Root hairs absorb water by osmosis. Water flows from an area of high concentration to an area of low concentration. If you apply too much fertilizer (usually a combination of salts, like nitrates), you reverse this osmotic process; instead of water flowing into the roots, water flows out of the roots. Scientists call the overfertilized area around the root a "hypertonic solution". The plant wilts (loses "tugor pressure") , partially dehydrates, and will die.
Follow directions carefully ,and apply the correct amount of fertilizer.