PLANTATION NEWS – Phytophthora palmivora is a pathogenic fungus that causes cocoa pod rot (BBK). This pathogen attacks various parts of the cocoa plant, including: leaves, base of stems, stems, twigs, shoots, flower beds, and fruit. P. palmivora can attack cocoa at various age levels, from nurseries to mature plants. The intensity of this pathogen attack can reach 85% in areas that have high rainfall. Economically, this pathogen attack has caused a decrease in world cocoa production by 10-30%, while in Indonesia it has resulted in a loss of 15-53%.
P. palmivora is very difficult to control because it generally survives in the form of mycelium and klamidospora on infected plant parts or in the soil. The implementation of cocoa pod rot disease control must be carried out in an integrated manner. Some control technology components that have been carried out and are able to reduce the intensity of this pathogen attack, include:
- Garden Sanitation. The most important step in an integrated disease control effort is to eliminate the source of pathogenic inoculum from the garden. Therefore, all fruits infected with P. palmivora either still in trees or that fall to the ground, the skin of fruit from harvest waste, twigs and leaves from pruning must be cleaned and then buried or decomposed to be used as organic fertilizer.
- Trimming maintenance. The development of P. palmivora depends on the humidity of the garden and is very sensitive to temperature stress and drought. Therefore pruning activities are very effective in reducing the intensity of cocoa pod rot disease.
- Utilization of antagonistic microorganisms. Utilization of Trichoderma viride antagonist fungus is proven to be effective in suppressing the development of pathogenic P. palmivora in nurseries. The application of biofungicides made from active T. viride spores is proven to be able to inhibit the development of fruit rot disease in the laboratory and field.
- Utilization of vegetable fungicides. Clove oil and lemongrass formulated proved to be able to reduce the intensity of fruit rot disease in the field.
- The use of liquid smoke. The potential of liquid smoke as an antimicrobial compound can be used to control plant pathogens. The use of liquid smoke from coconut shells with only a concentration of 0.1% can inhibit the growth of P. palmivora in petri dishes. The use of liquid smoke from cocoa plantation waste to control BBK disease is most likely to be developed at the farm level, because it is easy and inexpensive to make and the availability of abundant raw materials in the field.
This integrated cocoa pod rot disease (BBK) technology can reduce attack rates in the field by 80%. Figure (a) Symptoms of Phytophthora palmivora attack on cocoa pods, (b) Biofungicide products made from active antagonistic Trichoderma viride fungal spores .