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This annotated bibliography presents 434 journal and conference papers, technical reports and bulletins and guides published from 1951 to 2011 as a result of research carried out at the Winchmore Irrigation Research Station. [ABSTRACT FROM AUTHOR]

Classical weed biocontrol has long been criticised, worldwide, for a lack of post-release long-term monitoring. This paper reports on a rare opportunity to follow up, three agents and 35 years later, a biocontrol programme against nodding thistle (Carduus nutans) in New Zealand. In New Zealand, the establishment of all three agents has been reported previously, but impacts have only been assessed for the receptacle weevil (Rhinocyllus conicus). This paper reports on the abundance of the nodding thistle crown weevil (Trichosirocalus horridus), and on the abundance, phenology and impact of the seed predators, R. conicus and Urophora solstitialis, in Canterbury, based on field surveys and, for the seed predators, also from a cultivated population. Trichosirocalus horridus was abundant at all field sites and on rosettes of all sizes. Seed destruction per larva by R. conicus (34 seeds per larva) was similar to previous estimates, but U. solstitialis achieved rates (21 seeds per larva) three times higher than estimates elsewhere. Population-level seed predation by R. conicus (14 and 4% in the cultivated and field populations, respectively), by U. solstitialis (9 and 7%) and cumulatively by both (23 and 11%) is insufficient to cause nodding thistle populations in New Zealand to decline. The results show that the introduction of multiple biocontrol agents does not guarantee increased pressure on a target weed host population. [ABSTRACT FROM AUTHOR]

Soil invertebrates have limited defences against moisture stress but little is understood of how irrigation influences their community. This paper investigates the influence of five summer irrigation schedules on earthworms over a 15-month period in a long-term pasture irrigation study. The influence of the two extreme rates of irrigation on other soil invertebrates was also examined. The effects of frequent drought periods under dryland pasture favoured small and short-lived nematodes and oribatids. During wetter months, earthworm abundances were similar between dryland and irrigated treatments, while earthworms tended to migrate down the soil profile and aestivate in response to soil water deficits during summer. The higher abundance of earthworms in the summer months under irrigation may partly explain the lower soil carbon found under irrigation, due to enhanced rates of soil organic matter turnover, despite higher primary production and inputs of carbon. It is thus important to consider irrigation schedules not only to optimise plant growth, but also to optimise the invertebrate community and its activity. [ABSTRACT FROM AUTHOR]

Winchmore Irrigation Research Station was established in the late 1940s in the Ashburton–Lyndhurst irrigation scheme in Canterbury, New Zealand, to investigate problems associated with the introduction of border-strip irrigation to farming. Two large-scale field trials were established. The first, in 1949, aimed to investigate water requirements of permanent pasture and the second, in 1952, to examine fertiliser requirements of irrigated pasture. Initially designed to supply farmers with practical solutions, because of their longevity (61 and 58 years to date), consistent management, meticulous record keeping and archiving of regular soil and plant samples, both trials have yielded a rich source of material for many studies, some of which are reported in other papers in this issue of the journal. [ABSTRACT FROM AUTHOR]

Increasing substitution of dry land pastoral and arable farming for water-intensive practices is placing pressure on water resources in Canterbury. Although there is a large body of scientific data documenting environmental change, there is a general lack of information on the economic values of agricultural impacts on rivers and streams. This paper applies an economic non-market valuation method to help address this issue. Three impacts are considered: health risks of pathogens from animal waste; ecological effects of excess nutrients; and low-flow impacts of irrigation. This study provides a valuation of outcomes for public agri-environmental policy implemented in Canterbury such as The Dairy and Clean Streams Accord, Living Streams and The Restorative Programme for Lowland Streams. Modelling results indicate that the 5-year economic value for improvements to rivers and streams in Canterbury provided by agri-environmental policy is estimated to be about $186 million. [ABSTRACT FROM AUTHOR]

The Canterbury knobbled weevil, Hadramphus tuberculatus (Coleoptera: Curculionidae: Molytini), was once widespread in the Canterbury plains, foothills and fringing ranges, ranging from oxford in the north to Waimate in the south. Habitat degradation, reduction in host plant numbers through grazing and predation by rodents are thought to be responsible for the decline in its numbers and distribution. in December 2004, more than 80 years since the last sighting of H. tuberculatus in 1922, a single individual was found at Burkes Pass Scenic Reserve. This paper records the rediscovery of H. tuberculatus, reviews the historical distribution records for H. tuberculatus, discusses them with respect to changes in host plant habitat in the eastern South island, and suggests conservation strategies to protect this and other relictual populations that might be found in future. [ABSTRACT FROM AUTHOR]

There is mounting concern in New Zealand and worldwide about the impacts of current and projected land-use activities on freshwater quality. In 2011, the New Zealand government effected the National Policy Statement for Freshwater Management, requiring all regional councils to establish freshwater nutrient loads and water allocation measures in their land and water regional plans. These ‘limits’ must achieve locally defined social, economic and cultural outcomes while, as a minimum, halting any decline in water quality. The authors have participated in the Canterbury region’s strategic land and water planning activities. This has involved strategically assessing the social impacts of ‘limit options’ on aspects of catchment life and then integrating them into official reports and community deliberations, which ultimately inform the development of rules for catchment land use. This paper highlights practice issues which were confronted in the process and how they were managed. [ABSTRACT FROM PUBLISHER]

Nitrogen (N) leaching losses from grazed pasture systems pose a risk to the environment with mitigation strategies urgently required to achieve regulatory limits. There has been increased interest in alternative forages to manipulate excretion of urinary-N of livestock. This review summarises research on key forage attributes which affect the pattern of urine-N excretion. The literature showed an opportunity to alter both N concentration and moisture concentration of forages to reduce urine patch N loading. Complementary mitigations of extending the grazing rotation and reducing fertiliser were tested in simulations in addition to a diuresis effect on nitrate leaching in pastoral dairy systems. Findings suggested that forage species alone could not substantially reduce (by more than 20%) nitrate leaching. Combining all forage, management and systems-based solutions led to the greatest reductions in nitrate leaching, 59 and 31% for Waikato and Canterbury. Nonetheless, reductions in N loss came at the expense of pasture productivity which will likely affect profitability and farmer adoption of this suite of solutions in the absence of other drivers. The role of plant secondary metabolites in microbial dynamics has implications on N recycling in soil and rumen environments and this was identified as an area for further research. [ABSTRACT FROM AUTHOR]

Nitrate leaching from soil is a major problem in New Zealand pastoral systems, requiring development of practical methods to manage accumulation of nitrates. Nine feed trials were carried out in the Waikato (n = 3) and in Canterbury (n = 6) between 2013 and 2016; from which 424 samples were selected for forage quality testing. Only tick beans and forage rape met the lactating feed criteria for adequate crude protein (CP; > 16% DM) and soluble sugars and starch (SSS; > 25% DM). When an 'environmental' criterion was added to a feed value for lactating cows this reduced the options to fodder beet only. However, the CP measurements for fodder beet were suboptimal for milk production, requiring the fodder beet to be mixed with high protein feeds such as pasture or pasture silage. The lower protein requirements for non-lactating cows, including an additive environmental criterion enabled a wider range of feeds to be considered e.g. kale, sunflowers and swedes in Canterbury (12 entries) and fodder beet and rape in the Waikato (21 entries). Addition or restriction of nitrogen fertiliser was the only agronomic management intervention that consistently altered animal feed quality and potentially changed N excretion. Crop choice was likely to have the greatest impact at the farm level. By limiting feed quality assessment to CP, SSS and their ratio (SSS:CP) we were able to define a selection/feed monitoring method to minimise N content of feed, maximise SSS feed value and limit excess N intake to reduce the nitrate leaching risk. [ABSTRACT FROM AUTHOR]

A 3-year study was carried out in Canterbury, New Zealand, to determine the effect of a nitrification inhibitor dicyandiamide (DCD) on N2O emissions, nitrate () leaching and pasture yield. In all 3 years, DCD was highly effective in reducing N2O emissions from urine-nitrogen (N) applied in autumn (April and May), decreasing the N2O emission factor by 41%–82%. In addition, DCD consistently reduced-N leaching losses by 48%–69% from the animal urine applied in April. Pasture yield responses to DCD application varied from 0%–17%, probably due to other growth limiting factors and/or the methodology used in the pasture yield measurement. The reductions inleaching are of particular value at this point in time due to the increasingly strict regional council regulations that are being imposed on farmers to reduce N leaching losses. [ABSTRACT FROM AUTHOR]

A new low-concentration formulation of Feracol® paste containing 0.4% concentration cholecalciferol was tested for efficacy against possums in cage trials, and against possums and rodents in a single unreplicated field trial. A new low-concentration 0.4% cholecalciferol cereal pellet was also tested in the field against possums and rodents. 20 wild-caught possums, held in individual cages, were presented with 15 g of 0.4% cholecalciferol paste. Possum body weight, amount of paste eaten and days until death were recorded. The field trial occurred on Banks Peninsula, Canterbury, from September to November 2009, using a treatment site of c. 100 ha and a non-treatment site of c. 200 ha. The treatment site was divided into two even blocks, one for paste and one for pellets. Pre- and post-monitoring were carried out using leg-hold traps for possums, and tracking tunnels for rodents. Of the 20 caged possums, a kill rate of 89.5% with an average time to death of 7.0 days±0.41 SEM was achieved, similar to earlier work on cholecalciferol using a higher concentration. In the field trial pellet treatment block, possum numbers were reduced by 94±11%, mice numbers by 100±0% and rat numbers by 89±12%. In the paste treatment block, possum numbers were reduced by 93±16%, mice numbers by 75±29% and rat numbers by 100±0%. Under the current study conditions, the effectiveness of the new Feracol® paste and pellets containing 0.4% concentration cholecalciferol was comparable to the currently registered 0.8% concentration cholecalciferol Feracol® paste formula, and was effective in controlling multiple pest species while reducing the poisoning risk to non-target species. Replication of this field trial using the new bait matrices is necessary to increase confidence under similar and differing conditions, to ensure that the efficacy seen here is not arbitrary. [ABSTRACT FROM PUBLISHER]

The avifauna from the Glencrieff swamp deposit in North Canterbury, South Island, New Zealand, is described. Radiocarbon ages of moa bones bracket miring at the site to between 10,000 and 12,000 (uncalibrated) years BP. Heavy-footed moa (Pachyornis elephantopus) and eastern moa (Emeus crassus) dominated the moa assemblage at the site, while South Island giant moa (Dinornis robustus) and stout-legged moa (Euryapteryx curtus, formerly E. gravis (in part)) were rare. The total assemblage from the site consists of at least 1896 bones from 18 species of birds, of which nine are extinct and a further three locally extinct. In addition, we report on the discovery of the oldest known moa gizzard contents, the palynology of the Glencrieff deposit and comment on significant recent changes in site preservation conditions that are threatening the continued preservation of this significant fossil deposit. [ABSTRACT FROM AUTHOR]

Oystershell scale, Diaspidiotus ostreaeformis, is a pest of fruit crops in Otago and Canterbury that is well controlled within orchards but becomes a problem at harvest due to invasion from external host trees. Its major pest status on export crops comes from its being indistinguishable on harvested fruit from the critical quarantine pest San Jose scale Diaspidiotus perniciosus. Oystershell scale has a wide host range which includes trees frequently used as orchard shelter. The distribution of oystershell scale in apples adjacent to an infested shelter belt was investigated in Otago in 1995-96. Apple infestation was >90% next to the shelter and declined linearly to <1% 64 m away. The slope of this linear regression was similar on four cultivars of apple but infestation increased substantially from early- to late-harvested cultivars. The phenology of oystershell scale on apples in 1998-2000 was found to precede that on a range of other hosts, which extended the period of risk of fruit infestation by crawlers from December to April each year. Experiments were conducted in 1999-2000 on control of oystershell scale on a range of infested shelter trees using a vertical boom sprayer. Sprays timed for control of adult males and females in spring provided only a short-term reduction of winged males in sticky traps and failed to reduce crawler production and dispersal as measured by sticky bands and traps on tree branches. On the other hand, sprays timed for control of crawlers in mid-summer were effective in greatly reducing catches of crawlers. The options for management of oystershell scale on alternative hosts, particularly shelter, are discussed in relation to phenology, crop invasion by crawlers, host resistance and spraying. [ABSTRACT FROM AUTHOR]

White clover (Trifolium repens L.) is grown throughout New Zealand in pasture and as a seed crop in the South Island. This investigation was conducted to determine the number of honey bee visits necessary to fully pollinate white clover flowers; the number of foraging honey bees per hectare required to reach the maximum seed number per floret; and to assess the level of white clover pollination in Canterbury. The theoretical maximum number of seeds that can be produced per white clover floret is six, based on the number of ovules present. Based on the number of seeds resulting from a single bee visit (mean = 1.24), it is calculated that in an 8 h foraging day, 19,420 bees would be required per hectare to reach maximum seed number per floret, assuming that no floret received more visits than required. Bee activity was assessed at two clover sites with an estimated 20,124 foraging bees per hectare. This number should have been enough to reach maximum seed number per floret. However, seed set in these fields was approximately half of its theoretical potential. [ABSTRACT FROM AUTHOR]

Detailed field studies of the biology and ecology of Nysius huttoni were undertaken over 4 years in Canterbury, New Zealand. This study establishes beyond doubt that there are three generations a year, with generations overlapping between the first and second, and the second and third generations. Nysius huttoni overwinters as adults of the third (autumn) generation. Adults go into overwintering from mid April to early May and emerge from overwintering sites in late August or early September. The first generation (from newly laid egg to emergence of adult) completed development in a range of 55-65 days over the 4 years, and the second and third generations in ranges of 35-50 and 20-60 days, respectively. The period of occurrence for the first generation ranged from 120 to 135 days over the 4 years, and for the second and third generations ranged from 80 to 120 and 285 to 295 days, respectively. Each generation showed a distinct seasonal peak and pattern in mating and oviposition; the third-generation adults that emerge before winter mate and oviposit in spring after overwintering. The present results will be useful in predicting the field development and occurrence of N. huttoni in Canterbury. [ABSTRACT FROM AUTHOR]