bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of dairyshed effluent irrigation on the occurrence of plant pathogenic Pythium species in pasture
Authors: Waipara N.W. , Hawkins S.K.
Published: October 2019

A preliminary survey of pastures sprayirrigated with dairyshed effluent revealed a significant increase in the population of plant pathogenic Pythium species isolated from both soil and roots In vitro pathogenicity tests showed the majority of these isolates to be pathogenic when inoculated onto the seedlings of white clover subterranean clover and perennial ryegrass although both clover species were more susceptible to Pythiuminduced disease than ryegrass
Development of white rot disease in onion transplants in Canterbury
Authors: Swaminathan J. , McLean K.L. , Stewart A.
Published: October 2019

White rot disease was monitored in onions grown from transplants in two field sites in Canterbury and compared with disease development in direct seeded crops Onion seedlings cv Pukekohe Long Keeper (May and Ryan) were grown in seedling trays (25 ml volume) in the glasshouse for 12 weeks and transplanted to the field in August 1999 At both sites onset of disease occurred earlier in onion transplants and was more severe at all assessment times with 6070 disease recorded at harvest compared to 110 for direct seeded crops The benefits of an earlier harvest date for transplanted onions (January compared to March) was outweighed by the higher disease levels
Survey of olive leaf spot in New Zealand
Authors: MacDonald A.J. , Walter M. , Trought M.C. , Frampton C.M. , Burnip G.
Published: October 2019

Olive leaf spot (OLS) or peacock spot caused by the fungal pathogen Spilocaea oleagina can cause reduced growth and yield in olive trees (Olea eurapaea) Investigations were carried out during December 1999 and January 2000 to measure the prevalence and severity of olive leaf spot in the Auckland Waiheke Island Wairarapa Marlborough and Canterbury growing regions of New Zealand The susceptibility of six cultivars (Barnea Manzanillo Frantoio Leccino Nabali and Souri) to OLS was assessed OLS was found in all study areas with Auckland and Marlborough the worst affected OLS appeared to be particularly severe on trees that were growing in sheltered parts of an olive grove Severity increased with age and a correlation between prevalence and severity was found Souri and Nabali were the worst affected cultivars while Frantoio and Leccino were least affected
Occurrence of Phomopsis castanea as an endophyte in chestnut trees
Authors: Wadia K.D.R. , Klinac D. , McNeil D.L. , Osmonalieva A. , Stewart A. , Knowles R.D.
Published: October 2019

Epidemiological studies on Phomopsis nutrot disease of chestnuts in New Zealand revealed that the fungus Phomopsis castanea occurred as an endophyte in stems (except xylem) leaves flowers and immature burrs of chestnut trees Apparently healthy trees from nurseries grower properties and research orchards as well as wild trees in the North and South Island were sampled and P castanea was isolated from 92 of the trees Among the four edible chestnut species and several commercial cultivars tested the incidence was highest for trees of European chestnut (Castanea sativa) and cultivar 1002 and lowest in Japanese chestnut (Castanea crenata) The incidence of plant parts yielding P castanea was also lowest for young trees from nurseries Dieback and necrosis of male catkins and leaf spot symptoms caused by P castanea were observed in some trees of C sativa and American chestnut (Castanea dentata) Spore sampling techniques failed to recover any airborne propagules from November 1999 to March 2000
The role of adhering floral tissues in sclerotinia disease of kiwifruit
Authors: Hoyte S.
Published: October 2019

Field trials in 10 Bay of Plenty and two Waikato orchards during 1996/98 investigated the role of adhering floral tissues in the development of sclerotinia disease of kiwifruit caused by Sclerotinia sclerotiorum Petalfall and stamenfall extended over a period of at least six weeks S sclerotiorum was isolated from 053 of petals during flowering and 042 from adhering floral tissues on fruit Fruit from two orchards had a significantly higher incidence of fruit scarring on fruit with adhering floral tissues compared to fruit without adhering floral tissues The incidence of diseased fruitlets and fruit scarring was significantly reduced when floral tissues were physically removed after petalfall The data suggest that floral tissues are readily colonised by S sclerotiorum ascospores during flowering and that disease mostly arises directly from mycelial infection originating within adhering floral tissues This disease pathway will be exploited in developing disease management strategies
Inconsistent growth promotion of cabbage and lettuce from Trichoderma isolates
Authors: Rabeendran N. , Moot D.J. , Jones E.E. , Stewart A.
Published: October 2019

Trichoderma isolates were evaluated for growth promotion effects on cabbage seedlings (Brassica oleracea L) in glasshouse trials Dipping transplants in spore suspensions (107 conidia/ml) of T longipile (6Sr4 and 3Sr42) and T tomentosum (5Sr22) increased (P
Developing tests to determine viability of Ciborinia camelliae (Kohn) sclerotia
Authors: Van_Toor R.F. , Pay J.M. , Jaspers M.V. , Stewart A.
Published: October 2019

Two methods were developed to assess the viability of Ciborinia camelliae (Kohn) sclerotia for subsequent use in assays of sclerotial parasitisation In the first method external contaminants were removed by washing the sclerotia twice in 135 NaOCl and soaking them in antibiotics Bisected sclerotia grown on potato dextrose agar for 9 days at 20C produced identifiable colonies of C camelliae In the second method sclerotial softness which is proposed as an indicator of decay was measured The compression energy required to push a 276 mm diameter penetrometer with a force of 40 N into a healthy sclerotium gave an indication of sclerotial softness
Infection processes of Ciborinia camelliae on camellia flower tissue
Authors: Vingnana-Singam V. , Long P.G. , Rowland R.E.
Published: October 2019

The infection process of Ciborinia camelliae the cause of camellia flower blight was studied using light and confocal microscopy Germination and infection structures of the pathogen on petals were stained with trypan blue in lactophenol and with glutaraldehyde for light and confocal microscopy respectively Within 6 h of inoculation the ascospores germinated and formed short germ tubes The host cuticle was penetrated and within a further 6 to 18 h a large swollen structure formed underneath each penetration From here a hypha grew under the cuticle to the junction between two cells and then developed as intercellular hyphae The mycelium continues to develop intercellularly for the next 72 h but without causing extensive destruction of the host cell walls
An evaluation of Lycosa hilaris as a bioindicator of organophosphate insecticide contamination
Authors: Hodge S. , Vink C.J.
Published: October 2019

The potential of Lycosa hilaris as a bioindicator of organophosphate contamination was assessed experimentally in a crop of beans (Phaseolus vulgaris) in Canterbury New Zealand Although the numbers of L hilaris caught in pitfall traps fluctuated significantly as the crop aged there were no differences (P>005) in L hilaris abundance in plots sprayed with diazinon or chlorpyrifos compared with plots of beans sprayed with water The abundances of other beneficial arthropod predators (linyphiid spiders harvestmen centipedes) were also not affected by insecticide application (P>005) Although L hilaris may not represent a good bioindicator the use of this species as a laboratory bioassay organism should be further investigated especially with respect to sublethal physiological responses
Effect of surfactants on honey bees
Authors: Goodwin R.M. , McBrydie H.M.
Published: October 2019

The toxicity of surfactants applied topically and orally to honey bees (Apis mellifera L) was determined by laboratory bioassays Eleven surfactants (Citowett Pulse Boost Codacide oil Contact Raingard Peptoil Sunspray Ethokem Multifilm and Uptake) were applied topically to anoxiated bees Anoxiating bees and spraying them with water had no significant effect on their survival Four surfactants (Citowett Pulse Boost and Ethokem) were toxic when applied topically Ethokem and Boost also showed oral toxicity Field trials are necessary to assess the actual impact of surfactants As some surfactants were demonstrated to be toxic to bees in laboratory trials which suggests they may be toxic when used in the field they should go through the agrichemical registration process and honey bee warning labels should be included where appropriate
Spray deposit variability in New Zealand winegrape canopies and implications for agrichemical application practices
Authors: Manktelow D.W.L. , Praat J-P.
Published: October 2019

Introduction of new grape sprayers and vineyard planting systems in New Zealand has led to uncertainty over agrichemical application rate requirements in different canopies A 1998 survey of spray application practices on 15 Hawkes Bay vineyards found up to a sixfold difference between vineyards in the rates of sulphur fungicides applied to fully developed canopies Followup work in 199900 found that twofold withincanopy spray deposit variations were common Earlier work indicated that deposits on upper surfaces of leaves can be up to three times greater than on lower surfaces Methods for reducing deposit variations and for more precise definition of agrichemical application rate requirements are discussed
Biochemical and histopathological changes induced by sodium monofluoroacetate (1080) in mallard ducks
Authors: Ataria J.M. , Wickstrom M. , Arthur D. , Eason C.T.
Published: October 2019

Public concern over inadvertent kills of native birds following largescale aerial poisoning operations for possum has highlighted deficiencies in information concerning the effects of 1080 on nontarget species In this study biochemical and histopathological changes were measured in adult male mallard ducks (Anas platyrynchos) dosed orally with 1080 The toxin was quickly absorbed into the blood and distributed to the cardiac tissue The time taken to reach maximum 1080 concentrations in these tissues corresponded closely with the onset of clinical signs of toxicosis Tissue and serum citrate accumulation is a direct result of 1080induced inhibition of the Krebs Cycle enzyme aconitate hydratase Histopathological lesions indicated that skeletal muscle was a target organ for 1080induced damage in birds Dosedependent increases in serum creatinine kinase (CK) and aspartate aminotransferase (AST) were consistent with extensive muscle necrosis Skeletal muscle may be a unique avianspecific target organ for 1080
Feracol paste bait for possum control a cage trial
Authors: Morgan D.R. , Rhodes A.T.
Published: October 2019

Consumption and efficacy of FeraCol paste (containing 04 cholecalciferol) were assessed in a cage trial by presenting 20 captive possums with 18 g of paste a quantity predicted to be suitable for lowhazard use when presented in small paper bags attached to trees All possums ate some paste and 90 were killed The two survivors had both eaten moderate amounts of paste suggesting that it may be necessary to reassess the concentration of cholecalciferol once reliable data are gained from actual field use Consumption of FeraCol paste induced a stopfeed effect which together with its durable nature should permit use of the product in a relatively costeffective manner with low environmental risk
Selectivity of Ferafeed paste bait treated with a rodent repellent a cage trial
Authors: Morgan D.R. , Rhodes A.T.
Published: October 2019

FeraFeed is a nontoxic prefeed paste bait used in conjunction with Feratox cyanide capsules for the control of possums The selectivity of a formulation of FeraFeed containing a rodent repellent was tested in a cage trial with Norway rats and possums Rats were strongly discouraged from eating the material and yet readily consumed nontreated FeraFeed paste while possums were not deterred Incorporation of the repellent should therefore improve the costeffectiveness of using FeraFeed/Feratox in possum control Additionally use of FeraFeed/Feratox for monitoring possum populations may be improved by the reduced interference by rats
Longevity of buried ragwort seed in four soils
Authors: James T.K. , Rahman A.
Published: October 2019

The viability of ragwort (Senecio jacobaea L) seed buried for several years at 0 2 4 6 and 19 21 cm depths was evaluated in four different soil types Seed samples in nylon mesh bags were removed after 1 2 3 5 11 and 16 years burial and their viability determined by germination After 16 years no viable seed was found in the clay soil In the silt loam and peat soils 1 3 viable seed remained while in the sandy soil up to 13 remained viable In the surface 0 2 cm layer of soil it took from 109 to 146 years for the percentage of viable seed to fall to 1 of the original viable seed depending on soil type At the 4 6 and 19 21 cm depths the corresponding times were 128 165 years and 130 180 years
Longevity of Californian thistle roots
Authors: Bourd?t G.W. , Leathwick D.M. , Hurrell G.A.
Published: October 2019

In two experiments sheep pastures supporting manipulated ranges of root biomass of Californian thistle (Cirsium arvense (L) Scop) in autumn 1996 and 1997 were mown weekly over the subsequent growing seasons of 1997 and 1998 respectively This treatment minimised whole season photosynthetic opportunity in the Californian thistle and the formation of new root biomass allowing the survival of existing root biomass to be measured Autumnal root biomass in May 1997 was 6 of that in May 1996 and in May 1998 it was 10 of that in May 1997 These results support the hypothesis that a high percentage of the overwintering storage root biomass of Californian thistle does not survive beyond the end of the next growing season
Weed control in sweetpotatoes
Authors: Lewthwaite S.L. , Triggs C.M.
Published: October 2019

The sweetpotato (Ipomoea batatas (L) Lam) crop once established requires little field management apart from weed control Currently weeds are minimised by a combination of handweeding interrow cultivation and the application of paraquat (100 g ai/ha) over the crop In this study alternative herbicide treatments were examined in a field trial Handweeding produced the highest marketable yield (267 t/ha) significantly more than all other treatments apart from acetochlor (24 kg ai/ha) which produced 218 t/ha (P
Weed competition in maize crop under different timings for postemergence weed control
Authors: James T.K. , Rahman A. , Mellsop J.
Published: October 2019

The effect of early weed competition was determined for a maize (Zea mays) crop grown in Waikato Maize was established in three different environments viz weedy (no herbicide) grass weeds (preemergence atrazine) and broadleaf weeds (preemergence metolachlor) Surviving weeds were controlled with postemergence nicosulfuron (60 g/ha) after different periods of competition and the plots kept weed free for the remainder of the trial Weeds left completely uncontrolled for 4 weeks after emergence significantly reduced crop yields When a preemergence herbicide was used surviving weeds began to reduce maize yields after about 6 weeks with grasses having greater effect than broadleaf weeds The actual period before the weeds started affecting crop growth and yield appeared to be related to the time taken by the weeds to achieve complete ground cover
Assessment of two herbicide wiping devices
Authors: Harrington K.C. , Hood M.Z. , McKinnon K.C.
Published: October 2019

If herbicides were wiped on to weeds rather than sprayed the risk of spray drift would be eliminated Two devices designed to apply herbicides using rolling wipers were assessed for their ability to apply constant amounts of herbicide to treated surfaces The Weed Ball Applicator treated strips only 36 mm wide despite having a roller 100 mm wide whereas the Turf Girl applicator delivered a 500 mm wide band Both applicators suffered from a tendency to apply less herbicide as the herbicide reservoir emptied with the nearly empty Weed Ball delivering only 124 of that applied when full Adjustments to the flow rate as the reservoir emptied could be made using a tap in both devices A field evaluation of the Weed Ball applicator on dichondra showed that it had good potential for selective localized applications of herbicides to lawn weeds Of the treatments evaluated a metsulfuron solution (045 g/litre) gave the best control
Herbicide gels for controlling old mans beard (Clematis vitalba) in ecologically sensitive areas
Authors: Ward B.G. , Henzell R.F.
Published: October 2019

Old mans beard (Clematis vitalba) is a significant environmental weed and can completely smother the growth of native vegetation in many New Zealand parks and reserves Current herbicide application techniques are either not effective on the weed or can have nontarget effects on adjacent native plant species HortResearch has developed herbicidal gels for the direct application to cut stems to selectively kill target plants The gels were formulated with a range of active ingredients Piclorambased gels were the most effective treatments on old mans beard without causing any non target effects
Herbicides for weed control in the root crops Ullucus tuberosus and Amorphophallus konjac
Authors: James T.K. , Follett J.M.
Published: October 2019

Ullucus tuberosus and Amorphophallus konjac are new root crops being evaluated for commercial development in New Zealand Eighteen herbicides were screened in glasshouse experiments for pre or postemergence use in these crops Methabenzthiazuron chlorpropham diuron and linuron were well tolerated by Ullucus when applied preemergence while dimethanamid oryzalin and simazine warrant further study All the postemergence treatments damaged Ullucus although linuron might show acceptable tolerance at a lower rate Acetochlor chlopropham dimethanamid linuron methabenzthiazuron oryzalin oxadiazon oxyfluorfen and pendimethalin were all well tolerated by Amorphophallus when applied preemergence while asulam flumetsulam and tribenuron were safely used postemergence Bromoxynil was also safe on Amorphophallus if applied before leaves emerged from the developing shoot
Herbicide resistance in black nightshade and Onehunga weed
Authors: Harrington K.C. , Ward A.J. , Wells D.M
Published: October 2019

When black nightshade (Solanum nigrum) plants were poorly controlled by cyanazine in a Manawatu pea crop seeds were collected from these plants and susceptibility of the resulting seedlings to various herbicides was compared in pot experiments with other black nightshade plants The biotype was resistant to cyanazine terbuthylazine atrazine prometryn and possibly also terbutryn No damage occurred even when a 30fold increase in the recommended application rate of terbuthylazine was applied Pot trials were also conducted at Massey University to study the poor control of Onehunga weed (Soliva sessilis) by herbicides noticed in turf at Helensville This trial showed the Helensville ecotype to be resistant to pyridine herbicides resulting in no control by clopyralid triclopyr picloram/24D and picloram/triclopyr mixtures Strategies to control both resistant ecotypes are discussed
Crossresistance in chlorsulfuronresistant chickweed (Stellaria media)
Authors: Seefeldt S. , Peters E. , Armstrong M.L. , Rahman A.
Published: October 2019

In New Zealand chlorsulfuronresistant chickweed was discovered in 1995 Experiments were conducted in the field and glasshouse to determine whether these resistant plants were also cross and multipleresistant to other herbicides normally effective on chickweed A population of chlorsulfuronresistant chickweed growing in an oat crop near Winton in the South Island was treated with 13 different herbicides This population was not controlled by mecoprop methabenzthiazuron and pendimethalin and only partially controlled by bromoxynil ioxynil diflufenican isoproturon and diflufenican bromoxynil in the field trial Two followup glasshouse experiments using plants grown from seeds harvested from the surviving plants confirmed crossresistance to thifensulfuron and susceptibility to all the other herbicides including tribenuron
Weed seedbank dynamics in maize under different herbicide regimes
Authors: Rahman A. , James T.K. , Mellsop J. , Grbavac N.
Published: October 2019

The influence of different herbicide regimes on the size and composition of the soil weed seedbank in maize was studied over three years Preemergence atrazine alachlor atrazine alachlor or no herbicide treatments were imposed on the same plots each year Soil samples to 100 mm depth were collected each autumn and spring and the seedbank was estimated by seed extraction and seedling emergence Data showed strong positive correlation between the two methods Soil seedbank increased dramatically by each autumn but declined by spring The total seedbank increased over three years in the no herbicide treatment Good weed control by atrazine alachlor kept seedbank density at low levels However seed numbers increased particularly in the first two years with only partial weed control using atrazine or alachlor singly A sharp increase of fathen (Chenopodium album) seeds illustrated the danger of building seedbanks of weeds which become tolerant to the strategies used
Evaluation of mechanical weed management techniques on weed and crop populations
Authors: Reddiex S.J. , Wratten S.D. , Hill G.D. , Bourd?t G. , Frampton C.M.
Published: October 2019

One of the main barriers for conventional farmers converting to organic production is weed control An experiment was set up to evaluate the efficacy of three mechanical weed control methods tine weeder spoon weeder and interrow hoe (only in the beans (Phaseolus vulgaris)) in four organically grown crops In borage (Borago officinalis) weed dry matter (DM) was reduced by 41 in tineweeded plots but there was no treatment effect on crop DM or yield There was no treatment effect in the peas (Pisum sativum) In linseed (Linum usitatissimum) mechanical weeding reduced weed DM by 41 and resulted in a 28 increase in crop yield In beans weed DM was reduced by 74 in mechanicallyweeded plots but the tine weeder reduced crop DM compared with the other mechanical weeding treatments
Farmer perceptions of bird damage and control in arable crops
Authors: Coleman J. , Spurr E.B.
Published: October 2019

One hundred arable farmers from across New Zealand were randomly selected and interviewed in summer 2000 to assess their perceptions of the nature and extent of bird damage to their crops the bird species involved the factors affecting the level of damage and the type and cost of any bird control undertaken Most farmers considered birds caused serious damage to their crops with wheat barley peas and some speciality seed crops such as brassicas borage and evening primrose most at risk Damage was rarely perceived to exceed 5 in cereals but was often higher in speciality crops It was most severe at seed maturation The birds responsible for most of the damage were house sparrows and greenfinches Most farmers undertook some form of bird control to protect their crops with shooting gas guns and avicides most commonly used The overall expenditure on bird control was far less than the value of the damage reported
Can artificial Neural Network Systems be used for forecasting aphid flight patterns
Authors: Lankin G. , Worner S.P. , Samarasinghe S. , Teulon D.A.J.
Published: October 2019

In Canterbury the cereal aphid (Rhopalosiphum padi) has a bimodal annual flight pattern with peaks in autumn and late spring The autumn peak coincides with the migration of aphids into autumn and winter sown wheat The timing magnitude and duration of flights vary dramatically from year to year and can have important implications for the management of this aphid in cereals Twenty years of climatic and aphid flight data were used to train a neural network to obtain a model to predict the date and size of aphid migrations in cereal crops in Canterbury New Zealand The model provided an exceptional fit to the ten years of training data but gave disappointingly poor prediction for the eight years of validation data Possible reasons for poor prediction of validation data are given and suggestions are made concerning future developments
Fusarium levels in grain harvested from New Zealand wheat and barley crops in 2000
Authors: Cromey M.G. , Parkes R.A. , Fraser P.M.
Published: October 2019

Samples of grain from 40 New Zealand wheat and barley crops harvested in 2000 were assayed for Fusarium infection Grain from all crops was infected and Fusarium incidence ranged from 3 to 52 of grains infected with a mean of 14 Incidence of Fusarium was higher in spring wheat than in autumn wheat or spring barley The highest level of infection (52 grains infected) was found in Otane wheat (highly susceptible to Fusarium head blight) sown into a paddock after maize although there were no general effects of cropping history on grain infection Levels were lower when residues of the previous crop were burned rather than baled or incorporated Infection levels varied between cultivars corresponding to the variability in susceptibility to Fusarium head blight
Inheritance of resistance to Ascochyta blight in lentil
Authors: Ye G. , McNeil D.L. , Hill G.D.
Published: October 2019

Inheritance of foliar resistance to Ascochyta blight in lentil was studied using four resistant and one susceptible cultivars Two dominant genes one for resistance and one for moderate resistance are present in cv ILL 5588 One dominant gene which is allelic to the one for resistance in cv ILL 5588 confers the resistance in cv ILL 5684 One recessive gene is responsible for the resistance in cv Laird The resistance in cv Indian head is under control of two recessive genes with additive effects
Ecological risks and benefits of transgenic plants
Authors: L?vei G.
Published: October 2019

The spread of commercial growing of transgenic crops has been very rapid with such crops being grown on 442 million ha in 13 countries in 2000 Most currently grown transgenic plants are either herbicide or insect resistant but research into other possibilities is intense There are potentially significant environmental effects of this technology as well as sharply conflicting claims about its overall impact Among perceived risks this review concentrates on the possibility of damaging ecosystem services (biological control pollination decomposition and soil fertility maintenance) and effects on biodiversity Among the benefits lower environmental contamination by fewer pesticide applications less soil erosion due to less frequent agricultural operations and lower pressure on land resources due to increased yield are listed Both potential risks and benefits need careful documentation and validation for an appropriate assessment of the total ecological effects of this technology
Impacts of transgenic plants and microorganisms on soil biota
Authors: O'Callaghan M. , Glare T.R.
Published: October 2019

Little is known about the impacts of transgenic plants and microorganisms on soil biota and processes despite the large number of field releases of transgenic crops Recent work has shown that transgenic plants can cause changes in the soil biota (both invertebrates and microorganisms) associated with these plants Often the changes are transient but their impact on the soil ecosystem remains unknown Horizontal gene transfer from genetically modified (GM) bacteria to indigenous soil bacteria has been demonstrated but movement of genes from transgenic plants if it occurs at all has not yet been detected in natural systems Soil invertebrates appear to play an important role in horizontal gene transfer between bacteria in soil
Pampas grass control with haloxyfop in conservations sites on difficult terrain
Authors: Popay I. , Timmins S.
Published: October 2019

An effective method was sought to control pampas grass (Cortaderia selloana) in conservation sites with difficult terrain At one such site the dunes and dune slack communities on Pouto Peninsula we tested three methods of applying the herbicide haloxyfop from a helicopter beer keg weighted nozzle and lance All three methods gave a similar high level of control of pampas grass but differed considerably in cost One year after herbicide application many of the pampas grass plants in the plots had new shoots and native plant species had begun to colonise the old pampas clumps All sprayed plots needed treatment of the regrowth to completely control the pampas grass
Woody weed dispersal by birds wind and explosive dehiscence in New Zealand
Authors: Allen R.B. , Lee W.G.
Published: October 2019

Age and distance from source were measured in southern New Zealand for plants of lodgepole pine and Darwins barberry and for seeds and plants of broom These species are dispersed by wind birds and explosive dehiscence respectively and annual spread rates of 1200 m 30 m and 12 m were obtained Broom seeds can be dispersed much further by animals or machinery Lodgepole pine spreads in the prevailing wind direction whereas directionality of spread of the other species is controlled by the behaviour of animal vectors Lodgepole pine and broom seedlings establish only in short vegetation but barberry can establish in scrub forest or pasture All three species produce seeds at four years of age Control measures should target outlier plants first
Host suitability of some eucalypts for development of the Eucalyptus leafroller (Strepsicrates macropetana)
Authors: Mauchline N. , Withers T. , Wang Q.
Published: October 2019

Strepsicrates macropetana (Lepidoptera Tortricidae) is a pest occurring only on species of Eucalyptus Nochoice trials were carried out by inoculating eggs onto potted plants of E nitens E saligna E fastigata and E regnans held in a glasshouse A number of development parameters including pupal weight time to adult eclosion and survival from egg to adult were measured All hosts were suitable for complete development of larvae however mean survival to adult was highest on E fastigata (61) The shortest time to eclosion (40 days) occurred on E nitens There was no difference in pupal weight between host species Adult female fecundity was variable The results indicate that the species of Eucalyptus tested which were from subgenera containing economically important species all supported development of S macropetana
Calibration of possum density estimates from raised leghold traps
Authors: Thomas M. , Brown J.A.
Published: October 2019

We undertook field trials to compare differences between ground and raisedset leghold traps to measure population abundance of the brushtail possum (Trichosurus vulpecula) We discuss the observed differences in trap catch rates and the use and potential misuse of a calibration index to correct the raisedset estimates so they can be compared with the groundset estimates
Sticky pane monitoring of Froggatts apple leafhopper and two beneficial insects in three orchard management systems
Authors: Suckling D.M. , Gibb A.R. , Burnip G.M.
Published: October 2019

A convenient monitoring system for a range of pipfruit arthropods was investigated as part of the development of Integrated Fruit Production for apples The monitoring system based on clear sticky panes was used to monitor adults of Froggatts apple leafhopper (Edwardsiana crataegi) and two beneficial insects (Sejanus albisignata and Micromus tasmaniae) in Canterbury apple orchards under three management regimes over three seasons The results reconfirmed the presence of two generations of Froggatts apple leafhopper and S albisignata in Canterbury Differences in pest and beneficial insect abundance were evident between the three orchard production systems Numbers of S albisignata were consistently lowest in the conventional fruit production system but this was not the case for M tasmaniae or E crataegi
Alternative strategies to control New Zealand flower thrips on nectarines
Authors: McLaren G.F. , Fraser J.A.
Published: October 2019

Experiments conducted in both spring and preharvest (summer) aimed to prevent damage to nectarines caused by New Zealand flower thrips Thrips obscuratus and to minimise quarantine problems caused by thrips on export fruit Reflective mulch and three insecticide programmes were compared with the standard taufluvalinate/chlorpyrifos programme in spring Abamectin spinosad and Pyrethrum Plus reduced spring damage but none was more effective than the existing standard At harvest time carbaryl and spinosad plus Nufilm17 reduced thrips numbers 3 days after treatment but carbaryl was the only effective insecticide after 5 days Reflective mulch reduced thrips numbers in spring and preharvest providing a nonchemical alternative for thrips control However supplementary control measures would be needed for this treatment to meet quarantine standards at harvest time Alternative spring and preharvest programmes for both Integrated Fruit Production and organic systems are suggested for nectarines but registration is necessary before some insecticides can be used on summerfruit
Larval feeding behaviour and toxicity of Bacillus thuringiensis against Ctenopseustis obliquana on avocados
Authors: Stevens P. , Jamieson P. , Jamieson L.E. , Knights M.
Published: October 2019

Ctenopseustis obliquana is a serious pest of avocado in New Zealand Laboratory experiments to gain a greater understanding of the interaction between larval feeding behaviour and environmental degradation of Bacillus thuringiensis (Bt) residues were carried out Larval C obliquana were found to feed equally during light and dark periods and the application of Bt sprays in the evening did not consistently result in higher mortality than sprays applied in the morning First instar larvae were more susceptible to Bt sprays than third instar larvae However when first instar larvae were provided with leaf discs that had been sprayed with Bt seven days previously mortality was equivalent to that of larvae feeding on unsprayed leaves Mortality of first and third instar larvae provided with Bttreated leaf discs collected from within the shade of the avocado tree canopy (zero and one day after spraying) was significantly greater than that of larvae provided with Bttreated leaf discs collected from the outer perimeter of the canopy Results indicated that even very short exposure to sunlight (ie 3060 minutes) was sufficient to cause a significant reduction in the toxicity of Btsprayed leaves to C obliquana larvae
Recent introduction and establishment of the leafroller parasitoid Trigonospila brevifacies (Hardy) (Diptera Tachinidae) in Nelson
Authors: Shaw P.W. , Lo P. , Wallis D.R.
Published: October 2019

To assist the natural distribution of the leafroller parasitoid Trigonospila brevifacies to horticultural areas in the Nelson region 181 T brevifacies pupae and 329 adults were released in 1999 at four sites adjacent to apple orchards near Motueka Release material was supplied from fieldcollected parasitoids in Hawkes Bay and a laboratory colony held at the Mt Albert Research Centre in Auckland Successful establishment of the parasitoid was recorded at all four sites and at a nearby nonrelease site in 2000 In 2000 319 of fourth instar and older larvae were parasitised by T brevifacies while in 2001 parasitism was 1166 Important pest tortricid species including Epiphyas postvittana (Walker) (lightbrown apple moth) were among the hosts The successful establishment of T brevifacies in Nelson and its further natural dispersal will increase the potential for the reduction of economically important leafroller species by biocontrol agents
Introduction of a parasitoid for mealybug biocontrol a case study under new environmental legislation
Authors: Charles J.
Published: October 2019

Pseudaphycus maculipennis is one of the few known encyrtid parasitoids of the obscure mealybug (Pseudococcus viburni) It was released in New Zealand on 14 February 2001 The importation process under changing environmental legislation over an 8 year period is detailed and the implications of the new legislation for future classical biocontrol programmes is discussed
Preventative treatments for control of fungus gnats and shore flies
Authors: Van_Epenhuijsen C.W. , Page B.B.C , Koolaard J.P.
Published: October 2019

Preventative treatments for control of fungus gnats (Bradysia sp nr paupera Diptera Sciaridae) and shore flies (Scatella tonnoiri Hendel Diptera Ephydridae) were carried out by drenching potted tobacco plants with diflubenzuron and Bacillus thuringiensis var israelensis (Bti) The treatments were applied at different rates and times and compared with the use of sand and sawdust toppings to cover the potting mix Diflubenzuron treatments applied at three and nine weekly intervals and Bti applied at weekly intervals gave the lowest numbers of fungus gnats The sand topping for the control of shore flies gave significantly better results than the untreated control
Susceptibility of Diamondback moth (Plutella xylostella (L)) larvae to the entomopathogenic fungus Zoophthora radicans (Brefeld) Batko
Authors: Yeo H. , Pell J.K. , Walter M. , Boyd-Wilson K.S.H. , Snelling C. , Suckling D.M.
Published: October 2019

The fungus Zoophthora radicans is being developed as a biopesticide for control of diamondback moth (Plutella xylostella) A series of laboratory doseresponse bioassays was used to determine the virulence of five isolates of Z radicans to diamondback moths indigenous to New Zealand A reference isolate from Malaysia was compared to four isolates from New Zealand Late second and early third instar diamondback moth larvae were exposed to discs of broccoli leaves that had previously been inoculated with increasing densities of fungal conidia Isolates from New Zealand were consistently more infective than the Malaysian isolate LC50 values ranged from 092 conidia/mm2 for isolate NW337 (New Zealand) to 697 conidia/mm2 for NW250 (Malaysia) Resting spores were found in up to 30 of the total number of larvae that succumbed to infection with the New Zealand isolates but were never found in larvae that succumbed to infection with isolate NW250 A single isolate was identified with potential for future testing under field conditions
Honey bee response to high concentrations of some new spray adjuvants
Authors: Donovan B.J. , Elliott G.
Published: October 2019

The response of honey bees when treated orally and topically to the spray adjuvants DuWett Li700 Bond and Bond Xtra each at three different concentrations was evaluated in November 2000 under the OECD Guidelines for Testing of Chemicals of 21 September 1998 The concentrations ranged from 01 to 10 the highest of which were well above those used in the field Dimethoate at three concentrations was used as a standard and for the topical test distilled water was used as a nonchemical control For both tests about 1000 honey bees from the brood combs of a healthy colony were anaesthetized with carbon dioxide from which bees were treated and held in groups of 10 in cages at 25C and 70 RH for 48 hours Each treatment was replicated three times Despite some mortality for two of the three cages of Bond Xtra at 1 when applied topically none of the adjuvants were found to be toxic to honey bees at any concentrations tested
Evaluation of acibenzolarsmethyl for induction of resistance in camellia flowers to Ciborinia camelliae infection
Authors: Van_Toor R.F. , Jaspers M.V. , Stewart A.
Published: October 2019

The synthetic plant defence elicitor acibenzolarSmethyl (CGA245704 50WG Syngenta Crop Protection) was applied to Camellia japonica bushes to induce systemic acquired resistance for protection of flowers against ascospore infection by Ciborinia camelliae Bushes were sprayed weekly at 500 mg/litre either before flowering during flowering or both before and during flowering All untreated and treated flowers became infected with camellia blight to the same degree and produced similar numbers of sclerotia averaging 34 sclerotia/flower Thus acibenzolarSmethyl was not effective in reducing the incidence of camellia flower blight
Water and inoculation method affect germination and penetration by Ciborinia camelliae
Authors: Vingnana-Singam V. , Long P.G. , Rowland R.E.
Published: October 2019

Possible interactions between free water and methods of inoculating camellia petals with Ciborinia camelliae were investigated Spore suspensions were applied by pipette or atomiser while nonaqueous applications were made with a paintbrush or gravitational deposition from an apothecium Most spores germinated and penetrated the cuticle with pipetted spore suspensions or with gravitional deposition from an apothecium Brush and spray applications resulted in less germination and fewer infections Drying petal tissue before incubation in humid chambers reduced germination penetration and development of symptoms If water was added to petals with brush applied spores then multiple germ tubes and swollen hyphae were common and many germ tubes grew across the petal surface without penetrating
Bacteriophages a potential biocontrol agent against walnut blight (Xanthomonas campestris pv juglandis)
Authors: McNeil D.L. , Romero S. , Kandula J. , Stark C. , Stewart A. , Larsen S.
Published: October 2019

During autumn 2000 isolates of bacteria were collected from blighted nuts leaves buds and petioles of walnut trees from all over New Zealand From among these isolates Xanthomonas campestris pv juglandis lines were identified by a range of cultural DNA fingerprinting and morphological tests Concurrently bacteriophages which attack X campestris pv juglandis were isolated from the soils under the same trees Phages were readily isolated from a depth of 25 cm In the following spring phages were also isolated from the canopy of trees grown at Lincoln Phage typing was carried out to produce a set of phages capable of destroying all bacterial isolates A subset of the isolated phages was characterized Several phages isolated from the soil were identified under the electron microscope as being from the 955; phage group with long unsheathed tails and hexagonal heads Phages isolated from the canopy belonged to several other groups of phages Short term storage had little effect on canopy phage survivability Differences in hardiness were found between the phages The search to locate effective hardy phages for use as biobactericides continues
Sensitivity of Phaeomoniella chlamydospora to fungicides in vitro
Authors: Jaspers M.V.
Published: October 2019

Phaeomoniella chlamydospora has recently been shown to cause Petri vine decline in young grapevines No recommendations are available for management of the disease using fungicides In this study 22 fungicides were tested for their effect on the radial growth of three field isolates of P chlamydospora Systemic fungicides inhibited mycelial growth of the fungus at similar concentrations to those reported for other fungi The DMI fungicides cyproconazole bitertanol tebuconazole fenarimol myclobutanil and prochloraz gave EC50 values for reduction of mycelial growth of less than 03 mg/litre whereas triforine gave an EC50 value of 26 mg/litre For the benzimidazole fungicides benomyl carbendazim and thiophanate methyl the EC50 values were less than 04 mg/litre For the anilopyrimidines pyrimethanil and cyprodinil/fludioxonil (Switch) EC50 values were less than 002 mg/litre For the contact fungicides tested EC50 values were higher than those reported for similar fungi The potential role of the fungicides in disease management is discussed
Lack of relationship between aphid virus vector activity and potato leaf roll virus incidence
Authors: Teulon D.A.J. , Stufkens M.A.W.
Published: October 2019

The relationship between activity of aphid virus vectors and incidence of potato leaf roll virus (PLRV) in seed potato crops was investigated using historical data Numbers of PRLV aphid vectors (mainly green peach aphids) caught in a 75 m suction trap at Lincoln Canterbury and the incidence of primary and secondary PLRV for Ilam Hardy seed crops from the PT seed potato certification scheme in Canterbury were collated from 1982 to 2000 The degree of simple linear relatedness between aphid flight activity and virus incidence was examined Climate variables which may have contributed to aphid survival reproduction and movement in potato crops were also investigated Very low correlation coefficients between all variables tested were obtained Explanations for the lack of any relationship between potato aphid virus vector flights and virus incidence in potatoes are discussed
Aphids species on potato crops in Canterbury
Authors: Stufkens M.A.W. , Teulon D.A.J.
Published: October 2019

A survey of aphids infesting table processing and seed potato crops was undertaken in Canterbury during the 19992000 season (November March) The green peach aphid (Myzus persicae (Sulzer)) was the most common aphid found on potato plants (>85 of all aphids) followed by the foxglove aphid (Aulacorthum solani (Kaltenbach)) and the potato aphid (Macrosiphum euphorbiae (Thomas)) These three aphids are vectors of the potato leaf roll virus (PLRV) and other potato viruses A further eight species were found in low numbers including five species that are vectors of potato viruses (not PLRV) The melon aphid (Aphis gossypii Glover) was found in sizable numbers on sprayed potatoes in the Hawkes Bay This species which is known to have developed resistance to some insecticides on other crops in New Zealand was found in only low numbers in three crops in Canterbury
Thiamethoxam seed coating on rape seed for the control of cabbage aphid Brevicoryne brassicae (L)
Authors: Schroeder N.C. , Dumbleton A.J.
Published: October 2019

A glasshouse and a field experiment were conducted to determine the efficacy of thiamethoxam as a seed treatment on forage brassica for the control of aphids Cabbage aphid (Brevicoryne brassicae L) survival and reproductive rates were measured from rape plants (Brassica napus spp biennis cv Emerald) grown in both experiments The seed was treated with four different thiamethoxam rates (1 2 4 and 8 g ai/kg) and compared to the registered rate of imidacloprid (144 g ai/kg) and untreated seed over time Six weeks after sowing only thiamethoxam at 8 g ai/kg and imidacloprid at 144 g ai/kg had significantly lower (P
Effect of perennial ryegrass density on ragwort emergence
Authors: Armstrong M.L. , Seefeldt S. , Harrington K.C.
Published: October 2019

The effect of the density of perennial ryegrass (Lolium perenne) swards on the emergence of ragwort (Senecio jacobaea) was investigated in the field and in trays Ragwort seeds were sown into established perennial ryegrass and white clover (Trifolium repens) swards and the seedlings were mapped at intervals to aid in identification of new seedlings In the trays seedlings were counted and mapped at four week intervals and the experiment was continued for four months In the field plots ragwort seedlings were counted before and after each grazing There was no evidence for any negative effect of ryegrass tiller density on the number of ragwort seedlings emerging The presence of white clover in trays and clover and volunteer weeds in the field also provided competition for ragwort
Effect of plant condition on oviposition by ragwort flea beetle
Authors: Page B.B. C , Betteridge K. , McGregor P.G. , Rapson J. , Costall D.A.
Published: October 2019

The impact of grazing animals on oviposition behaviour of ragwort flea beetle (RFB) (Longitarsus jacobaeae) was investigated in two field experiments In the first trial manually damaged ragwort plants were exposed for 5 days to RFB In the second trial ragwort plants grown in sheep and cattlegrazed pasture were collected both in April and May 1997 for the counting of eggs on plants and in the surrounding soil Removal of the majority of ragwort leaves reduced egg numbers/plant whereas damage to leaves did not Similarly ragwort from sheepgrazed pastures which was smaller than ragwort from cattlegrazed pastures had fewer eggs/plant but a similar number/g fresh weight of ragwort High local humidity under rosette ragwort plants is suggested as the critical factor determining oviposition behaviour of RFB