Spices and Condiments (1+1)

Pests and diseases

Pests
Shoot borer (Sahyadrassus malabaricus)
The adult female lays eggs on the branches, sometimes near the growing tips. The larvae, on hatching, bore into the branches making long galleries, and may reach the main trunk. In severe cases, it leads to die-back. To control the pest, the plants should be sprayed with 0.05% dimethcate or Methyl dimethon or Quinalphos (0.1%) should be injected into the bore hole.
Termites, leaf eating caterpillar, black scale (Saissetia eugeniae), masked scale (Mycetaspis personata), wax scale (Ceroplastes floridensis), Kilifia accuminata, Attacus atlas, crickets, mealy bugs, grasshoppers and cockchafer grubs are the other common pests of clove.
Termites can be controlled by drenching the soil with 0.05% Chlorphyriphos EC. Spraying of 0.05% Monocrotophos controls the leaf eating caterpillar and scale insects. Hindola striata and H.fulua are reported to be the vectors of the Sumatra disease.

Diseases
Sudden death of cloves (Valsa eugeniae)
This disease is characterised by heavy leaf-fall, coupled with wilting symptoms, usually during prolonged drought periods. This wilting can be arrested by providing copious irrigation to the trees.

Die-back (Cryptosporella eugeniae)
This disease is commonly observed in neglected clove plantations and is associated with low soil fertility, weed competition and algal infection.
The symptoms include dark red spots on both sides of the leaves, which gradually spread and increase in size. The leaves turn chlorotic and ultimately fall off. The young leaves are more prone to this disease.
These diseases can be controlled by adopting proper management practices along with spraying the trees with 1% Bordeaux mixture. Seedling wilt (Cylindrocladium Sp, Fusarium sp, Colletotrichum sp, Rhizoctonia sp., Phythophora sp.), leaf-spot, leaf rot (Cylindrocladium quinqueseptatum), twig blight [Colletotrichum gloeosporiodes (Glomeralla cingulata)1, grey leaf blight (Pestalotiopsis versicolor), Sumatra disease (Pseudomonas syzygii) and flower bud shedding are some of the other fungal diseases which are found to attack clove trees.
To control these diseases, the plants could be sprayed with Bavistin (0.2%) or 1% Bordeaux or 0.30% Copper oxychloride. The infected plants promote further spread of the seedling wilt disease, hence they should be removed and the remaining seedlings should be drenched with any of the copper fungicides.

Problems
• Apart from the diseases, some other problems connected with clove cultivation are: very low percentage and slow germination of seeds and slow seedling growth, difficulty in harvesting due to the inaccessible heights of the plant which results in nearly 30 to 35% loss of the crop and which deserves attention. There is also the need to develop short¬statured plants with early yielding habits.