Controlling Cocoa Pod Borer: seeing is believing
Cultural techniques have proved successful in greatly reducing the damage caused by Cocoa Pod Borer (CPB), a serious pest of cocoa in Indonesia, within one crop cycle. Technology transfer has been the emphasis of a collaborative project initiated by the cocoa industry, in response to the increasing effect of the pest on smallholder cocoa growers in Sulawesi. And, through the success of demonstration plots, local farmers have been convinced that the additional labour required to keep the pest under control has resulted in better farm management and increased incomes. In addition, a computer simulation model has been produced as a result of the research which has global implications for other cocoa-growing regions where pests and diseases cause damage to maturing pods.
The Cocoa Pod Borer (Conopomorpha cramerella Snellen) is present on most of the larger cocoa producing islands in Indonesia, with the exception of Java. It is also present in Malaysia and the Philippines and, whilst it remains present in an isolated island of Irian Jaya, the pest poses a serious threat to Papua New Guinea. With limited control, production losses in infested areas are significant (between 20-50%) for smallholders who rely on the year-round cash income provided by cocoa. The majority of the 100,000 farmers in Sulawesi (who produce about 75% of cocoa in Indonesia) farm an average area of 1-2 ha (500-2000 trees). Some smallholders have diversified to grow fruit trees and have small vegetable plots but few own livestock and the majority of their income is derived from the sale of their dried cocoa beans. CPB is not only a direct problem to these farmers and the cocoa industry but, indirectly, it also poses a serious ecological and health hazard. When cash is available, some farmers use pesticides in an attempt to control the pest but chemicals are generally ineffective against the larvae which burrow into cocoa pods. Controlling the adult moth is also potentially dangerous as it involves large amounts of toxic insecticides being sprayed high into the canopy of trees. In addition, with decreasing yields from existing plantations, farmers often resort to cutting down surrounding forest to plant more cocoa trees.
In order to limit the further expansion of CPB infestation, ASKINDO, ACRI and BCCCA joined together in 1997 to develop and implement integrated pest management techniques to control the pest. Cultural practices, employed on a number of demonstration plots at several different locations in South Sulawesi during 1997-8, were shown to disrupt the insect's life cycle and bring about effective control of the pest. The most important techniques included the practice of 'Complete, Frequent, Regular Harvesting' (CFRH) at weekly intervals and pruning trees every six months to achieve an open canopy at a maximum height of 3m. These improved farm practices quickly resulted in increased yields leading to a two to three-fold rise in income. Extension information provided on village boards was made available at the demonstration plots for visiting farmers and the impact was quickly noticed with the spread of techniques being practised by smallholders in the region. These recommendations also decrease losses caused by disease and rats since pruning the higher branches of the cocoa trees allows old diseased pods to be removed and prevents rats from feeding whilst hidden in the canopy. Fertilizers may also be used to balance the effect of pruning, and side grafting is advisable for low yielding or highly damaged trees.
The further effectiveness of the Cocoa Pod Borer Management Project has been demonstrated by the expansion of demonstration plots which were set up in 1998 by the Extension service in Central Sulawesi, where the problem of CPB is particularly serious. This has involved an informal training of trainers i.e. extension officers training others in the techniques and more farmers being invited to visit the plots and observe the results.
The results have also provided the basis for the development of a computer simulation model to demonstrate the impact of different harvesting/pruning regimes on the CPB population and on cocoa yields. Output from the model has confirmed the importance of maintaining these management practices in controlling CPB as any lapse in CFRH results in increased pest numbers. The computer model will also be important in the development of quarantine procedures to prevent the spread of CPB. This is particularly important as cocoa pods could be transported from one island to another in Indonesia or possibly across the border from Irian Jaya to Papua New Guinea. CPB is also known to affect certain fruit species e.g. rambutan. While CPB is only a minor pest of these varieties, global trade poses a potential risk to other regions although exports of these fruits are mainly to non cocoa-growing regions.
The importance of the CPB Management Project during the course of the last three years has not only demonstrated that the pest can be effectively controlled but that the management practices employed are appropriate even in the absence of CPB. This is due to the development of larger pods or bigger beans, an increased number of pods, more efficient pod collection and reduced loss through disease and rats. For this reason, it is hoped that the technology could be transferred to other cocoa regions affected by pod diseases, such as Black Pod (Phytophthora pod rot) which is a global problem, or by pod feeding pests such as capsids in West Africa. (see 99-2 Focus On; New combat strategies for cocoa)ACRI - American Cocoa Research Institute, 7900 Westpark Drive, Suite A 320, McLean, Virginia 22102 4203 USA
ASKINDO - Indonesian Cocoa Association, Jl Sultan Hasanuddin 6, Jakarta 12160, Indonesia (fax +62 216910576)
BCCCA - Biscuit, Cake, Chocolate and Confectionery Alliance of the UK, 37-41 Bedford Row, London, W1R 4JH