If excess fertilizer is applied to a plant without water, the plant will

Applying excess fertilizer without sufficient water creates a hypertonic environment in the soil. Fertilizers are essentially soluble salt compounds [t5]. When the concentration of these salts in the soil exceeds the concentration within the plant's root cells, it creates an osmotic gradient that draws water out of the plant [t4]. This process is known as plasmolysis, where the cell loses water, the plasma membrane pulls away from the cell wall, and turgor pressure is lost [t1][t3]. Without water to dissolve and dilute these salts, the osmotic stress becomes severe, leading to 'fertilizer burn' [t4][t8]. This dehydration causes the plant tissues to wilt and eventually results in the death of the plant due to the inability to maintain cellular functions and hydration [t6][t7].

Sources

1. [1] https://en.wikipedia.org/wiki/Plasmolysis
2. [2] https://www.sciencedirect.com/topics/earth-and-planetary-sciences/plasmolysis
3. [3] https://pmc.ncbi.nlm.nih.gov/articles/PMC10300796/