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Item Restricted Using metabarcoding and droplet digital PCR to investigate drivers of historical shifts in cyanobacteria from six contrasting lakes(Springer Nature, 2022-07-27) Picard, Maïlys; Pochon, Xavier; Atalah, Javier; Pearman, John K; Rees, Andrew; Howarth, Jamie D; Moy, Christopher M; Vandergoes, Marcus J; Hawes, Ian; Khan, Samiullah; Wood, SusannaThe frequency and intensity of cyanobacterial blooms is increasing worldwide. Multiple factors are implicated, most of which are anthropogenic. New Zealand provides a useful location to study the impacts of human settlement on lake ecosystems. The first humans (Polynesians) arrived about 750 years ago. Following their settlement, there were marked landscape modifications which intensified after European settlement about 150 years ago. The aims of this study were to reconstruct cyanobacterial communities in six lakes over the last 1000 years and explore key drivers of change. Cyanobacterial environmental DNA was extracted from sediment cores and analysed using metabarcoding and droplet digital PCR. Cyanobacteria, including potentially toxic or bloom forming species, were already present in these lakes prior to human arrival, however their overall abundance was low. Total cyanobacteria abundance and richness increased in all lakes after European settlement but was very pronounced in four lakes, where bloom-forming taxa became dominant. These shifts occurred concomitant with land-use change. The catchment of one deteriorated lake is only moderately modified, thus the introduction of non-native fish is posited as the key factor driving this change. The paleolimnological approach used in this study has enabled new insights into timing and potential causes of changes in cyanobacterial communities.Item Restricted Human access and deterministic processes play a major role in structuring planktonic and sedimentary bacterial and eukaryotic communities in lakes(PeerJ, 2022-11-11) Pearman, John K; Thomson-Laing, Georgia; Thompson, Lucy; Waters, Sean; Vandergoes, Marcus J; Howarth, Jamie D; Duggan, Ian C; Hogg, Ian D; Wood, SusannaLakes provide habitat for a diverse array of species and offer a wide range of ecosystem services for humanity. However, they are highly vulnerable as they are not only impacted by adverse actions directly affecting them, but also those on the surrounding environment. Improving knowledge on the processes responsible for community assembly in different biotic components will aid in the protection and restoration of lakes. Studies to date suggested a combination of deterministic (where biotic/abiotic factors act on fitness differences amongst taxa) and stochastic (where dispersal plays a larger factor in community assembly) processes are responsible for structuring biotic communities, but there is no consensus on the relative roles these processes play, and data is lacking for lakes. In the present study, we sampled different biotic components in 34 lakes located on the South Island of New Zealand. To obtain a holistic view of assembly processes in lakes we used metabarcoding to investigate bacteria in the sediment and surface waters, and eukaryotes in the sediment and two different size fractions of the water column. Physicochemical parameters were collected in parallel. Results showed that deterministic processes dominated the assembly of lake communities although the relative importance of variable and homogeneous selection differed among the biotic components. Variable selection was more important in the sediment (SSbact and SSeuks) and for the bacterioplankton (Pbact) while the assembly of the eukaryotic plankton (SPeuks, LPeuks) was driven more by homogeneous selection. The ease of human access to the lakes had a significant effect on lake communities. In particular, clade III of SAR11 and Daphnia pulex were only present in lakes with public access. This study provides insights into the distribution patterns of different biotic components and highlights the value in understanding the drivers of different biological communities within lakes.Item Restricted Effects of power and implicit theories on donation(SAGE Publications, 2020-08-01) Khalil, Maryam; Khan, Saira; Septianto, FelixCharities have difficulty raising money to execute their plans, which are mainly focused on addressing social challenges. As a big proportion of donations come from individual consumers, understanding their different characteristics and psychological states is important. Power has a psychological quality that varies during everyday interactions and influences consumers’ actions. Investigating the impact of power state on donation intentions across two studies, this research first illustrates that powerless consumers with a high level of incremental theory of emotion show an increased willingness to donate, and second, negative affect is the underlying mechanism in the interaction between sense of powerlessness and the incremental theory of emotion on donation intentions. These results have theoretical and empirical implications.Item Restricted Engagement in genetic technologies for biological conservation: for whom, how, and for what ends?(2024) Nissen, Sylvia; Buelow, Franca‘Engagement’ is increasingly seen as critical to genetic technology governance. It is the most wide-spread principle in gene drive governance documents internationally and is widely included in relevant codes of ethical conduct and risk assessment processes. However, there are clear shortcomings in emerging practices of engagement for genetic technologies. It is therefore important and necessary to foreground critical perspectives on ‘engagement’: that is, to ask questions of whom is engaged and by whom, how and on what terms, and for whom or what those processes serve. This paper unpacks the concept’s normative expectations and empirical conditions in the context of gene drive developments for biological conservation. It demonstrates that despite the rise of rhetoric of engagement for genetic technologies, these efforts strongly lean towards superficial practices that reinforce knowledge hierarchies and existing power dynamics. This work is as part of a five-year interdisciplinary project that looks at gene-drive development in the context of wasp management.Item Restricted Effect of forage plantain integration into a grazing dairy system on urination behaviour and urinary nitrogen concentration in late-lactation cows(ADSS, 2024-11-25) Orellana Howe, I; Herath, G; Mellow, M; Bryant, Racheal; Beckett, Paige; Al-Marashdeh, OmarAs part of a farm-system study, this sub-study aimed to contribute to existing evidence on the effects of varying dietary levels of plantain (Plantago lanceolata L.) on urinary N (UN) concentration and urination behaviour in cows managed under typical farming practices. In late July 2021, 108 dairy cows were blocked into nine herds of 12 cows. The herds were randomly allocated into one of three replicated pasture treatments sown with an increasing plantain seed rate: (i) RGWC with nil plantain (PL0); (ii) RGWC+3 kg/ha plantain (PL3) or (iii) RGWC+6 kg/ha plantain (PL6). Over a 10-day sub-study period in late March-early April 2022, UN concentration was measured in morning and afternoon spot samples collected from 18 monitor cows (n=6; three cows each from two of the three farmlets per treatment) on two occasions. Urination behaviour (daily urine volume and urination frequency) was measured using a Lincoln University PEETER V.1.0 sensor attached to the monitor cows for 24-48 hours. During the sub-study period, the dietary levels of plantain leaves in dry matter were nil in PL0, 31.7% in PL3 and 47.5% in PL6. Pasture silage fed (kg/cow/day) to maintain regrowth interval was higher in PL3 (1.7 kg) than PL0 (0.7 kg) and PL6 (nil), resulting in 7-8% lower N intake (g/d) in PL3 (402) compared to PL0 (438) and PL6 (430). Urine N concentration tended (P=0.07) to be lower in PL3 and PL6 than PL0. Urine volume (P=0.005) and urination frequency (P=0.007) were higher in cows in PL6 than in those in PL0 and PL3, but similar between PL0 and PL3. While these results showed a tendency for plantain to reduce UN concentration, they highlight the opportunity to explore stacking strategies that combine plantain with low-N supplements for additional environmental benefits.Item Restricted Milk urea concentration and nitrogen use efficiency of dairy cows grazing different levels of forage plantain with ryegrass-white clover(2024-11-25) Al-Marashdeh, Omar; Woods, Roshean; Zindove, Titus; Charissa, Thomas; Natalie, McMillan; Bryant, RachealContext: Milk urea (MU) is a by-product of crude protein metabolism in dairy cattle whereby diets with lower nitrogen (N) utilisation are typically associated with greater MU concentrations. Thus, MU is recognised as a useful indicator of dietary N use efficiency (milk N divided by N intake; NUE). Forage plantain has been shown to decrease MU, potentially due to its lower content of ruminal degradable protein compared with ryegrass-white clover (RGWC). However, there are limited data on how including plantain in a farm system affects MU concentration and NUE in dairy cattle throughout an entire lactation period. Aims: In this study, we investigated the effects of different levels of forage plantain in the farm system on MU and NUE. Methods: Data were collected over two dairy production years (2021/22 and 2022/23) as part of a farm system study established in late July 2021 at Lincoln University Research Dairy Farm. Nine herds (12 cows each) were randomly allocated into one of three replicated pasture treatments (n=3) sown with an increasing plantain (cv. Ecotain) seed rate: (i) RGWC with nil plantain (PL0); (ii) RGWC+3 kg/ha plantain (PL3); or (iii) RGWC+6 kg/ha plantain (PL6). Individual cow milk volume was measured at each milking (DelPro, DeLaval), with milk composition determined fortnightly (CRV, Hamilton, New Zealand) using samples collected at consecutive afternoon and morning milkings. Fortnightly pre-grazing pasture samples, coinciding with milk samples, were collected to determine botanical and chemical composition. Dry matter (DM) intake was back-calculated from the energy requirements for cows in each herd. Statistical analysis was conducted using General Analysis of Variance with pasture treatment, season of the year and production year included as factors, and farmlet as the experimental unit. Key results: There was an interaction between treatment × season for plantain % in diet DM, N intake, diet N:ME ratio and NUE, and between treatment × season × year for N intake and diet N:ME ratio. Regardless of season and year effects, average dietary content (% DM) of plantain leaves was 0.1% in PL0, 14.7% in PL3 and 17.7% in PL6. Average estimated daily intake of pasture (14.4 kg DM/cow), supplement (baleage; 1.2 kg DM/cow) and N (476 g/cow) were similar across treatments. Average daily milksolids production per cow was similar between PL0 (1.65 kg) and PL3, and PL0 and PL6, but higher (P=0.015) in PL6 than PL3 (1.66 vs 1.61 kg). Average MU concentration was higher in PL0 than PL3 and PL6 (P<0.001), which did not significantly differ from each other (Table 1). The two-way interaction effect showed that NUE was lower in PL3 than PL0 and PL6 in late-winter, similar between treatments in spring, higher in PL6 than PL3 in summer and higher in PL6 than PL0 in autumn. Conclusions: While the effect of plantain incorporation into RGWC- based dairy systems at either 14.7 or 17.7% of diet DM resulted in a seasonally dependent response in cows' NUE, it consistently reduced their MU concentration. Implications: The presence of forage plantain may need to be considered if MU concentrations are used as indicators to help manage herd nutritional status and environmental risk.Item Restricted Stacking mitigations to reduce N losses at farmlet scale: Year one results of farm performance in a dairy systems comparison in Canterbury(ADSS, 2024-11-25) Wheadon, NM; Bryant, Racheal; Williamson, H; Kok, JC; Chikazhe, TL; Beukes, PC; Al-Marashdeh, Omar; Edwards, JP; Ledgard, SF; Phyn, CVCTo meet regulatory targets for nitrogen (N) losses, farmers may need to adopt multiple mitigations. Here, we describe the first lactation season (2023-24) of a multi-year farmlet trial that evaluates the effects of ‘stacked’ complementary mitigations on milk production, N leaching, and profitability in a Canterbury farm system. The farmlet trial involved two non-replicated ~12 ha milking platforms and consisted of a 'Control' farmlet following current best practice, and a 'Stacked' farmlet incorporating a multi-species pasture, reduced N fertiliser, and lower stocking rate. Farm physical results were modelled in FARMAX Dairy and OverseerFM to evaluate financial and environmental performance. Milksolids per cow were similar, but production per hectare was 7% lower for the Stacked farmlet relative to the Control farmlet. The Stacked farmlet produced 5% less total pasture (t DM/ha) and differed in seasonal growth. Predicted N leaching (kg/ha) and greenhouse gas (GHG) emissions (kg CO₂e/ha) were 39% and 12% lower, respectively, for the Stacked farmlet, but it also had 8% less profit per hectare due to lower milk revenue and higher costs for pasture conservation and regrassing. Opportunities to improve profitability while maintaining environmental benefits for the Stacked farmlet are discussed.Item Restricted Travel to UK in attendance at 13th Pangborn Sensory Science Symposium and visits to European research organisations(Wine Australia, 2019-09-30) Wang, ShaoyangShaoyang Wang attended the 13th Pangborn Sensory Science Symposium (28 July – 1 August 2019) and visited to A/Prof Gleb Yakubov at The University of Nottingham (5 August 2019) and A/Prof Elke Scholten at Wageningen University and Research (7 August 2019). He presented a poster at Pangborn Symposium and gave oral presentations at seminars organised in both universities. The travel provided Shaoyang with feasible ideas thus adding scientific value to his own research. Also, it created terrific opportunities to make contacts with leading scientists in the related fields, which would bring enormous benefits both to his own research and Australian wine sector.Item Restricted Reproducibility of a farmyard stress model used to evaluate predictive biomarkers for high pH in lamb(Sistema Congressi, 2023, 2023-08) Lee, Hannah; Ross, Alastair; Bentley, Kelly-Anne; Sigua, Lloreli; Prasad, Doreen; Fletcher, Scout; Taukiri, Kevin; Maes, Everlyne; Clerens, Stefan; Morton, James; Zotte, Antonella Dalle; Brugiapaglia, Alberto; Cullere, MarcoWe have reported on a simple farmyard stress model which was a useful way of causing high pH meat under controlled yet realistic conditions for further research. The study showed that moderate stress resulted in changes to several important meat quality markers [1]. Samples from this trial have been used for fingerprinting mass spectrometry to identify new potential predictive markers of high ultimate pH [2]. The current study was designed as follow up validation trial to confirm the reproducibility of this model and potential metabolic biomarkers. These muscles in the early post-mortem period were also analysed for four protein biomarkers identified by our international collaborators [3]. This data will contribute towards defining and designing much larger experiments run in commercial processing plants. The aim is to develop rapid screening systems to predict ultimate pH as meat is processed. In future, biomarkers of high pH in the meat could be also used for enhancing animal welfare and confirm the relationship between minimising pre-slaughter stress and improving the consistency of meat quality.Item Restricted Throwing out the rule book: A creative approach to researching events with integrity(Routledge, 2025) Walters, TEthical considerations and approval are compulsory prior to data collection in any research process, and this is especially the case when adopting creative approaches to ensure research is carried out with the highest levels of integrity. This chapter examines this, drawing on the author’s own attempts to share the voices of marginalised communities by navigating the tensions between ethics committees’ expectations and pragmatic realities in the field.Item Restricted 2024 Moana Oceania soil judging competition handbook(New Zealand Society of Soil Science, 2024-11) Smith, Carol; Deuss, K; Nelson, J; Lowe, D; Penny, V; Mazzetto, JWelcome to the 2024 Moana Oceania Soil Judging Competition, held in Rotorua, New Zealand, from 28 November to 1 December 2024! This event serves as an exciting prelude to SOILS ROTORUA 2024 - the Joint New Zealand Society of Soil Science and Soil Science Australia Conference, "Te Kiri o Papatūānuku/ Weaving Soil Science Across Cultures and Events", scheduled for 2-5 December at the Rotorua Energy Events Centre. This year’s competition is the product of 18 months of dedicated planning, building on the experience and expertise of past organising committees from both New Zealand and Australia. We’re fortunate to have had a dedicated organising committee and support from the SOILS ROTORUA 2024 conference team, all of whom have helped make this what we think may be the largest soil judging competition ever held worldwide! With over 200 participants, coaches, and volunteers from 20+ universities, nine regional councils, and more than 15 scientific and governmental organisations, societies, and consultancies across New Zealand, Australia and the Pacific Islands, this event promises an unparalleled experience for learning and networking in an engaging, hands-on environment. Soil judging provides a wonderful opportunity for students and coaches alike to develop the skills of describing soil profiles, and then translating this into a basic land capability assessment. It is a highly effective way to build practical, field-based skills in a supportive atmosphere. We would like to sincerely thank this year’s sponsors, whose generous support has enabled the New Zealand Society of Soil Science and Soil Science Australia to host the 2024 Moana Oceania Soil Judging Competition on this impressive scale. We encourage all participants to acknowledge and promote these sponsors on social media throughout the event. The competition includes two days of immersive training, which for many of you will be your first time in a soil pit. Most importantly, being an inductee into the ‘Art and Science’ of soil judging is not an impediment, as demonstrated in previous events where even first-time participants have excelled, sometimes achieving top placements on Competition Day. This is an opportunity to connect with experts, academics, students, land managers and consultants. For students, this event offers a glimpse into potential careers in research, teaching, consultancy, and various roles across academia, government, and the private sector. As the event concludes, we hope you will find that this hands on learning experience has enriched your understanding and boosted your confidence with soil science. We encourage you to share your experience with fellow students and colleagues, inspiring them to come along to the next Australian Soil Judging Competition in Armidale, NSW in November 2025.Item Restricted Prediction of 24h pH and lamb meat quality parameters in different muscle fibre types using rapid evaporative ionisation mass spectrometry(Japan Society for Meat Science and Technology, 2022-08-01) Lee, Hannah; Ross, Alastair; Mou, D; Maes, E; Clerens, Stefan; Morton, James; Arihara, K; Kawahara, S; Komiya, Y; Shibata, M; Gotoh, TAccurate prediction of meat muscle quality is an important goal for ensuring that meat is graded for its most appropriate use, improving consumer experience and ensuring maximal return to farmers and meat processors. One of the key predictors of meat quality is pH, with high pH meat generally scoring badly for flavour and colour. Several technologies have been assessed for in-plant measurement of meat quality, though to date most meat processors still use visual inspection when evaluating carcass quality. Rapid evaporative ionisation mass spectrometry (REIMS) is a relatively new tool for direct measurement of samples, producing a fingerprint based on the metabolites and lipids present in the sample within a few seconds of a measurement. REIMS can be easily used on solid samples such as meat (Ross, Brunius et al. 2021) and has been successfully tested in abattoirs for detection of boar taint (Verplanken, Stead et al. 2017).Item Restricted Exploring 3D printing. Design and analysis of novel 3D printed foods with re-purposed animal and plant proteins(The New Zealand Institute of Food Science and Technology (Inc.), 2022) Lee, Hannah; Hampton, Jessica; Pope, Isobel; Peddisetti, Sahiti; Torrico, Damir; Kaur, Lovedeep; Singh, Jaspreet; Morton, JamesFood 3D printing is the most impressive novel technology available to the food industry for preparing complex shaped foods with improved functional and nutritional value. Currently, this technology is being considered for implementation by many food companies (1,2,3,4). Students from the Food Science & Innovation programme (Lincoln University, photo 1) have been using the newly installed benchtop 30 food printers ('FOODINI', manufactured by Natural Machines) to produce nutritious and attractive food constructs. The team has a particular interest and enthusiasm towards creating 3D constructs by upcycling low value protein sources. They have optimised key parameters such as the behaviour of the food inks and alternative gelling agents, as the success of 3D food production relies on the consistency and properties of these mixtures. This article shares some insights into the development of protein rich food inks and 30 food products using meat, dairy, pea and combinations of these ingredients, as a part of creating future food product concepts.Item Restricted Assessing economic impact of weed control strategies in autumn sown wheat crops in New Zealand(NZPPS, 2024) Holmes, Cameron; Hendriks, Pieter-Willem; Smith, Daniel; Drummond, JoGlobally, weeds are major biotic stressors in crop production systems causing yield loses of up to 35%. Herbicides have been a cost-effective way to mitigate yield losses due to weeds. However, extensive use has resulted in the development of herbicide resistance across multiple weed species and herbicide mode-of action groups. An Australian study reported the overall cost of weeds to grain growers was $3.5 billion. There is an opportunity for similar evaluations to provide value to the New Zealand cropping industry. In the face of herbicide resistance and increasing weed control costs, the development of economically viable integrated weed management strategies are increasingly important. Crop competition is such a tool that has been successfully implemented overseas but assessment in New Zealand context. This non-chemical weed control option may provide the opportunity to reduce herbicide use, mitigate herbicide resistance, reducing the cost of weed management programmes while increasing life expectancy of chemicals. This study will seek to quantify the economics of weed management in autumn sown wheat and test whether competitive wheat cultivars with different growth characteristics is a viable non-chemical weed control option for New Zealand growers. The experimental design features a paired plot Youden design that incorporates three herbicide management programmes and three autumn-sown wheat cultivars. The aim of this study is to develop integrated weed management programmes that balance profitability, crop productivity, acceptable levels of weed control and herbicide resistance management.Item Restricted Selection for early vigour in wheat modifies shoot and root epidermis cell size, numbers and competitive abilityHendriks, Pieter-Willem; Ryan, Peter; Gurusinghe, Sal; Hands, Phil; Rolland, Vivien; Rebetzke, Greg; Weston, Leslie; Delhaize, EmmanuelPoster presentation of the impact of recurrent selection for early vigour in wheat on cellular level.Item Unknown The economic impact of the screen entertainment industry in Canterbury(Department of the Prime Minister and Cabinet, 2019-07-25) Dyason, DavidHistorically, Canterbury has successfully attracted on-site filming of major international films but lacked the infrastructure to benefit from pre-and post-production activity. Canterbury can take advantage of the expanding international screen industry by investing in suitable infrastructure to increase the attractiveness of the region and attract new businesses. This economic benefit of the two scenarios presented in this report, namely i) increasing Canterbury’s industry spending share and ii) attracting a share of the LOTR series, is new employment totaling 1,343 and $138 million of additional GVA.Item Restricted The peri-urban conundrum stakeholder engagement for land use and site planning through digital tools(IGI Global, 2025) Charters, Stuart; Davis, Shannon; Eggers, James; Chen, Hanley (Guanyu); Gregorini, Pablo; Nunes Silva, CNew Zealand is facing immense pressure for urban expansion as populations grow and demand for housing increases. Located on some of the most highly productive soils, New Zealand cities are expanding into these productive hinterland landscapes, with valuable soil resources indefinitely lost. This chapter explores how digital tools can be used to engage stakeholders with the issue of peri-urban land use change, and how these tools can be utilised to consider and evaluate alternative futures. Outlining two case studies, this chapter presents methods and outcomes of two participatory processes for engaging with the peri-urban land use conundrum. The first case presents a site-scale project where digital design outputs were used to engage with multiple stakeholder groups. The second case presents a landscape-scale project where local government was engaged in an alternative futures scenario-based activity where GIS mapping was used to create the scenario plans. Communication benefits and constraints for bridging viewpoints between different stakeholders are illustrated and discussed.Item Restricted Mystery on the Bounty: The family-level status of Pacificana cockayni Hogg, 1904 (Araneae)(Elsevier, 2025-03) Gorneau, JA; Cala-Riquelme, F; Crews, SC; Montana, KO; Spagna, JC; Vink, Cornelis; Esposito, LAThe family-level placement of the species Pacificana cockayni Hogg, 1904 (Araneae, Miturgidae) has been ambiguous for over a century, with the monotypic genus Pacificana initially placed in Agelenidae, later transferred to Amaurobioidinae (Anyphaenidae), and presently in Miturgidae. A recent work describing the male and molecular data consisting of a single mitochondrial gene, cytochrome c oxidase subunit I, confirmed that the species is part of the marronoid clade; however, these data did not result in a conclusive family-level placement. Here, we use low-coverage whole genome sequencing (lcWGS) combined with data from the Sequence Read Archive to infer a phylogeny from ultraconserved elements (UCEs) and six legacy Sanger loci. Indications of potential family placements from prior work and the topologies from this study support a transfer of Pacificana Hogg, 1904 to Cycloctenidae Simon, 1898 (new family placement).Item Restricted House prices and airport proximity: Are they valued equally?Squires, Graham; Ngo, Thanh; McCord, Michael; Lo, Daniel; Wang, XueqiThis study contributes to understanding the link between the housing market, airport location proximity examining the entirety of the price distribution. The research investigates this association across four key urban areas within New Zealand proximal to an international airport - Auckland, Wellington, Christchurch, and Queenstown. Applying hedonic and Quantile regression, the analysis reveals that proximity to airports on house prices has a heterogeneous pricing effect. The regression analysis exhibits distance to comprise a positive effect within Auckland and Christchurch, whereas in Wellington and Queenstown the pricing effect is negative. The quantile regression findings further revealed differences between lower and higher priced properties value, given distance and proximity to airports within each city region. Auckland exhibits a positive distance decay effect moving from the lowest to the highest quantiles which diminishes and becomes negative illustrating that the highest priced properties consider closer proximity to airports comprise a dis-amenity effect on property value, alternatively, the lowest priced properties perceive adjacency to the airport as a positive amenity. Wellington also displays higher priced housing to exhibit much larger negative effects with proximity to the airport than lower priced housing. The findings show that whilst there is a negative impact for proximity to airport this is more pronounced for higher priced properties relative to lower priced properties. The Christchurch region reveals contrasting findings showing there to be a higher positive pricing effect for higher priced housing which gradually decreases when moving down the quantiles. With respect to Queenstown, the findings show a nominal but positive pricing effect for lower priced housing with a negative effect for the highest priced properties.Item Restricted The impact of soil, year and genotypic vigour on the release of allelopathic metabolites by wheat(2024-06) Hendriks, Pieter-Willem; Ryan, Peter; Weston, Paul; Delhaize, Emmanuel; Gurusinghe, Saliya; Rebetzke, Greg; Ryan, LeslieRecurrent selection for increased shoot vigour produced germplasm with enhanced leaf width and leaf area. Genotypes produced in the third cycle of the recurrent selection were top-crossed with two Australian commercial wheat cultivars (Yitpi and Wyalkatchem) generating high vigour lines. Here, in replicated controlled environment experiments and over two years in the field, the effect of the breeding with early shoot vigour on root development, and the presence of secondary allelopathic metabolites and microbially transformed phytotoxic molecules as part of below-ground competitiveness, were examined. The vigour lines were assessed for early root growth and interaction with annual ryegrass, both physical and chemical, in hydroponics and field soil. Breeding lines were compared to Australian commercial cultivars, genotypes of the third cycle of the recurrent selection, the heritage cultivar Federation and triticale. Below-ground, compared to commercial cultivars, the increased vigour lines demonstrated increased competitive ability. In all the experiments, vigorous lines possessed longer total root length and root hair length. In the controlled environment, numerous secondary metabolites, some previously identified to have allelopathic effects on weeds, were detected in the roots and the rhizosphere. In the two-year field study results showed significant differences of secondary phytotoxic metabolite levels between the drier than long-term average 2019 and wetter than average 2020. Contrary to previous results, this work showed increased levels of metabolites and microbial-transformed molecules in the wetter season. However, the genetic variation for early vigour didn’t result in significant differences in the presence of allelopathic molecules.