Notice: This project page is no longer being updated as of January 2023.
One third of all of our food comes from pollinated crops.
Because increasing temperatures impact both plants and the pollinators they rely on, climate change poses a dual threat to crop production. Shifts in dates when plants flower or pollinators are present could lead to a mismatch in timing, reduced crop pollination, and declining yields. Even a slight change in temperature can impact crop production in many ways. This, in turn, can affect pollinator survival. Pollinators are needed by many plants so they can produce fruit and seeds, and pollinators rely on plant nectar and pollen for food. Because of this delicate balance, it is important to understand how climate change affects both pollinator and plant populations.
West Virginia University (WVU) researchers are working with McConnell’s Berry Farm to study climate impacts on blueberry production. They are looking at blueberry flowering as well as interactions between bee and mite populations. In this tour, you will visit beehives at the WVU Organic Farm, a cooperators farm south of Morgantown, WV, and the WVU greenhouses.
“Blueberries are an economically valuable crop, and they are susceptible and vulnerable to climate change. We’ve been looking at flower development, and what we’ve found is that a 2 to 4 °C increase has led to a decline in blueberry flower production.”
– Sarah Mills, Graduate Student, West Virginia University
The McConnell Berry Farm is located near Morgantown, WV. This exclusively pick-your-own operation is open for four, 4-hour picking sessions a week and by appointment. About 1,500 pickers come to the farm every year! Dr. Bob McConnell is the owner/operator and says the pick-your-own setup is a great way to get young people interested in farming.
Dr. McConnell is also a retired professor from West Virginia University (WVU). He is a strong supporter of applied research and continues to work with WVU scientists. Together they are studying the impacts of different pollinators and bees, pests, and the effects of temperature on crop production.
To produce a good blueberry crop, plants require adequate pollination every year. Currently there is a decline in pollinators (honeybees and wild bees), partly due to parasitic mites. This is a serious problem for blueberry pollination. Many growers are now seeking alternative pollinators so they do not need to rely on the dwindling number of honeybees.
In 2005, WVU and Dr. Bob McConnell were studying which pollinators worked best with blueberries. This Partnership Project was funded by a SARE (Sustainable Agriculture Research and Education) grant. The researchers tested four kinds of pollinators: hornfaced bees, honeybees, natural pollinators, and no pollinators. The project showed that hornfaced bees were more efficient and less expensive than honeybees at pollinating blueberries.
Bee populations face a number of pressures that can affect the health of the hive. Such factors include climate change, chemical controls, natural predators, and parasites, like mites. When a bee brood cell is infested with mites, both the adult bees and eggs can be harmed. Varroa mites are the most common type of parasite that infests honeybee hives. They can be found in almost every colony, and these mites can kill a hive within a year if left untreated. Dr. Yong Lak Park, Associate Professor of Entomology, studied the effects of Krombein’s hairy-footed mite (Chaetodactylus krombeini) on his populations of hornfaced bees.
In this video, Dr. Yong Lak Park explains the effects of temperature increases on bees and mites and how they interact with the blueberries. By looking at how the insects and plants interact at different temperatures, researchers can see how climate change might impact blueberry production.
This research was funded by a USDA Agriculture and Food Research Initiative (AFRI) grant. Biophysical models developed in the lab help to predict the impacts of different climate scenarios. To validate the models, data were collected from five field sites in Michigan, Ohio, and West Virginia. Bees, temperature logs, and bee propagation systems were set up at each site. Data, including date of bee emergence from the cocoon state, bee developmental times, and number of days to flowering were used to evaluate model performance.
Dr. Michael Gutensohn, Assistant Professor of Horticulture, talks about his research project. Dr. Gutensohn is studying how scent compounds and nectar in flowers are affected by an increase in temperature.
It takes 7 years to establish blueberries and they can grow for 30-40 years. So, with climate projections of warmer temperatures, growers who are planting now should think ahead! Farmers may want to consider selecting cultivars that do better under slightly warmer conditions since they will be working with those plants for decades.
Many pollinators, including honey bees, are currently at risk. But why should we care? Pollination is the transfer of pollen grains from the male reproductive structure (anther) to the female reproductive structure (stigma). This can occur within flowers on the same plant or between flowers of different plants. In the case of blueberry, cross pollination can lead to higher yields. Pollination is vital for crop reproduction. Some crops depend on a specific pollinator, which means that if the pollinator disappears, so does the crop. At least 30 percent of the world’s crops, including many that provide the food we eat, rely on cross-pollination! Landowners may want to consider ways to restore, enhance, or create habitat for organisms that pollinate crops. This resource center has useful tools for those looking for such conservation practices.
Sarah Mills is a West Virginia University (WVU) graduate student working under Dr. Nicole Waterland’s supervision. She is researching blueberry flowering at the WVU greenhouse as part of a USDA Agriculture and Food Research Initiative (ARFI) grant. Sarah found that temperature increases of as little as 2 to 4 ̊C can affect flower development in blueberry. Small temperature increases led to a decline in the number of flowers, a shift in flowering time, and a change in the duration of flowering. Combined, these changes can lead to decreased blueberry production.
Over the last few years, Dr. Mirjana Bulatoviz-Danilovich, has noticed that blueberry season is starting earlier. As an Extension Specialist at WVU, she has seen the start of bud development shift from April to as early as February and March in recent years. A warm, early spring gets the sap moving and pushes bud development, but the plants can be harmed if there is a frost. The season is also becoming longer and now extends into mid-November. As the climate changes, farmers are encouraged to think about strategies to protect their crops, including which varieties of blueberry to plant.
Dr. Nicole Waterland, Assistant Professor of Horticulture at West Virginia University (WVU), talks about her research. Her experiment in the WVU greenhouse is designed to study how temperature impacts blueberry growth and development.
To study the effects of temperature on blueberry, five bays (rooms) in the greenhouse were used for this project. Each bay was set to a different temperature (18, 20, 24, 28, and 31 °C or 64.4, 68, 75.2, 82.4, and 87.8 °F), and two cultivars of blueberry, Blueray and Jersey, were grown in each bay. Floral longevity, the number of floral clusters, and the rate of floral development were measured and recorded. The greatest numbers of flowers were produced on plants growing at temperatures of 20 and 24 °C (68 and 75.2 °F). In contrast, almost all flower clusters were aborted on plants growing at 31 °C (87.8 °F). In summary, Dr. Waterland’s team found that even a slight change in temperature can impact the flower development of blueberries.
Blueberry plants depend on their flowers to attract pollinators in order to produce fruit. Both the flowering of plants and the emergence of bees are dependent on temperature. Changes in temperature can affect flower production and the timing of flowering. In this experiment, plants of both cultivars reached full bloom almost 2 weeks earlier at 28 °C than plants grown at 18 °C. These results suggest that climate change could alter the plant and pollinator relationship. A potential decrease in fruit yield could lead to a decline in pollen and nectar for pollinators.
Dr. Yong Lak Park and Dr. Nicole Waterland are involved in an exciting new project at WVU where they are working with a team to develop a robot pollinator. The 3 year, $1.1 million project is funded by the National Robotics Initiative. The recent decline in honeybee populations is a threat to the $24 billion U.S. crop production industry. A robotic pollinator could be a possible solution to this problem. The research team is using Cataglyphis, the winner of the Sample Return Robot Challenge, to build their pollinator. The collection basket will be replaced with a robotic arm for pollinating, with soft brush tips on the end to mimic bee hairs.
Dr. Mirjana Bulatovic- Danilovich is an associate professor and ornamental horticulture Extension Specialist at WVU. An important part of this project is redistributing the knowledge they gain to the growers. Dr. Bulatovi-Danilovich explains how they are sharing this information.