Steven Callaham, CEO of Dundee Citrus Growers Association, is a champion of Citrus Under Protective Screen (CUPS)—an innovative approach to protecting crops from citrus greening disease. In this episode of In Our Expert Opinion Podcast, Steven joins Todd Dantzler, Managing Director & Partner at Saunders Real Estate, to share how CUPS is helping citrus growers increase yields, improve fruit quality, and combat industry challenges in Florida.
Below is an excerpt from the interview. Listen above for the full podcast.
Steven Callaham, Dundee Citrus Growers Association
The inception of CUPS. Back in 2014, myself and some of our colleagues started following the research that Dr. Arnold Schumann with the UF/IFAS Citrus Research and Education Center in Lake Alfred was doing. He had a one-acre screen structure with wooden telephone poles, a flat roof, and flat sides.
His goal with his research was to exclude the Asian citrus psyllid, which is the insect that spreads citrus greening disease. If he could do that with the screen and still grow trees profitably–grow the volume and grow the quality of the fruit needed to overcome the capital expense of putting that screen structure up–then it could be a way that citrus growers could live in an endemic greening environment.
We followed that research. We were very, very pleased with the results that Dr. Schumann was getting after his first two and a half to three years. So, we took it to a commercial level, breaking ground in 2017 on our first sizable project which is about 110 acres under screen. Since that time, we've expanded almost every single year and as of the spring of 2025, we'll have just under 1,000 acres of CUPS planted.
How has the CUPS program assisted growers? The main purpose is to use a screen mesh that will exclude the Asian citrus psyllid–that's your primary goal so that you do not get citrus greening. We know citrus greening is the biggest challenge, as Florida citrus growers, that we have ever faced in history.
You also are providing a better quality light. When the sun hits the screen, it disperses the light so you have less shading inside that structure. Even though the screen provides a certain percentage of shade, it helps distribute that light so that the tree grows faster; it photosynthesizes at a more rapid rate.
We're seeing these trees grow 2.5 times faster. It's a very, very “happy” environment as we say in our company. You can tell they just grow faster and they produce more.
This episode of In Our Expert Opinion Podcast explores how Citrus Under Protective Screen (CUPS) is transforming Florida agriculture, as Steven Callaham shares insights with Todd Dantzler on its impact on fruit quality and disease prevention.
Recent improvements. As far as experimentation, we are constructing a dedicated variety trial CUPS pod. That pod is going to have dozens of citrus varieties in there, from acid fruits to mandarins, tangerines, specialty citrus, grapefruit, every type of orange you can think of, new varieties, and old varieties.
You have to grow them in that environment and find out, first of all, will they produce the quantity of fruit you need? Will it be the quality of fruit that you need to overcome that expense? So, that is an ongoing project; we need to figure out what other varieties will grow in that [CUPS] environment.
CUPS versus hurricanes. We've had our fill of hurricanes, and it's been a challenge for us. I'm hoping that, whatever that trend is, we're done with it. I mean, our structures are engineered very, very well; they're very, very strong structures, but when you have a category two direct impact from a hurricane, you're going to have screen damage.
That's been something that we've had to contend with after each hurricane–you have to repair the screen. Of course, the older the screen is and the longer it's on the structure, the more UV continues to degrade it over time. So, you'll see the oldest structures suffer the most damage from hurricanes. The newer structures with new screen on them have withstood category two hurricanes without any screen damage.