Effects of Boron on Avocado Yields


To test which application of Boron is most effective on avocado trees.


Avocados are a large and growing industry here in New Zealand, but avocados require the element Boron. Boron is found in very low levels in New Zealand soils, so farmers must apply Boron to Avocado orchards. Avocados are a rainforest tree from Central America and they have a very limited ability to extract Boron from soil; this limits the trees’ ability to set fruit.
The current practice is to:

  1. Apply regular applications of Solubor Boron to the soil under the trees (Solubor, Granubor) and
  2. Apply a foliar spray of a weak Boron solution to the trees while flowering. This is repeated three times between September and November.

Two experiment trials are to be assessed:

  1. Using a special Boron spray – Biomin. This is a new product that has the Boron atom attached to an amino acid called Glycine. Glycine is actively transported into the leaves carrying Boron with it, like a Trojan Horse.
  2. Injection of Boron solution directly into the trunk of the tree. Injecting avocado trees is an established technique used for controlling root rot (Phytophthora).

It is thought that the Biomin sprayed/injected Boron trees will have higher Boron levels and a heavy crop.

Read the full trial here.