blight

1. a. Any of numerous plant diseases resulting in sudden conspicuous wilting and dying of affected parts, especially young, growing tissues. b. The condition or causative agent, such as a bacterium, fungus, or virus, that results in blight.
2. An extremely adverse environmental condition, such as air pollution.
3. Something that impairs growth, withers hopes and ambitions, or impedes progress and prosperity.
e.g.
Nothing has hurt our country more than the blight of drugs.
There are two ways of looking at TV: as a blight that dulls the mind or as a valuable source of information.