Karl Foord, UMN Extension Educator
I recently attended a conference on native pollinators presented by Jennifer Hopwood of the Xerces Society. The Xerces Society (founded in 1971) has worked to conserve invertebrates and their habitat by focusing on conservation policy, advocacy, education, and research.
One rather alarming topic presented at the conference involved Maoxian County in the Chinese province of Sichuan (see map). In this region farmers have been forced to pollinate their apples and pears by hand because there are insufficient natural insect pollinators to ensure proper fruit set and thus a crop. These are high value crops that must be free of cosmetic defects to be marketable. To achieve this, the growers have resorting to spraying when there is the least hint of a problem. This has resulted in marketable material, but at the cost of having destroyed all the native pollinators in the region. There are beekeeping services but these individuals hesitate to locate their bees in the area because of the danger presented to their hives by the pesticide use strategies of the fruit producers. The result hand pollination by humans. This report comes from one county in a province that produces a little more than 1% of Chinese apples. Nonetheless, the province still produces some 409,000 metric tons of apples (in 2009). And this pollination problem is not an isolated case, but rather extends to other countries in the region such as Pakistan, India, and Nepal.
Such a situation does not translate well into American agriculture especially considering labor wages. If we were to do so it would look like this: It takes twenty Chinese workers working for 10 hours to pollinate a half acre (see pictures). Translated into an orchard in the United States where the workers were paid $9 per hour, it would cost the growers $3,600 in pollination services. This would probably double the cost of apples.
How can we best relate to this situation? A certain amount of the problem comes from an ignorance of the complexities involved in the relationships between insect pollinators and crop plants. However, we in the U.S. are not immune, even though the problems we face may be different. Our commercially managed honeybee populations are facing a number of challenges as noted by Dr. Marla Spivak in a previous article. We have also seen a dramatic decline in a number of native bumblebee species that were previously quite numerous. The exact causes for such a decline have not been definitively identified, however it is likely that there is no one cause but rather a series of causes. And again the complexity we face with biological systems rears its head.
Hand pollination of fruit crops is about as unsustainable as a system can get. The fact that it exists anywhere sends me a strong signal to be extremely vigilant about land management, pollinator habitat, and pesticide use to avoid such an outcome in our fruit production systems.
POLLINATION FAILURE IN APPLE CROP AND FARMERS' MANAGEMENT STRATEGIES IN HENGDUAN MOUNTAINS, CHINA
Pollination problems in China
Status Review of Three Formerly Common Species of Bumble Bee in the Subgenus Bombus