Pest and diseases of cocoa (presentation)

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    05-Dec-2014

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This slide is a general pest and diseases that happen toward specific crop like cocoa that included scientific names, symptoms and also the methods to control them.

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<ul><li> 1. Conopomorpha cramerella Snellen Life cycle 27 to 33 days Symptoms: Attack from size of 7cm until 10 weeks before the fruit ripen. Occurrence of a exit and entry hole on the pod surface. The cocoa beans were hard to remove from placenta. Control: Pruning-control canopy and height Rapid harvesting- ripe pod should be harvested in the 10-14 days interval Insecticide-Deltamethrin, Alphacypermethrin, Cypermethrin,Chlorpyrifos, Chlorpyrifos+cypermetrin Biological control- parasitoid (Trichogrammatoidea bactrae fumata), black ant (Dolichoderus thoracicus) Pod wrapping. </li> <li> 2. Conopomorpha cramerella Snellen </li> <li> 3. Helopeltis theivora (P. Msia) and H. clavifer (Sabah) Life cycle : H. theivora (20-25 days) and H. clavifer (34-45 days) Symptoms: Both nymph and adult attack fruits and shoot Attack shoot when the fruit is reducing Small water-soaked areas of tissue, circular (1-4mm diameter) Lead to the secondary pests and fungal infections Control: Insecticide (end of fruiting season)-morning Good canopy management Cypermethrin, deltamethrin, chlorpyrifos Biological control- black ant (Dolichoderus thorachicus) </li> <li> 4. Helopeltis theivora and Helopeltis clavifer </li> <li> 5. There are 2 species: Zeuzera coffea and Z. conferta Life cycle- 4-5.5 months Symptom: Larvae bore into trunks The galleries formed are especially damaging to young cocoa, often causing the snapping-off of smaller branches. may introduce diseases such as Phytophthora palmivora cankers: possibly resulting in tree death. Control: Pruned the infected branches Pesticide- dimethoate, monoctophos (trunk injection) </li> <li> 6. Zeuzera coffea and Zeuzera conferta </li> <li> 7. Glenia celia Life cycle- 5-6 months Symptoms: Bore into branches and shoots Infected part will start to wilt and die Control: Concentrate on the infected part and killed the larvae Insecticide is not effective </li> <li> 8. Cataenocococus hispidus, Pseudococcus pelisae, Pseudococcus sp., Crypticerya jacobsoni, Ferrisiana vigata, Planococcus lilacinus and P. pacificus. symptom: Attack on the buds and young plant can stunt the tree Control: Spray chlorpyrifos and carbosulfan on the infected part Use black ant (Dolichoderus thorachicus) </li> <li> 9. Phytophthora palmivora infected at any age Significant loss if infected 2 months before ripening. Symptoms: Appearance of a small translucent spot on the pod surface- normally appearing about 2 days after infection under condition of high humidity. This spot soon turns to a chocolate brown colour, then darkens and expand rapidly with a slightly irregular margin so that the whole surface of the pod is blackened within 14 days. Control: Good cultural practices- reduction of shade, regular weeding and pruning. Chemical- copper fungicides, metalaxyl, fosetyl-Aluminium, phosphonate. </li> <li> 10. Crinipellis perniciosa/ Marasmius perniciosus Symptoms: Characteristic shoots or brooms, caused by the hypertrophic growth of an infected bud. Usually infected fan branches Infection can also occur on chupons in the form of localized lesions. Control: Planting of material resistant to the disease Applying prophylactic fungicides Remove and destroy all the infected branches/ shoots away from field (pruning) </li> <li> 11. Oncobasidium theobromae (fungi) Common in cocoa nurseries (5 mnths) and immature stands. Generally refers to the condition of progressive desiccation of the branches of a cocoa tree from the tip inwards. The severity of the damage can vary from a few twigs to complete tree mortality. Symptoms: The 1st indication of infection is a yellowing of one or two leaves in the second or third flush from the growing tip with the development of a very characteristic pattern of green spots scattered over the yellow background; the infected leaves will fall within a few days of turning yellow; neighbouring leaves then progressively develop similar patterns and are lost; a distinctive situation where the youngest and oldest leaves are still present, but all the middle ones have fallen. Control: Use resistance planting materials. Eg KKM 25, PBC 123, PBC 159, ICS 95 Cut back the infected branches Systematic and proper manuring system will reduce the incidence of VSD. Reduce shading Fungicides (triademenol, flutiriafol and cyproconazole)- nursery </li> <li> 12. Phytophthora spp. Symptoms: Difficult to detect in its early stage because infected bark does not show external symptoms, though a pink-red discoloration of the cambial tissue will be found beneath the bark. The pink colour of this tissue darkens after a few minutes exposure. Subsequent development of the infection depend on the susceptibility of the cultivar. From pod to cushion then to the stem Early indication is watery brown lesion on the bark. Can caused mortality Control: Selecting and planting resistant cultivars. Fungicides application- matalaxyl, fosetyl-Aluminum, phosphonate and copper fungicides (spray, trunk injection and brush) Good cultural practice Remove and destroyed infected tree from the field. </li> <li> 13. Corticium salmonicolor Symptom: 1st indication of infection is the death of the branch or the tree. On examination of the bark of a dead or dying tree the salmon pink encrustation of fruiting bodies would be seen. The penetration of the fungus to the cortical tissue disrupts the physiological processes of the tree and quickly leads to defoliation and death of the distal parts of the branch. Prolonged insolation will bleach the pink colour of the fruiting bodies to a greyish white colour. Control: Fungicide (tridermorph, oxycaboxin, captafol and copper) Good cultural practices; regular pruning, remove and destroy infected branches and reduce shade. </li> <li> 14. Symptoms: Early indication of the infection is the leaves start to wilt Changing of color from green to yellow and finally to brown. Dead leaves usually remain on the tree before falling. Control: Remove all debris before replanting Regular inspection in the field Remove the infected tree from the field. Make a trench around the infected tree to avoid infection to other tree. </li> </ul>

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