Researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) are taking a whole-systems approach to update current recommendations for new plantings.
A research project, “Establishing Healthy Citrus Plantings in the Face of Persistent HLB Pressure,” is led by UF/IFAS entomologist Lauren Diepenbrock.
According to Diepenbrock, current guidelines were created pre-HLB and therefore are out of date and do not consider the disease.
“Our goal is to come up with some guidelines to help growers establish new plantings … using some of the tools that growers are already implementing that we have zero guidelines on,” Diepenbrock says.
Those tools are reflective mulch, individual protective covers (IPCs) and kaolin clay.
“Growers are trying to use these new tools. But when they ask for help, we don’t know what to tell them. So we’re hoping that through this research we will be able to give our growers some evidence-based guidelines to help them be successful,” Diepenbrock says.
Researchers Megan Dewdney, Evan Johnson, Davie Kadyampakeni and Christopher Vincent are all working collaboratively on the project. Dewdney and Johnson are looking at pathology both above ground and below ground, Kadyampakeni is tackling nutrition and irrigation, and Vincent is assessing overall tree growth.
Kadyampakeni says fertilizer is being applied to trees consistently to ensure uniform response across treatment tools. He is looking at different irrigation management strategies across the different tools. Soil moisture sensors are being used to capture moisture data in addition to soil temperature up to 48 inches below ground.
Kadyampakeni believes it will take a few growing seasons before seeing consistent, accurate conclusions for recommendations.
“Each of the treatments we’re assessing is expected to impact pest management and disease transmission, but they’re also expected to directly influence tree growth,” Vincent says.
According to Vincent, each treatment impacts the distribution of light within the tree canopy. IPCs shade the canopy and enhance temperature and relative humidity, which are expected to increase growth. Reflective mulch redistributes light, allowing more light to come from below into the center of the canopy. Particle films shade the outside of the canopy and redistribute light further into the canopy.
“Citrus trees grow quite slowly, so it takes us time to really confidently detect differences in growth,” says Vincent. “We haven’t seen any differences yet, but we didn’t expect to see differences this early.”
However, he says he definitely expects for all of the treatments to improve growth and yield over the current recommended guidelines.
“We assume that increased growth in the beginning means earlier yield and perhaps more yield down the road,” Vincent says.
Hear more from the research team in the April 2021 episode of the All In For Citrus podcast, a joint project of UF/IFAS and AgNet Media. Listen to the full podcast.