The physiological changes that show up during disease attack on crop plants are referred to as

The physiological changes that show up during disease attack on crop plants are referred to as symptoms. Symptoms are the plant’s response to the disease and can include a wide range of expressions such as wilting, leaf curling, yellowing, stunting, and many others. Signs, on the other hand, are physical evidence of the pathogen, such as fungal spores, bacterial ooze, etc.