When you next sip on a cup of locally grown Arabica coffee, the variety of tree from which it was sourced may be irrelevant to you, but it is to growers. While the K7 has excelled in all of those areas, its excessive vigour, which was initially welcomed 20 years ago, now jeopardises the industry’s viability.
Southern Cross Plant Science researchers, supported by AgriFutures Emerging Industries, are collaborating with the Australian Sub Tropical Coffee Association to trial 25 new varieties from around the world.
Associate Professor Dr Tobias Kretzschmar explained that their coffee varietal project was part of an international multi-variety trial.
“This means that the same varieties will be trialled in 17 countries around the world, allowing us to pool data and determine which varieties perform best in different environments,” he explained.
The primary characteristic that growers seek is a dwarf or semi-dwarf variety that requires no pruning.
Professor Dr Terry Rose stated that the K7 was too vigourous, especially in the red volcanic soils of the Northern Rivers, and grew too tall for machine harvesting.
“You get into a pruning cycle where you have to prune to get the harvester over the top, you lose some yield the following year, and you’re back to pruning in a few years,” he explained.
“Because the bush expends a lot of energy growing new shoots rather than producing beans, what we really need is a dwarf variety that will grow to about the right height for harvesters and then concentrate entirely on producing beans rather than excess shoots.”