Fact 1: Plants respond to daily and seasonal cycles and to disease.

Fact 2: Green manures can be managed to disrupt plant disease cycles or to suppress nematodes .

Given the two facts above, answer the question "Plants respond to what to disrupt plant disease?" with the following options: 
- reducing acid rain
 - competition
 - bending light rays
 - Leptospirosis
 - temperature changes
 - green manures
 - Localized damage
 - sun's heat


 

      green manures   