For nearly 20 years now, Florida citrus growers have been living with a scourge — HLB (aka, citrus greening). The debilitating plant disease spread by a tiny insect has taken a huge toll on the industry. The latest orange crop forecast from USDA (18.8 million boxes) is but a fraction of the record-setting season of 1997-1998 when 244 million boxes of oranges were produced in the Sunshine State. A similar story is playing out for Florida grapefruit, too. Scientists and growers have been hard at work trying to find solutions. One of those potential solutions — growing citrus under protective screen — is gaining more ground.
Dr. Arnold Schumann, a UF/IFAS Professor of Soil and Water Science, was on the front lines of the movement toward growing citrus under protective screen (CUPS). The concept of growing citrus trees in a protected environment helps exclude the biggest threat — exposure to HLB and its vector the Asian citrus psyllid. That was part of the thought process when Schumann and his colleagues helped construct the first CUPS structure at the Citrus Research and Education Center in Lake Alfred a decade ago.
In addition to protection from pest and disease pressures, the protected environment also promotes a more sustainable approach to growing oranges, grapefruit, and other specialty citrus crops.
According to UF/IFAS research, a little more than 650 planted acres of CUPS were reported in 2023. One of the early adopters of CUPS was Dundee Citrus Growers Association.
Steven Callaham, CEO of the cooperative, says the commitment to grow this way is not one to be taken lightly. There is much to consider.
“CUPS is garnering a lot of interest in Florida as well as in other citrus producing states in the U.S.,” he says. “However, there are only a few growers that have taken the leap and developed commercial-scale plantings.”
A bird’s eye view of Dundee Citrus Growers Association’s complex of CUPS structures in Central Florida.
Photo courtesy of Dundee Citrus Growers Association
Callaham says Dundee Citrus Growers Association has 500 acres of CUPS planted with another 500 acres being developed. “By spring 2025, we will have 1,000 acres of CUPS. In addition to that, future projects are in the planning stage.”
Steven Callaham
A main factor that drew Callaham into the CUPS world is having a sustainable way to grow more with less. “We are using substantially less land, water, and fertilizer to produce each piece of fruit with the CUPS method. The interior and exterior quality of CUPS grown fruit is spectacular.”
Despite the low adoption rate of CUPS so far, Callaham expects to see CUPS acreage expanding in Florida. “We are trialing dozens of citrus varieties in CUPS to determine what is best suited to fuel our future expansion.”
Though Callaham doesn’t believe CUPS is the ultimate answer to all the production challenges facing Florida growers, he certainly sees the benefit and potential. “It will represent a significant portion of the fresh market fruit our members produce in the future.”
These red grapefruit trees are thriving under cover at one of Dundee’s CUPS facilities.
Photo courtesy of Dundee Citrus Growers Association
Benefits of the CUPS Growing System*
- Provides an environment for sustainable growing practices
- Protects natural resources
- Requires less water, pesticides, and fertilizers
- Protection from the citrus psyllid/HLB and other pests and diseases
- Encourages faster growth
- Produces higher quality and yields per acre
- Ensures highest level of food safety and security
- Grown locally in Central Florida
*Source: Dundee Citrus Growers Association
Steven Callaham of Dundee Citrus Growers Association is impressed with the quality of fruit being produced in the cooperative’s CUPS system.
Photo courtesy of Dundee Citrus Growers Association
Potential Challenges To CUPS*
- Start-up Cost/Investment: On average of $1 per square foot with screenhouse construction
- Equipment maintenance: Screen replacement is recommended at least every 7 to 10 years, depending on exposure to tropical storm/hurricane-force winds
- Novel approaches required for optimizing all indoor management, and production practices.
*Source: UF/IFAS 2023-2024 Citrus Production Guide: CUPS Production Systems