Forestry economics agriculture student of

Forestry economics

1. DISEASES OF CHRYSANTHEMUM DHIVYA. T 2021022024

2. DISEASES OF CHRYSANTHEMUM 1.Wilt : Fusarium oxysporum f.sp chrysanthemi 2. Rust : Puccinia chrysanthemi 3. Septoria leaf spot : Sepotria chrysanthemella 4. Powdery mildew : Oidium chrysanthemi 5.Grey mou Botrytis cinerea

3. WILT- Fusarium oxysporum f.sp.chrysanthemi

4. SYMPTOMS : Initial symptoms are in the form of yellowing and browning of leaves. Infected plants are stunted and often fail to produce flower. Wilting may cause rotting of root or the base of the stem. MODE OF SPREAD: The fungus is soil borne. The disease spread Through cuttings.

5. MANAGEMENT Drenching the soil with Carbendazim 0.1%. Before planting the rooted cuttings in a solution of Thiram 1.5g/ litre of water.

6. RUST- Puccinia chrysanthemi

7. SYMPTOMS : The disease symptoms are in the form of brown blister-like swellings, which appear on the undersides of leaves. Severely infected plants become very weak and fail to bloom properly. MODE OF SPREAD: The disease spread through irrigation water and wind.

8. MANAGEMENT Spraying the plants with Mancozeb 0.25% is effective in controlling the disease.

9. SEPTORIA LEAFSPOT – Septoria chrysanthemella

10. SYMPTOMS : Leaf spots occur during cool-wet periods of the rainy season. Serious infection may result in premature withering of the leaves; the dead leaves hang to the stem for some time. When flowering starts the infection occurs on flower buds, which rots completely. MODE OF SPREAD: The pathogens are spread through rain splashes the lowermost leaves get infected first.

11. MANAGEMENT The disease can be controlled by Spraying Carbendazim 0.1%. Destruction of disease debris and avoiding excessive irrigation is recommended.

12. POWDERY MILDEW – Oidium chrysanthemi

13. SYMPTOMS: Infection is more severe in older plants under humid conditions. The growth of the fungus on the leaves appears as powdery coating. Infected leaves turn yellow and dry out. Infected plants remains stunted and fail to flower. MODE OF SPREAD: The disease spread through air borne and spread through other plants.

14. MANAGEMENT The disease can be controlled by spraying wettable sulphur 0.1% Or Dinocap (karathene-0.05%)

15. GRAY MOULD – Botrytis cinerea

16. SYMPTOMS: May occur on petals, leaves, or stem cankers as brown, water-soaked spots. Infected plant parts may be covered with gray to brown, powdery masses of spores.
Senescing tissues are most susceptible.gray mold is favored by extended periods of cloudy, humid, and wet weather

17. MANAGEMENT 1. Practice good sanitation including Removing senescing flowers and leaves.
2. Avoid wetting flowers when watering and Don’t overcrowd the plants.
3. Provide good air circulation and keep humidity low by a combination of heating and venting (SEE fact sheet on reducing humidity in the greenhouse).

18. THANK YOU