Kara May Barry

University of Tasmania ·  Tasmanian Institute of Agriculture (TIA)

The timing of ascospore release is critical in the prediction of Blackleg infection, particularly if the timing of spore release coincides with early development of canola seedlings. Historically, prediction models have used average daily temperature and an environment calibration to estimate a minimum rainfall amount to trigger development. This p...

Tasmannia lanceolata (native pepper) has been reported as susceptible to Phytophthora cinnamomi and the objective of this study was to identify variability in native pepper resistance to P. cinnamomi . Plant material was collected from native pepper populations across Tasmania (four regions) and selected commercially grown cultivars, and 47 clones...

Impacts of pest and diseases on crop productivity comprise one of the greatest existential threats to food security in the 21st century. Despite this, crop models have historically adopted an abiotic lens. Here, we reviewed previous methods aimed at modelling effects of pests on crops and revealed a dearth of integrated approaches that account for...

Pollination is essential for the production of most fruit and nut crops, yet it is often a limiting factor for both yield and product quality. Mechanical pollination (MP) systems offer the potential to increase productivity of a broad range of horticultural fruit and nut crops, and to manage the risk of reliance on current insect pollination servic...

Poor agricultural productivity has led to food shortages for smallholder farmers in Ethiopia. Agroforestry may improve food security by increasing soil fertility, crop production, and livelihoods. Agroforestry simulation models can be useful for predicting the effects of tree management on crop growth when designing modifications to these systems....

Alkaloid concentration, which represents the quality of industrial poppy, needs to be estimated in a spatially explicit manner to predict the value of crop prior to harvesting. Current practice is to estimate alkaloid concentration using destructive sampling and laboratory analysis. However, in order to estimate the value of the whole crop, a metho...

The incursion of a plant pathogen into a new geographic area initiates a series of decisions about appropriate control or eradication efforts. Incomplete, erroneous, and/or selective information may be used by diverse stakeholders to support individual goals and positions on how an incursion should be managed. We discuss the complex social, politic...

Powdery mildew (Blumeria graminis f. sp. tritici) results in serious economic loss in wheat production. Exploration of plant resistance to wheat powdery mildew over several decades has led to the discovery of a wealth of resistance genes and quantitative trait loci (QTLs). We have provided a comprehensive summary of over 200 powdery mildew genes (p...

Blumeria graminis f. sp. tritici, the causal agent of wheat powdery mildew disease, can occur at all stages of the crop and constantly threatens wheat production. To identify candidate resistance genes for powdery mildew, we performed GWAS (genome-wide association studies) on a total set of 329 wheat varieties obtained from different origins. These...

Faidherbia albida is an important tree species in the parkland agroforestry system of the Rift Valley region, central and south-eastern Ethiopia. Positive effects of F. albida on crop production are widely recognised. However, the effects of tree pruning, zone and fertiliser interactions on crop growth have not been addressed in earlier studies. A...

Zinc (Zn) occurs in high concentrations in heavy metal polluted ecosystems which are colonized by bacterial populations. Some members of these communities are attractive candidates for phytoremediation of Zn-contaminated soils as they are able to convert insoluble forms of Zn into soluble forms, making Zn available to plants as a micronutrient. How...

Agroforestry parklands are a common land-use in Ethiopia and many parts of the tropics. These systems play an important role in climate change mitigation and adaptation, through carbon (C) sequestration. However, C sequestration in both tree biomass and soil has not been extensively studied for parklands of the Central Rift Valley (CRV), Ethiopia....

A number of agroforestry models have been developed to simulate growth outcomes based on the interactions between components of agroforestry systems. A major component of this interaction is the impact of shade from trees on crop growth and yield. Capability in the agricultural production systems simulator (APSIM) model to simulate the impacts of s...

Objectives: To examine the impact of guided mindfulness practice on psychological distress and psychological capital (hope, optimism, resilience, and efficacy) in doctoral candidates. Participants: Recruitment of a convenience sample of doctoral candidates occurred in July 2015 and participants were randomly allocated to the control or intervent...

Improved prediction of poppy capsule volume is essential for optimal management of poppy crop. In order to estimate poppy capsule volume accurately using remotely sensed imagery, the selection of most appropriate models and predictor variables is essential. Multiple spectral indices with random forest (RF) regression were tested to estimate poppy c...

Biological farming practices using bio-inoculants and renewable organic supplements are being increasingly adopted by primary producers although little is known about their benefits compared to conventional fertiliser practices. Two trials were conducted on sunflower (Helianthus annuus L., ‘Dwarf Sunsation’) to compare the influence and interaction...

Unmanned aircraft system (UAS) in combination with multispectral sensors stimulate the utilisation of site-specific technologies to manage crop production according to intrafield variability. Crop monitoring requires accurate calibration. However, radiometric calibration methods in practice are difficult to implement for UAS remote sensing as every...

Psychological distress is prevalent in doctoral degree training and affects students' completion time. It is crucial to monitor the amount of distress experienced and understand the causes for it to inform the type of support most needed. This mixed method study explored challenges related to candidature, self-reported progress and measures of perc...

AMF improve propagation success Glasshouse trials were established with sweet cherry cuttings inoculated with Rhizophagus irregularis. Colonization of cherry roots by AMF was detected in 27.9 to 61.3% of root lengths examined, while no colonisation was found in the un-inoculated plants. After two months since establishment of cherry cuttings it was...

Aim: To investigate selected factors of two non-aerated compost teas and mechanisms that influence the restriction of several fungal potato pathogens. Methods and results: Two non-aerated compost teas (NCTs, commercial compost, CCT; vineyard compost, VCT) were tested for their ability to suppress potato pathogens. The VCT was more suppressive th...

The objective of this study was to estimate poppy plant height and capsule volume with remote sensing using an Unmanned Aircraft System (UAS). Data were obtained from field measurements and UAS flights over two poppy crops at Cambridge and Cressy in Tasmania. Imagery acquired from the UAS was used to produce dense point clouds using structure from...

The objective of this study was to estimate poppy plant height with remote sensing using an Unmanned Aircraft System (UAS). Data was obtained from field measurements and UAS flights over a poppy field at Cambridge, Tasmania along two transects. Biophysical measurements of plants were taken from each sample plot. Imagery acquired from the UAS was us...

Non-aerated compost teas (NCTs) are water extracts of composted organic materials and are used to suppress soil borne and foliar disease in many pathosystems. Greenhouse trials were used to test the effectiveness of NCTs to suppress potato bacterial wilt caused by Ralstonia solanacearum on plants grown in soils inoculated with a virulent isolate of...

Defoliation may initiate physiological recovery and chemical defence mechanisms that allow a plant to improve fitness after damage. Such responses may result in changes in plant resource allocation that influence growth and foliar chemistry. In this study, we investigated the nature and stability of the defoliation response of juvenile plants from...

Brown rot and grey mould cause significant losses in sweet cherry due to rot of fruit at harvest, particularly in wet years. Studies in a Tasmanian orchard found that Botrytis cinerea was associated with 95% of fruit which was symptomatic at harvest, while Monilinia spp. were not detected. Total rot at harvest varied significantly with cherry culti...

Plant hormones play key roles in defence against pathogen attack. Recent work has begun to extend this role to encompass not just the traditional disease/stress hormones such as ethylene but also the growth-promoting hormones. Strigolactones (SLs) are the most recently defined group of plant hormones with important roles in plant-microbe interactio...

Root-rots are known to be latent diseases that may be present in plants for an extended period without any noticeable expression of symptoms above ground. Photosynthetic responses of Eucalyptus nitens saplings artificially inoculated with the root-rot pathogen, Armillaria luteobubalina were examined to characterize the initial stages of root-rot in...

Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of...

Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of...

Fungal rot of sweet cherry fruit leads to reduced yield and quality at harvest. This study investigated a range of host factors related to cherry rot and also identified the main species present in latently infected-fruit and fruit with visible rot at harvest in a Tasmanian orchard. There was a significant effect of tree cultivar on total rot found...

This work investigated the importance of the ability of leaf mesophyll cells to control K(+) flux across the plasma membrane as a trait conferring tissue tolerance mechanism in plants grown under saline conditions. Four wheat (Triticum aestivum and Triticum turgidum) and four barley (Hordeum vulgare) genotypes contrasting in their salinity toleranc...

CABALA, a productivity model for temperate plantation eucalypts, accounts for the impact of eucalypt defoliation on growth but does not yet account for differences in damage type. Consideration of both leaf and bud damage may result in a more realistic representation of growth outcomes for sites with different pest ecologies. We tested whether bud,...

Bunch rot symptoms can appear weeks after the infection of grape flowers by Botrytis cinerea. Quantitative polymerase chain reaction (qPCR) detects changes in the DNA mass of a target organism and is a potential tool for studying quiescent infections. The aim was to optimise a duplex qPCR to quantify B. cinerea DNA in the background of endogenous V...

Recovery following defoliation can be modified by co-occurring site resource limitations. The growth response of young Eucalyptus globulus saplings to two defoliation events was examined in an experimental plantation with combinations of low (-) or high (+) water (W) and nitrogen (N) resources. Artificial defoliation was applied at 3 and 9 months o...

Necrosis is one of a range of symptoms resulting from a number of different biotic and abiotic damage agents that may be detected and quantified with remote sensing as part of an operational forest health monitoring system. Mycosphaerella leaf disease (MLD) caused by Teratosphaeria spp. (formerly known as Mycosphaerella spp.) is the most common fol...

Detection of stress with remote sensing in any vegetation type relies on development of methods that highlight properties associated with stress which are discernable from background variation, such as phenological changes. Therefore the nature (and timing) of phenological foliar change needs to be systematically compared to foliar stress symptoms...

Fungal sporocarps and cultures associated with signs and symptoms of root-rot disease were collected from Acacia mangium and other tropical hardwood species. The collections were identified by either morphological characters and/or by phylogenetic analysis based on DNA sequences as Ganoderma philippii, G. mastoporum, G. aff. steyaertanum, G. austra...

This communication presents the performance of the PROSPECT leaf optical model to derive chlorophyll content (Cab) estimates from reflectance and transmittance spectra of Eucalyptus globulus foliage. Estimates were compared to measured chlorophyll of 100% acetone extractions. The analysis showed that recent modifications to the absorption coefficie...

Acacia mangium is a fast-growing tree species. It is mainly planted in large monocultures for pulpwood in South-East Asia. Root rot has become the most economically damaging disease of this species with high tree mortality rates observed during second and third rotations. Two main types of root rots have been found in A. mangium, viz. brown root-ro...

Since 1988, there has been a major focus in Tasmania on research for the management of temperate eucalypt plantations for solid wood. This coincided with the formal transfer of large areas of native forest that had previously been part of the production forest estate into reserves, a decision that triggered the establishment of eucalypt plantations...

Remote sensing for evaluation of canopy health in plantation eucalypts is a realistic option for forest managers in the near future if reliable and robust methods of spectral analysis can be developed. Pot-grown eucalypts of three species important to the Australian plantation industry were used for crown-scale spectral (400–1000 nm) evaluations of...

Wounding caused by certain silvicultural practices such as pruning and thinning can facilitate the development of wood decay. In plantation trees grown for the purpose of timber production, wood decay commonly develops from dead branches and is usually confined into the mature portion of wood than in the sound sapwood. To better predict the suscept...

Small volumes of timber are now being produced from Acacia mangium plantations in Indonesia. These trees require pruning and thinning to increase the strength and appearance of the wood. However, cut surfaces from pruning are potential infection courts for the entry of decay-causing fungi like heart rot. This study investigated the effects of pruni...

Root rot caused by Ganoderma spp. is a serious concern in commercial plantations of Acacia mangium in Indonesia. This study surveyed root rot incidence and spatial arrangement in commercial plantations and trials. In second rotation commercial plantations in Sumatra and Kalimantan, root rot incidence was recorded between 3 and 28% in trees aged fro...

Infection of heartwood by decay fungi (heartrot) is a concern for growers of Acacia mangium for solid-wood products as the incidence can be high in some regions of Indonesia. Variation of heartrot incidence for different provenances of A. mangium was determined using two field trials in Sumatra, Indonesia. In a Riau Province trial of 21 provenances...

The heartwood of Acacia mangium is vulnerable to heart rot and this is the first study to investigate the role of heartwood extractives in its susceptibility. Acacia auriculiformis was compared with A. mangium because it is rarely associated with heart rot. The heartwood extracts of both species were dominated by three flavonoids (2,3-trans-3,4′,7,...

The effect of heartwood extracts from Acacia mangium (heartrot-susceptible) and A. auriculiformis (heartrot-resistant) was examined on the growth of wood rotting fungi with in vitro assays. A. auriculiformis heartwood extracts had higher antifungal activity than A. mangium. The compounds 3,4',7,8-tetrahydroxyflavanone and teracacidin (the most abun...

Quantitative information on stem decay in eucalypt plantations grown for solid wood products, with consideration of the effect of site, pruning, and spread of decay with time, is required for the prediction of harvest yield and quality. A trial at three Eucalyptus nitens (Dean & Maiden) Maiden plantations in Tasmania revealed that the effect of tim...

The potential to use plantation-grown Acacia mangium for solid-timber products is limited by heartrot, caused by decay fungi. A rapid method of surveying logs stacked in the plantation following harvest was developed which is an alternative to time-consuming whole tree destructive assessments. Logs were randomly chosen from the stacks using a trans...

In Australia large areas of forest have been closed to industrial forestry and it is necessary to compensate for lost production. Future wood products will come from intensively managed silvicultural regimes — eucalypt regrowth forest and plantations. Solid-wood regimes involving high-cost operations such as pruning and thinning will be economicall...

This is the first report of post-harvest wood staining in blackwood (Acacia melanoxylon R. Br). In Tasmanian sawmills, an orange-brown stain commonly occurs upon cutting fresh blackwood. An investigation of the causal mechanism of stain development was completed using fresh flitches and stockpiled logs. Some fungi and bacteria were isolated from st...

In Australia large areas of forest have been closed to industrial forestry and it is necessary to compensate for lost production. Future wood products will come from intensively managed silvicultural regimes — eucalypt regrowth forest and plantations. Solid-wood regimes involving high-cost operations such as pruning and thinning will be economicall...

Pot-grown and plantation-grown Eucalyptus nitens trees (approximately 2 and 3 years old, respectively) were experimentally wounded and inoculated with different fungi and in different seasons. Decay lesion development and defence zones were assessed. Two zones were described, a narrow brown decay interface (interface reaction zone, IRZ) and a diffu...

Decay columns resulting from naturally infected pruning wounds in 5- to 8-year-old plantation-grown Eucalyptus nitens in Tasmania are interfaced by a reaction zone in the sapwood. The reaction zone is blue-purple in colour and occasionally associated with a white zone at the reaction zone/healthy sapwood interface. A log incubation experiment has s...

The first detailed analysis of the phenolic constituents of the reaction zones (tissue of antimicrobial defence) from the sapwood of a Eucalyptus spp. is presented. Plantation-grown Eucalyptus nitens trees with stem decay resulting from pruning wounds were sampled and extracts were prepared from healthy sapwood and from reaction zone tissue. Analys...

Xylem defence responses occurring in pot-grown Eucalyptus nitens(Maiden) saplings were analysed within the first few weeks following stem wounding and inoculation with the non-aggressive decay fungus Ganoderma adspersum(Schulz). The fungus colonized the dead xylem cells up to 5 mm above and below the wound after 30 days. Evidence of xylem cell deat...

Xylem defence responses occurring in pot-grown Eucalyptus nitens (Maiden) saplings were analysed within the first few weeks following stem wounding and inoculation with the non-aggressive decay fungus Ganoderma adspersum (Schulz). The fungus colonized the dead xylem cells up to 5 mm above and below; the wound after 30 days. Evidence of xylem cell d...

Heart rot in Acacia mangium is a typical white rot caused by hymenomycetes, which attack cellulose and lignin. Its development is associated with changes in colour, texture and appearance of rotted wood. These were used as the basis for the rapid assessment of the incidence and severity of heart rot on harvested log- ends in the field. The results...