bluuebunny/crossref_metadata_2025 huggingface dataset:
A nondestructive method to assess rot root severity of Lactuca sativa L
Authors: Suvarnaphaet P. , Tanmala V. , Kanjanamaneesathian M.
Published: October 2019

Root rot disease caused by aquatic fungi such as Aphanomyces sp and Pythium sp is prevalent in Lactuca sativa grown in a dynamic root floating technique (DRFT) hydroponic system in Phetchaburi College of Agriculture and Technology Thailand Roots of this plant have been severely infected with these fungi and plant growth has been affected resulting in a decline of yield over time Symptoms of root rot are initially characterised by tissue discoloration in some parts of the root followed by a loss of tissue integrity of the whole root In the DRFT system root rot symptoms of L sativa range from severe (complete) root rot to a healthylooking root (no symptoms)This study investigated the potential for using digital images as an objective tool for assessing disease severity with the aim of the tool being applied by assessors with no previous experience in disease assessment Lactuca sativa that had been grown in DRFT for 30 days and had various degrees of root rot symptoms were selected for the study Visual evaluation of the diseased root indicated that there were six levels of disease severity with root colour ranging from white (healthy looking) to completely black (severe root rot)When the diseased root samples were subjected to digital image analysis between the black and white extremes there was one shade of grey and three shades of brown The images of these six levels of severity were analysed using Hunter L a and b values It was found that the six levels of root rot severity could be distinguished based upon the L parameters The value of Lightness (Hunter L) which is transformed from RGB digital image (using a color calculator in http//wwweasyrgbcom) decreased exponentially (from severity level 1 to 6) with a constant value at 048 This indicates that digital image analysis using this simple tool can be utilised to objectively assess root rot disease in L sativa Once this technology is thoroughly studied developed and validated for lettuce growing in the DRFT system there is potential for it to be a useful tool to assist lettuce growers in making a decision to implement control measures
Biorational insecticides for control of the tomato potato psyllid
Authors: Jorgensen N. , Butler R.C. , Vereijssen J.
Published: October 2019

Since its discovery in 2006 the tomato potato psyllid Bactericera cockerelli (ulc) (TPP) has been considered a significant pest of solanaceous crops in New Zealand resulting in an intensification of insect pest control measures often with the use of broadspectrum insecticides In the search for more sustainable control methods in outdoor potato crops several biorational insecticides were tested in laboratory bioassays to assess their effects on TPP behaviour and mortality The products tested were Organic JMS StyletOil Excel Oil EcoOil Neem 600 WP and Sap Sucker Plus Given the efficacy of JMS Stylet Oil Sap Sucker Plus and Excel Oil at reducing TPP numbers and their probing/feeding deterrent qualities these products are now being tested in a field trial The impacts of the tested biorational insecticides on beneficial insects are also being assessed in laboratory and field trials
Subsampling plants to monitor tomatopotato psyllid (Bactericera cockerelli) and associated insect predators in potato crops
Authors: Walker G.P. , MacDonald F.H. , Larsen N.J. , Wright P.J. , Wallace A.R.
Published: October 2019

Subsampling of potato plants was assessed as a practical tool for monitoring Bactericera cockerelli tomatopotato psyllid (TPP) and other key pests and their predators at Pukekohe The total numbers of the key insect species and all their life stages on (1) the bottom leaf; (2) a middle leaf (the bottom leaf on the top half of the stem); (3) the bottom half of the stem; and (4) the top half of the stem were compared with numbers on the whole stem Assessing the top half of the stem was the most reliable subsampling method for the three main insects sampled while assessing a middle leaf also gave a reliable estimate for two out of the three insects A crop scouting protocol for monitoring TPP infestations based on sampling 100 middle leaves off 50 randomly selected plants in a crop is now recommended by the potato industry in New Zealand
A survey of Maori potato (taewa) seed tubers for the presence of Candidatus Liberibacter solanacearum
Authors: Puketapu A.J. , Gardner-Gee R. , Tooman L.K. , Beard S.S.
Published: October 2019

Taewa (Solanum tuberosum L) production is threatened by a new insect pest the tomato potato psyllid (Bactericera cockerelli Sulc) and the bacterium (Candidatus Liberibacter solanacearum (Lso)) vectored by the psyllid Lso is known to reduce potato yields and can infect seed tubers but less is known for taewa specifically In this study tubers from 17 taewa lines were tested for Lso using a qPCR assay grown in a greenhouse and assessed for symptoms of tuberborne Lso Lso was detected by qPCR in three tubers The Lsopositive tubers were from three lines from two North Island seed sources; no Lso was detected in the seven South Island lines tested In the greenhouse trial two of the three Lsopositive tubers emerged and one grew normally The greenhouse trial detected disease symptoms associated with Lso in several other lines but other potato viruses and diseases cause similar symptoms and this area needs further study
Using qPCR to monitor populations of Pseudomonas syringae pv actinidiae on kiwifruit vines
Authors: Pushparajah I.P.S. , Ryan T.R. , Hawes L.G. , Smith B.N. , Follas G.B. , Rees-George J. , Everett K.R.
Published: October 2019

Populations of Pseudomonas syringae pv actinidiae (Psa) on vines sprayed with a biological control agent (Bacstar; Bacillus amyloliquefaciens D747; Ba) and on untreated control vines were monitored using qPCR Leaf discs were taken from vines in February 2014 3 months after the final of three spray applications of Bacstar in October and November 2013 An aliquot of leaf washings in bacterial saline (BS) was spread on to potato dextrose agar in Petri plates and the numbers of colonies of Ba were counted DNA was extracted from the remaining BS and the quantity of Psa DNA was determined using qPCR Ba was recovered from leaf discs that had been sprayed with Bacstartrade; in greater numbers than from unsprayed leaf discs (P
Effect of culture medium light and air circulation on sporulation of Neonectria ditissima
Authors: Scheper R.W.A. , Fisher B.M. , Amponsah N.T. , Walter M.
Published: October 2019

In culture most isolates of Neonectria ditissima the causal organism of European canker do not produce conidia Those that do often produce singlecelled conidia rather than the typical multicelled conidia that are found in nature A series of experiments was conducted to determine the conditions needed for conidium production Four culture media (malt extract agar modified Matsushimas medium (MM) apple sap amended water agar (ASAWA) and water agar) five light regimes including darkness near ultra violet (NUV) light and white fluorescent light and three plate sealing patterns were tested Subculturing isolates producing large numbers of viable conidia of which 71 produced multicelled conidia Similarly under a white fluorescent light/darkness regime all isolates produced viable conidia on MM and ASAWA and 100 and 97 of the isolates produced multicelled conidia respectively
Effects of chemical and natural product treatments on bunch openness and botrytis bunch rot in Sauvignon blanc grapes
Authors: Mundy D.C. , Haycock S.R. , Raw V. , Agnew R.H. , Sherman E. , McLachlan A.R.G. , Hagerty G.C.
Published: October 2019

Products containing different gibberellic acids (GA) and GA inhibitors were applied to grapevines during the 2009/10 and 2010/11 growing seasons to evaluate possible effects on bunch architecture and subsequent botrytis bunch rot (BBR) severity In the 2010/11 season the timing formulation and dose responses of the GA inhibitors in association with a biological control agent were also evaluated for their effects on BBR In both seasons the effects on yield and fruit quality and quantity were also measured to determine whether the treatments might affect commercial production There were no significant differences in either BBR incidence or severity in either season between any treatments including the standard fungicide programme Bunch openness was significantly modified by treatments but with no consistent pattern
Towards a test to verify that wood has been heattreated to the ISPM15 standard
Authors: Iline I.I. , Novoselov M.A. , Richards N.K. , Phillips C.B.
Published: October 2019

International trade of wood including dunnage is a wellknown pathway for spreading diseases and woodboring insects between countries To mitigate this risk the International Standard for Phytosanitary Measures No 15 (ISPM15) states that wood to confirm that wood has been properly heattreated After preliminary investigations of 12 enzymes and 3 sugars from pine xylem experiments focused on malate dehydrogenase (MDH) and fructose Samples from the surfaces of heattreated Pinus radiata wood exhibited decreased MDH activity and increased fructose concentration However samples from 5 mm deeper in the profile of heated wood showed similar MDH activity to unheated wood but contained relatively lower fructose concentrations There is potential to exploit heatinduced changes in MDH activity and fructose concentration to develop a quick easilyused assay for verifying compliance of wood packaging materials with ISPM15
Is this imported food compliant with biosecurity regulations
Authors: Novoselov M.A. , Iline I.I. , Sinovcic Z. , Phillips C.B.
Published: October 2019

Imported food products can carry biosecurity hazards such as animal plant and human diseases To reduce this risk imported foods that contain ingredients of animal origin must be retorted in compliance with a New Zealand Ministry for Primary Industries (MPI) Import Health Standard AgResearch and MPI have developed a proofofconcept enzymatic colorimetric assay (Iline et al 2013; Proof of concept for a biochemical test that differentiates between heattreated and nonheattreated food products New Zealand Plant Protection 66 3439) In April 2014 MPI asked for a test to determine if a tinned food imported from India had been retorted to standard Using the proofofconcept assay all 10 samples showed weak enzyme activity while control samples heated to the MPI standard produced no enzyme activity Normally the test detects activity of the enzyme glucose phosphate isomerase (GPI) but additional testing showed that GPI was inactive A possible source of the activity was a bacterial enzyme The results suggested the product had not been retorted to the MPI standard
Can bees eavesdrop on biosecurity targets
Authors: Mas F.A. , Suckling D.M. , Welsh T.J. , Horner R.M. , Henderson C.B. , Bromenshenk J.J.
Published: October 2019

Surveillance of unwanted organisms without lures is one of the greatest challenges in biosecurity Previous work in the USA has shown that honey bees (Apis mellifera) can be trained to detect land mines Based on this successfully proven method the possibility of detecting key species of agricultural and biosecurity interest in a field environment was examined Application examples presented here include detection of a weed in a crop such as rosemary (Rosmarinus officinalis) in wheat and detection of the Argentine ant (Linepithema humile) in a field Bees were trained at the colony level on the specific odours of each target and their ability to locate these odours in the field was measured with video cameras Bees were able to detect rosemary hidden in a wheat crop and the cluster of four plants attracted significantly more bees than the positive and negative controls Similarly bees were shown to learn to detect the Argentine ant (Linepithema humile) trail pheromone z9hexadecenal and their response ranged down to partspertrillion (ppt 1012) However there was a clear preference for higher concentrations that may be associated with higher expected rewards Detection thresholds and the sensitivity of bees are discussed
Sexual state of grape powdery mildew (Erysiphe necator) newly recorded for New Zealand
Authors: Johnston P.R. , Cooper J.A. , Park D. , Sutherland P.W. , Wood P.N.
Published: October 2019

Grape powdery mildew first reported in New Zealand in 1901 is widespread in New Zealand grape growing regions causing significant losses in some seasons In the summer of 2014 the sexual stage of this fungus was observed for the first time in New Zealand Subsequent surveys showed the sexual state as widespread in Gisborne Hawkes Bay and Marlborough Internationally two E necator populations are recognised Group A being asexual while Group B undergoes sexual recombination DNA was obtained from a sexual isolate from Hawkes Bay and from an asexual isolate from Canterbury and they matched Group B and Group A respectively Asexual populations overwinter in dormant buds and develop new infections at budbreak whereas sexual populations overwinter as cleistothecia (sexual fruiting bodies) with primary infections following ascospore release In Europe where both sexual and asexual populations are widespread overwintering through cleistothecia is considered most important for between season transmission The impact of this newly introduced powdery mildew population is as yet unknown but with the additional source of new season inoculum coupled with greater genetic diversity increasing the risk of fungicide resistance future control of the disease may become more difficult
Impact of Puccinia psidii on M257;ori taonga plant species
Authors: Alipia T.T. , Teulon D.A.J. , Cromey M.G. , Marsh A.T. , Viljanen-Rollinson S.L.H.
Published: October 2019

Myrtle rust caused by the pathogen Puccinia psidii sensu lato is a disease of species in the plant family Myrtaceae that is not found in New Zealand It originates in South America but it has steadily spread around the world and is now found in Australia and New Caledonia While the potential economic and environmental impact of myrtle rust establishment in New Zealand has been well documented the potential sociocultural consequences including those for M257;ori have not All New Zealand Myrtaceae species including indigenous species are at risk from P psidii infection but the potential impact on their health is not known All indigenous Myrtaceae species can be considered as Taonga (or treasure) by M257;ori who have utilised the properties (eg spiritual medicinal construction tools food) of some species in many ways both tangible and intangible Optimally preparedness and response plans for a myrtle rust incursion in New Zealand should consider the unique spiritual and other values that M257;ori associate with these plants
A study of codling moth (Cydia pomonella) parasitism by Ascogaster quadridentata in a derelict apple orchard
Authors: Shaw P.W. , Wallis D.R.
Published: October 2019

Ascogaster quadridentata (Hymenoptera Braconidae) is a codling moth parasitoid native to Europe and established in New Zealand following introductions from the UK in the 1930s Ascogaster quadridentata parasitises the eggs of codling moth and develops and overwinters throughout the larval period of the host finally emerging from the host larval cocoon in spring As a result of its slow development the parasitoid does not protect the fruit from larval feeding damage Codling moth larvae in overwintering cocoons concealed under bark on apple trees were collected from a derelict orchard in Upper Moutere Nelson Larvae (n117) were carefully extracted from their cocoons and introduced into rolls of corrugated cardboard to complete their development Eightyeight larvae were successfully reared and 37 of these (42) were parasitized by A quadridentata This result is similar to a limited number of other records for this parasitoid in New Zealand and indicates that A quadridentata assists in reducing high populations of codling moth in derelict orchards or wild apple trees which are the main source for codling moth infestations in nearby commercial orchards
Effect of temperature on flight initiation in Mastrus ridens
Authors: Davis V.A. , Sandanayaka W.R.M , Chhagan A. , Charles J.G.
Published: October 2019

Mastrus ridens (Horstmann) (Hymenoptera Ichneumonidae) is a gregarious ectoparasitoid of cocooned larvae of codling moth Cydia pomonella (L) (Lepidoptera Tortricidae) This host stage is available for parasitism by M ridens (which is not known to diapause) throughout winter and early spring A study was conducted at ambient field temperatures during this period to investigate the minimum temperature required for flight initiation by M ridens Ten female and 10 male adults (37 days old) from the laboratory were transferred into two containers and placed in an apple orchard for 1 h for temperatures to equilibrate The container was then opened inside a large net cage and the numbers of parasitoids that flew into the cage at different temperatures were recorded The experiment release periods while establishing the parasitoid throughout New Zealand and (2) determine when the females are first active in spring before the codling moth larvae pupate
Onorchard habitats for Nysius huttoni an important kiwifruit passenger pest
Authors: Rowe C.A. , Hill M.G. , Logan D.P.
Published: October 2019

Nysius huttoni is a native species of wheat bug which is an occasional quarantine pest on export kiwifruit Wheat bug has a wide range of host plants including wheat and brassica crops as well as many weed species The kiwifruit harvest of 2013 had a high incidence of wheat bug finds on fruit in packhouses In response an orchard survey was undertaken to identify orchard habitats used by wheat bug Twentyfive orchards where wheat bug was found during packing in 2013 were surveyed from the Te Puke area from February to March At each orchard four habitats were searched (1) ground vegetation under the kiwifruit canopy (2) the loadout zone (3) edge of the loadout zone and (4) grassland surrounding the was found in and around the loadout zone associated with weed species notably Polygonum aviculare the dominant weed species in loadout zones No wheat bug was found under the kiwifruit canopy and the remaining 4 were found in grassland This preliminary survey suggests that the risk of wheat bug infestation can be reduced considerably by keeping loadout zones free of weeds during spring and summer
Larval development of the plantainfeeding moth Scopula rubraria (Doubleday) (Lepidoptera Geometridae)
Authors: Philip B.A. , Ferguson C.M.
Published: October 2019

Tonic plantain has become a popular forage crop but several Lepidoptera species not traditionally considered pests have caused significant damage in some stands At least two species of looper caterpillars (Family Geometridae) commonly referred to as plantain moths Scopula rubraria and Epyaxa rosearia have been associated with serious defoliation Both are thought to be New Zealand native species with S rubraria also present in Australia Leafroller caterpillars (Family Tortricidae) Merophyas leucaniana (New Zealand native) and M divulsana (Australian species) have also been found damaging plant crowns Scopula rubraria were collected from a Manawatu plantain/grass sward A laboratory colony was Five larval instars for both sexes were observed; mean weights at the start of each instar were 004 032 164 460 and 995 mg Most larval growth occurred in the fifth instar with mean maximum weight being 3565 mg Mean durations of each instar were 54 48 35 42 and 101 days and the total larval stage was 280 days Pupal duration averaged 118 days Resultant adults began laying eggs 12 days after eclosion and these hatched in 7 days The total length of the life cycle was approximately 49 days
Retrospective host specificity testing of Cotesia urabae to assess the risk posed to the New Zealand nolid moth Celama parvitis
Authors: Avila G.A. , Withers T.M. , Holwell G.I.
Published: October 2019

Additional retrospective testing of the gum leaf skeletoniser (Uraba lugens) biological control agent Cotesia urabae was conducted against the endemic moth Celama parvitis Although this native was included in host specificity testing before EPA approved the parasitoids release this work aimed to increase the sample size to better assess the potential risk posed The effect that different periods of host deprivation and prior oviposition experience had on the parasitoids readiness to attack was examined in a sequence of nochoice tests No parasitoids emerged from the 52 of larvae that survived to pupation thus confirming C parvitis as a nonhost Dissections of larvae that died during laboratory rearing revealed that 63 had contained a parasitoid but no C urabae parasitoid larvae developed beyond the second instar Significant differences were found in the attack times according to the parasitoids deprivation levels (age) and it was also observed that the duration until first attack significantly decreased after each nontarget presentation
Delivering Trichoderma spp spores via seed coating and storage stability at 20 and 25C
Authors: Swaminathan J. , Wilson M.J. , Jackson T.A.
Published: October 2019

Trichoderma species have been reported to augment seedling establishment and provide protection from soil borne diseases Many Trichoderma products are simply mixed into soil or compost but seed treatment offers the potential to reduce spore application rates by directly targeting the developing rhizosphere where efficacy is realised This study evaluated the ability of five formulations based on oils and/or biocompatible polymers to adhere Trichoderma spores to wheat seeds and maintain in their initial loading (colony forming units) moisture content () water activity (aw) and spore germination () Spore loading ranged from 22105 20107 spores/seed with the xanthan gumbased biopolymer formulation providing the highest loading Best survival (43 of initial loading) after 3 months of storage at 20C was recorded in the biopolymerbased formulation followed by the polyvinyl pyrrolidone formulation (24) The remaining three formulations had
The southern ladybird (Cleobora mellyi) as a new species association biocontrol agent of tomatopotato psyllid (Bactericera cockerelli)
Authors: Pugh A.R. , O'Connell D.M. , Wratten S.D.
Published: October 2019

Since its discovery in New Zealand in 2006 the tomatopotato psyllid (Bactericera cockerelli) (TPP) has emerged as a major pest of solanaceous crops In potato crops the management of TPP has predominantly relied on insecticide applications as biological control by generalist predators has been constrained by both insecticide use and temporal and spatial scales This research sought to further investigate a generalist predator already established in New Zealand the southern ladybird (Cleobora mellyi) introduced from Tasmania as a biocontrol agent for Paropsis charybdis in the 1970s and 1980s as a potential biocontrol agent of TPP The southern ladybirds prey selection ladybird longevity and ladybirdTPP predatorprey dynamics were investigated A choice test assay utilised small experimental arenas of three alternative choices between (1) TPP and green peach aphid Myzus persicae (2) TPP and potato aphid Macrosiphum euphorbiae and (3) TPP and greenhouse whitefly Trialeurodes vaporariorum Cleobora mellyi larvae and adults did not demonstrate a significant prey preference between TPP and either green peach aphid or potato aphid but did show a significant aversion to greenhouse whitefly Longevity trials consisted of a water only control and three treatments (1) a floral resource (flowering buckwheat) (2) 10 TPP/day or (3) flowering buckwheat 10 TPP/day All three treatments lived significantly longer than the water only control and southern ladybirds adults lived significantly longer when given both the floral resource and TPP compared to only being given TPP A glasshouse mesocosm study was used to investigate ladybirdTPP predatorprey dynamics Within 3 weeks the southern ladybird had significantly reduced TPP densities in the treatment in which they were present along with potato plants and TPP compared to the treatment without ladybirds a reduction that was maintained until the completion of the experiment Where there was only TPP and no ladybird no potato tubers were formed; in the presence of southern ladybird small and few potato tubers were formed while the most tubers were produced in insectfree controls This indicates a specieslevel trophic cascade This study has shown that the southern ladybird is capable of predating upon TPP and reducing densities within the controlled conditions of a glasshouse However with the current state of knowledge the southern ladybird is not likely to be a viable predator for controlling TPP in potato crops outside glasshouses in New Zealand This is due in part to the freedom to disperse in the field the economics of such large scale rearing and fundamental differences in habitat type compared to their natural environment but applications in alternative contexts cannot be ruled out
Are shelter belts potential inoculum sources for Neonectria ditissima apple tree infections
Authors: NA M.Walter , Glaister M.K. , Clarke N.R. , Lutz H. von , Eld Z. , Amponsah N.T. , Shaw N.F.
Published: October 2019

The susceptibility of plants around apple orchards to Neonectria ditissima infections in the Tasman region was determined during summer 2013/14 Shelter belt and other neighbouring plants (in the absence of shelter trees) surrounding 20 apple orchards (approximately 51 km shelter length) were identified and compared with known European canker hosts Onethird of all neighbouring plants identified were either species known to be European canker hosts or shared a genus with a known host Nine nonpomaceous plant species were selected for inoculation studies Two rasp wounds were created (July 2014) and one was inoculated with N ditissima conidia the other with mycelium Symptoms were recorded and the pathogen reisolated In February 2015 all symptomless inoculation sites were harvested to determine potential latent infections Neonectria ditissima was reisolated from 38 of inoculations including from symptomless inoculation sites The fungus could be reisolated from all species inoculated
Comparison of fire blight resistance screening protocols in two international breeding programmes
Authors: Horner M.B. , Richter K. , Peil A. , Bus V.G.M.
Published: October 2019

Experiments were carried out to compare fire blight resistance screening methodologies used in the German and New Zealand pipfruit breeding programmes The small differences between the respective screening methodologies did not result in significant differences in the incidence of fire blight infection or the amount of resistance observed in plants Differences in bacterial growth media inoculum suspension and inoculation technique did not have a significant effect on the incidence of fire blight infection or the extent of resistance expression in various apple cultivars Some of the Erwinia amylovora isolates had a significant effect on the level of disease expression on different cultivars These differences can be used as tools to identify resistance quantitative trait loci in different cultivars Results from these experiments have led to standardisation of screening methods between the two countries and provided confidence in comparing the findings of the New Zealand/German collaborative resistance research programme
Highpressurewashing to manage insect infestations on capsicums
Authors: Page-Weir N.E.M. , Jamieson L.E. , Redpath S.P. , Griffin M.J. , Olsson S.R. , Chhagan A. , Biswas P. , Woolf A.B.
Published: October 2019

Pests on capsicum fruit can cause market access issues resulting in costly methyl bromide fumigation High pressure washing (HPW) removes insects and other surface contaminants and has been commercialised for capsicums This paper reports on performance of a commercial HPW system and compares it to an experimental HPW system that the commercial system was based on The experimental highpressure washing system operated at 75 or 100 psi (517 or 689 kPa respectively) resulted in complete removal of aphids on capsicum fruit The commercial washer at the same pressures removed 981989 of aphids resulting in 8595 clean fruit HPW treatment increased incidence of soft rot and stem blackening with higher rot blackening at 100 psi These results indicate the potential of HPW to be included as a mitigation measure in a systems approach to improve market access for capsicum However further optimisation in a commercial setting and evidence for efficacy against other pests of capsicum such as tomato potato psyllid is required
Biology of Ostenia robusta observations on life history and behaviour
Authors: Mansfield S. , Watkins L.M. , Townsend R.J. , Chynoweth R.J.
Published: October 2019

Ostenia robusta (Hutton) is an endemic dolichopodid fly that sometimes occurs in the soil under agricultural crops and pastures Little is known about its biology and the role it may play in agroecosystems A population of these flies near Southbridge Canterbury was observed from 2013 to 2015 Adult flies emerged between December and March each year and were monitored with yellow sticky traps placed in wheat ryegrass radish and white clover crops Adults will drink water and feed on 10 honey solution under laboratory conditions but no predatory behaviour was observed and attempts to induce oviposition were unsuccessful From dissection maximum female egg load was approximately 6065 eggs Very few O robusta larvae were found in 2014 and none were associated with pupae of Costelytra zealandica (White) a result contradictory to 2012 and 2013 The diet range of larval O robusta remains unknown but this predator appears unlikely to play a significant role in the control of C zealandica
Comparison of measured and modelled wetness duration as inputs to a grape disease model
Authors: Henshall W.R. , Hill G.N. , Beresford R.M.
Published: October 2019

Measured surface wetness duration is often used in disease risk prediction models but is only available from a few weather stations Wetness can be modelled from more widely available weather station networks using other meteorological variables This study compared wetness duration measured using different methods of interpreting wetness sensor output and from different sensor types with wetness calculated from a classification and regression tree (CART) model The model calculated wetness from temperature relative humidity and wind speed Different wetness sensors and different wetness calculation methods from the same sensor made little difference to recorded wetness duration Total wetness duration was greater for modelled than for measured wetness at all but one of seven sites investigated The use of modelled and measured wetness inputs into a grape botrytis prediction model indicated that modelled wetness is unsuitable for use in New Zealand without being calibrated for local conditions
Influence of leaf age on infection of Actinidia species by Pseudomonas syringae pv actinidiae
Authors: Tyson J.L. , Horner I.J. , Curtis C.L. , Blackmore A. , Manning M.A.
Published: October 2019

The influence of leaf age on infection of Actinidia species by Pseudomonas syringae pv actinidiae (Psa) was investigated using two approaches (a) inoculation of potted Hayward and Hort16A kiwifruit plants and (b) inoculation of whole leaves in a detached leaf assay Whole plants and detached leaves were spray inoculated with Psa biovar 3 (haplotype NZV; PsaV) and maintained in a saturated environment Flecking was evident on some of the leaves 8 days after inoculation Many of the flecks later became necrotic spots with halos similar to the Psa leaf infections that have been observed in the field With both methods a higher percentage of leaves that were 13 weeks of age at inoculation had flecking and spotting than did leaves of other ages Leaves that were 7 weeks or older did not show any symptoms of infection by Psa Overall leaves of Hort16A showed slightly more flecking and spotting than Hayward
Comparative virulence of Beauveria bassiana isolates against clover root weevil (Sitona obsoletus)
Authors: Nelson T.L. , McNeill M.R. , Van_Koten C. , Goldson S.L.
Published: October 2019

Clover root weevil (Sitona obsoletus) (CRW) is of Palearctic origin and in New Zealand has become an invasive pest of white clover A major survey was undertaken in 2000 to identify and collect the most promising CRW biocontrol agents from a wide range of locations in Europe and the UK Subsequently several Beauveria bassiana strains obtained from the cadavers of weevils originally collected live from England Wales France and Romania were isolated in containment at AgResearch Lincoln Thereafter bioassays using New Zealand fieldcollected CRW populations showed that all the European isolates were virulent against the adults with two being particularly effective Notably all of the European B bassiana isolates exhibited greater virulence against CRW than a New Zealand isolate collected from local CRW populations and a commercial B bassiana product registered in the USA as Botanigardreg;
Enhanced growth of cabbage seedlings by a Paenibacillus isolate in the presence of Xanthomonas campestris pv campestris
Authors: Ghazalibiglar H. , Hampton J.G. , De_Jong E. van_Zijll , Holyoake A.
Published: October 2019

Paenibacillus spp are rhizobacteria that can promote plant growth through a range of mechanisms A New Zealand isolate of Paenibacillus P16 has reduced the incidence of black rot caused by Xanthamonas campestris pv campestris (Xcc) in brassicas To investigate if this response was provided through plant growth promotion isolate P16 was coapplied with Xcc as a seed treatment In the presence of Xcc P16treated seedlings had significantly greater root length leaf area and root and shoot dry weight compared to the positive control (Xcc alone) There were no significant differences in plant growth parameters between P16treated seedlings in the absence of the pathogen and the negative control (seeds without Xcc or P16) Isolate P16 enabled plants to survive and grow normally by preventing disease development; the mechanism of disease suppression requires further investigation
Exploring potential nontarget impacts of spinetoram against beneficial natural enemies of Eucalyptus forests
Authors: Pugh A.R. , Davis M.W. , Watson M.C. , Withers T.M.
Published: October 2019

Forest Stewardship Councilcertified Eucalyptus nitens plantations are seeking an alternative insecticide that is more compatible with biological control agents than the current broadspectrum insecticide used Various methods were trialled for evaluating spinetoram on beneficials including Enoggera nassaui an egg parasitioid of Paropsis charybdis Cleobora mellyi a predatory ladybird and Cotesia urabae a larval parasitoid of Uraba lugens While eggs could be directly sprayed very mobile larvae and adults instead had to be transferred onto recentlysprayed foliage For ladybirds the assay environment was supplemented with an artificial diet to avoid mortality from starvation These practical challenges limit the ability to confidently draw conclusions about impacts in the field Despite the limitations it can be reported that C mellyi suffered no mortality from exposure to spinetoram and females continued to lay viable eggs In contrast the endoparasitoid C urabae did not survive spinetoram treatment due to the rapid mortality of its host Both P charybdis eggs and their parasitoids developing within them appeared unharmed by spinetoram These mixed results suggest spinetoram does have potential as a possible replacement for alphacypermethrin although further investigation of efficacy in the field is needed
Survival and reproduction of Liberibacterinfected tomato potato psyllid reared under cold environmental conditions
Authors: Sandanayaka W.R.M. , Davis V.A. , Walker G.P.
Published: October 2019

The tomato potato psyllid (TPP Bactericera cockerelli) survives on volunteer potatoes growing in frostfree areas in winter in the Auckland region and therefore could transmit Candidatus Liberibacter solanacearum (Lso) to commercial crops The survival and oviposition of laboratoryreared Lsoinfected TPP were tested under four selected environmental conditions 1212 h lightdark at 10C; 1311 h lightdark at 12C; 1410 h lightdark at 14C; and 159 h lightdark at 16C on excised leaves from volunteer potatoes (grown in the field during winter) and tomato (grown in the glasshouse) One hundred pairs of adult TPP (10 pairs/leaf) were tested on either potato or tomato in each environmental condition for 7 days Survival of females on potato or tomato was not significantly different between photoperiod but remained unhatched in all tested temperatures Results revealed that Lsoinfected TPP could feed (as indicated by excretory droplets) oviposit and survive on volunteer potatoes in Auckland winterlike conditions and potentially transmit Lso to crops grown in these cooler months
The application of 980 degree days as a trigger for rapid increases in Bactericera cockerelli in Hawkes Bay solanaceae crops
Authors: Taylor N.M. , Butler R.C. , Vereijssen J.
Published: October 2019

During 200708 the tomato potato psyllid (TPP Bactericera cockerelli) was observed in outdoor tomato and potato crops in Hawkes Bay Many crops were heavily infested resulting in severe yield losses and in some cases crop abandonment Since then growers have been proactive in plant monitoring and sticky trap use but these methods are expensive and quite often a calendar spray programme is begun once the first adult TPP have been observed in traps It has been proposed that 980 degreedays (DDs) from 1 July is used as an indicator of when TPP numbers are about to increase rapidly in North Island crops This study describes the application of 980 DDs to recent sticky trap data from Hawkes Bay For most sites 980 DDs occurred just before rapid increases in adult TPP numbers However there were a small number of sites where this was not so The presence of noncrop TPP host plants bordering these sites may explain rapid increases in TPP trap catches well before reaching 980 DDs
Yellow bristle grass seed killed in maize silage
Authors: Trolove M.R. , Dowsett C.A.
Published: October 2019

Yellow bristle grass (Setaria pumila) is a serious weed that reduces dairy farm profitability and could potentially infest productive land throughout New Zealand Supplementary feed is used extensively in the dairy industry and farmers are concerned that yellow bristle grass seed may be spread with maize silage Previous studies showed that its seeds did not survive burial in covered silage stacks after 1 week To further investigate the decline in seed viability mesh bags containing 50 seeds were buried at 0 and/or 400 mm depth in two covered Waikato silage stacks and retrieved after 1 2 3 5 and 7 days Germination prior to seed burial was 69 and viability using tetrazolium staining was 88 Germination was reduced after 1 day to 1236 2 days to 030 3 days to 04 and 5 days to 0 Viability was reduced after 1 week from 50 to 40 Temperature and pH conditions during this study were not considered sufficient for rapid seed decay and therefore it appeared that chemicals released after ensiling were responsible Further investigation into mechanisms behind this rapid decay and its potential for effective weed seed control is warranted
Endophytic colonisation of perennial ryegrass by Trichoderma atroviride
Authors: Daryaei A. , Falloon R.E. , Jones E.E. , Kandula D.R.W. , Ghazalibiglar H. , Alizadeh H. , Glare T.R. , Hampton J.G.
Published: October 2019

Trichoderma spp are widely used as biocontrol agents and plant growth promoters Endophytic colonisation of perennial ryegrass (Lolium perenne) by T atroviride strains was studied in laboratory greenhouse and field experiments Four strains of T atroviride were inoculated into in vitro agar cultures or potting mix with ryegrass seeds for colonisation studies The strains were also produced as prill or granule formulations for application in the field experiment Microscopy was used to observe fungal structures in plant tissue segments from pot or fieldgrown plants Segments were also surface sterilised and placed onto Trichoderma selective media Fungal colonies recovered were verified as T atroviride by sequencing the tef1 gene No endophytic colonisation occurred in any noninoculated plants and no Trichoderma endophytic colonisation was observed in fieldgrown plants However microscopy revealed fungal hyphae and reproductive structures characteristic of Trichoderma in root and stem sheath tissues of inoculated plants from in vitro cultures and pots These results were verified by sequencing the tef1 gene This study has demonstrated endophytic colonisation of ryegrass by T atroviride strains which may be related to beneficial effects on plant growth and disease control
Antimicrobial potential of bacterial endophytes that inhabit New Zealands medicinal plant Pseudowintera colorata
Authors: Purushotham N. , Jones E.E. , Monk J. , Ridgway H.J.
Published: October 2019

Medicinal plants are valued for the naturally bioactive compounds they produce International research has demonstrated that these plants contain endophytic microorganisms that through close interaction with the plants physiology contribute to the production of host metabolites either directly or via involvement in biochemical pathways Some endophytes can produce bioactive compounds that are either the same or similar to those originating from their host plants Pseudowintera colorata (horopito or NZ pepper tree) an endemic New Zealand plant used in traditional Maori medicine (rongo257;) is recognised for its antimicrobial properties The biologically active chemical constituent polygodial is used for treating candidiasis A total of 340 endophytic bacteria were recovered from surface sterilised horopito leaves stems and roots from nine sites across New Zealand; strains were assessed for their ability to inhibit the phytopathogens Neofusicoccum parvum N luteum Ilyonectria liriodendri Nectria galligena Pectobacterium atrosepticum and P brasiliensis using a dual culture assay Inhibition zones 1048726;3 mm were considered a positive result Out of the strains tested seven showed activity against all the phytopathogenic fungi tested and ten strains were active against at least three phytopathogens Future work will determine if any of the endophytic bacteria produce polygodial
Nysius huttoni on exported kiwifruit the role of olfactory cues
Authors: Giejsztowt J. , Hill M.G. , Nielsen M-C. , Davidson M.M. , Butler R.C.
Published: October 2019

Nysius huttoni (Hemiptera Orsillidae; wheat bug) is endemic to New Zealand It is occasionally intercepted in overseas markets on exported kiwifruit jeopardising market access and leading to costly remedial processes (eg fumigation reexport) Studies have shown that N huttoni aggregate on weeds in orchard loadout areas and may gain access to kiwifruit whilst these are in wooden bins used for transport to the packhouse This behaviour may be moderated by olfactory cues The effect of olfactory cues released by kiwifruit and wooden bins (pallet wood) on the walking response of N huttoni was tested in a Ytube olfactometer over 4 months using fieldcollected adults Nysius huttoni collected in December showed no response to either of the odour cues tested Those collected during January/ February showed no response to pallet wood but they exhibited avoidance behaviour when exposed to kiwifruit odour Nysius huttoni collected during March emulated the January/February trends These results suggest that aggregations of N huttoni on wooden bins and kiwifruit during picking and transport may not be caused by olfactory cues rather from the texture of kiwifruit or bins which afford N huttoni an overwintering habitat particularly if the response of individuals in flight is similar to those walking
Flupropanate in vitro pasture species susceptibilities
Authors: Lamoureaux S.L. , Bourd?t G.W. , Noble A.D.L. , Dowsett C.A.
Published: October 2019

Flupropanate a soilactive herbicide that inhibits lipid biosynthesis has become available in New Zealand for the selective control of the stipoid grasses Nassella neesiana and N trichotoma in pasture In commercial spray operations and field trials the selectivity of the herbicide has been extremely variable As a first step towards identifying pasture species that could be safely sown following application of the herbicide the in vitro doseresponse of 33 species and cultivars (grasses and dicotyledons) was determined Ranking the cultivars based on the slopes of linear regressions fitted to their radicle lengths (relative to untreated control) against the logarithm of flupropanate dose suggested that ryegrass and Nassella spp are among the most sensitive whilst plantain chicory and some legumes including lucerne are relatively tolerant The rankings from this study will be subjected to validation in a field trial using a subset of the species
Identification and enumeration of weed seeds in chopped maize being transported for silage
Authors: James T.K. , Dowsett C.A. , Trolove M.R.
Published: October 2019

Maize silage is an important dairy feed supplement and is often transported many kilometres from where it is grown to where it is ensiled Debris has been observed to blow from the transporting trucks as they travel along the road raising concerns about the spread of weeds In this study trucks carrying freshly chopped maize were intercepted as they departed the field and samples from inside and outside the loaded crate were collected and analysed for weed seeds Seeds from 15 weed species were found in numbers up to 1300 seeds/kg of freshly chopped maize Generally more seed was found in trucks collecting from the headland area compared with the main crop area and additionally in the first year there was more debris on the outside of the headland trucks Some mitigating practices to reduce the potential for dispersal of weed seeds in chopped maize are discussed
Protection of budding wounds in apple nursery trees from European canker
Authors: Scheper R.W.A. , Stevenson O.D. , Hedderley D.I.
Published: October 2019

The fungus Neonectria ditissima can cause European canker in apple nursery trees In this study ten treatments of EMLA 9 rootstocks budded with Royal Gala were examined 5 Treatments included combinations of five budding tapes two budding methods and three fungicidal treatments Fifteen months after inoculation all Tbudded trees had died Chipbudded trees inoculated after tying with either Flexiband type C or plastic precut strips displayed significantly more canker (21 and 22 respectively) than those tied with Buddy tape (11 P
Apple washers removal of insect pests and contaminants from export apples
Authors: Rogers D.J. , Woolf A.B. , McDonald R.M. , Cole L.M. , McLeod S. , Brookfield P. , Robertson J. , Walker J.T.S.
Published: October 2019

Export markets require highquality fruit free from insects and mites of quarantine significance and with minimal or no agrichemical residues This presents a challenge for New Zealands pipfruit sector when developing novel pest management systems to meet these market requirements Brushbed apple washers are an important component of a systems approach to remove insects and mites in packhouses before fruit are exported A new apple washer using multinozzle rotors significantly reduced the incidence of insects and mites on apples Weathered residues of kaolin and hydrated lime were similarly reduced by this apple washer Assessment of fruit quality after apple washing and cool storage did not identify any commercially significant quality issues on the three apple cultivars examined Apple washer design to optimise pest removal from all locations on the fruit is discussed