of elements outside the cells.

• Also it is found in the center of the plant defense mechanisms, which help to detect and to react against external stress. Both roles in the plant defense and on the tissue firmness are important for the resistance against pathogens attack and deterioration during the fruit storage. A particular calcium fact is that its transport is almost exclusively done with the transpiration flow along the xylem. This is mainly distributed from the roots toward the leaves, which are the principal transpirations organs. Besides, fruits with low transpiration rate are supplied with scare calcium. Only 5% of calcium goes to the fruit. Then, a transitory calcium deficiency easily can occur in the fruits and above all in the period when the growing rate is high. This produces a necrosis of the fruit apical extreme, identified as BER.