Contents lists available at ScienceDirect European Journal of Agronomy journal homepage: www.elsevier.com/locate/eja Examining the yield potential of barley near-isogenic lines using a genotype by environment by management analysis Ahmed Ibrahim a,b , Matthew Tom Harrison a, ⁎ , Holger Meinke a , Meixue Zhou a a Tasmanian Institute of Agriculture (TIA), University of Tasmania, Tasmania, Australia b Institute for Agricultural Research, Ahmadu Bello University, Zaria, Nigeria ARTICLE INFO Keywords: Barley APSIM-Barley GxExM Phenology Adaptation Tolerance Drought stress Wheat-belt Gene-to-phenotype modelling ABSTRACT Here we modelled the influence of phenology of barley crops under diverse environmental and management conditions. Such trait manipulation can assist breeders in genotype selection and growers in better managing barley crops to achieve their yield potential. We first developed two near isogenic lines (NILs) of barley (Eps- 317-1-E, and Eps-317-1-L). NILs were developed from a cross between TX9425, a Chinese landrace, and Franklin, an Australian malting barley. Field experiments were then conducted in Tasmania, Australia, using three sowing dates per year during 2015, 2016 and 2017 to parameterise and test the barley module of the APSIM model (APSIM-Barley). We then conducted a genotype by environment by management (GxExM) analysis using ten sites across the Australian wheat-belt, with a range of sowing dates, fertiliser rates and planting densities. The early genotype (Eps-317-1-E) performed better in environments prone to terminal drought and heat stress effects. This was due to earlier flowering and a propensity for greater transpiration-use efficiency from growth stage (GS) 50 to 87. The late NIL (Eps-317-1-L) generally produced higher yield in long-season environments with high rainfall and cool terminal temperatures. Performance of all genotypes was generally better for May sowings (being mid-autumn in the southern hemisphere), wherein yields of the two NILs were highest. Overall, our study showed that Eps-317-1-E was more adapted to regions prone to drought and heat stress, while Eps-317-1-L was more suited to regions with longer growing seasons. This study exemplifies how models can be used in concert with breeding experiments and thus provides farmers and breeders with op- portunities to examine how new genotypes will perform in diverse environments under multiple management conditions. 1. Introduction Barley (Hordeum vulgare L.) crops are cultivated globally for live- stock and human consumption (FAO 2015), with the latter mostly used in the malting and brewing industries (Muñoz-Amatriaín et al., 2010). The global production of this crop reduced from 155.3 Mt in 2008/2009 to 142.37 in 2017/2018 (Statista, 2018). The production in Europe (EU) doubled the sum of all other nations with Australia being the fourth highest producing nation on the list (Statista, 2018). A total of 8500 kt of barley was harvested in the 2016-17 growing season in Australia (ABARES, 2017). This value fell short by 500 Mt in 2017/18 (Statista, 2018), illustrating the importance of this crop to the annual Australian cereal crop harvest and fluctuation in the production. As at 2009, the global production was approximately 140 Mt from about 55 million hectares (Zhou, 2009) and of this value, about 122 Mt was used for animal feed and human foods, while 18 Mt (13%) was processed into malt (FAO, 2009). Barley production occurs throughout the mixed wheat-sheep region of Australia, with greatest annual average pro- ductivity in the South Australian and Victorian Mallee, central and northern NSW, and south-eastern WA (AEGIC, 2017) (Fig. S1). Global demand for this crop has increased from 133 million tonnes in 2000 to 146 million tonnes in 2017 without an obvious increase in production (IGC, 2017), indicating an increasing supply/demand mismatch. Im- proving grain yield whilst maintaining grain quality to meet this de- mand in increasingly variable environmental conditions is a serious challenge facing barley breeders. Abiotic environmental stresses, such as waterlogging, drought, frost and heat events, are key factors that significantly affect barley growth and development and ultimately yield and quality. Damage due to frost between spikelet initiation (Zadoks growth stage 30; GS30) to ear emergence (GS50) causes sterility of flowers (Al- Issawi et al., 2012) and results in yield loss amounting to $120 million https://doi.org/10.1016/j.eja.2019.02.003 Received 14 June 2018; Received in revised form 11 December 2018; Accepted 5 February 2019 ⁎ Corresponding author. E-mail address: matthew.harrison@utas.edu.au (M.T. Harrison). European Journal of Agronomy 105 (2019) 41–51 1161-0301/ © 2019 Elsevier B.V. All rights reserved. T