Innovating a new cultivar in partnership with the Australian sweetpotato industry: Agronomic adaptation issues

Abstract

Australian sweetpotato production has grown remarkably (1700%) in the last 16 years. Growers currently market 75000 t per annum, worth $80-90 million at farm gate. Gold-fleshed dessert types dominate (90% of total production), almost exclusively cultivar 'Beauregard', bred at Louisiana State University Agricultural Center (LSU AgCenter) in the USA. Australian sweetpotato growers desire alternative cultivars, to reduce risks associated with relying on one genotype. They also wish to expand demand, by offering diverse products. Recent research identified 'Evangeline', another LSU AgCenter cultivar, as an alternate gold sweetpotato possessing attributes desired by consumers (regular, smooth shape; highly coloured skin and flesh). In experimental and grower evaluations across key Australian growing regions in Queensland and New South Wales, 'Evangeline' produced marketable yields similar to 'Beauregard'. 'Evangeline' had a high proportion of premium small-medium sweetpotatoes. In sandy locations, 'Evangeline' also demonstrated superior root-knot nematode resistance to 'Beauregard'. However, compared to 'Beauregard', 'Evangeline' had greater risks of splitting, or over-purple skin colouration, at harvest, particularly when dug in Winter/Spring. Initial evidence suggested splitting was more common with increased fertiliser nitrogen inputs. Split roots or off-specification colours are unmarketable; the associated risks are currently substantial impediments to adoption of 'Evangeline' by Australian sweetpotato growers. Scientists from Agri- Science Queensland and Central Queensland University are currently partnering with Australian Sweetpotato Growers (Inc.) to develop strategies for maximising performance and mitigating risks of growing 'Evangeline' in Australian conditions. This will enhance industry profitability and resilience; improve understanding of sweetpotato physiology; and increase diversity and quality of sweetpotato products available to consumers.