What is the Difference Between Chlorosis and Necrosis

The main difference between chlorosis and necrosis is that chlorosis is yellowing due to the breakdown of chlorophyll or reduced production of chlorophyll, whereas necrosis is the cellular death that results in tissue turning dry and brown to black.

Chlorosis and necrosis are two plant diseases. Major nutrient deficiencies in plants can cause chlorosis and necrosis. They can also occur due to viral infections.

Key Areas Covered

1. What is Chlorosis
– Definition, Facts, Features
2. What is Necrosis
– Definition, Facts, Features
3. Similarities Between Chlorosis and Necrosis
– Outline of Common Features
4. Difference Between Chlorosis and Necrosis
– Comparison of Key Differences
5. FAQ: Chlorosis and Necrosis
– Answers to frequently asked questions

Key Terms

Chlorosis, Necrosis 

What is Chlorosis

Chlorosis is a plant disease that turns green parts into yellow. Yellow patches or spots are observable in foliage in chlorosis. Concerning the causes, the degradation of chlorophyll causes chlorosis. Nutrient deficiency is the major reason for chlorosis. Magnesium, iron, and manganese deficiency is the main cause of chlorosis. Importantly, magnesium and iron are the integral parts of chlorophyll structure. Apart from that, the interruption of pigment formation in leaves is another reason for chlorosis. Water drainage, poor soil quality, damaged roots, herbicide injury, and high alkalinity also can lead to chlorosis. However, by using proper fertilizers, you could overcome chlorosis issues. Furthermore, viral and fungal infections are also associated with chlorosis.

Figure 1: Chlorosis

What is Necrosis

Necrosis is cellular death characterized by localized death in living tissue. It results in drying out leaves. Also, the color of the leaves changes from black to brown. Brown or black dots appear on leaves in necrosis. Firstly, the edges of the leaves are affected. It grows to other areas later. The concentration of anthocyanin and other pigments also changes in necrosis, leading to leaf bronzing. Concerning the causes, both nutrient deficiencies and viral infections cause necrosis. The tobacco necrosis virus causes necrosis in tobacco plants. Cymbidium mosaic virus infects orchid flowers.

Figure 2: Necrosis

Similarities Between Chlorosis and Necrosis

• Chlorosis and necrosis are two plant diseases that can occur due to nutrient deficiencies or viral infections.

Difference Between Chlorosis and Necrosis

Definition

Chlorosis refers to the loss of the normal green coloration of leaves of plants caused by iron deficiency in lime-rich soils, disease, or lack of light. At the same time, necrosis refers to the death of a circumscribed plant or animal tissue area due to disease or injury.

Significance

Chlorosis is the yellowing of leaves due to reduced chlorophyll content, while necrosis is the death of a cell or group of cells.

Cause

Chlorosis occurs due to a deficiency of magnesium, iron, copper, manganese, or nitrogen, while necrosis occurs due to a deficiency of calcium, copper, and chlorine.

Appearance

Chlorosis appears as yellow spots, while necrosis appears as brown spots.

Mosaic Pattern

The yellow appearance of spots gives a mosaic pattern in chlorosis, while the brown color spots do not produce a mosaic pattern in necrosis.

FAQ: Chlorosis and Necrosis

What is necrosis and chlorosis in plants?

The yellowing of leaf tissue due to the lack of chlorophyll is chlorosis. In comparison, the death of plant cells or tissues. Yellow spots appear in chlorosis, while brown or black spots appear in necrosis.

What causes chlorosis and necrosis?

Nutrient deficiencies such as nitrogen, phosphorus, magnesium, and potassium cause chlorosis, the yellowing leaves, and eventually necrosis, the older mature leaves.

What is the cause of leaf necrosis?

The rapid synthesis of gibberellins is triggered by environmental factors that cause necrotic leaf botch. Treating trees with Zinc-containing fungicides such as Ziram decreases the severity of leaf necrosis.

Conclusion

In brief, chlorosis and necrosis are plant diseases that occur due to nutrient deficiencies or viral diseases. Magnesium, iron, copper, nitrogen, or manganese deficiencies cause chlorosis. It appears in yellow spots. Also, the yellow appearance of spots gives a mosaic pattern in chlorosis. In comparison, necrosis is the death of a cell or a group of cells. It occurs due to a deficiency of calcium, copper, and chlorine. Additionally, it appears in brown spots that do not produce a mosaic pattern. Therefore, the main difference between chlorosis and necrosis is their appearance.

References:

1. Disease or disorder: How do I tell the difference? Part 1, Michigan State University.

Image Courtesy:

1. “Raspberry vein chlorosis virus NT5 (2)” By Jerzy Opioła – Own Work (CC-BY SA 4.0) via Commons Wikimedia
2. “K-deficient maize on Cedara 4 2003-01-13” By Alandmanson – Own Work (CC-BY SA 4.0) via Commons Wikimedia