Sugarcane has been researched in the Ord River Irrigation Area (ORIA) since the 1950s. A commercial sugar industry was finally established in 1995. However, the sugar mill was closed in 2007.
The Ord Sugar Mill was built by CSR and opened in 1995. It had a raw sugar production capacity of 60 000 tonnes per annum. In 2000, CSR sold the mill to Cheil Jedang Corporation, South Korea’s largest food manufacturer. Cheil Jedang Corporation’s fermentation plant in Indonesia had been the main customer of raw sugar produced by the Ord Sugar Mill up to that time.
The mill operated until 2007 when it was the sold to Ord River Canegrowers Pty Ltd after the group received a $4m loan from the State Government. The 2007 crush was the last and the mill stopped operating at the end of that season.
Low world sugar prices, shrinking production and uncertainty about expansion of the irrigation area were cited as the main reasons for the mill closure.
The area planted to sugarcane had slowly declined over the final years of the industry (Table 1), the main reason being competition for land from the sandalwood industry. Sugar yields also declined during those years, probably because of lower inputs being committed to the crop. The industry had an uncertain future and low profit margins. Sugarcane yields of more than 200 tonnes per hectare were common in the early years of the industry.
At the time of the mill’s closure, sugar was the dominant crop in the ORIA and the demise of the sugar industry was a devastating blow to agriculture in the region.
Surveys of water use in the early years of the industry found that growers were applying an average of 32.5ML/ha/year. Research in the ORIA found that sugarcane had its highest crop water use before the wet season and much lower crop water use after the wet season. Lower irrigation frequency after the wet season on maturing crops improved irrigation efficiency without reducing sucrose levels.
Irrigation efficiency can also be improved by having longer furrows and irrigating for shorter periods of time. As a result of research, growers reduced irrigation water applications to about 22ML/ha/year.
Popular varieties grown commercially in the ORIA included Q95, Q96, Q99 and Q101. Since the collapse of the industry, DAFWA has maintained a small nursery area of superior varieties (Table 2). The varieties that are currently being held have been selected as having the most potential in the area according to yield, sucrose levels and their resistance to smut.
Smut had a significant impact on the local sugar industry. The ORIA was the first location in Australia to contract this disease. It first appeared in 1998 and is thought to have blown in from Asia.
Table 2 Varieties currently grown at the Kununurra Research Station
Q208 is considered the standout variety in terms of productivity. However, it is still being monitored for its tolerance to smut.
Other diseases that also affect sugarcane in the area are brown rust and red rot, first identified in 2003.
While sugarcane is suited to the climate of the ORIA, it is unlikely to become part of the farming mix in the foreseeable future. The main limiting factors are the scale of the industry required, cost of infrastructure to establish a processing plant and fluctuating world prices.