Question

Differentiate between chlorosis and necrosis.

Answer 1

Hint: Alteration in pH, proper irrigation and soluble salts results in the occurrence of most common nutritional disorders in vegetable transplants. Chlorosis and necrosis are the symptoms linked with nutrient discrepancies. Other symptoms may include stunting and color change of the foliage.

Complete answer:
Chlorosis in green plants depicts the diseased state. It is marked by planching. It results in yellowing of complete or some part of green colored leaves due to breakdown of chlorophyll pigment or disruption of the pigment production in the leaves. It often appears as yellow spots on the leaves.
On the other hand, necrosis refers to the death of the plant cells therefore necrosis is sometimes also referred to as the cellular death. Generally, necrosis is marked by localized death in the living tissues. It results in the drying of leaves. The color of the leaf changes from brown to black and therefore often appears as brown or black spots on the leaves. The margins of the leaves are the first regions to be affected. Later, it expands to other regions also. It also results in altering the concentration of anthocyanin and several other pigments resulting in leaf bronzing. A delay in growth is observed as stunting. More than one symptom is depicted in the nutrient deficient conditions. Like color changes (may be yellow or dark green) are found associated with the stunted growth.
Moreover, chlorosis can be reversed in cases of early identification but in severe cases, it can’t be reversed while in necrosis, reversal is not at all possible.

Note: Chlorosis and necrosis are the deficiency symptoms depicted by the plants. Nutrient deficiency is one of the major causes of chlorosis and necrosis conditions. Viral infection can result in both of these symptoms.