A Shift Toward Soil Microbes in Young Citrus Tree Care

Josh McGill Citrus, Sponsored Content

SUMMARY: Many Florida citrus growers have made the decision to shift their focus away from saving older HLB-infected trees and toward protecting and strengthening young citrus trees, using soil probiotics, before too much damage is done.

Understanding citrus trees’ vascular systems
Citrus trees have developed a complex but effective circulatory system for the uptake, storage, and utilization of water and nutrients. Similar to the vascular system in humans, a plant’s network of xylem and phloem tissues extend throughout the plant. They start at the [IP1] roots and weave up the trunk, before journeying out into the branches and into every single leaf.

A well-functioning tree vascular system will transport and help absorb water and critical nutrients to the plant for nourishment.

Alternatively, citrus greening destroys the vascular system of citrus trees, resulting in less fruit produced, smaller fruit, and higher rates of early fruit drop.


Why the focus on young citrus trees?

Because no known cure for citrus greening exists, protocols typically treat symptoms rather than addressing the root cause. Treatment plans also suffer from starting too late, after a tree is nearly (or already) completely infected.

New research is showing the importance of taking preventive measures during key stages of citrus tree development and before HLB-spreading psyllids accelerate their attack.

Shoot development in citrus trees is divided into six phases:

  • V1: Emergence
  • V2 and V3: Development
  • V4 and V5: Maturation
  • V6: Dormancy

Psyllids prefer V1 to V4 for feeding and reproduction–making these development stages the most vulnerable. Because of this, the emerging and developmental phases are the best time to focus on a control strategy to reduce the biotic impact of psyllids.

What most growers are doing to protect young citrus trees

Nets: Citrus growers often place nets over young trees to keep the HLB-spreading psyllids physically separated from the tree’s shoots. The nets are kept on the young trees for 1.5-2 years. When the nets are removed, the psyllids will inevitably infect the trees. However, there are ways to give the trees a better chance at withstanding the stresses of HLB.

Figure 1 Root dig comparison, showing the roots of young citrus trees grown using the grower’s standard practice (left) vs. using Locus AG’s soil microbial treatment program (right).

Soil Probiotics: Recently, Florida farmers have combined use of nets with powerful soil biologicals, such as Locus Agricultural Solution’s (Locus AG’s) soil probiotics, which strengthen the roots and vascular system of the tree.

Bolstering young citrus trees’ vascular systems in those early, formative years with soil probiotics can help make young citrus trees more tolerant to biotic and abiotic stressors when the nets come off.  


How soil probiotics work to strengthen young citrus trees

Fertile soils require a balanced microbial population performing critical activities, including nutrient utilization and protection against biotic and abiotic stressors.

A lack of enough beneficial microbes leads to a range of negative impacts, including an imbalance of soil pH in the rhizosphere, die-off of young and new roots, less nutrient uptake, and greater destruction from citrus greening and other plant diseases.

Using the correct strains of soil probiotics will help to create a network of trees with hardy root systems, addressing one of the root causes of declining citrus groves. Locus AG’s soil probiotics have been shown to increase root mass and therefore can be a major piece of the puzzle for establishing a strong foundation, including a strong root and vascular system, in citrus trees.

Additionally, certain soil probiotics contain endophytic strains that reside in plant tissues, encouraging long-term benefits to trees’ roots and overall vascular system functioning into the future.


Figure 2 Phillip Rucks Citrus Nursery in Frostproof, Florida uses Locus AG soil probiotics on young citrus trees in his nursery.

Get started today

Now is the time to invest in building up the strongest root system possible so that your citrus trees will have greater resilience as they grow.

Locus AG ‘ s soil probiotics are specifically tailored to colonize roots and promote early root development. The company is actively partnering with citrus groves throughout Florida to maximize root growth and soil biology in young citrus trees’ early years, and investing in third-party studies to independently gather data to support the results Locus AG’s customers have been seeing for years.

Learn more about how to incorporate soil probiotics into your citrus grove management plan today.  Contact us at LocusAG.com or 888.331.5008.