by Ian McCall


In West Africa it is not only people who are assailed by bugs. One of the things that concerned the Marketing Boards, and the Produce Inspection Service in particular, was the problem of maintaining the quality of stored produce in adverse weather conditions, difficulties of evacuation and the peculiar infestations that could appear when storage was necessary for longer periods than were desirable. Even perceived infestation, where no harm was actually done, could affect the price paid if arbitration was called for by the buyer. So it was with palm kernels which could be suddenly infested by the necrobia rufipes known more familiarly as the red-legged ham beetle. It gave colour to the dullness of the kernels and added a bright movement as it legged it round a bag in quick darts that defied any attempt to remove it or do it in. It did not harm the kernels but buyers did not like them.

Groundnuts could similarly be invaded, in this case by trogoderma infestation, which left the nuts in a weevily condition and if left too long before fumigation or evacuation, could be of unmerchantable quality when they arrived at their destination. Just as great a problem with them in value terms was seepage of the valuable oil content of the nuts caused by the weight of the upper bags in a stack exerting pressure on the lower layers, or drying out by harmattan winds, and here the solution was to get them moved as quickly as possibly to their final destination. But the biggest headache of all was with cocoa. Given the care taken in planting the young cocoa trees, looking after them assiduously in their early years until they bore their fruit, cutlassing the grass around them, cutting out black pod and swollen shoot, harvesting the pods at the most favourable time, and preparing the cocoa beans for the market merited meticulous attention to the process. This last activity of preparing the beans for market included removing the beans from the pods, burying the pods to prevent decay and possible creation of harmful bacteria, and fermenting the beans in banana or plantain leaves, turning them regularly to ensure all the beans were properly fermented over a controlled period, drying, and picking to remove trash and animal ordure (dry pellets from goats), spreading ready for inspection and grading by the Produce Inspection Service, bagging in suitably marked bags, weighing and sewing ready for sealing and storage locally until evacuated to port by lorry or sometimes barge. It was only right that every care should be taken that it arrive at the buyer’s premises overseas in the very best of condition. That was the objective achieved after years of experience and experimentation and remained the basis of the Nigerian crop’s reputation and why it became the custom in the terminal markets to quote prices for best fermented Lagos/Accra cocoa rather than benchmark quality against other countries of origin.

Inspection was carried out by taking a sample of beans from a parcel of cocoa thoroughly mixed with shovels. A produce inspector would draw a sample from the whole parcel from which he would then select randomly 300 beans which he would proceed to inspect one by one by cutting the bean in half longitudinally and classify them to establish the grade of the cocoa by calculating the percentage of underfermented, mouldy, weevily and germinated beans before they were sewn with continuous twine and sealed as the guarantee of quality. In store, before transport to the port of shipment, they were required to be protected from infestation by the lasioderma serricorne, the tobacco beetle. This was done by the placing of sticks coated with a combination of heated and slightly diluted funtumia rubber which gave a tackiness to the sticks which were then called até strands. If the tobacco beetle was around, it tended to stick to the strands and gave an indication of the degree of infestation should it take place. The rubber used was a local wild variety, not to be confused with the Hevea Brasiliensis or para rubber which is the cultivated species of rubber grown for industrial applications.

The problem was greater in the vast warehouses at the ports, but principally at Apapa, the port of Lagos, from which the majority of the cocoa crop was shipped. By the time they arrived at the port the bags could have been in storage for a number of weeks. In addition to the provision of até strands, the stacks were ‘sealed’ with a spray at port warehouse that, in its pattern of dispersal of insecticide, left in theory no spot unprotected. The insecticide was a mixture of risella oil and pyrethrin, the latter imported from Kenya. Unfortunately the insecticide only prevented further infestation and had no effect on beans already infested. If the build-up of infestation was unacceptably high, the cocoa concerned had then to be removed to a fumigation chamber specially constructed for the purpose where the tobacco beetle was killed off by an appropriate fumigant. But there was still a problem. Once fumigated, not only were the tobacco beetles killed off but so were the predators that kept them in check. If cross-infestation from new arrivals in the warehouse took place after fumigation, the rate of infestation took off at an even faster rate. For that reason, priority shipment had to be given to fumigated stocks. The irony is that the tobacco beetle cannot survive temperate climates. Regular shipment would eradicate the infestation but shipping companies like, indeed need if profits are to be made, to fill their ships. To do this means that waiting for a full shipload cannot be avoided.

‘Didn’t know they grew tobacco in Nigeria’ you might say. And a good statement of a question it would be. For tobacco is grown far from where the cocoa trees grow. Tobacco is grown in the centre and north of the country. Apparently, so the entomologists of the West African Stored Products Research Unit informed us, the tobacco beetle attaches itself to cowpeas which are grown in the north and mostly sold in the south of Nigeria and no one has yet found a way to stop the cowpeas acting as a carrier on their way to or through the cocoa growing country.

Perhaps in a quiet moment when you are having a cup of hot chocolate and smoking a cigarette, more likely admittedly if you are French, you will remember having read this and marvel at the connection between the two.

Ian Mcall Auchencrow
Berwickshire, Scotland July 2003