[ACCRA] A primary reason for Ghana's cocoa and oil palm production decline is the killing of pollinating insects by pesticides used on farms, says a study.
The research, carried out by entomologists and plant scientists from Kwame Nkrumah University of Science and Technology (KNUST), was presented at a seminar on pollination in Fumesua, Ghana last month (16 April).
It found that the pesticides currently used by farmers are killing pollinators such as beetles and midges, which are important pollinators for oil palm and cocoa, respectively.
Eric Frimpong, one of the researchers, told SciDev.Net that the main objective of the study was to find out how to manage the ecosystem for effective pollination.
They sprayed conventional chemical insecticides and new insecticides made of plant extracts on farms in Kumasi, in Ghana's Ashanti region, and assessed the results over a 30-day period.
The researchers found that following the application of both types of insecticide, the population of pollinators dropped immediately. Two days after application, numbers continued to drop, but more severely with chemical insecticides.
The researchers found no difference between farms close to the forest reserve compared to those in a cultivated environment.
"It appears that most pollinators breed within the farming environment rather [than] outside the farm. Therefore, it is better to maintain the internal conditions of the farm for immediate breeding," said Frimpong.
Peter Kwapong, Ghana national coordinator for the Global Pollination Project, said: "In this case the population of pollinators [visiting] each cocoa flower has been reduced because they are killed together with the pests during chemical spraying".
Kwapong said that the oil palm pollinator beetle was also threatened by habitat destruction, bush burning and other farming activities.
Frimpong said pollinators breed in the stagnant water which collects in the stems of plantains or bananas. He suggested that farmers should plant both cocoa and bananas or plantains to increase the population of pollinators.
Walter Alhassan, coordinator of the Project on Strengthening Capacity for Safe Biotechnology Management in sub-Sahara Africa (SABIMA) at the Forum For Agricultural Research (FARA) said that intercropping in this way could create a more genial ecosystem for the breeding of midges, but added that this would require guidance as the canopy effects of intercropping with tree crops would need to be examined.
"We will need a close working relation between farmers, the scientists and the extension agents to develop an effective conservation agriculture package," he said.