A UF/IFAS Tip of the Week looks at citrus tree sectoring, a result of recent trunk injections to fight citrus greening in Florida citrus.

Citrus growers who utilized trunk injections to combat citrus greening, also known as HLB, are seeing a phenomenon known as citrus tree sectoring, according to a UF/IFAS Tip of the Week article. This is where the citrus trees are evidently healthier on the injection side. The article shares the results of recent research and tips for ensuring the entire tree is healthy. See the details below.

A Look at Citrus Tree Sectoring Research

According to the article, UF/IFAS researchers conducted a trial in September of 2023 in a commercial citrus grove; there they “injected nearly 200 Valencia/X-639 trees with 1.1 grams of OTC per tree (11,000 parts per million rate) using the FLexInject injectors. Injections were done into the rootstock trunk.” Citrus tree sectoring started with “considerable yellowing and “bronzing” of the leaves on the side of the tree that had been injected.” By April of 2024, the sectoring was obvious in the appearance of the trees. Tree health observations included:

  • A “125% yield increase was measured in response to the injections.”
  • “Average Brix was 11.2 on the injected side and 9.3 on the opposite side! In comparison, the Brix for the non-injected trees was only 8.5.”
  • “The same was found for the Brix/acid ratio and the fruit rind color. Both were significantly better on the injected side than the opposite side.”

The researchers also noted that while the numbers on the injected side were better than those on the non-injected side, both numbers were still better than those for non-injected control trees.

Dealing with Sectoring

The article shared the following tips for dealing with sectoring:

  • “The sectoring, and likely any leaf phytotoxic effects, may be moderated by splitting the injections into two on opposite sides of the trunk.” Though the cost may be prohibitive.
  • “Perform the second-year injections on the side of the trunk opposite to first-year injections.”
  • “Injecting in line with the crotch of the scaffold branches may also reduce some of the sectoring.”

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions -or concerns about your farm or pasture, contact us and one of our team will be in touch.