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Banana production in Australia is under threat from Fusarium wilt Tropical Race 4 (TR4), and the option of growing a disease-resistant variety is sought after by many farmers. Goldfinger is one such alternative; however, it was previously rejected by Australian consumers. In Phase I of this investigation, mutagenesis was employed as a practical method to generate large numbers of novel variants. In Phase II, 631 variants were established in a field trial where agronomic and postharvest assessments, including taste-testing, identified 20 improved selections. Phase III involved a replicated field evaluation of the selections with favourable mutations, where further taste-testing revealed five selections with the most promising eating characteristics. In Phase IV, the five selections underwent large-scale consumer and sensory evaluations where four of them performed as well as the industry standard controls ‘Williams’ Cavendish and Lady Finger. The sensory analysis revealed differences in the fruit flavour profile and textural attributes, and these features will play a key role in bringing a new banana variety to market and for promotion to consumers. Screening of the variants’ resistance to yellow Sigatoka was integrated into the project, but further work is needed to ensure these four selections have retained their TR4 resistance.

Mango is a vigorous evergreen subtropical tree that is traditionally grown at a low planting density. The tree’s naturally vigorous dense canopy requires excessive pruning to maintain tree size and allow sunlight into the canopy. Excessive pruning is expensive and often reduces flowering and productivity. Improving economic production of mango through higher density planting of smaller trees has been studied for 9 years in a field experiment with four combinations of planting densities and tree training systems: low and high density untrained multi leader (conventional) (LDC, HDC respectively), medium density single leader (MDSL), and high-density espalier (HDE), each in combination with three varieties − ‘Calypso’, ‘Keitt’ and ‘NMBP–1243’. At the branch level, light transmission in each training systems was studied by partitioning branches into four quadrants from trunk to canopy edge. In each quadrant the number of leaves, terminal panicles, the number and weight of fruit and light transmission monitored over 2 years. In the HDE and MDSL trees, light transmission in the inner canopy was significantly higher than in HDC and LDC trees, and the number of terminal flowers and fruit were also higher. HDE trees had a greater number of leaves in the inner canopy. In both years, MDSL trees had significantly higher mean light transmission than all other treatments at each time of day. No significant difference was found in fruit weight at the measured branch level. © 2023 International Society for Horticultural Science. All rights reserved.

Mango flowering is interannually variable and temperature dependent. Flowering intensity declines with increasing pre-flowering temperatures associated with global warming, potentially limiting yields. Additionally, floral density that does not contribute to greater yield represents an unnecessary drain on plant resources such as nutrients, water, and carbohydrates. This can lead to reduced fruit bearing capacity in later stages of cropping or contribute to interannual yield variation. The objective of this work was to identify the floral density compensation point (FDCP), above which additional flowering becomes redundant, and below which surplus carbohydrates are partitioned to existing flowers, fruit, vegetative growth, or stored. Over two growing seasons, the number of inflorescences on 32 Calypso® mango trees in Dimbulah, Australia were thinned by up to 95%, resulting in floral densities between 0.09 and 4.14 inflorescences per trunk cross sectional area (cm2). Fruit yield, number, composition, vegetative growth, and starch concentration in terminal growth units were measured for each of the trees. Calypso® mango trees have excess floral density, beyond the maximum fruit biomass the tree can support to harvest. Below the FDCP, the tree is unable to compensate for low numbers of inflorescences, and floral density was strongly positively correlated with fruit number and yield, and strongly negatively correlated with fruit per panicle and total soluble solids concentration of ripe fruit. Above the FDCP fruit yield, number and total soluble solids concentration were only weakly related to floral density as they appear limited by carbohydrate availability rather than flowering. Fruit weight, vegetative regrowth of fruiting and non-fruiting terminals, and the starch concentration in terminal growth units were less dependent upon the FDCP and changed continuously across the floral densities evaluated. This information will be valuable for managing mango flowering unde

Mango productivity and fruit quality in Australia can be improved through transforming low-density plantings to high-density plantings and intensive training systems. Several planting density and training systems were established in Australia to investigate optimizing light interception and distribution, yield and fruit quality, and to reduce tree vigor and biennial bearing through the manipulation of canopy architecture. In this research, we studied light relations and yield in conventional low-density commercial orchards of different ages and investigated light relations and yield of ‘National Mango Breeding Program NMBP1243’, ‘Keitt’ and ‘Calypso’ grafted to ‘Kensington Pride (KP)’ rootstock in a replicated experiment. Trees were trained to five planting systems: high-density espalier and conventional, medium-density single leader and conventional, and low-density conventional. Our study in commercial orchards showed that maximum yield was ~16,000 kg/ha when light interception reached ~49% and declined at higher levels of light interception. In the high-density intensive training systems, we found that light interception increased with canopy volume, with high-density espalier training systems intercepting more available light compared to medium-density training systems and low-density conventional trees. Yield/ha increased to ~50,000 kg/ha in espalier training systems when light interception was ~40%. Light interception, canopy volume and yield/ha varied between varieties.

Trading partners often require phytosanitary or quarantine treatments for fresh horticultural produce to ensure no economically important pest species are moved with the imported product. When developing such treatments, it is essential that the level of treatment efficacy can be determined. This is often based on the mortality of the total number of target pests exposed to treatment, but in naturally infested products this number is not always known. In such cases, the infestation rate and subsequently an estimate of the number of pests are obtained directly from a set of untreated control samples of the host product. The International Plant Protection Convention (IPPC) Secretariat has provided 2 formulas for these situations that place an interval around the point estimate obtained from the control samples to obtain an estimate of the infestation rate. However, these formulas do not allow a confidence level to be assigned to the estimate, and there are concerns with the assumptions regarding the distribution and the measure of variability used in the formulas. In this article, we propose 2 alternative formulas. We propose that the lower one-sided confidence limit should be applied to all infestation datasets that are approximately normally distributed. As infestation data are sometimes skewed, it is proposed the lower one-sided modified Cox confidence limit is applied to data approximately log-normal distributed. These well-recognized formulas are compared to the formulas recommended by the IPPC and applied to 3 datasets involving natural infestation.

This year, the Australian Barramundi Farmer’s Association (ABFA) has learned how harvest teams on farms can take simple preparatory steps to ensure the quality and consistency of Australian farmed Barramundi reaching the market. Seafood scientists from the Queensland Department of Agriculture and Fisheries (DAF) have worked with the farmers that have nurtured their Barramundi for the last two years through the grow-out phase and have demonstrated through on-farm trials that the harvest phase is just as crucial. Research undertaken with farmers has shown that it is important to keep water dissolved oxygen levels above 5.0 mg/L as the fish are concentrated together beside the pond bank for harvest, particularly at high water temperatures. The next step is to have the correct number of ice slurry bins on hand to receive the tonnage the farm plans to harvest, with the correct ratio of fish, brine and ice to ensure a rapid chill. The researchers put forth these recommendations after comparing post-mortem changes in key quality indicators in Barramundi harvested at three farms in North Queensland. These were compared to results in similar fish harvested under controlled conditions at a Barramundi farm (rested versus stressed). All data gained will serve as a baseline ‘toolbox’ to compare future harvest technologies that will be adopted to progress the pursuit of quality.

Researchers from Queensland’s Department of Agriculture and Fisheries, James Cook University, and the University of Western Australia tested a range of otolith-based and genetic methods to identify hatchery-born from wild-born Barramundi. The project took place in the Dry Tropics region, where extensive historical and ongoing impoundment stocking (release of hatchery-born Barramundi into freshwater bodies) may be contributing to the downstream wild-capture marine and estuarine fishery. Fish samples were collected from the commercial and recreational wild-capture marine and estuarine fishery in 2019 and 2020, following the major Townsville floods in February 2019. The team identified a cost-effective means of using trace elements in fish otoliths to reliably distinguish hatchery-origin from wild-origin fish, measure the contribution of stocked fish to the wild population, and assess the sustainability of the wild-capture fishery.

Colletotrichum species are one of the most common causes of postharvest fruit rot in mango in Australia, particularly in the tropical region of north Queensland, and can result in significant losses if not managed. The research aims were to identify sources of anthracnose tolerance and to determine if host material other than fruit could improve or fast track the screening process and result in improved breeding efficiency. Access to the Australian National Mango Genebank (ANMG) collection enabled fruit screening of more than 100 Mangifera indica cultivars or Mangifera species for tolerance to anthracnose by artificial inoculation with Colletotrichum asianum over a period of 14 years. Mean lesion diameters were compared with those on a known susceptible M. indica cultivar Kensington Pride (KP) and a tolerant M. laurina cultivar Lombok. Inoculation of leaf discs and entire leaves was evaluated in the laboratory and the field as alternative assays for tolerance to anthracnose and was assessed by presence/absence of disease. Screening of fruit has shown that anthracnose tolerance within the mango germplasm is highly variable and needs to be assessed over multiple years. None of the alternative laboratory bioassays provided consistent or reliable data. The in-field artificial inoculation of immature leaf flush was successful but was not deemed suitable for adoption due to practical restraints. While resistance to anthracnose in fruit has not yet been identified, some cultivars and Mangifera spp. showed promise for inclusion as parents in future breeding programs.

An intensification experiment in Far North Queensland, Australia, has shown that planting Mango (Mangifera indica) orchards at high density (>1250 trees ha-1) can increase orchard productivity early in an orchard’s development. Despite this, there is little information available on the best training systems (TS) to apply in high density orchards. The aim of this research was to review three different TS (palmette, cordon and espalier systems on trellis), planted at high density (1,250 trees ha-1) to understand how TS influences canopy characteristics and yield of three different mango cultivars (‘Keitt’,’Calypso’ and ‘National Mango Breeding Program (NMBP) accession 1243’ and ‘4069’) between 2 and 5 years of age. Light interception, canopy characteristics (volume and canopy dimensions), vegetative terminals and flowering rate, tree productivity, orchard yield, and yield efficiency were compared. HD TS were compared to low-density (LD) (208 trees ha-1) and high-density (HD) (1,250 trees ha-1) trees trained using a conventional, closed vase TS of a similar age. While the alternate TS at high density led to taller and thinner canopies by 5 year-of-age, they were also characterized by lower individual tree productivity. Despite this, the increased tree density led to an increased light interception and improved orchard yields compared to the conventional LD orchards of the same age. There were also some interactions between cultivar and the alternate TS. Future research should aim to understand the mechanisms behind these results better. © 2022 International Society for Horticultural Science. All rights reserved.

In Australia, commercial tree size management in mango orchards involves annual machine hedging and heavy hand pruning. In tropical growing regions, heavy pruning often stimulates strong vegetative regrowth that is less likely to flower due to insufficient terminal growth-unit dormancy required for flowering. A few mango rootstocks have been shown to reduce scion vigour and maintain regular, high yields; however, there is a lack of rigorous field-testing of these and other rootstocks under Australian scions growing in Queensland. Apart from some scion vigour control, the effects of mango rootstocks on scion architecture have not been studied in Australia and reports in the international literature are scarce. In this study, 90 genetically diverse rootstocks have been evaluated for their ability to reduce vigour in two Australian mango scion varieties from the National Mango Breeding Program (NMBP); ‘NMBP-1243’ and ‘NMBP-4069’. Tree height, canopy volume and shape, rootstock and scion trunk cross-sectional area were measured in young trees 30 months after planting to evaluate tree growth and vigour. Branch angle, length and diameter, number of growth units, number of leaves, and leaf size were also measured to characterize scion architecture. Ten rootstocks were identified as reducing vigour while maintaining the percentage of flowering terminals per canopy volume. Four rootstocks were also found to influence scion architecture by altering secondary branch angles to be closer to horizontal, potentially making them more suited to single-leader training used in high-density orchards systems. Canopy architecture parameters measured in this study suggest that rootstocks may be a useful technique for reducing tree vigour and altering the architecture of mango scion canopies to make them more suited to intensive orchard systems. © 2022 International Society for Horticultural Science. All rights reserved.

Queensland lemons are exported at low (i.e. <3°C) temperature to meet market access protocols. While the fruit generally tolerate these conditions, skin damage consistent with chilling injury (CI) is occasionally encountered and results in significant economic and reputational loss. The robustness of fruit to withstand export handling is inherently variable and difficult to predict. This study evaluated the potential of hyperspectral imaging to detect and predict CI in fruit before it was visible to the human eye. Seeded and seedless Eureka lemons were sourced from a north Queensland orchard. They were treated with either 2.6 or 18.5 parts per million (ppm) ethylene gas at 20.4 or 28.9oC for 5 days to hasten the loss of green skin colour, as per commercial degreening practice. The degreened fruit were stored at 1.9oC for 5 weeks to simulate seafreight to export markets, followed by 10 days at 20oC to assess CI under typical retail display conditions. Spectral data was collected within 2-3 h after harvest, degreening or cold storage. Three near infrared (NIR) devices were used; Bruker Matrix-F for spot assessment; Pika NIR 320 and Pika XC2 for hyperspectral imaging, covering wavelengths from 830-2500 nm, 900-1700 nm and 400-1000 nm, respectively. The supervised classification method of linear discriminate analysis was applied to the spectra collected from the Bruker Matrix-F, whereas partial least squares discriminant analysis (PLS-DA) was used to analyse spectra and images obtained from the Pika XC2 and NIR 320 instruments. The results showed that there is potential for NIR hyperspectral imaging to predict CI in seeded and seedless Eureka lemons, when assessed after degreening and particularly after cold shipment. Spectra collected after degreening and cold storage demonstrated reasonable levels (i.e. 70%) of correct classification. The highest correct classification was obtained for scans taken after storage and is likely due to CI having been induced in the fruit.

The age of whole otoliths from barramundi (Lates calcarifer) obtained from the southern Gulf of Carpentaria were estimated using Fourier transform near-infrared (FT-NIR) spectroscopy. Otoliths from 1716 barramundi collected in 2006, 2009 and 2012–2015 were used in this study. Partial least-squares regression models (PLS-R) and multiple linear regression models (MLR) were developed from the diffuse reflectance spectra and the age was obtained from traditional sectioned otoliths. Calibration models were built up over consecutive years (2012–2015) by using a subset of the samples and used to predict the age of the remaining samples and samples from the following year. Results suggest that when seasonal (temporal) variability is incorporated into the calibration model, FT-NIR has the ability to predict barramundi age (validation R2 ranged from 0.73 to 0.78; RMSEP ranged from 6.92 to 7.64 months). The predicted age class was within 1 year of the reference age in over 96% of the samples. These models were also able to predict the age of otoliths from 2006 and 2009, which were retrieved from long-term storage (validation R2 ranged from 0.77 to 0.84; RMSEP ranged from 8.66 to 10.88 months). The results from this study have shown the potential for barramundi from the southern Gulf of Carpentaria to be aged quickly and accurately by using FT-NIR.

Mangoes are grown in over 100 countries throughout the tropical and subtropical world with a total production of over 42×106 t of fruit sold in both local and export markets. In tropical regions, mangos are typically large, vigorous, low yielding trees with very low production and harvest efficiencies. In Queensland, Australia, a collaborative research project between the Department of Agriculture and Fisheries, the University of Queensland and Hort Innovation Australia has been developing high density, intensive production orchard systems in tropical and subtropical tree fruits. The project is investigating and documenting the relationships between the key drivers of productivity orchards. In mango, the aim of this research is to radically redesign orchard systems, increasing their production efficiency and profitability. Experimental intensification using higher planting densities and single leader training of canopies has led to early gains in productivity (~47 t ha‑1 in year 4). This paper outlines some of the key relationships that are underpinning these early productivity gains in areas such as tree architecture and canopy volume, canopy training, canopy light interception and light distribution.

The effect of preharvest applications of nitrogen (N) fertiliser to mango trees during the late fruit maturation stage was investigated over 3 years (2012-2014) to determine the effects on canopy growth in 8 year-old 'Kensington Pride' (KP) mango trees grown in Queensland. The experiment consisted of six treatments where 156 g N tree-1 was applied as a single treatment, as 340 g of urea or split between three different times. The N treatments were 1) 100% of N 2 weeks postharvest (control), 2) 50% of N 2 weeks preharvest, plus 50% 2 weeks postharvest, 3) 65% 2 weeks preharvest, plus 35% 2 weeks postharvest, 4) 35% 4 weeks preharvest plus 65% 2 weeks postharvest, and 5) 65% 4 weeks preharvest, plus 35% 2 weeks postharvest. Vegetative growth was investigated at the branch, sub-branch (shoots), growth unit (GU) and leaf scales. Branches from different aspects (north, south, east and west), in the upper and lower canopy were assessed, and for 2 branch types (apical or lateral) was considered. Fruit counts were also considered at the branch level. Results showed that when 50-65% of the N was applied 2 and 4 weeks before harvest with the balance 2 weeks postharvest, the number of branches, branch length and fruit count increased. When 35% N was applied 4 weeks preharvest with the balance 2 weeks postharvest, only stem biomass was increased. Generally, branches in the upper canopy had longer sub-branches, longer and thicker, first level growth units, shorter leaf petioles and shorter and thinner leaves compared to those in the lower canopy. The SPAD N index was lowest in the northern canopy aspect. Differences were also observed between lateral and apical branches. Lateral branches had longer leaves than apical branches while apical branches had a trend for higher leaf area, stem biomass and leaf counts. There were also negative relationships between fruit count and measurements for stem biomass, leaf count and leaf area for apical branches however for lateral branches the

Panama disease caused by Fusarium oxysporum f. sp. cubense (Foc) has devastated banana production worldwide. This work aimed to determine effective disinfectants against two races of Foc, race 1 and tropical race 4 (TR4), for implementation with on-farm biosecurity procedures against this disease following the outbreak of TR4 in North Queensland in 2015. A total of 32 commercial disinfectants were screened and their activity was assessed after ≤ 30 sec, 5 min, 30 min and 24 hr of contact with a Foc suspension containing 105/ml chlamydospores without and with soil added (0.05 g/ml). Of the disinfectants tested, the quaternary ammonium compounds containing ≥ 10% active ingredient were found to be the most effective against both Foc races. These products, when used at a 1:100 dilution, completely inhibited the survival of all Foc propagules across all the contact times regardless of the absence or presence of soil. The bioflavonoids product EvoTech 213 and bleach (10% sodium hypochlorite) used at a 1:10 dilution also eliminated all Foc propagules across all the contact times. None of the detergent-based or miscellaneous products tested were completely effective against both Foc races even used at a 1:10 dilution. Soil decreases the efficacy of disinfectants and therefore must be removed from contaminated items before treatments are applied.

The amount of light intercepted by a tree and its distribution within the canopy is critical in optimizing tree photosynthesis efficiency, carbon partitioning and productivity. Here we compare light relations in experimental high-density mango orchard systems with current commercial orchards. A baseline study of current commercial mango orchards showed a maximum light interception of approximately 67% was reached in trees aged between 26-31 years old, with canopy volume of approximately 15,187 m3/ha. Light interception did not significantly increase beyond 67% regardless of increase in canopy volume per hectare or the increase in orchard age. In these conventional orchards, maximum yields were reached approximately 16 t/ha when light interception was around 49% and as light interception increased above 49%, yields declined. In the high density orchard systems, light interception increased with canopy volume, with high density systems intercepting more available light than medium and low density orchard systems. In 5 year old high-density, espalier trained trees with approximately 5000 m3/ha canopy volume, yields reached close to 50 t/ha at 40% light interception. Trees trained as single leader or espalier had more evenly distributed light in the inner canopy compared to conventionally closed vase trained trees. in current commercial orchards, increasing the canopy volume and light interception above the maximums noted above had no benefit to increase economic returns whereas in high density mango orchards with alternate tree training, yields increases more than four times early in the orchards development. Further productivity gains are likely as the experimental high density have yet to fill their allocated space in the orchard.

In 2009 the Queensland Government introduced a suite of environmental regulations aimed at reducing the amount of herbicides, fertilizers and sediment entering the Great Barrier Reef Lagoon. Staff from the Queensland Government were conducting spray-drift management workshops throughout the Wet Tropics region of far-northern Queensland when growers attending the workshops asked if it was possible to design a spray system for existing Irvin-type booms that could apply glyphosate to the interrow of sugarcane using air-induction nozzles, eliminating the need for shields or hoods. They thought that this would assist them to comply with the new regulations, as well as generally reduce use of residual herbicides. Early design and static testing commenced in October 2010 with various combinations of spray nozzles and spray bar angles tested. Prototype engineering drawings were also completed. No evidence of glyphosate toxicity to sugarcane was detected in replicated trials using the ‘Dual Herbicide Sprayer’ (DHS) in the 2012-2013 growing season. Yield data were not significantly different between plots where glyphosate was applied in the interrow and the standard grower practice of a mixture of diuron and paraquat applied over the entire paddock. Other indicators of phytotoxicity used in the trials, including stalks per metre of row, Brix, CCS, stalk diameter and height, showed no significant differences among treatments. A user manual for the DHS has been developed and is available free-of-charge to equipment manufacturers and growers. Based on sales of spray bars and new sprayers, approximately 11,000 ha are now being sprayed using DHS technology. © 2019 Australian Society of Sugar Cane Technologists. All rights reserved.

Estimating the age structure of fish populations is an important component of sustainable fisheries management. Traditional methods for ageing fish are time-consuming, labor-intensive, and expensive. Previous Australian research has shown that near-infrared spectroscopy (NIRS) has the potential to estimate the age of saddletail snapper (Lutjanus malabricus) (Wedding et al. 2014), deepwater sharks (Rigby et al. 2015, Rigby et al. 2014), barramundi (Lates calcarifer) and pink snapper (Pagrus auratus) (Robins et al. 2015). This current study investigated the effect of seasonal variability for barramundi collected from the Gulf of Carpentaria over four years, 2012-2015. Partial least squares regression (PLS-R) calibration models were developed using samples from successive years with a final model incorporating samples from all four years. The prediction statistics improved as more seasonal variability was introduced into the calibration set. Prediction statistics incorporating seasonal variability from four years with three latent variables, were r2 = 0.81, RMSEP = 7.88 and SDR = 2.3. These results indicate the potential of NIRS to predict the age of barramundi otoliths and the importance of incorporating seasonal variation into a calibration model.

Part of a project to transform subtropical/tropical tree productivity in Queensland is a study of light relations in mango (Mangifera indica) orchards in Far North Queensland. A study of the baseline relationship between light interception, canopy volume and yield in ‘Kensington Pride’ trees found that as canopy volume increased, light interception reached a maximum between 61 and 68%. The relationship between light interception and tree yield (t ha-1) varied over two years highlighting the biennial bearing habit of mango. An associated ongoing study is looking at the effects on light interception, canopy volume and yield for three mango cultivars, resulting from various planting density and tree training systems. The planting systems being studied include three planting densities: low density (208 trees ha-1, 8×6 m), medium density (450 tree ha-1, 6×4 m) and high density (1250 trees ha-1, 4×2 m) and two training systems (conventional and single leader) in three commercial mango cultivars (‘Keitt, CalypsoTM’ and ‘NMBP 1243’). The first year’s results have indicated that density and cultivar had significant effects on light interception in 1.5-year-old trees. ‘Keitt’ canopies had higher light interception than ‘CalypsoTM’ or ‘NMBP1243’, while high density plantings intercepted significantly more light. Training system also increased light interception from 1.38% in the low-density conventional planting to 9.5% in the single leader, high-density planting although this increase was not significant. There were also significant positive relationships between light interception and canopy volume (m3 ha-1). When both experiments are considered the results suggest the total light interception in 1.5-year-old, high-density trees (9.2%) was similar to the total light interception of 4-year-old trees (11.0%) in the baseline study. These results highlight the benefits of high density plantings in increasing total orchard light interception earlier than in conventional low-densi

Vigour reduction in many tree crops is an essential element of highly productive, high density systems that is often achieved through rootstocks. Mangoes are large vigorous tropical trees that are traditionally grown at low density as suitable vigour reducing technologies are not commercially available. The aim of this work was to identify rootstock cultivars for mango that reduced scion vigour while maintaining or boosting yields. Ninety rootstocks are being evaluated for their ability to reduce vigour in two Australian mango scion cultivars from the National Mango Breeding Program (NMBP); ‘NMBP-1243’ and ‘NMBP-4069’. The evaluated rootstocks were sourced from a wide genetic range within Mangifera indica and related Mangifera spp. from the Australian National Mango Gene Bank and the Australian Mango Breeding Program. Rootstock-scion combinations were field planted at Walkamin, Queensland, Australia over three years, from May 2014 in randomised incomplete blocks. Tree height, canopy depth, canopy length (along the row), canopy width (across the row), rootstock trunk diameter (10 cm above the ground and 10 cm below the graft point) and scion diameter (10 cm above the graft) were measured every six months as indicators of tree growth and vigour. This is a report on the progress of 29 rootstocks from the May 2014 planting. There was a significant (p<0.05) effect of rootstock on tree height, canopy size and trunk diameter at 24 months. Seven rootstocks were consistently among the 13 lowest vigour trees for tree height, canopy length, canopy width and scion/rootstock trunk diameters, when ranked from lowest to highest vigour. These rootstocks show promise for high-density mango orchard systems. Evaluation is ongoing and will evaluate effect of rootstock on scion flowering and cropping.

The activities of the soil microbiota are essential to the long-term sustainability of agricultural systems, through their influences on biological, chemical and physical processes, which drive essential ecosystem services. Moreover, changes in microbial communities are considered as precursors to changes in the health and viability of the soil environment, due to their responses to changes in agricultural management practices. Therefore, measurements of soil microbial activity and diversity are ideal indicators for monitoring soil status and the efficacy of soil management. However, due to the vast taxonomic diversity of soil microorganisms, analysis of microbial diversity is often problematic, time consuming and costly. Two banana experiments were established in far north Queensland, Australia, under different nutrient and groundcover management practices, to understand the dynamic changes in soil microbial communities and their effectiveness to sustain ecosystem services, such as organic matter decomposition and disease suppression. Using a functional approach, soil biological communities were analysed using trophic analysis of soil nematode communities, community level physiological profiles and enzyme activity assays. A reduction in nitrogen fertiliser inputs was related to a greater number of fungivorous nematodes which was also linked to greater suppression of Fusarium oxysporum f. sp. cubense using a novel soil-baiting bioassay. Furthermore, community-level physiological profiles enabled differentiation of soils over time demonstrating a shift in soil microbial functional diversity. The results highlight how soil management can drive differences in soil microbial activity and diversity to improve soil functions in banana production.

Queensland fruit fly, Bactrocera tryoni, is one of Australia’s most damaging fruit fly pests. Male Annihilation Technique (MAT) is a method used to manage fruit fly populations by luring and killing male flies, which limits population growth by preventing female flies from mating. MAT devices consist of an attractant and a toxicant, such as maldison or fipronil. Fipronil has a slow knockdown effect, which has been exploited to induce indirect toxicity of a number of insect pests, including cockroaches and termites. This indirect effect, called horizontal transfer, is facilitated through the sharing of food or contact with exposed individuals. Horizontal transfer has been reported in Queensland fruit fly, where exposed males have transferred lethal doses of fipronil to virgin females during courtship and mating. In the present study, we explored three possible modes of horizontal transfer of fipronil against Queensland fruit fly under laboratory conditions. These included: (1) direct contact of females with exposed males (2) contact of males to the regurgitant of exposed males and (3) contact of males with dead exposed males. Our results demonstrated that lethal doses of fipronil were not transferred from males to females during courtship and mating. Male flies that were exposed to fipronil one and six hours prior to dusk were all knocked down, moribund or dead at dusk and therefore did not participate in courtship displays or mating. However, we found that horizontal transfer and subsequent death occurred in males that fed on the regurgitant of exposed males, and in males that were in contact with dead exposed males. Therefore, MAT devices that contain fipronil should not be used as a standalone treatment but rather be used in combination with other control methods, such as protein bait sprays to ensure the control of female flies.

The activities of the soil microbiota are essential to the long-term sustainability of agricultural systems, through their influences on biological, chemical and physical processes, which drive essential ecosystem services. Moreover, changes in microbial communities are considered as precursors to changes in the health and viability of the soil environment, due to their responses to changes in agricultural management practices. Therefore, measurements of soil microbial activity and diversity are ideal indicators for monitoring soil status and the efficacy of soil management. However, due to the vast taxonomic diversity of soil microorganisms, analysis of microbial diversity is often problematic, time consuming and costly. Two banana experiments were established in far north Queensland, Australia, under different nutrient and groundcover management practices, to understand the dynamic changes in soil microbial communities and their effectiveness to sustain ecosystem services, such as organic matter decomposition and disease suppression. Using a functional approach, soil biological communities were analysed using trophic analysis of soil nematode communities, community level physiological profiles and enzyme activity assays. A reduction in nitrogen fertiliser inputs was related to a greater number of fungivorous nematodes which was also linked to greater suppression of Fusarium oxysporum f. sp. cubense using a novel soil-baiting bioassay. Furthermore, community-level physiological profiles enabled differentiation of soils over time demonstrating a shift in soil microbial functional diversity. The results highlight how soil management can drive differences in soil microbial activity and diversity to improve soil functions in banana production.

Understanding how and why canopy structural growth imposes productivity limitations is critical to managing high yielding, regular bearing mango (Mangifera indica) orchards. This study aimed to see how vegetative and reproductive growth responds to canopy management including bending. To investigate the relationship between shoot architecture, flowering and fruiting we measured structural, functional and temporal patterns of branching and flowering at the tree, scaffold and growth unit levels. Mango architectural analysis found strong varietal effects on vegetative growth, while increasing tree density led to increasing flowering across the orchard area. Single leader medium density trees had a significantly higher mean flower count (m-3 canopy volume tree-1) compared to the conventional training systems, and there was no significant difference between the densities within the conventional system. Limb bending of a parent in the single leader training systems led to an increase in the length of children growth units (bent = 16.07 cm, unbent = 12.05 cm). This paper outlines briefly the techniques used to collect architecture data and summarises the first year of vegetative and reproductive growth in each of the management scenarios. © 2018 International Society for Horticultural Science. All Rights Reserved.

Future mango orchards systems will have canopies optimally designed for tree size, density, light and crop load relationships. Poor distribution of light within mango canopies is one of the reasons for current low orchard efficiency. Light (radiation), plays an important role in driving the photosynthesis, the developmental tree morphology, crop load and fruit quality. This study established a baseline for light transmission through the canopy (distribution) in four different ages of 'Kensington Pride' trees in Queensland commercial mango orchards. Light distribution patterns were established by measuring photosynthetically active radiation (PAR) (µmol m-2 s-1) distribution in three dimensional matrix inside the canopy, at seven equally separated transects across the canopy from north to south and 4 sectors (west, middle-west, middle-east and east) on each transect at 5 heights above the ground. Mean light transmission within the canopy increased with tree age and canopy volume, and was related to pruning and training method. Highest light transmission was recorded 73.91 µmol m-2 s-1 at 75% of tree height. Light transmission was 60.90 µmol m-2 s-1 at 50% tree height, 58.23 µmol m-2 s-1 at 25% tree height and 62.81 µmol m-2 s-1 on the ground. In the horizontal plains, light distribution was lower in the middle parts of the canopy compared to the edges. There was a significant (p<0.05) relationship between light transmission and tree height, indicating large variation in light distribution within the canopy, with many leaves in shade where photosynthesis efficiency may be low. Some of the outer canopy may be receiving too much light and possible photo-inhibition as indicted by sun burn on leaves and fruit. This baseline understanding of light distribution will assist research in to improved light distribution in mango canopies and in the development of high density mango orchard systems.Future mango orchards systems will have canopies optimally designed for tree size

Three Gros Michel mutants (‘IBP 5-B’, ‘IBP 5–61’ and ‘IBP 12’) from the Cuban Instituto de Biotecnología de las Plantas, two semi-dwarf Gros Michel varieties (‘Highgate’ and ‘Cocos’) and a Thai accession (‘Hom Thong Mokho’) were evaluated in Australia over a five year period. They were screened for their resistance to Fusarium wilt Race 1 (FocR1) caused by the pathogen Fusarium oxysporum f.sp. cubense, as well as resistance to yellow Sigatoka (Pseudocercospora musae Zimm [teleomorph Mycosphaerella musicola Leach]). They were also grown for a plant and ratoon crop in the tropics (17°S) and a plant crop in the subtropics (28°S) with no disease pressure to record their agronomic characteristics. They were compared with Australian industry standards, ‘Williams’ (AAA, Cavendish subgroup) and ‘Lady Finger’ (AAB, Pome subgroup). In the subtropics the Gros Michel mutants and semi-dwarf accessions were sensitive to cold and very susceptible to FocR1 and yellow Sigatoka while their agronomic performance in the tropics was good, with ‘Highgate’ having the best bunch weight on a shorter, more manageable plant. Of the six accessions evaluated, ‘Hom Thong Mokho’ showed the highest level of resistance to FocR1 although it had poor cold tolerance, as did the other Gros Michel selections, and consequently had low productivity compared to ‘Williams’ and even ‘Lady Finger’. However in the warmer, more humid tropics ‘Hom Thong Mokho's performance was much better and it was less susceptible to yellow Sigatoka than the other Gros Michel selections. Subsequent genetic analysis by Christelová et al. (2011) has revealed that although ‘Hom Thong Mokho’ is marketed as a Gros Michel variety in Asia, it is closer to the Rio subgroup (AAA) of dessert bananas.

In-field management of Bactrocera tryoni (Froggatt) and Zeugodacus cucumis (French) (Diptera: Tephritidae) in fruiting vegetable crops has relied almost exclusively on organophosphate cover sprays. Laboratory and semifield trials were performed to compare a number of alternative insecticides for efficacy against these species. A novel semifield method was used whereby the insecticides were applied to crops as cover sprays under field conditions, and treated plants bearing fruit were transferred to large cages and exposed to fruit flies. Efficacy was assessed in terms of numbers of pupae developing from treated fruit. A laboratory cage method was also used to assess effects on adult mortality and comparative effects of 1- and 3-d-aged residues. The neonicotinoids clothianidin and thiacloprid were very effective against B. tryoni and Z. cucumis. Clothianidin was the only insecticide other than dimethoate to affect adult mortality. The synthetic pyrethroid alpha-cypermethrin was also very effective, particularly in semifield trials, although higher incidence of aphid and whitefly infestation was observed in this treatment compared to others. Cyantraniliprole was effective against B. tryoni, but less effective against Z. cucumis. Imidacloprid, bifenthrin, spinetoram, and abamectin were all relatively less effective, although all demonstrated a suppressive effect.

Productivity in temperate tree crops such as apple has been lifted several-fold by research focusing on optimising a combination of canopy components including light relations, vigour control, tree architecture and crop load. This paper outlines the research behind the Small Tree-High Productivity Initiative (STHPI), which is focused on improving productivity of mango, avocado and macadamia. Preliminary results from work we are undertaking for each of the above canopy components in mango will be outlined. A rootstock screening trial to identify vigour-managing, high-productivity rootstocks is being undertaken, and we present a comparison of the best-performing low-medium vigour rootstock varieties compared with control 'Kensington Pride' (KP) rootstock at 6 months old. Comparisons between 'Keitt', 'NMBP 1243' and 'Calypso' scion cultivars with regard to tree diameter, height and canopy growth at different orchard densities and training systems will also be presented. Preliminary results from an orchard light-relations study indicate that mango yields continued to increase with light interception up to 50%, and reached a maximum of 20-30 t ha-1 at 68% light interception in KP trees approximately 25 years old. In a crop load trial, inflorescence thinning in a 'Calypso' orchard did not significantly reduce yields when up to 90% of inflorescences were removed, but did when 95% of inflorescences were removed, as trees were unable to compensate by adjusting fruit set, size and yield. Inflorescence thinning beyond 80% increased the number of fruit set per panicle, and thinning up to and including 90% of inflorescences increased fruit weight from 340 g to ›400 g per fruit. This project is still in its initial stages; however, early indications suggest there may be opportunities to improve early orchard yields through optimising light interception in an orchard's life, potentially through the use of higher densities, and that rootstocks and tree training methods, once identi

The effects of fulvic acid as a supplement to potassium (K) applications on mango fruit quality, flower synchronisation and yield were investigated in an 8-year-old 'Kensington Pride' (KP) orchard over two seasons, at Southedge Research Station in Far North Queensland, Australia. The aim of the trial was to determine whether fulvic acid (FA) improved the efficiency of potassium uptake. Experimental treatments included i) nil K + nil FA, ii) 800 g K tree-1, and iii) 800 g K + 300 mL FA tree-1. Treatments were applied approximately every 3 weeks, after fruit set and during the fruit filling stage through to harvest. Treatment effects were assessed by measuring tree yield, fruit weight, length, depth and width, the incidence of post-harvest disease, ground skin colour at eating-ripe stage, as well as the proportion of canopy flowering in different stages in the following season. Results indicated that neither K fertiliser nor FA increased average fruit number or yield. In the first year, K combined with FA significantly increased the proportion of fruit with no lenticel spotting and the lightness of the ground skin colour of eating-ripe mangoes. By the second season, K with or without FA significantly increased the average fruit length and foliar dry-matter K concentration, while fruit weight was only marginally increased when compared to the nil K treatment. In summary, the addition of K applied during fruit development led to improved fruit size and maintenance of foliar K concentrations 2 years after application. However, although the addition of FA with K fertiliser reduced the proportion of fruit with lenticel spotting, this result was only observed in the first season of the trial and hence would require further research to confirm.

Capsicums (Capsicum annuum) were fumigated with methyl bromide (MB) at a nominal treatment dose of 18g m-3 at 18°C for 5 hours as a quarantine disinfestation treatment against Bactrocera tryoni, the Queensland fruit fly. Three large scale trials were conducted against each of the four immature lifestages, eggs and first, second and third instars. There were no survivors from the estimated 35,551 eggs, 53,720 first instars, 40,371 second instars and 43,901 third instars treated in capsicums, thereby resulting in an efficacy of >99.99% mortality at the 95% confidence level for each lifestage. Commercial fruit were also fumigated under the same conditions and then held at 6°C for 16 days or 6°C for 10 days followed by 10°C for 6 days. This was to simulate transport at 6°C followed by retail display at 10°C. Fruit quality parameters of weight loss, total soluble solids and external quality including, visual appearance, skin wrinkling, skin pitting, and incidence and severity of rots were assessed and no significant adverse treatment effects were present. This research aims to develop a new protocol for the export of Australian capsicums to New Zealand as an alternative to the current protocol of 40g m-3 MB for 2 hours at 17°C. The new protocol uses half the concentration of fumigant but applied for double the treatment time to maintain the efficacy against Queensland fruit fly a significant quarantine pest in Australia. Whilst the reduction in quantity of MB used is environmentally beneficial, the research was primarily undertaken to improve out-turn quality of the treated capsicums. The existing protocol impacts fruit quality while the lower dose tested in our research had no significant effects on the range of fruit quality attributes tested.

Breeding mango is a long-term commitment, and from time of pollination to release of a new variety can take at least 20 years. Currently, in Australia, hand-pollination is used to target traits of known parents. Field assessment of hybrid progeny currently occurs without confirmation that the progeny are from the desired selected parents. Open pollination is a more cost-effective alternative to hand pollination; however, ensuring the desired parentage and, therefore, the inheritance of targeted traits is problematic. The use of molecular markers can confirm the parentage of the hybrids, with rogues eliminated at an early stage of the assessment. In this study, 12 microsatellite markers were used to determine parentage in hand- and open-pollinated mango hybrid progeny. Over 80% of hand-pollinated hybrid individuals were successfully identified for the most likely candidate father using a strict (95%) confidence level. In open-pollinated individuals, parentage was assigned with 95% confidence to 15 samples and to almost half the population with 80% confidence or more, assuming 75% of the candidate pollen donor population had been sampled. The result indicates that simple sequence repeat (SSR) analysis is an efficient method for cultivar identification. Although marker selection will not shorten the time to evaluate hybrid progeny, it can improve breeding efficiency by allowing the culling of unwanted hybrids prior to field evaluation. Development of additional molecular markers directly associated with traits of interest will allow further selection of hybrid populations for desirable traits prior to field planting.

The effect of application timing of nitrogen to mango trees was investigated over 3 years to determine whether pre-harvest applications of N affected fruit quality, canopy growth, flowering and tree yield in 8-year-old 'Kensington Pride' (KP) and 'R2E2' mango trees growing in Far North Queensland. The experiment consisted of six treatments, where a total of 156 g N tree-1 was applied as 340 g urea at different application times and proportions. The treatments were applied as: 1) 100% postharvest at 2 weeks postharvest (control), 2) 50% 2 weeks pre-harvest plus 50% 2 weeks postharvest, 3) 35% 2 weeks pre-harvest plus 65% 2 weeks postharvest, 4) 65% 2 weeks pre-harvest plus 35% 2 weeks postharvest, 5) 35% 4 weeks pre-harvest plus 65% 2 weeks postharvest, and 6) 65% 4 weeks pre-harvest plus 35% 2 weeks postharvest. The results indicated that the pre-harvest applications of N did not significantly affect tree or orchard yield, fruit weight, size or number, nor did they negatively influence background skin colour or disease incidence at eating ripe in either cultivar, when compared with the control (100% N added postharvest). In the 'R2E2' trees, treatments 4 and 6 had an increased total panicle count. For the KP trees, pre-harvest applications of N in treatments 5, 6, 4 and 2 had increased stages of floral development when compared with the control trees, at the early stages of flowering. These results indicate that applications of N fertiliser prior to harvest can positively influence seasonal vegetative growth and early inflorescence development, but responses are cultivar specific. Therefore, N fertiliser applications can be added prior to harvest to encourage rapid floral and vegetative development after pruning without negative effects on fruit quality, particularly if N is applied as split applications at the recommended rate for tree size and cultivar.

THE USE OF controlled release and nitrification inhibiting fertilisers may improve the availability and uptake of Nitrogen (N) by sugarcane under certain soil and climatic conditions, while reducing losses via leaching, runoff and denitrification, and increasing nitrogen use efficiency. This paper utilises production and operational data from twelve Burdekin trial sites during the 2014-15 growing season to evaluate the profitability of using these fertilisers. In particular, this paper examines whether these fertilisers can maintain farmer profitability at N application rates lower than a conventional rate based on the Six Easy Steps guidelines. Out of the 12 trial sites, nine tested rates 40 kg N/ha lower and three tested rates 60 kg N/ha lower. Two controlled release blends were investigated in these trials. One treatment had 25% of total N coated with sulphur and polymer, while the other had 50% coated. For the nine sites that tested rates 40 kg N/ha lower than a conventional rate, analyses of variance were completed for each individual trial site but none identified a significant treatment effect. As all sites in each group had identical fertiliser treatments, multi-environment trial analyses were undertaken to improve statistical power. The results identified that the controlled release treatment with a 50% blend was significantly less profitable than all the other treatments except for the controlled release treatment with a 25% blend. In contrast, for the three sites comparing the conventional N rate with rates 60 kg N/ha less, treatment effects were identified at two of the three individual sites. However, the multi-environment trial analysis indicated no significant effect of treatment.

Perimeter-baiting of non-crop vegetation using toxic protein baits was developed overseas as a technique for control of melon fly, Zeugodacus (Zeugodacus) cucurbitae (Coquillett) (formerly Bactrocera (Zeugodacus) cucurbitae), and evidence suggests that this technique may also be effective in Australia for control of local fruit fly species in vegetable crops. Using field cage trials and laboratory reared flies, primary data were generated to support this approach by testing fruit flies' feeding response to protein when applied to eight plant species (forage sorghum, grain sorghum, sweet corn, sugarcane, eggplant, cassava, lilly pilly and orange jessamine) and applied at three heights (1, 1.5 and 2 m). When compared across the plants, Queensland fruit fly, Bactrocera tryoni (Froggatt), most commonly fed on protein bait applied to sugarcane and cassava, whereas more cucumber fly, Zeugodacus (Austrodacus) cucumis (French) (formerly Bactrocera (Austrodacus) cucumis), fed on bait applied to sweet corn and forage sorghum. When protein bait was applied at different heights, B. tryoni responded most to bait placed in the upper part of the plants (2 m), whereas Z. cucumis preferred bait placed lower on the plants (1 and 1.5 m). These results have implications for optimal placement of protein bait for best practice control of fruit flies in vegetable crops and suggest that the two species exhibit different foraging behaviours.

The efficacy of chlorothalonil and paraffinic oil alone and in combinations with the registered fungicides propiconazole, tebuconazole, difenoconazole, epoxiconazole and pyrimethanil was evaluated in a field experiment over two cropping cycles in 2013 and 2014 in Northern Queensland, Australia, for control of yellow Sigatoka (caused by Mycosphaerella musicola) of banana. The predominantly applied by the banana industry treatment mancozeb with paraffinic oil was included for comparison. The results from the two cropping cycles suggested that all chemicals used with paraffinic oil were as effective or more effective than when applied with chlorothalonil, and chlorothalonil alone. Difenoconazole and epoxiconazole with paraffinic oil followed by propiconazole with paraffinic oil were the most effective treatments. Pyrimethanil and tebuconazole plus chlorothalonil were the least effective treatments. None of the chemical treatments was phytotoxic or reduced yield.

Spiders are thought to play a significant role in limiting pest outbreaks in agroecosystems such as vineyards, orchards and cotton. The diversity and impact of spiders in vegetable crops are less well understood, although there is evidence that predators may be important for suppression of lepidopteran pests in Brassica crops, particularly early in the season before parasitoids become established. Sampling was conducted in early season plantings of Brassicas in the Lockyer Valley (South East Queensland, Australia) in order to determine the most commonly occurring spider families. The most numerous were Theridiidae, which were more strongly associated with cauliflower and poorly associated with cabbage. The Lycosidae and Clubionidae/Miturgidae (formerly in the ‘catch-all’ family Clubionidae) also occurred commonly. Lycosidae (and to a lesser extent Salticidae) had above average abundance in Chinese cabbage and below average abundance in broccoli compared with average abundance for these spider families; Clubionidae/Miturgidae had above average abundance in cauliflower. Laboratory studies were then conducted to explore the predatory capacity of these three most commonly occurring spider families. All three were capable of feeding on larvae of the diamondback moth, Plutella xylostella (Linnaeus), and cabbage cluster caterpillar, Crocidolomia pavonana (Fabricius), under laboratory conditions. Theridiidae, which are thought to prey on small pests such as leafhoppers and aphids, were able to successfully attack larvae up to five times their body size. Predation rates varied from an average of 1.7 (SE = 0.47) (1.6 control corrected) larvae consumed over a 24 h period in the case of the Theridiidae, to 3.3 (SE = 0.60) larvae for the Clubionidae/Miturgidae.

Bactrocera frauenfeldi (Schiner), the ‘mango fruit fly’, is a horticultural pest originating from the Papua New Guinea region. It was first detected in Australia on Cape York Peninsula in north Queensland in 1974 and had spread to Cairns by 1994 and Townsville by 1997. Bactrocera frauenfeldi has not been recorded further south since then despite its invasive potential, an absence of any controls and an abundance of hosts in southern areas. Analysis of cue-lure trapping data from 1997 to 2012 in relation to environmental variables shows that the distribution of B. frauenfeldi in Queensland correlates to locations with a minimum temperature for the coldest month >13.2°C, annual temperature range <19.3°C, mean temperature of the driest quarter >20.2°C, precipitation of the wettest month >268 mm, precipitation of the wettest quarter >697 mm, temperature seasonality <30.9°C (i.e. lower temperature variability) and areas with higher human population per square kilometre. Annual temperature range was the most important variable in predicting this species' distribution. Predictive distribution maps based on an uncorrelated subset of these variables reasonably reflected the current distribution of this species in northern Australia and predicted other areas in the world potentially at risk from invasion by this species. This analysis shows that the distribution of B. frauenfeldi in Australia is correlated to certain environmental variables that have most likely limited this species' spread southward in Queensland. This is of importance to Australian horticulture in demonstrating that B. frauenfeldi is unlikely to establish in horticultural production areas further south than Townsville.

Management of cucumber fly (Bactrocera cucumis) has relied heavily on cover sprays of broad spectrum insecticides such as dimethoate and fenthion. Long term access to these insecticides is uncertain, and their use can disrupt integrated pest management programs for other pests such as whitefly, aphids and mites. Application of a protein bait spray for fruit fly control is common practice in tree crops. However, vegetable crops present different challenges as fruit flies are thought to enter these crops only to oviposit, spending the majority of their time in roosting sites outside of the cropping area. Perimeter baiting of non-crop vegetation was developed overseas as a technique for control of melon fly (B. cucurbitae) in cucurbits in Hawaii. More recent work has refined the technique further, with certain types of perimeter vegetation proving more attractive to melon fly than the sorghum or corn crops which are commonly utilised. Trials were performed to investigate the potential of developing a similar system for cucumber fly. Commercially available fruit fly baits were compared for attractiveness to cucumber fly. Eight plant species were evaluated for their relative attractiveness to cucumber flies as roosting sites. Differences were observed in the number of flies feeding at protein bait applied to each of the plants. Results are discussed in the context of the development of a perimeter baiting system for cucumber fly in cucurbit crops.

The project aimed to evaluate the innovative application of NIRS as a reliable, repeatable, and cost-effective method of ageing fish, using otoliths of Barramundi and Snapper as study species. Specific research questions included assessing how geographic and seasonal variation in otoliths affects NIRS predictive models of fish age, as well as how the NIR spectra of otoliths change in the short-term (i.e., <12 months) and long-term (i.e., historical otolith collections) and what effect this has on the predictive ability of NIRS models. The cost-effectiveness of using NIRS to supplement standard fish ageing methods was also evaluated using a hypothetical case study of Barramundi.

Queensland fruit fly (Bactrocera tryoni) is a significant quarantine pest of stonefruit. To access domestic markets within Australia stonefruit require treatment to ensure they are free of fruit flies. Due to the recent restriction of the organophosphate pesticides, fenthion and dimethoate, the stonefruit industry now faces a significant challenge to control fruit flies. In this field trial we quantified the level of control achieved by a 'best case' systems approach that relied on currently available and registered control measures. This system included protein bait sprays, Male Annihilation Technique, insecticide cover sprays of trichlorfon, maldison and spinetoram and inspection and culling of damaged fruit. We found that in two out of the three trial orchards, packed fruit samples from Gatton (QLD) and Bangalow (NSW) had low levels of fruit fly infestation; 1.47 and 2.97% respectively. However, at the third property located at Alstonville (NSW) a high level of infestation (51.63%) was found in packed nectarines, which was likely attributed to the late implementation of the systems approach. This trial has demonstrated the potential for fruit fly control without relying on fenthion, however further modification of the system is needed to refine and increase efficacy.

In this study, a collection of 24,840 expressed sequence tags (ESTs) generated from five mango (Mangifera indica L.) cDNA libraries was mined for EST-based simple sequence repeat (SSR) markers. Over 1,000 ESTs with SSR motifs were detected from more than 24,000 EST sequences with di- and tri-nucleotide repeat motifs the most abundant. Of these, 25 EST-SSRs in genes involved in plant development, stress response, and fruit color and flavor development pathways were selected, developed into PCR markers and characterized in a population of 32 mango selections including M. indica varieties, and related Mangifera species. Twenty-four of the 25 EST-SSR markers exhibited polymorphisms, identifying a total of 86 alleles with an average of 5.38 alleles per locus, and distinguished between all Mangifera selections. Private alleles were identified for Mangifera species. These newly developed EST-SSR markers enhance the current 11 SSR mango genetic identity panel utilized by the Australian Mango Breeding Program. The current panel has been used to identify progeny and parents for selection and the application of this extended panel will further improve and help to design mango hybridization strategies for increased breeding efficiency.