Pomegranate: Diseases, Symptoms and their Management
Diseases of Pomegranate
1. Cercospora Fruit Spot
Causal organism: Fungus; Cercospora punicae.
- The disease affects pomegranate plants and causes spots on leaves and fruits.
- Early-stage symptoms include yellowish spots with a halo around them, which grow in size and become blackish.
- The lesions are covered with a dull white crust of fungal growth.
- Severe infection can lead to defoliation and hamper plant growth.
- The disease also affects flower buds and fruits, causing brownish-black irregular spots that grow in size and become deeper and more prominent.
- Mature fruits show numerous black, irregular, slightly corky patches of the infected hard necrotic tissue, and severe infection can cause cracking. The disease is more severe in high-humidity areas and during the rainy season.
- The disease can be controlled by spraying with fungicides such as Hexaconazole (Contaf 0.1%) or Carbendazim (Bavistin 0.1%), or thiophanate methyl (Topsin M or Roko 0.1%).
2. Anthracnose Diseases of Pomegranate
Causal organism: Fungus; Colletrotrichum gloeosporioides.
- The disease manifests in various forms of symptoms causing leaf blight, fruit spot, wither tip, die back and fruit rotting as described below:
- Leaf blight: The disease begins as small, dull violet-black or black dots surrounded by yellow necrotic patches on the leaves, then expand and combine to produce huge, aniline black blotches. Severely infected leaves have necrotic regions covering the entire blade, curling and falling off, and occasionally displaying a shot hole stage.
- Fruit spot: The disease affects pomegranate fruits from the beginning of their development, causing little brownish patches to become larger and depressed. At the colour-breaking stage, symptoms emerge, with mature fruits displaying many brownish-black dots that aggregate to create bigger patches. The infected section turns reddish brown and causes fruit rot, which can result in flower buds and fruit drops, mummified fruit, and fruit exocarp rupturing during storage.
- Wither tip and die back: The pathogen kills younger shoot tips and causes emerging branches to dry from the tips backwards, with necrotic regions extending downwards. These branches lose their foliage, become dry, and appear to die back. Older trees and neglected orchards exhibit more pronounced symptoms.
- After pruning, a broad spray of copper oxychloride (Blitox 0.3%) and copper fungicide pasting of cut ends are recommended.
3. Bacterial Blight Diseases of Pomegranate
Causal organism: Bacteria; Xanthomonas axonopodis pv. punicae.
- The disease causes symptoms in fruits, leaves, branches, and stems.
- Circular brown to black lesions develops on fruits with L, Y, or star-shaped cracks.
- Water-soaked pinhead size lesions with yellow halo appear on leaves.
- Brown to black water-soaked elliptical lesions near the auxiliary bud is seen on the node.
- Severely affected orchards show defoliation of infected leaves.
- Nodal blight can lead to the cracking of nodes and the death of branches from the infected portion. Management strategies are required.
- Apply Streptocycline or Bacterinol-100 at 500 ppm and Copper oxychloride (0.3%) in two to three sprays every ten days.
- Apply one application of the Bordeaux mixture (1%).
- Prune badly afflicted plants to a height of 12.5cm above the ground.
- Apply Bordeaux paste to the trimmed area.
Causal organism: Fungus; Fusarium oxysporum.
- Pomegranate orchards may endure branch dieback, fading foliage, and eventual leaf shedding.
- Over time, the afflicted branches may become dry and lifeless.
- In severe circumstances, the entire adult tree, even if it was bearing fruit, may die unexpectedly.
- The wood of the damaged tree appears dark greyish-brown upon inspection.
- Soil drenching with benomyl (Benlate 0.1%) or Carbendazim (Carbendazim 0.1%), or Propiconazole (Tilt 0.1%) should be performed on plants exhibiting symptoms as well as surrounding apparently healthy plants.
Hello, I am Sonu Verma, M.Sc. (Horti.) Agriculture content writer, and an enthusiast who loves to share knowledge. No Culture Without Agriculture.