Which of the following are examples of necrotic plant disease symptoms?

Necrotic plant disease symptoms are characterized by the death of plant tissue, leading to visible signs such as browning, decay, or the complete dying off of parts of the plant. The symptoms listed in the correct choice include scald, rot, mummification, and damping off—all of which are indicative of tissue death and breakdown.

Scald refers to the browning of leaves due to high temperatures or water stress, where the affected tissue becomes necrotic. Rot involves the decay of plant tissues, often due to fungal infections or excess moisture, leading to soft, mushy areas. Mummification typically affects fruits or plant parts, where the tissue dries out and becomes hard, often showing signs of decay in the process. Damping off is a condition in seedlings caused by pathogens that lead to wilting and decay at the soil line, causing the seedling to collapse and die.

These symptoms are distinct from other options which may involve related symptoms like wilting, yellowing, or stunted growth but do not specifically highlight the necrotic aspect. This specificity is essential for identifying necrotic symptoms, as the others mainly describe physiological stress or growth issues rather than the death of tissue.