Macadamias: optimise inputs to beat low prices

South Africa's relatively young macadamia industry has a long way to go to establish optimal farming practices and efficiencies. However, with nut prices falling, producers need to focus on cost savings that will balance inputs with output. Lindi Botha reports on key areas that macadamia farmers should be paying attention to.

- Lindi Botha

Fertiliser prices have surged dramatically over the past year, resulting in near-unsustainable production costs for farmers. Nonetheless, while these input costs are not expected to decrease in the near future, there is hope for macadamia farmers in South Africa.

At a macadamia farmers’ day held in Nelspruit in early March, Lindsay Tredgold, an agronomist at Fertech, explained that the high cost of fertiliser had as much to do with price as it did overapplication.

“Recent research has highlighted the fact that we’re overfertilising macadamias, which leads to mass and unnecessary foliar growth. I often see figures of over 140kg/ha nitrogen, when the tree is only using about half of that,” he said.

“Overfertilisation also adds significant unnecessary stress to the trees, as they’re sensitive to salts, and fertilisers are, after all, salts.”

Tredgold suggested that when preparing their fertiliser programmes, farmers should aim to apply only what the trees require to remain healthy and produce an optimal crop. This means they need to forego the all-too-common rationale of adding “just a little bit extra” for the sake of prosperity.

“The trees will only take up what they need, and any excess fertiliser will stay in the rhizosphere and burn the very sensitive proteoid roots. The trees will then redirect their energy from producing nuts to replacing the burnt roots,” he explained.

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