Major Clove diseases are:-
1.Cardamom Seedling Wilt: Cylindrocladium sp., Fusarium sp., Colletotrichum sp., Rhizoctonia sp., and Trichoderma sp
- Seedling wilt is found mainly in nurseries and causes five to 40% death of seedlings. Leaves of affected seedlings loose natural lustre, tend to droop and ultimately die.
- The root system and collar region of the seedling show varying degrees of, discolouration and decay.
- Since the infected seedlings promote spread of the disease they are to be removed and destroyed and the nursery is drenched with Copper oxychloride 0.25 %.
2. Cardamom Leaf rot: Cylindrocladium quinquiseptatum
- It is noticed in the nurseries as well as in the main field both at young and mature stages.
- The infection starts as dark spots at the leaf margin and spreads sometimes with no definite pattern.
- Rotting may be in the whole leaf or at the tip resulting in defoliation.
- Seedling and young plants can be sprayed with systemic fungicides Carbendazim 0.1%.
3.Last Spot, Twig Blight and Flower Bud shedding: Gloeosporium gleosporioides
- Necrotic spots of variable size and shapes are noticed on the leaves.
- Severely affected leaves wither, droop down and dry up.
- In the nursery, seedlings die back symptoms are seen. Twigs are infected as the symptoms extend from the leaves through petioles.
- The affected branches stand without leaves or only with young leaves at tips. Flower buds are attacked by spreading infection from the twigs.
- Shedding of flower buds occurs during periods of heavy and continuous rainfall.
- Spraying 0.25% Copper oxychloride at monthly interval reduces disease intensity, defoliation and flower bud shedding.
- Initial spray is given just prior to flower bud formation and continued till the harvest of buds.
- TamilNadu Agritech Portal