Blueberry fields forever

For Zilfina Rubio Ames, blueberry research begins after the plant is bred and in the ground.

An assistant professor of horticulture in the University of Georgia’s College of Agricultural and Environmental Sciences and a small-fruit specialist with UGA Cooperative Extension, Rubio Ames endeavors to better understand blueberry plant physiology and how it can be manipulated to increase production efficiency.

“We are in a moment in time where we are concerned about how much fertilizer we are providing to the production system and how that affects the sustainability of the system, not only in terms of the environment but also how fertilizer affects the sustainability of the industry in economic terms,” Rubio Ames said.

Over the past decade, fertilizer prices have risen substantially, making it increasingly expensive for growers to keep producing the state’s primary specialty fruit crop. Researchers are looking at methods to improve the blueberry production system, making it more sustainable without reducing yield or impacting fruit quality.

Rubio Ames is focused on creating a balanced nutrient plan for blueberry producers around the state. While growers know a lack of nitrogen, for example, can cause damage to yield, excessive nitrogen fertilization will both increase expense and likely create a plant with increased vegetative growth and less fruit.

“This is not only for nitrogen, but for phosphorus, potassium, calcium, boron and all these fertilizers the plant needs — those nutrients are important,” Rubio Ames said. “My main area of research is looking at fertilization practices and how reducing or increasing those fertilization practices alters plant physiology, in this case blueberry physiology.”

Rubio Ames also focuses on improving management practices, including pruning techniques and the use of plant growth regulators, to protect crops from variable climate conditions — especially Georgia’s spring freezes. 

“Last year we had a detrimental freeze that wiped out almost 50% of the crop,” Rubio Ames said. “How can we find tools that could help us overcome these biotic and abiotic challenges that the blueberry production system has in the state of Georgia?” 

Implementing proper pruning techniques, while far from a new practice, is vitally important to improved blueberry production. 

“If we increase nitrogen fertilization we increase vegetative growth, and then we have an unbalanced plant that has more leaves than flowers,” Rubio Ames said. “Pruning is a technique that allows us to manage the plant, shaping and training the plant the way you want so it is able to harvest all the light possible.” 

Rubio Ames is managing several projects involving pruning, from timing — as pruning can invigorate growth — and how pruning impacts the physiology of the blueberry plant and influences production. 

“We usually prune in July, in the summer, right after the harvest is finished. But what if we don’t prune at that time? What if we wait until wintertime to prune? Will that be beneficial?” she asks.

Rubio Ames’ research has one overarching goal: to make production more efficient and economically viable for growers, which leads to more blueberries for consumers to enjoy.