Developing and maintaining a healthy root system is crucial for establishment and long-term productivity of citrus trees.
The presence of HLB can greatly complicate citrus root-health management. The infection causes severe damage to fibrous roots that amplify the detrimental effects caused by other root pests and pathogens, such as phytophthora root rot. Due to HLB’s widespread presence throughout Florida, root-health management has become more important than ever.
During the most recent University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) OJ Break webinar, Evan Johnson discussed efforts to help citrus tree roots cope with HLB.
According to Johnson, plant pathologist at the Citrus Research and Education Center, HLB severely affects root health. HLB causes 30 to 50% root loss early in disease development. As the disease progresses, root loss can be as high as 70 to 80%.
Currently, there is no proven management option for prevention of HLB-associated root loss. However, to lengthen tree productivity, Johnson recommends growers alter soil applications to adapt to the root’s limited uptake capacity and to prevent further damage to existing roots. Irrigating and applying fertilizer in small, frequent doses is recommended to balance the water and nutrient supply. More frequent applications allow trees to make better use of inputs.
Johnson advised growers to avoid using root growth stimulating treatments, as they have proven to be counterproductive in managing citrus root health.
He said growers should maintain a soil pH level of 6.5 to avoid additional stress on root systems. To ensure greater root health in new plantings, he recommended selecting rootstocks that are best suited to the grove’s conditions and that fare well under HLB stress. Growers who have followed these recommendations have reported a significant increase in root mass in their groves.
To participate in upcoming UF/IFAS OJ Break meetings, register here.