The global chocolate industry is worth roughly $100 billion per year and provides income for upwards of 6 million smallholder farmers in the tropics. It’s a vital industry for much of the world, but a new study finds cacao production is limited by two important factors: pollination and temperature. As pollinators decline globally and the world continues to warm amid climate change, researchers warn that cocoa production may suffer.
Cacao plants are naturally pollinated by insects and sometimes by wind or water. To evaluate how effective natural pollination is in cacao production, the researchers conducted a series of experiments on cacao trees in Brazil, Ghana and Indonesia.
At each study site, the researchers subjected cacao trees to one of six pollination treatments. They ranged from 0%, in which all flowers were naturally pollinated, to 100%, in which all flowers were hand-pollinated; the researchers manually transferred pollen to recipient flowers.
To calculate the influence of temperature on the trees’ yields, the researchers used climate data from the European Union’s Copernicus Climate Change Service and calculated the monthly average temperature for their study sites at 2 meters (6.5 feet) above ground level.
The study found that on average, only around 17% of the flowers were naturally pollinated. But hand-pollination increased cacao yield by 20%.
It also found that in December, during the hot season in Brazil and Indonesia, sites that were cooler by 7° Celsius (12.6° Fahrenheit) had increased cacao yield by up to 31% compared with the warmer sites.
With rising global temperatures due to climate change, these findings highlight potential challenges for chocolate lovers and the millions of farmers who rely on cultivating the crop.
Thomas Cherico Wanger, a co-author of the study and group leader with Agroscope, the federal agricultural research institute of Switzerland, said that increasing pollination can offset the decreased production resulting from warmer temperatures.
“In sites where you have higher temperatures, you have lower yields but you can actually have higher yields with pollination. Through maintaining levels of pollination, you can kind of buffer these negative impacts,” Wanger told Mongabay in a phone call.
To encourage more pollinators, the study’s authors recommend reducing the use of pesticides and increasing leaf litter around cacao trees to provide habitat for pollinators.
Gustavo Júnior Araújo and Tereza Cristina Giannini, researchers at the Vale Institute of Technology in Brazil, not involved in the study, told Mongabay’s Sean Mowbray that the suggestions presented in the study “offer an excellent model of best practices to promote a more profitable and sustainable cocoa industry in the future.”
Wanger suggested agroforestry as a way to address both pollination and temperature challenges. By integrating cacao cultivation with surrounding forests, farmers can create a cooler microclimate while also providing essential habitats for pollinators.
“If we want to continue eating chocolate in the future, our agroforestry systems are our best options,” he said.
Banner image: of cacao pods by Merryjack via Flickr (CC BY 2.0).
