The findings, which will be published in the November/December 2009 issue of Crop Science, offer promise for the use of bumble bee crop pollinators as an alternative to European honey bees, whose populations have recently declined in many areas of the United States.
Red clover, which is grown for forage and as a rotation crop to improve soil, is raised for seed in western Oregon's Willamette Valley. It will not produce seed without pollination, so growers typically place two to five European honey bee hives on each hectare. However, bee diseases, mites, and colony collapse disorder have recently limited availability and resulted in higher costs for hive rentals. Given these changes, an alternative pollinator for red clover seed crops is needed.
Worldwide there are over 200 species of bumble bees; some of whom are known to pollinate red clover. While commercially reared bumble bee species are available to growers elsewhere, they are considered exotic species in Oregon and cannot be introduced into the state. This leaves Oregon growers dependent on naturally occurring populations of bumble bees as pollinators. However, there is currently no information on the pollination efficiency of native bumble bee species.
Through funding from the Clover Commission, scientists at Oregon State University investigated native bumble bees in commercial fields of red clover seed crops in the Polk County region of the Willamette Valley. Prior to bloom, researchers covered plants with mesh-screened cages. European honey bee hives were placed in some cages and nests of B. vosnesenskii, a native Oregon bumble bee,in others. Some cages were also left vacant. After bloom, seed yield and seed set were compared amongst the different cages. Seed set was also evaluated in four different fields without cages to assess the efficiency of existing bee pollinators. In addition to analyzing seed set, researchers assessed the diversity and abundance of native bumble bees through visual observations of foragers on red clover flowers and through trapping bumble bees in blue vane traps.
While there were no differences in seed yield or average seed set in cages with bumble bees compared to honey bees, the study revealed that variability across cages was lower with bumble bees indicating that bumble bee pollination is more uniform than pollination by European honey bees. The researchers observed that the abundance of bumble bee peaked during mid-to-late bloom. They recorded six species of bumble bees gathering pollen from red clover flowers. Of these, more than 92 percent consisted of B. vosnesenskii, indicating that it is the key pollinator in Oregon. In addition to the six native bumble bee species that were seen gathering pollen from the red clover, 25 more species of native solitary bees, belonging to 12 genera and five families, were collected in the bee traps.
The study has not only documented a great diversity of native bees in synchrony with red clover bloom, but it has also found that seed set was uniform and high across four fields. Under current pollinator regimes, researchers believe red clover seed production is close to its maximum in Oregon.
"To sustain these high yields in Oregon, we must conserve the habitat of bees, use pesticides judiciously and provide floral resources prior to red clover bloom," said Oregon State University entomologist Sujaya Rao, one of the researchers on the study. "Globally, where red clover seed is produced, similar studies are needed. If seed set is found to be well below the maximum, appropriate alternative options such as augmentation with commercial bumble bees could be considered."
Research is ongoing at Oregon State University to determine whether high yields can be achieved by native pollinators alone. If so, European honey bee hive rentals would not be required, and this could lead to more economic red clover seed production in Oregon.
The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://crop.scijournals.org/cgi/content/abstract/49/6/2207.
Crop Science is the flagship journal of the Crop Science Society of America. Original research is peer-reviewed and published in this highly cited journal. It also contains invited review and interpretation articles and perspectives that offer insight and commentary on recent advances in crop science. For more information, visit http://crop.scijournals.org.
The Crop Science Society of America (CSSA), founded in 1955, is an international scientific society comprised of 6,000+ members with its headquarters in Madison, WI. Members advance the discipline of crop science by acquiring and disseminating information about crop breeding and genetics; crop physiology; crop ecology, management, and quality; seed physiology, production, and technology; turfgrass science; forage and grazinglands; genomics, molecular genetics, and biotechnology; and biomedical and enhanced plants.
CSSA fosters the transfer of knowledge through an array of programs and services, including publications, meetings, career services, and science policy initiatives.
Sara Uttech | Newswise Science News
New insight into why Pierce's disease is so deadly to grapevines
11.06.2018 | University of California - Davis
Where are Europe’s last primary forests?
29.05.2018 | Humboldt-Universität zu Berlin
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
20.06.2018 | Materials Sciences
20.06.2018 | Materials Sciences
20.06.2018 | Materials Sciences