Guava: Diseases, Symptoms and their Management
1. Guava Wilt
Causal Organism: Fungus; Fusarium oxysporum f.sp. psidii
- Guava Diseases wilt a serious disease, is occasionally found, particularly in alkaline soils.
- Browning and wilting of the leaves, discolouration of the stem, and mortality of the branches on one side are the signs.
- The emergence of yellow colouration with mild curling of the leaves of the terminal branches is the first visible indication of the disease.
- All of the damaged branches’ fruits remain undeveloped, hard, and rocky.
- Sometimes the infection encircles the entire stem, causing the plant to wilt.
- At 15 days, saturate the soil with Brasicol and spray Bavistin (0.1%) around the roots and leaves to reduce infection.
Causal Organism: Fungus; Gloesporium psidii, Glomerella psidii
- The affected plants showed signs of die back from the tip of the branch.
- Young shoots, leaves, and fruits are easily connected while still delicate.
- Spraying the trees with Copper Oxychloride, Cuprous Oxide or Difolatan controls the disease.
- Application of a bioagent, Streptosporangium pseudovulgare, to fruits prior to symptom development.
3. Cercospora Leaf Spot
Causal Organism: Fungus; Cercospora sawadae
- Guava diseases, Leaf spot appears, and Water-soaked patches under the leaf are the characteristic symptoms of the disease.
- The older leaves are the most damaged, and the badly impacted leaves curl and fall off.
- Spraying copper oxychloride at 0.3 per cent can reduce the infection.
4. Guava Scab / Guava Canker
Causal Organism: Fungus; Pestalotia psidii
- The fungus mainly attacks the unripe fruits to produce dark scabby lesions, 2-4mm in diameter.
- The scab disfigures the fruits and their market value is considerably reduced.
- Application of Zineb 20g or Chlorthalonil-20g/10 litres of water during flowering, followed by 15-day interval sprays, aids in disease management.
5. Guava Red Rust
Causal Organism: Algae; Cephaleuros virescens
- During the early spring flush, algae affect immature guava leaves.
- Spots on leaves can range from specks to large swaths.
- The disease appears in April and becomes more severe from May through August.
- Sprays of Copper oxychloride (0.3%) at 15-day intervals can be used to manage alga.
Hello, I am Sonu Verma, M.Sc. (Horti.) Agriculture content writer, and an enthusiast who loves to share knowledge. No Culture Without Agriculture.