Orange rust location map and information

Map updated 10 February 2012

About orange rust

There are two well-known rust diseases of sugarcane – orange rust caused by Puccinia kuehnii and brown rust caused by Puccinia melanocephala. During the 1970s brown rust spread to many sugar industries throughout the world and, consequently, was known as ‘common’ rust. It appeared in Australia in 1978. Orange rust, although present in Australia since the 1890s, was considered a minor disease and confined to the Asia- Pacific region.

Of course, things changed in 2000 when an orange rust epidemic swept through the industry – the ‘rare’ rust became ‘common’ in Australia. To avoid confusion ‘common rust’ was given the more descriptive name of brown rust. The two rusts can be distinguished by symptoms, environmental requirements and spore characteristics. Both diseases show elongated lesions on the leaf. In a fresh infection, the underside of the leaf shows masses of spores erupting from the lesion, known as a pustule.

Orange rust occurs in all cane-growing districts in Queensland and New South Wales and the disease is prevalent in humid summer conditions. Orange rust pustules are orange when fresh, shorter than those of brown rust and tend to form in clumps, more towards the leaf base (Figure 1).

Brown rust occurs during dry weather with cool nights and dews. Brown rust is most often seen in the spring in northern districts, and in late spring and into the summer in the south. Brown rust pustules are brown and are more elongated. The pustules are spread evenly, located more towards the leaf tip (Figure 2).

Orange rust spores are larger than brown rust and golden-orange in colour (Figure 3). By looking at the spores under the microscope, you can easily see that the spores have a thick wall at the apex and have large spines.

Brown rust spores are smaller than orange rust, and are red-brown in colour (Figure 4). When observed under the microscope, brown rust spores can be distinguished from orange rust spores because the entire wall of the spore is
of uniform thickness, the spines are very small but more numerous and several pores will be prominent. The pustules also contain some very distinctive structures known as paraphyses (see Figure 4).

Orange rust is favoured by periods of hot humid weather. Extended periods of showery overcast days during December to April are ideal for development of the disease. When the disease reaches high levels in the younger leaves it can cause yield losses of up to 40%. The rust fungus (Puccinia kuehnii) infects leaves and produces millions of spores which are spread by wind and rain.

Brown rust yield loss research was carried out soon after the disease entered Australia, in the late 1970s to the early 1980s. Trials were undertaken with fungicides and in the most susceptible varieties losses were around 25%. As with orange rust, losses will vary with season and weather conditions.

Figure 1: Orange rust pustules in clumps.		Figure2: Brown rust in 190A. Pustules are more towards the tip.
Figure 3: Orange rust spores. Optimum temperature for orange rust spore germination is 17-23oC. Orange rust Symptoms Spores   Pustules orange   Pustules form clumps, more towards leaf base   Favoured by warm humid weather   Disease peaks late summer and early autumn   Semi mature to mature cane   Larger than brown rust   Golden orange   Fewer, larger spines   Obvious apical thickening
Figure 4: Brown rust spores. Optimum temperature for brown rust spore germination is 11-27oC. Brown rust Symptoms Spores   Pustules reds-brown   Pustules spread evenly, more towards leaf tip   Favoured by cool nights (dew) and warm sunny days   Disease peaks spring and early summer   Young cane    Smaller than orange rust   Red-brown   Many small spines   Walls uniform thickness   Distinctive paraphyses   Prominent pores

References:

Please note: Some reference have links to complete report or Bulletin article. References listed without links can be requested via email to info@bses.com.au.

BSES. (2012). Do you know your rusts? BSES Information Sheet IS12001. More...

Magarey, RC et al. (2011). A brief history of disease epidemis in Queensland and of some economic outcomes. Proc. of the Aust. Soc. of Sugar Cane Technol., 33: 12 p.

McFarlane, S. (2011). Orange rust. South African Sugar Journal. Vol 95, No 1, p 27.

McDonald, E. (2010). Brazil sees orange. BSES Bulletin. Issue 24, p 24-27. More...

Braithwaite, K. (2010). Do you know your rusts? BSES Bulletin. Issue 26, p 26-27. More...

Ovalle, W et al., (2009). Orange rust in Guatemala and management strategies. Sugar Journal. Vol 72, No 3, p 18-23.

Magarey, RC, Bull, J. (2009). Orange rust resistance screening in parent canes at BSES Meringa 2000-2008. Proc. of the Aust. Soc. of Sugar Cane Technol., 31: p 204-211.

Magarey, RC Bull, J. (2009). Environmental parameters affecting the reliability of resistance-screening trials for orange rust and yellow spot. Proc. of the Aust. Soc. of Sugar Cane Technol., 33: p 307-315.

Braithwaite, KS, et al. (2009). Phylogenetic placement of the sugarcane orange rust pathogen Puccinia kuehnii in a historical and regional context. Australasian Plant Pathology. Vol 38, p 380-388.

Magarey, RC, Bull, J and Tomasin, WA. (2008). Yield losses caused by leaf diseases : 1999 and 2003 selection trial analyses. Proc. of the Aust. Soc. of Sugar Cane Technol., 30: p 309-321.

Australian Canegrower. (2007). Orange rust found in sugarcane in Florida. Australian Canegrower. Vol 29, No 19, p 11.

Magarey, RC. (2007). Estimating disease-associated yield losses in breeding selection trials - Endemic diseases: Pachymetra root rot, orange rust and yellow spot. BSES Internal Report PR07004. More...

Braithwaite, KS. (2006. Sugarcane rusts: how many are out there? BSES Bulletin, issue 9, p 3-5. More...

Magarey, RC and Staier, TN. (2005). Weather and disease interaction - what it means to you! BSES Bulletin, issue 5, p 13-15. More...

Magarey, RC, et al. (2005). The resistance of the Australian sugarcane germplasm to disease in Queenaland. Proc. of the Aust. Soc. of Sugar Cane Technol., 27: p 199-210.

Magarey, RC (2005). The incidence of sugarcane diseases in Queensland. Proc. of the Aust. Soc. of Sugar Cane Technol., 27: p 252-265.

Rauka, GB, Magarey, RC and Kuniata, LS. (2005). The current disease situation on the commercial estate of Ramu Sugar, Papua New Guinea. Proc. of the Aust. Soc. of Sugar Cane Technol., 27: p 266-272.

Croft, BJ, et al. (2005). Sugarcane disease management for the 21st century : contribution of the CRC for Tropical Plant Protection. Proc. of the Aust. Soc. of Sugar Cane Technol., 27: p 273-281.

Braithwaite, KS. (2005). Assessing the impact that pathogen variation has on the sugarcane breeding program. Final SRDC Report BSS258. BSES Internal Report SD05018. More...

Magarey, RC, Neilsen, WA and Magnanini, AJ. (2004). Environmental requirements for spore germination on three sugarcane leaf pathogens. Proc. of the Aust. Soc. of Sugar Cane Technol., 26: 7 p.

Staier, TN, Magarey, RC and Finlayson, WA. Meteorological data collection, analysis and sugarcane disease forecasting for orange rust. Proc. of the Aust. Soc. of Sugar Cane Technol., 26: 6 p.

Magarey, RC, Neilsen, WA and Bull, J. (2004). The effect of orange rust on sugarcane in breeding selection trials in central Queensland: 1999-2001. Proc. of the Aust. Soc. of Sugar Cane Technol., 26: 6 p.

Braithwaite, KS, Croft, B and Brumbley, S. (2004). Genetic diversity within collections of the sguarcane orange rust fungus (poster paper). Proc. of the Aust. Soc. of Sugar Cane Technol., 26: 1 p.

Australian Canegrower. (2003). Drought-breaking rain seeds new rust outbreak. Australian Canegrower. Vol 25, No 7, p 5.

Magarey, RC, Bull, J and Neilsen, WA. (2003) Yield losses caused by several endemic diseases in Queensland. Proc. of the Aust. Soc. of Sugar Cane Technol., 25: 8 p.

Staier, T, Magarey, RC and Willcox, TG. (2003). Control of orange rust in sugarcane with fungicides. Proc. of the Aust. Soc. of Sugar Cane Technol., 25: 14 p.

Allsopp, P. (2003). Mites and maybes. BSES Bulletin, issue 83, p 3. More...

Goeldner, D. (2002). Seedling technology gets set to strike at orange rust. Australian Sugarcane. Vol 6, No 5, p 6-10.

Magarey, RC, et al. (2002). The use of breeding trial to estimate disease-ionduced yield losses and to refine selection strategies. Proc. of the Aust. Soc. of Sugar Cane Technol., 24: p 113-122.

Magarey, RC, Staier, TN and Willcox, TG. (2002). Fungicides for control of orange rust in the 2001 Queensland crop. Proc. of the Aust. Soc. of Sugar Cane Technol., 24: p 269-274.

Magarey, RC, et al. (2001). Orange rust, a major pathogen affecting crops of Q214 in queensland in 2000. Proc. of the Aust. Soc. of Sugar Cane Technol., 23: p 274-280.

Hussey, B and Staier, TN. (2001). Rust proofing : how Mackay fought the fungus. BSES Bulletin, issue 74, p 10-11. More...

BSES. (2001). Rubber vine rust not to be confused with orange rust. BSES Bulletin, issue 74, p 13. More...

Ryan, CC and Magarey, RC. (2000). Orange rust outbreak in Q124. Australian Sugarcane. Vol 3, No 6, p 15.

Magarey, RC. (2000). Orange rust causes concern in Q124. BSES Bulletin, issue 70, p 4. More...

Willcox, TG, Agnew, J and Hussey, B. (2000). Vareities take on orange rust. BSES Bulletin, issue 72, p 6. More...

Magarey, RC. (2000). Orange rust. A guide to sugarcane diseases (eds Rott, P, et al.), p 121-125. CIRAD and ISSCT.