Greater yield through irrigation and limestone
In order to harvest more coffee, however, the farmers have got other options than merely banking on the work of bees, as Ghazoul discovered. They can increase the yield through liming, irrespective of bee density. And instead of relying on rainfall, it is worth the farmers' while to induce flowering with artificial irrigation. "It is particularly in a farmer's interests to irrigate his plantations at a different time to other farmers in the vicinity," says Ghazoul. After all, this will turn his plantations into bee magnets. This concentrated pollination increases the yield from the plantation enormously, the ETH-Zurich researchers reveal in their publication. It is a different story if the rain makes all the coffee plants in the region flower at the same time, however: the bees spread out over a wide area, the pollination is less effective and the harvest is poorer.
Trend towards deforestation
In an agroforestry system, the farmer also has another trick up his sleeve: felling trees or the forest to shed more light onto his coffee plants, which also increases the harvest. In doing so, however, he destroys the habitat of the giant honeybee (Apis dorsata).
A farmer who combines both courses of action is especially successful, initially unaffected by the disappearance of the large bees on his own plantation. Only when all farmers opt for this course of action do things take a turn for the worse. "From a
|Contact: Jaboury Ghazoul|