Water is a limiting factor in Florida citrus production during the majority of the year. Florida citrus trees may require irrigation throughout the year due to the low water-holding capacity of sandy soils and the warm subtropical climate with distinct drought periods during the spring.
Davie Kadyampakeni, assistant professor of soil and water sciences at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, believes that irrigation management is key to optimize water use and increase fruit yield.
“Maintaining daily irrigation is important in managing huanglongbing (HLB)-affected trees,” Kadyampakeni says. “By irrigating daily, this will reduce tree water stress and improve tree water use.”
According to Kadyampakeni, citrus trees affected by HLB experience approximately 40 to 70 percent root loss, leaving them with a compromised root system. He advises growers to keep water in the top 12 inches of the soil (where 70 percent of the roots are) to improve water use and fruit yields while reducing nutrient leaching.
“Some growers may even find that irrigating multiple times during the day may be beneficial,” Kadyampakeni says. “It’s important to keep the moisture content at an optimal level at all times to optimize nutrient uptake and overall tree performance.”
To best manage irrigation practices for HLB-affected trees, Kadyampakeni recommends the use of soil moisture sensors to determine when and how much to irrigate. He says it is important to place the sensors where most of the roots are located, in the top 12 inches of the soil. Growers need to know the soil water-holding capacity and tree root-zone depth. He advises placing multiple sensors throughout the grove to improve accuracy.
Kadyampakeni encourages growers to avoid over-watering, which can be a common problem when using microjet irrigation systems. “For growers using a microjet irrigation system, we recommend irrigating twice daily. However, some growers feel like they need to water for a long time, which isn’t the case. We recommend growers who practice frequent irrigation to irrigate for shorter durations of about 20 to 30 minutes. This will be ideal for optimizing tree health.”
UF/IFAS researchers are working to refine their current irrigation guidelines, which growers can expect to see in a couple of years.
In addition, Kadyampakeni and his team have begun experimenting with plastic mulch. He says that growers may experience up to 40 percent water savings with plastic mulch, due to little or no water being lost to evaporation.
This article was written by Ashley Robinson, AgNet Media communications intern.