📈 Diseases of Pomegranate and Guava

Pomegranate (Punica granatum) and guava (Psidium guajava) are important fruit crops in India. Both are affected by several diseases that reduce fruit quality and yield.

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Diseases of Pomegranate

Bacterial Blight (Oily Spot)

Causal Organism: Xanthomonas axonopodis pv. punicae

This is the most devastating disease of pomegranate in India, particularly in Maharashtra and Karnataka.

Symptoms

• Small, irregular, dark brown to black spots on leaves with a water-soaked, oily appearance
• Spots coalesce to form large necrotic patches leading to defoliation
• On fruits, dark brown to black raised lesions that crack, making them unmarketable
• Stems show elongated cankers that may girdle young branches

Management

• Spray Streptocycline (500 ppm) + Copper oxychloride (0.3%) at 15-day intervals
• Prune and destroy infected branches during summer
• Avoid overhead irrigation that promotes splash dispersal
• Use tolerant varieties such as Bhagwa where possible

Wilt

Causal Organism: Ceratocystis fimbriata (Fungus)

Symptom	Description
Initial	Yellowing and drooping of leaves on one or more branches
Advanced	Progressive wilting of the entire tree within weeks
Internal	Dark brown to black discolouration of wood and vascular tissue
Final	Complete tree death

Management

• Remove and burn wilted trees along with root system to prevent spread
• Apply Trichoderma viride (50 g/tree) to the soil around healthy trees
• Drench the soil with Carbendazim (0.1%) or Propiconazole (0.15%)
• Avoid planting in fields with a history of wilt

Fruit Rot

Causal Organism: Aspergillus niger, Alternaria alternata, and others

• Internal rotting of arils without visible external symptoms
• Cracked fruits are especially susceptible to fungal entry
• Spray Carbendazim (0.1%) at fruit development stage to reduce infection

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Diseases of Guava

Guava Wilt

Causal Organism: Fusarium oxysporum f. sp. psidii (often in association with Macrophomina phaseolina and root-knot nematodes)

Symptoms

• Yellowing and wilting of leaves, initially on a few branches (partial wilting)
• Wilting progresses to the entire tree over weeks to months
• Bark on the main trunk shows brown discolouration beneath
• Root system shows decay and browning

Management

• Uproot and destroy affected trees
• Apply Trichoderma harzianum + neem cake to the soil around healthy trees
• Soil drenching with Carbendazim (0.1%) at the tree base
• Use resistant rootstocks and maintain proper drainage

Anthracnose (Fruit Rot)

Causal Organism: Colletotrichum gloeosporioides

Symptoms

• Sunken, dark brown to black necrotic spots on ripening fruits
• Pin-prick-sized dark spots on leaves that enlarge into irregular lesions
• Twig dieback and blossom blight in severe infections

Management

• Pre-harvest spray of Carbendazim (0.1%) or Mancozeb (0.25%)
• Harvest fruits at mature green stage and handle carefully to avoid wounds
• Remove and destroy fallen diseased fruits from the orchard floor

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Summary Cheat Sheet

Crop	Major Disease	Hallmark Symptom	Core Management
Pomegranate	Bacterial blight	Oily dark lesions and fruit cracking	Streptocycline + copper + sanitation
Pomegranate	Wilt	Progressive branch/tree wilting	Uprooting + biocontrol + drenching
Guava	Guava wilt	Partial to complete wilt with root decay	Rogue plants + soil biocontrol + drainage
Guava	Anthracnose	Sunken black fruit spots	Pre-harvest fungicidal protection

References

2 sources • [1] [2]

[1]

Indian Council of Agricultural Research (ICAR)

Official

[2]

CABI Crop Protection Compendium

Website