Researching variety performance in Australia

Coffee has been grown in Australia since the 1800s, though never in a commercial capacity. High labor costs meant that coffee was mostly limited to a novelty product. The resurgence in Australia's coffee plantations during the 1980s and 1990s can be attributed to the efforts of a few pioneers keen to develop a coffee of quality, as well as developments in mechanized harvesting, which brought down labor costs dramatically. Moreover, a program of evaluation and importation of Arabica coffee varieties for the subtropical climate was launched by Rural Industries Research and Development Corporation (RIRDC). The variety that showed the most promise for Australia’s long ripening season and subtropical climate was a Kenyan variety called K7, which produces high-quality beans, is high-yielding and rust-resistant, and was deemed suitable for machine harvesting.

With nearly all of the approximately 40 coffee farms in Australia using machine harvesting, and relying heavily on K7 as their variety of choice, the Australian coffee production industry established itself as a commercial entity, delivering high-quality product to the domestic, tourist, and specialty export markets in the last 30 years.

However, according to Professor Kretzschmar, the vigor of K7 on the red soils of Northeastern NSW and South East Queensland has proven to be a problem. Over time, this excess vigor has resulted in coffee trees that are too large for machines to harvest them effectively. The best way to control the size of these trees is cutting them back, but while pruning is a successful management practice with other coffee varieties in different coffee-growing environments, it is unsatisfactory with Australian subtropical-grown K7. For example, little benefit arises if the plants are pruned high, while cutting the plants low results in multiple stems that are unsuitable for machine harvesting. Trying to prune the trees correctly becomes a frustrating art, Kretzschmar explains. At best, one year of production from mature plants is lost after pruning, followed by two years of production, with pruning again required in the fourth year. This is too much maintenance for most Australian coffee farmers, who are looking to harvest coffee, not run a landscaping business.

WCR, in turn, was excited to see how varieties perform in Australia. “Adding a subtropic region to our IMLVT data adds nuance that we wouldn’t have otherwise had, and we’re excited to see how our 31 varieties do in this new environment,” says Solene Pruvot-Woehl, World Coffee Research's IMLVT Program Coordinator. Moreover, as WCR expands into Asia and the South Pacific, the desire of Australia and Southern Cross University to “assist regionally” is an asset. “We see opportunity for the derived data to have impact in the greater Asia Pacific region,” Kretzschmar explains, “where coffee is often a significant source of income.”

Another unique element of Australia is that the country is relatively free of coffee-specific diseases and pests that plague other growing areas. Kretzschmar says, “This makes Australia a safe haven for coffee germplasm management and conservation. By assessing performance of an international diverse set of coffee such as the IMLVT varieties, we can get a better idea if and how Australia can contribute to global coffee conservation efforts, with the potential to serve as a regional coffee genetic resource center."

After spending over half a year under quarantine at Southern Cross University, as part of Australia’s strict biosecurity measures, the IMLVT trees were planted in the summer of 2019. Kretzschmar says that “the public interest in the trial and the industry engagement in helping establish this trial have been exceptional.”