19366 research outputs found
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New regulatory toxicology and field efficacy advances to support the registration of norbormide
No full textTo develop a new or re-register an older rodenticide a large financial investment and commitment is required similar to that occurred recently in Europe with cholecalciferol. Norbormide has unique attributes, being 100 to 150-fold more toxic to rats than to birds and most other mammals, and therefore also justifies this investment. Differences in the effects of norbormide, and its selective contractile effect on rat peripheral arteries and the lack of an effect on the peripheral or small blood vessels in other species appear to be responsible for species differences in toxicity. This understanding of the mechanism of toxicity in rats and species-specific changes is complemented by molecular toxicology explaining why this compound has an effect that is rapid, irreversible, and unique to rats.
There is an extensive database in over 50 species with most of the publications circa 1965. These studies have not been carried out in accordance with recent test guidelines. Standard Organization for Economic Cooperation and Development (OECD) guideline studies are being completed to focus on data-gaps in chemistry, genetic toxicology, non-target toxicity, general ecotoxicity, and environmental fate. To date norbormide has been shown to lack genotoxicity in OECD 477, 487 and 490, in-vitro studies and it lacked irritancy in OECD 404, 406 and 407. Further OECD studies are yielding results consistent with historical data that reported LD50 ranges, following oral administration for Norway rats (Rattus norvegicus), between 5.3 and 15.0 mg/kg. The lack of toxicity (i.e., LD50 > 1,000 mg/kg) is previously reported in five bird species and numerous mammalian species, including rhesus monkeys.
Inconsistencies in palatability hampered norbormide use when it was first developed. Prior to embarking on new chemistry and toxicology OECD studies over a decade of research which focused on synthetic processes yielded a manufacturing approach which consistently produced palatable and effective norbormide. This has enabled consistent efficacy of 1% norbormide-containing baits in laboratory and field trials with both Norway rats and black rats (Rattus rattus). Details on new developments including results from the current programme of testing, ranging from the Ames test to non-target testing in birds and earthworms, addressing new data requirements or verification of early data to enable registration, will be presented
Exploring the combined use of biocontrol agents Trichoderma atroviride and Engytatus nicotianae against the tomato psyllid (Bactericera cockerelli)
No full textControl of tomato potato psyllid (TPP), Bactericera cockerelli, is problematic because of pesticide resistance and environmental issues. The predatory bug Engytatus nicotianae has proven to be an efficient biocontrol agent against TPP in glasshouse grown tomatoes. Trichoderma fungi offer numerous benefits to plants and soil, including biocontrol of pathogens, enhanced plant growth, increased nutrient uptake, and improved soil health. Therefore, there could be advantages to the combined use of Trichoderma and E. nicotianae. However, Trichoderma spp. have the potential to alter the behaviour of pests or their enemies by modifying plant defence metabolites such as volatile organic compounds (VOCs). This study investigated the individual and combined efficacy of Trichoderma atroviride and E. nicotianae in reducing TPP abundance across different developmental stages (eggs, nymphs, adults) and the number of infested leaves in glasshouse grown tomatoes. Plant VOC emissions were also investigated under the different treatments. Across all measured TPP stages all three treatments (E. nicotianae alone, T. atroviride alone, and T. atroviride + E. nicotianae) significantly reduced mean TPP counts relative to the control but there were no significant differences in VOC emissions among the treatments. Trichoderma atroviride alone was less effective than E. nicotianae alone or its combination with Trichoderma atroviride to suppress TPP populations. The combined use of T. atroviride + E. nicotianae did not show significant advantages over the use of E. nicotiana alone but did not appear to negatively affect the predatory bug’s performance. This suggests that the combined use of these biocontrol agents is feasible and can be considered in the light of other potential advantages of Trichoderma to the crop such as growth promotion and pathogen defence
Engagement for genetic modification technologies in conservation: For whom, how, and for what ends?
No full textQuestions of engagement loom large for the use of genetic modification technologies in conservation. As scientific teams rapidly move towards implementing changes that will fundamentally alter entire species, concerns are regularly raised that associated engagement activities are inadequate. It is therefore vital to take stock of recent social research that critically examines how engagement is being enacted: who is engaged and by whom, how and on what terms, and for whom or what those processes serve. Despite a rise in calls for engagement, our review shows emergent gestures towards engagement by developers and regulators lean strongly towards narrow instrumental approaches that reinforce knowledge hierarchies and existing power imbalances. It contributes to engagement practices that are often vague and tokenistic, and focused on one-way education and snapshots of opinion, rather than mutual reciprocity and dialogue. To counter these undercurrents, our review draws attention to the ways social researchers are seeking to reorient engagement for genetic modification towards its more substantive and democratic possibilities, through articulating process, amplifying plurality, and acknowledging contestation
Good People, Good Kaupapa: A Māori kiwifruit grower collective and the value of its partnerships in Aotearoa New Zealand
No full textThe concept of partnering to achieve mutually prosperous outcomes can have significant implications for Indigenous economies. The purpose of this study, as part of my doctoral research, is to explore what ‘good’ looks like in an Indigenous/non-Indigenous business partnership from a Māori worldview, using the case of the Māori Kiwifruit Growers Incorporated (MKGI) and Zespri International Limited (Zespri) kiwifruit export partnership to Hawaii. It has implications for Māori and non-Māori partnerships in Aotearoa (New Zealand), and may have wider applications for Indigenous and non-Indigenous partnerships globally. Semi-structured interviews with participants involved in the MKGI-Zespri partnership were conducted from September 2024. The MKGI Executive Committee, a nationally representative body of Māori growers, supported the design and development of the research project and remains a key research partner. Interviews were transcribed and analysed for common themes. Existing relationships, on either an individual or organisational level, accelerated the speed of positive partnership outcomes across the kiwifruit value chain. All Māori participants agreed that forming a partnership is impossible without first establishing an alignment of values. Participants also agreed that partnerships were successful when they were built on shared values and for the long-term. Some saw opportunities to work with other Indigenous cultures around the world as a unique point of difference, and worthy of further exploration. Using MKGI’s, and others’, success in today’s globalised world, how can we demonstrate this value, and leverage it to create new (and better) partnerships that enable Indigenous Peoples to thrive, today and tomorrow
An examination of the ability of plantain (Plantago lanceolata L.) to mitigate nitrogen leaching from pasture systems
No full textPlantain (Plantago lanceolata L.) has recently been thrust into the limelight as a potential tool for mitigating nitrogen losses from the New Zealand pastoral environment. It is claimed to possess characteristics to reduce nitrogen leaching through both animal and soil-based mechanisms. This review examines the use of plantain in New Zealand pastures and the research that has led to these claims. The focus is on the evaluation of scientific evidence for the mechanisms through which plantain is proposed to reduce nitrate leaching, as well as the research on the implementation of plantain into pastoral farm systems. Plantain clearly increases the urination of grazing animals; a trait not unique to plantain. This review concludes that many research studies supporting the beneficial impact of plantain do not stand up against scientific scrutiny associated with methodology and interpretation of data. It is recommended more research should be undertaken on other pasture species and management tools, that may be more effective alternatives to plantain for nitrogen mitigation in pastures
Microbial responses to regenerative and conventional farming practices in dryland pasture systems : A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Agriculture Science ay Lincoln University
No full textRegenerative agriculture is proposed as a sustainable farming system that will protect biodiversity and maintain sufficient food production for future generations. The aim of this experiment was to assess the effects of conventional and regenerative farming practices on soil microbiology in a grazed grassland context. The goal was to be able to provide empirical evidence on the outcomes of regenerative versus conventional practices in a New Zealand dryland pasture and whether regenerative farming is a viable and productive option for farmers. The study was conducted at the Lincoln University Regenerative Agriculture Dryland Experiment (RADE) in Lincoln, New Zealand. We focused on block 5 of the experiment, which includes 16 grazed plots arranged in a Latin square design. The treatments included high-phosphorous input conventional agriculture (HCA), high-phosphorous regenerative agriculture (HRA), low-phosphorous input conventional agriculture (LCA), and low-phosphorous regenerative agriculture (LRA). Conventional plots were sown with a cocksfoot/subterranean clover mix, while regenerative plots contained a diverse 12-species pasture blend. Soil samples were collected twice within the experiment, once in the autumn (May 6th, 2024) and once in the spring (October 10th, 2024). Our study focused on how the treatments and seasons impacted potential soil microbial extracellular enzyme activities (EEA), labile nutrient concentrations, microbial functioning, and soil chemical properties. We found that temporal effects had more of an influence on microbial enzyme activities than the treatments (HCA, HRA, LCA, LRA) themselves. Potential microbial enzyme activities increased significantly in the spring, including leucine aminopeptidase (LAP) (P < 0.001), phosphatase (PHOS) (P < 0.01), and β-xylosidase (XYL) (P < 0.05). This was likely driven by seasonal changes in labile nutrient availability, gravimetric soil moisture, and metabolic demand. The only enzyme to show a significant treatment effect was α-glucosidase (AG), which had higher activity under the LRA treatment (P < 0.01). Labile carbon and microbial respiration increased in spring, while labile nitrogen and phosphorus pools declined, suggesting that nutrient cycling was closely tied to seasonal plant growth and microbial activity. Soil properties such as labile nutrients strongly influenced microbial nutrient acquisition ratios, with labile carbon (HWEOC) having the largest impact on both enzymatic C:N and C:P ratios. This study is among the first to explore microbial nutrient acquisition strategies in RA and CA dryland pasture systems. Our findings highlight the potential of regenerative practices to enhance microbial functional capacity under low-phosphorus soil conditions and also emphasise the importance of temporal variability in influencing microbial processes
The effects of a small dose of tannin supplementation on in vitro fermentation characteristics of different forages
No full textPastoral systems in New Zealand are under societal pressure due to their increasing negative environmental impact in terms of greenhouse gas emissions. This study was conducted to investigate the effects of supplementing a mixture containing hydrolysable and condensed tannins on the in vitro fermentation characteristics and gas production of three different forages, Lolium perenne, Medicago sativa, and Plantago lanceolata. Three fermentation runs of 48 h were conducted using the ANKOM gas production technique, with each pertaining to a particular forage with or without (control) tannin. Tannins were added to the fermentable substrate (i.e., forage) at a level of 0.3%. For each run, rumen fluid was collected from two fistulated Holstein Friesian × Jersey cows. The ANKOM RF gas production modules were used to monitor gas pressure and temperature every 5 min. At the end of each run, the pH of the fluid was measured, gas vials were taken for methane (CH₄) measurements and liquor samples were taken to measure volatile fatty acids (VFA) and NH₃ concentrations. The addition of tannins reduced the fractional rate of gas production for alfalfa (p ≤ 0.04) but increased it for ryegrass and plantain. There was a tendency for reduced gas production for ryegrass when tannins were added (p = 0.10). There was also a tendency for CH₄ production to reduce (p 0.05) or VFA concentrations (p > 0.05) when fermenting alfalfa. Under the condition of this study, these results may suggest that low-level tannin addition to the diet may affect rumen-fermentation pattern with a potential reduction of CH₄ production in Lolium perenne-based diets. Further research is required on the effect of low levels of tannin supplementation under ex vitro and in vivo conditions as tannin supplementation effects might be substrate-dependen
Rice blast in the Indo-Pacific Region impacting food security highlights the need for better biosecurity
No full textPlant pests significantly reduce crop yield, which impacts access, availability and food utilisation. Rice is a staple crop for almost half of the world’s population. Asia (including the Indo-Pacific Region, IPR) contributes 90% and consumes 86% of global rice production, but is among the most food-insecure regions in the world, with an increase of 16 million (to 113 million) moderately/severely food-insecure people in the region in the last 5 years. Outbreaks of the rice blast pathogen Pyricularia oryzae in the IPR could significantly affect global food security. Modelling indicates that an extreme case of 80% loss of rice crops across the IPR could increase global rice prices by 50–95%, increasing food insecurity for net exporter countries while creating price shocks in importing countries. This study used the four pillars of food security as a framework to evaluate the impact of rice blast on food availability, access, utilisation, and stability. The objective was to determine if biosecurity measures might be easily implemented to reduce the risk of the disease and increase food security in the region. Biosecurity was claimed as essential for managing rice blast across the pre-border/border/post-border continuum to reduce the risk to food security. Australia and New Zealand may be able to assist with the implementation of biosecurity measures as they are the most significant leaders in this field in the IPR. Regional agencies such as the Asia and Pacific Plant Protection Commission might assist the IPR in identifying threats through intelligence gathering and pathway modelling for pre-border activities. To be effective, the biosecurity system needs all stakeholders to work together
Off-farm work, cigarette and alcohol expenditure, and body weight outcomes: Insights from Rural China
No full textAlthough the effects of off-farm work have been widely studied, its influence on cigarette and alcohol (CA) consumption in rural areas remains underexplored. Likewise, while the health impacts of CA consumption are well documented, limited evidence exists on how CA expenditures affect body weight outcomes, particularly among rural populations. This thesis addresses these research gaps by pursuing two key objectives: (1) to investigate how rural household heads’ off-farm work participation and intensity influence household expenditure on cigarettes and alcohol, and (2) to examine the subsequent effects of such expenditures on body weight outcomes, including underweight, normal weight, overweight, and obesity. Using data from 1,487 rural households in China, this thesis employs a conditional mixed process (CMP) model to address the endogeneity of off-farm work variables in the first part of the analysis. Off-farm work intensity is measured through time (months) allocated to off-farm employment and off-farm income. In the second part, this thesis applies a two-stage residual inclusion (2SRI) approach—using Tobit and multinomial logit models—to account for the endogeneity of CA expenditures when assessing their effects on body weight outcomes. Findings reveal that off-farm work participation significantly increases total CA expenditure by 52.7 yuan per capita per week, with cigarette expenditure rising by 63.1 yuan, while alcohol expenditure remains unaffected. Off-farm income, rather than time spent working, drives increased alcohol spending. Higher CA, cigarette, and alcohol expenditures are each significantly associated with a lower probability of being underweight or maintaining a normal weight and with an increased likelihood of obesity. These effects are particularly pronounced among male household heads, while no significant relationships are observed for female heads. The thesis highlights an important unintended consequence of promoting off-farm employment in rural settings: increased CA expenditure and the associated risk of obesity, particularly among men. These findings call for integrated rural development policies that align labor market incentives with public health objectives, ensuring that efforts to raise rural incomes do not inadvertently compromise long-term health and social well-being
One Biosecurity is essential to implement One Health
No full textAlthough One Health and biosecurity both aim to protect the health of people, animals, and ecosystems from biological hazards, the two fields remain heavily siloed across distinct policy and research domains. One Health has yet to fully integrate environmental perspectives, especially biological invasions, into its workplan, whereas biosecurity lacks an effective inclusion of the social and health sciences, further hindering collaboration. One Biosecurity offers a vital interdisciplinary framework that bridges human, animal, plant, and ecosystem health sectors, fostering a stronger connection between biosecurity and One Health. This comprehensive approach spans the entire biosecurity continuum, from pre-border intelligence scans to border inspections and post-border incursion management, enabling more effective responses to the threats posed by biological invasions. By unifying these efforts, One Biosecurity will engage a broader group of multilateral organizations, bring together diverse stakeholders, and implement balanced strategies that better safeguard human health, agriculture production systems, and the natural environment