Non-invasive assessment of pineapple and mango fruit quality using near infra-red spectroscopy

The potential of near infra-red (NIR) spectroscopy for non-invasive measurement of fruit quality of pineapple (Ananas comosus var. Smooth Cayenne) and mango (Magnifera indica var. Kensington) fruit was assessed. A remote reflectance fibre optic probe, placed in contact with the fruit skin surface in a light-proof box, was used to deliver monochromatic light to the fruit, and to collect NIR reflectance spectra (760–2500 nm). The probe illuminated and collected reflected radiation from an area of about 16 cm2. The NIR spectral attributes were correlated with pineapple juice Brix and with mango flesh dry matter (DM) measured from fruit flesh directly underlying the scanned area. The highest correlations for both fruit were found using the second derivative of the spectra (d2 log 1/R) and an additive calibration equation. Multiple linear regression (MLR) on pineapple fruit spectra (n = 85) gave a calibration equation using d2 log 1/R at wavelengths of 866, 760, 1232 and 832 nm with a multiple coefficient of determination (R2) of 0.75, and a standard error of calibration (SEC) of 1.21 °Brix. Modified partial least squares (MPLS) regression analysis yielded a calibration equation with R2 = 0.91, SEC = 0.69, and a standard error of cross validation (SECV) of 1.09 oBrix. For mango, MLR gave a calibration equation using d2 log 1/R at 904, 872, 1660 and 1516 nm with R2 = 0.90, and SEC = 0.85% DM and a bias of 0.39. Using MPLS analysis, a calibration equation with R2 = 0.98, SEC = 0.54 and SECV = 1.19 was obtained. We conclude that NIR technology offers the potential to assess fruit sweetness in intact whole pineapple and DM in mango fruit, respectively, to within 1° Brix and 1% DM, and could be used for the grading of fruit in fruit packing sheds.

Robustness of NIR calibrations for soluble solids in intact melon and pineapple

The soluble solids content of intact fruit can be measured non-invasively by near infrared spectroscopy, allowing “sweetness” grading of individual fruit. However, little information is available in the literature with respect to the robustness of such calibrations. We developed calibrations based on a restricted wavelength range (700–1100 nm), suitable for use with low-cost silicon detector systems, using a stepwise multiple linear regression routine. Calibrations for total soluble solids (°Brix) in intact pineapple fruit were not transferable between summer and winter growing seasons. A combined calibration (data of three harvest dates) validated reasonably well against a population set drawn from all harvest dates (r2 = 0.72, SEP = 1.84 °Brix). Calibrations for Brix in melon were transferable between two of the three varieties examined. However, a lack of robustness of calibration was indicated by poor validation within populations of fruit harvested at different times. Further work is planned to investigate the robustness of calibration across varieties, growing districts and seasons.

A towed instrument package for fisheries research in great barrier reef waters

A tethered remote instrument package (TRIP) has been developed for biological surveys over Queensland's continental shelf and slope. The present system, evolved from an earlier sled configuration, is suspended above the sea bed and towed at low speeds. Survey information is collected through video and film cameras while instrument and environmental variables are handled by a minicomputer. The operator was able to "fly" the instrument package above the substrate by using an altitude echosounder, forward-looking sonar and real-time television viewing. Unwanted movements of the viewing system were stabilized through a gyro-controlled camera-head panning system. the hydrodynamic drag of the umbilical presented a major control problem which could be overcome only by a reduction in towing speed. Despite the constraints of towing a device such as this through the coral reef environment, the package performed well during a recent biological survey where it was worked at 50% of its 350 m design depth.

Germination and hardseededness in desmanthus

The mechanisms and control of hardseededness in the 3 Australian cultivars of the genus Desmanthus were investigated in a series of experiments in which the effects of various seedsoftening treatments, particularly boiling water, were measured. Desmanthus seed is predominantly hard, only defective seeds being normally otherwise. As it has only very brief, early embryo dormancy, hardseededness is the only serious barrier to germination. Seed is most readily softened through rupture of the palisade at the lens (strophiole). The lens is of a typically mimosaceous type which is readily ruptured by immersion in boiling water or less readily by application of pressure to adjacent parts of the testa. Ruptures may consist only of separation of the palisade from underlying tissue, which alone does not confer permeability; mostly they also result in fractures to the palisade that then render seeds irreversibly permeable. The palisade becomes reflective as it separates, which allows the event to be witnessed at the moment of separation if suitable pressure is applied to the testa of an individual seed while it is viewed under magnification. Brief (4–10 seconds) immersion of highquality seed in boiling water consistently softened a high proportion of seeds without causing serious damage. Extending the duration of immersion led to a progressive increase in the proportion of seed deaths. Neither previous boiling water treatment nor scarification damage to the testa materially affected results of treatment, but immature and small seeds behaved differently, being more vulnerable to damage than mature seed, and less likely to undergo lens rupture. Adaptation of boiling water treatment to farm-scale seed handling was simple and reliable. Commercial treatment of seed by an alternative method suitable for greater bulks and consisting of passage through a rice-whitener was checked and found to be successful through a combination of gentle scarification and lens rupture, both attributable to the numerous minor impacts of the process. Percentage emergence of seedlings from soil in the greenhouse closely followed percentage laboratory germination, except when inferior seed grades were included in the comparison, when emergence was poor. Very little seed softened in soil. Already-permeable seed either germinated rapidly or died, while buried hard seed mostly remained hard and viable even more than a year after sowing.

Dynamics of plant populations in Heteropogon contortus(black speargrass) pastures on a granite landscape in southern Queensland. 2. Seed production and soil seed banks of H. contortus

Seed production and soil seed hanks of H. contortus were studied in a subset of treatments within an extensive grazing study conducted in H. contortus pasture in southern Queensland between 1990 and 1996. Seed production of H. contortus in autumn ranged from 260 to 1800 seeds/m2 with much of this variation due to differences in rainfall between years. Seed production was generally higher in the silver-leaved ironbark than in the narrow-leaved ironbark land class and was also influenced by a consistent stocking rate x pasture type interaction. Inflorescence density was the main factor contributing to the variable seed production and was related to the rainfall received during February. The number of seeds per inflorescence was unaffected by seasonal rainfall, landscape position, stocking rate or legume oversowing. Seed viability was related to the rainfall received during March. Soil seed banks in spring varied from 130 to 520 seeds/m2 between 1990 and 1995 with generally more seed present in the silver-leaved ironbark than in the narrow-leaved ironbark land class. There were poor relationships between viable seed production and the size of the soil seed bank, and between the size of the soil seed bank and seedling recruitment. This study indicates that H. contortus has the potential to produce relatively large amounts of seed and showed that the seasonal pattern of rainfall plays a major role in achieving this potential

Dynamics of plant populations in Heteropogon contortus(black speargrass) pastures on a granite landscape in southern Queensland. 1. Dynamics of H. contortus populations

The dynamics of Heteropogon contortus (black speargrass) populations were measured in a subset of treatments contained within an extensive grazing study conducted between 1990 and 1996 in H. contortus pasture in southern Queensland. This subset included 2 landscape positions and 3 stocking rates in both native pasture and legume-oversown native pasture. Severe drought conditions throughout much of the study necessitated ongoing adjustments to the original stocking rates and, as a result, drought was the major influence on the dynamics of H. contortus populations. Plant density and basal area in the silver-leaved ironbark landscape were consistently higher than those in the narrow-leaved ironbark landscape. There was limited evidence of any impact by either light or moderate stocking rate but there was evidence of an impact at the heaviest stocking rate. There was minimal impact of legume oversowing. Relatively large fluctuations in plant density occurred during this study resulting from the death of existing plants, due mainly to drought, and seedling recruitment. Similarly, there were relatively large fluctuations in basal area caused mainly by changes in plant size. Rates for turnover of plant numbers were relatively high whereas plant turnover rates of basal areas were relatively low. Regular seedling recruitment appeared necessary to ensure the persistence of this species. Despite the high turnover, populations were maintained at reasonable levels indicating the overall resilience of H. contortus.

Composition of chemical attractants affects trap catches of the Australian sheep blowfly, lucilia cuprina, and other blowflies

Numbers of Lucilia cuprina (Australian sheep blowfly), Chrysomya spp., and Calliphora spp. blowflies caught on sticky traps baited with various synthetic attractants or a standard liver/sodium sulfide attractant in western Queensland were recorded. Numbers of each genus collected were influenced by the composition of the chemical attractants. Attractant mixtures based on 2-mercaptoethanol, indole, butanoic/pentanoic acid, and a sodium sulfide solution gave 5- to 20-fold higher L. cuprina catches than the liver standard. These blends attracted similar numbers of Chrysomya spp. (0.85–2.7× ) and fewer Calliphora spp. (0.02–0.2× ) compared to the liver standard. These synthetic attractants were more effective and selective for L. cuprina than the standard liver/sodium sulfide attractant, and they can be packaged in controlled-release dispensers to generate constant, prolonged release of the attractant.

Stretching water - Queensland’s water use efficiency cotton and grains adoption program

The Cotton and Grain Adoption Program of the Queensland Rural Water Use Efficiency Initiative is targeting five major irrigation regions in the state with the objective to develop better irrigation water use efficiency (WUE) through the adoption of best management practices in irrigation. The major beneficiaries of the program will be industries, irrigators and local communities. The benefits will flow via two avenues: increased production and profit resulting from improved WUE and improved environmental health as a consequence of greatly reduced runoff of irrigation tailwater into rivers and streams. This in turn will reduce the risk of nutrient and pesticide contamination of waterways. As a side effect, the work is likely to contribute to an improved public image of the cotton and grain industries. In each of the five regions, WUE officers have established grower groups to assist in providing local input into the specific objectives of extension and demonstration activities. The groups also assist in developing growers' perceptions of ownership of the work. Activities are based around four on-farm demonstration sites in each region where irrigation management techniques and hardware are showcased. A key theme of the program is monitoring water use. This is applied both to on-farm storage and distribution as well as to application methods and in-field management. This paper describes the project, its activities and successes.

Revision of the dung beetle genus Temnoplectron Westwood (Coleoptera: Scarabaeidae: Scarabaeini)

Temnoplectron Westwood is revised and five new species described, four from North Queensland: cooki, finnigani, lewisense, monteithi, one from New Guinea: wareo. Temnoplectron reyi Paulian is removed from synonymy with T. politulum Macleay, Temnoplectron laevigatum Matthews is placed in synonymy with T. boucomonti Paulian, T. heurni Paulian and Z howdeni Paulian are synonymised with Z atropolitum Gillet, and T. major Paulian is recognised in Australia for the first time. All known species are redescribed. A key is provided for the 19 species of Temnoplectron and new distribution records are noted. A cladistic analysis of the genus is presented, the results of which suggest at least two origins for flightlessness in the genus. The biogeography of Temnoplectran is discussed with reference to isolation of rainforest blocks during periods of maximum aridity.

Five new species of Aptenocanthon Matthews (Coleoptera: Scarabaeidae: Scarabaeinae) from tropical Australia, with notes on distribution

Five new species of the flightless scarabaeine genus Aptenocanthon Matthews are described from northern Australia: jimara sp. nov. from the Northern Territory; kabura sp. nov., wollumbin sp. nov., winyur sp. nov. and speewah sp. nov. from mountains in the wet tropics of northern Queensland. A key is given to the eight species in the genus. A. jimara is the first record of the genus away from the east coast. Biology and distribution are discussed.

A new species of Aptenocanthorn Mathews from North Queensland. (Coleoptera: Scarabaeidae: Scarabaeinae)

Aptenocanthorn monteithi sp. Nov. is described from Atherton Tableland areas in northern Queensland. The nearest relatives are from mountains in eastern New South Wales.

Coriza infecciosa: revisión de métodos de diagnóstico y vacunas

La coriza infecciosa es una enfermedad respiratoria aguda de las gallinas domesti- cas causada por la bacteria Haemophilus parugallinarum. Excepcionalmente pueden enfermarse tambien los faisanes y gallinas de Guinea. El H. paragallinarum infecta al ave por via respiratoria y luego de un cor- to periodo de incubation, que varia entre 1 a 3 dias, produce una enfermedad que se manifiesta por inflamacion catarral de los senos paranasales. Este cuadro puede estar asociado a inflamacion de los barbillones, conjuntivitis o queratitis. Los casos de neu- nionia y aerosaculitis son menos frecuentes pero tambien suelen ocurrir en las infeccio- nes puras por estos hemofilos. En las gallinas en produccion causa alta morbilidad, baja o nula mortalidad y una importante perdida en la produccion de huevos, la que generalmente oscila entre 10% y 40%. En pollos parrilleros puede cau- sar un cuadro descrito como «cabeza hin- chada» y ocasionalmente tambien producir septicemia y muerte (48). Esta bacteria ge- neralmente se asocia con otros agentes bacterianos, viricos o parasitarios y cuan- do esto ocurre se agrava el curso de la en- fermedad. Entre los agentes bacterianos mas comunes deben mencionarse los mycoplasinas y las pasteurelas. Cuando H . paragallinarum se asocia con otros agentes esta enfermedad se denomina .«coriza infec- ciosa complicada» (48). En esta recopilacion se aportaran deta- lles sobre la clasificacion, identificacion y serotipificacion del agente causal. Tambien se resumira la informacion disponible sobre nuevos metodos de diagnostico y programas de vacunacion para prevenir esta enferme-dad. A lo largo de esta revision se hara re-ferencia a los hemofilos aviarios que, para el proposito de este trabajo, seran definidos como organisnios gram negativos aislados de aves y que necesariamente requieren factores de crecimiento in vitro. Los dos factores que pueden ser requeridos por los hemofilos para su crecimiento in vitro son hemina (factor X) y/o nicotin-adenin-dinucleirtido (NAD o factor V).

Improving Knowledge and Practices in Mango Supply Chains

Mangoes consigned to domestic markets suffered from fruit quality problems from 1997 to 2000. A high incidence of disease breakdown and green-ripe fruit resulted in loss of confidence by marketers, and reduced profits for everyone from grower to retailer. The ‘Better Mangoes’ project was initiated to identify where, and why quality was being lost, and to use this information to improve the knowledge and practices of supply chain businesses.

Induced Resistance: Potential for Control of Postharvest Diseases of Horticultural Crops

Fortunately, plants have developed highly effective mechanisms with which to defend themselves when attacked by potentially disease-causing microorganisms. If not, then they would succumb to the many pathogenic fungi, bacteria, viruses, nematodes and insect pests, and disease would prevail. These natural defence systems of plants can be deliberately activated to provide some protection against the major pathogens responsible for causing severe yield losses in agricultural and horticultural crops. This is the basis of what is known as ‘induced’ or ‘acquired’ disease resistance in plants. Although the phenomenon of induced resistance has been known amongst plant pathologists for over 100 years, its inclusion into pest and disease management programmes has been a relatively recent development, ie. within the last 5 years. This review will discuss very briefly some of the characteristics of the induced resistance phenomenon, outline some of the advantages and limitations to its implementation and provide some examples within a postharvest pathology context. Finally some approaches being investigated by the fruit pathology team at DPI Indooroopilly and collaborators will be outlined.

Activating Mango Fruit Defence to Anthracnose Disease

The fungus causing anthracnose disease in mango, Colletotrichum gloeosporioides, (C g.), infects immature fruit early in the season, then enters a long latent phase. After harvest, when fruit start to ripen, the latency breaks and the fungus ramifies through the peel and pulp tissues causing black disease lesions. The breaking of pathogen latency in ripening mango fruit has been correlated with decreasing concentrations of the endogenous antifungal resorcinol compounds (Droby et al., 1986). The level of these antifungal resorcinols vary among mango cultivars (Droby et a1 , 1986). Controlling diseases by managing natural resistance of fruit to fungal attack could minimize the use of pesticides, which have become of major public concern on health and environmental grounds. The plant resistance activator benzo(l,2,3)thiadiazole-7-carbothioic acid S-methyl ester (trade name Bion®) has been widely reported as an effective inducer of systemic resistance. For example, Bion® was reported to induce pathogenesis-related proteins (PR proteins) and stimulate plant defence in peas (Dann and Deverall, 2000) and roses (Suo and Leung, 2001). However, until now, there is no information about the role of Bion® in activation of mango (cv. Kensington Pride) fruit resistance to anthracnose disease. The aim of this research is to determine the effect of resistance activators on defence responses of mango fruit to anthracnose disease.