Citation: Snowball, R.; Dhammu, H.S.; D’Antuono, M.F.; Troldahl, D.; Biggs, I.; Thompson, C.; Warmington, M.; Pearce, A.; Sharma, D.L. Adaptation of Quinoa (Chenopodium quinoa Willd.) to Australian Environments. Agronomy 2022, 12, 2026. https://doi.org/10.3390/ agronomy12092026 Academic Editor: Bertrand Hirel Received: 29 July 2022 Accepted: 24 August 2022 Published: 26 August 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). agronomy Article Adaptation of Quinoa (Chenopodium quinoa Willd.) to Australian Environments Richard Snowball 1, * , Harmohinder S. Dhammu 1, *, Mario Francesco D’Antuono 1 , David Troldahl 2 , Ian Biggs 3 , Callen Thompson 4 , Mark Warmington 1 , Amanda Pearce 5 and Darshan L. Sharma 1,6, * 1 Department of Primary Industries and Regional Development, South Perth, WA 6151, Australia 2 Department of Primary Industries, Yanco, NSW 2703, Australia 3 CRC for Developing Northern Australia, Townsville, QLD 4810, Australia 4 Agstarprojects, Coonabarabran, NSW 2357, Australia 5 South Australian Research and Development Institute, Naracoorte, SA 5271, Australia 6 College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA 6150, Australia * Correspondence: richardsnowball1959@gmail.com (R.S.); harmohinder.dhammu@dpird.wa.gov.au (H.S.D.); darshan.sharma@dpird.wa.gov.au (D.L.S.) Abstract: Quinoa is being evaluated in cropping systems in many countries outside of its natural range of South America. Very few attempts have been made by farmers or researchers to grow or evaluate quinoa under Australian environments. Given the growing popularity of quinoa with consumers, new commercial opportunities for farmers and international interest in the crop, it was timely to undertake a comprehensive evaluation of the potential of quinoa in Australia. Two advanced selections and nine germplasm lines (six of Chilean and three of Bolivian origin) identified in an earlier project were tested in 23 field trials at 14 locations on mainland Australia. Targets included irrigated sites in tropical, Mediterranean, semi-arid and desert climates, and rain-fed sites of south- western Australia with a Mediterranean climate. The field experiments were either a randomised complete block design (RBCD) or a split plot/factorial design with 2–4 replicates, and a linear mixed model was used to compare the treatment lines. Seed yield of quinoa was highest when grown in winter and spring under rain-fed conditions in Geraldton, in spring and summer under irrigation at Bool Lagoon, and summer, autumn and winter under irrigation at Leeton. The highest seed yield achieved was 3 t/ha for a germplasm line from Chile, while the highest yield for a germplasm line from Bolivia was 2.6 t/ha. Advanced selections from Australia yielded well in comparison at most trial sites. Declining seed yield was associated with mean daily temperatures during seed development increasing above 17 ◦ C, mean daily temperatures during flowering declining below 15 ◦ C, and rainfall during seed development under rain-fed conditions falling below 50 mm. Seed produced at Bool Lagoon was the closest in colour to white quinoa imported from Peru; however, it was more than noticeably different. Seed produced at Geraldton and Leeton was significantly larger than from other field sites; however, none were larger than 2 mm in diameter as found in Royal white quinoa from Bolivia. Superior seed colour and seed size were associated with dry conditions at maturity and cool conditions during seed development, respectively. We conclude that quinoa can become a potential crop option for Australian agriculture by exploiting genetic diversity and supplementing with suitable management practices matched to agro-climatic environments. There are reasonable prospects to raise the seed yield potential in areas in all states, especially in the regions where quinoa grew well in our experiments. Keywords: quinoa; germplasm; adaptation; climate; yield; quality 1. Introduction Most of the world production of quinoa (Chenopodium quinoa Willd.) takes place at high altitudes in Peru and Bolivia, with smaller production in neighbouring countries including Ecuador, Chile and Argentina. Countries outside of South America also have Agronomy 2022, 12, 2026. https://doi.org/10.3390/agronomy12092026 https://www.mdpi.com/journal/agronomy