Application of commercially available, low-cost, miniaturised NIR spectrometers to the assessment of the sugar content of intact fruit

Recent decreases in costs, and improvements in performance, of silicon array detectors open a range of potential applications of relevance to plant physiologists, associated with spectral analysis in the visible and short-wave near infra-red (far-red) spectrum. The performance characteristics of three commercially available ‘miniature’ spectrometers based on silicon array detectors operating in the 650–1050-nm spectral region (MMS1 from Zeiss, S2000 from Ocean Optics, and FICS from Oriel, operated with a Larry detector) were compared with respect to the application of non-invasive prediction of sugar content of fruit using near infra-red spectroscopy (NIRS). The FICS–Larry gave the best wavelength resolution; however, the narrow slit and small pixel size of the charge-coupled device detector resulted in a very low sensitivity, and this instrumentation was not considered further. Wavelength resolution was poor with the MMS1 relative to the S2000 (e.g. full width at half maximum of the 912 nm Hg peak, 13 and 2 nm for the MMS1 and S2000, respectively), but the large pixel height of the array used in the MMS1 gave it sensitivity comparable to the S2000. The signal-to-signal standard error ratio of spectra was greater by an order of magnitude with the MMS1, relative to the S2000, at both near saturation and low light levels. Calibrations were developed using reflectance spectra of filter paper soaked in range of concentrations (0–20% w/v) of sucrose, using a modified partial least squares procedure. Calibrations developed with the MMS1 were superior to those developed using the S2000 (e.g. coefficient of correlation of 0.90 and 0.62, and standard error of cross-validation of 1.9 and 5.4%, respectively), indicating the importance of high signal to noise ratio over wavelength resolution to calibration accuracy. The design of a bench top assembly using the MMS1 for the non-invasive assessment of mesocarp sugar content of (intact) melon fruit is reported in terms of light source and angle between detector and light source, and optimisation of math treatment (derivative condition and smoothing function).

Near infrared reflectance as a rapid and inexpensive surrogate measure for fatty acid composition and oil content in peanuts (Arachis hypogaea L.)

The fatty acid composition of ground nuts (Arachis hypogaea L.) commonly known as peanuts, is an important consideration when a new variety is being released. The composition impacts on nutrition and, importantly, self-life of peanut products. To select for suitable breeding material, it was necessary to develop a rapid, non-derstructive and cost-efficient method. Near infrared spectroscopy was chosen as that methodology. Calibrations were developed for two major fatty-acid components, oleic and linoleic acids and two minor components, palmitic and stearic acids, as well as total oil content. Partial least squares models indicated a high level of precision with a squared multiple correlation coefficient of greater than 0.90 for each constitutent. Standard errors for prediction for oleic, linoleic, palmitic, stearic acids and total oil content were 6.4%, 4.5%, 0.8%, 0.9% and 1.3% respectively. The results demonstrated that reasonable calibrations could be developed to predict oil composition and content of peanuts for a breeding programme.

Designing better on-farm research in Australia using a participatory workshop process

There are renewed calls for end-user participation and the integration of local knowledge in agricultural research. In Australia, the response has included an increased emphasis on participatory on-farm research with farmers and commercial agronomists that tests accepted principals to answer practical local farming questions. However, this pursuit of greater relevance has often led to compromises in research designs, unclear results and frustration amongst farmers, commercial agronomists and Research Development and Extension (RDE) agency researchers. This paper reports on a series of pre-season planning workshops from `Doing successful on-farm research', a workshop-based initiative that provides guidelines and a series of interactive activities to plan better participatory on-farm research. The workshop approach helps people design on-farm research that is appropriate to their own needs and local conditions. It assists them to clearly identify their issues, develop specific research questions and decide the best approach to answer those questions with the appropriate rigour for their own situations. These `Doing successful on-farm research' workshops address four potential deficiencies in on-farm research and farming systems RDE more generally in Australia: (1) variable participation of scientists and farmers in on-farm research; (2) the lack of clear guidelines for effective participatory practice and on-farm research; (3) limited support for on-farm research beyond the intensive investigations conducted by RDE agencies and (4) limited support for industry and farmers to contextualise information and research outcomes for specific individual circumstances and faster adaptation of technology. This may be a valuable contribution to balancing the demands for both relevance and rigour in on-farm research in Australia. In "Ground–breaking Stuff’- Proceedings of the 13th Australian Society of Agronomy Conference, 10-14 September 2006, Perth, Western Australia.

Characterization of tree-to-tree variation in morphological, nutritional and medicinal properties of Canarium indicum nuts

As part of a feasibility study of the commercialization potential of C. indicum nuts as Agroforestry Tree Products in Papua New Guinea, preliminary characterization studies have examined the tree-to-tree variation in morphological traits (nut and kernel mass and kernel:nut ratio), as well as nutritional (carbohydrate, fat, protein, sodium, vitamin E) and medicinal traits (anti-oxidant activity, anti-inflammatory activity and phenolic content) of kernels from 18 to 72 trees in a small number of different villages of Papua New Guinea (East New Britain Province). There was continuous variation in these traits indicating opportunities for multiple trait cultivar development targeted at food and pharmaceutical markets. Certain traits, for example anti-inflammatory activity, in which tree-to-tree variation was highly significant, present greater opportunities than others, such as saturated:unsaturated fatty acid ratio. This intraspecific variation was greater within populations than between populations. The data presented has allowed the development of a strategy to domesticate C. indicum for cultivation in homegardens and cocoa-coconut agroforests, using a participatory approach aimed at the production of agroforestry tree products (AFTPs) to empower small-holders and enhance their livelihoods and income.

Carotenoid and vitamin content of Karat and other Micronesian banana cultivars.

We previously found high carotenoid levels in Karat and other Micronesian bananas, indicating potential importance for alleviating vitamin A deficiency and other nutritionally related health problems in the Federated States of Micronesia. Past work focused on carotenoid and mineral analyses, whereas here we investigated 16 cultivars (most not previously analysed) for a broader micronutrient profile, including seven vitamins. Karat carotenoid levels were higher than in previous analyses, confirming Karat as exceptionally carotenoid-rich. We identified an additional 10 carotenoid-rich cultivars, expanding the range having potential for alleviating vitamin A deficiency. A striking finding is the high riboflavin level in Karat, including high levels of uncharacterized flavonoids. Niacin and α-tocopherol are at levels that may contribute importantly to dietary intake within normal patterns of consumption. These data present a more complete basis for promoting the nutritional benefits of these banana cultivars where they are consumed in the Pacific, and potential benefits for promoting elsewhere.

Carotenoid content and flesh color of selected banana cultivars growing in Australia.

Background: The problems of vitamin A deficiency and chronic diseases have emerged in recent years in some countries in the Micronesian region. These problems are associated with the dietary shift towards imported processed foods and lifestyle changes. Research in the Federated States of Micronesia indicates that yellow- and orange-fleshed banana cultivars contain significant levels of provitamin A carotenoids. Objective: To identify further banana cultivars that may be promoted to alleviate vitamin A deficiency among children and women and chronic disease problems among adults. Methods: Ripe fruit of banana cultivars growing in Australia (sourced mostly from a field research collection) were assessed for carotenoid content and flesh color. Ten cultivars with yellow or yellow/orange flesh color (including common cultivars of Southeast Asia and the Pacific Islands) were selected and compared with two cream-fleshed cultivars, including Williams, of the Cavendish group, the most commonly marketed banana worldwide. Carotenoid content was analyzed by high-performance liquid chromatography (HPLC). Flesh color was analyzed by HunterLab colorimetry. Results: The yellow/orange-fleshed Asupina (a Fe'i banana) contained the highest level (1,412 μg/100 g) of trans β-carotene, the most important provitamin A carotenoid, a level more than 20 times higher than that of Williams. All 10 yellow or yellow/orange-fleshed cultivars (Asupina, Kirkirnan, Pisang Raja, Horn Plantain, Pacific Plantain, Kluai Khai Bonng, Wain, Red Dacca, Lakatan, and Sucrier) had significant carotenoid levels, potentially meeting half or all of the estimated vitamin A requirements for a nonpregnant, nonlactating adult woman within normal consumption patterns. All were acceptable for taste and other attributes. The cream-fleshed cultivars had minimal carotenoid levels. There was a positive significant correlation between carotenoid content and deeper yellow/orange coloration indicators. Conclusions: These yellow- or yellow/orange-fleshed carotenoid-rich banana cultivars should be considered for promotion in order to alleviate vitamin A deficiency and chronic disease in susceptible target communities and to provide variety and enjoyment as exotic fruits in both developing and industrialized countries.

Genetic control of wheat quality: interactions between chromosomal regions determining protein content and composition, dough rheology, and sponge and dough baking properties

While the genetic control of wheat processing characteristics such as dough rheology is well understood, limited information is available concerning the genetic control of baking parameters, particularly sponge and dough (S&D) baking. In this study, a quantitative trait loci (QTL) analysis was performed using a population of doubled haploid lines derived from a cross between Australian cultivars Kukri x Janz grown at sites across different Australian wheat production zones (Queensland in 2001 and 2002 and Southern and Northern New South Wales in 2003) in order to examine the genetic control of protein content, protein expression, dough rheology and sponge and dough baking performance. The study highlighted the inconsistent genetic control of protein content across the test sites, with only two loci (3A and 7A) showing QTL at three of the five sites. Dough rheology QTL were highly consistent across the 5 sites, with major effects associated with the Glu-B1 and Glu-D1 loci. The Glu-D1 5 + 10 allele had consistent effects on S&D properties across sites; however, there was no evidence for a positive effect of the high dough strength Glu-B1-al allele at Glu-B1. A second locus on 5D had positive effects on S&D baking at three of five sites. This study demonstrated that dough rheology measurements were poor predictors of S&D quality. In the absence of robust predictive tests, high heritability values for S&D demonstrate that direct selection is the current best option for achieving genetic gain in this product category.

Measuring and predicting canopy nitrogen nutrition in wheat using a spectral index—The canopy chlorophyll content index (CCCI).

Varying the spatial distribution of applied nitrogen (N) fertilizer to match demand in crops has been shown to increase profits in Australia. Better matching the timing of N inputs to plant requirements has been shown to improve nitrogen use efficiency and crop yields and could reduce nitrous oxide emissions from broad acre grains. Farmers in the wheat production area of south eastern Australia are increasingly splitting N application with the second timing applied at stem elongation (Zadoks 30). Spectral indices have shown the ability to detect crop canopy N status but a robust method using a consistent calibration that functions across seasons has been lacking. One spectral index, the canopy chlorophyll content index (CCCI) designed to detect canopy N using three wavebands along the "red edge" of the spectrum was combined with the canopy nitrogen index (CNI), which was developed to normalize for crop biomass and correct for the N dilution effect of crop canopies. The CCCI-CNI index approach was applied to a 3-year study to develop a single calibration derived from a wheat crop sown in research plots near Horsham, Victoria, Australia. The index was able to predict canopy N (g m-2) from Zadoks 14-37 with an r2 of 0.97 and RMSE of 0.65 g N m-2 when dry weight biomass by area was also considered. We suggest that measures of N estimated from remote methods use N per unit area as the metric and that reference directly to canopy %N is not an appropriate method for estimating plant concentration without first accounting for the N dilution effect. This approach provides a link to crop development rather than creating a purely numerical relationship. The sole biophysical input, biomass, is challenging to quantify robustly via spectral methods. Combining remote sensing with crop modelling could provide a robust method for estimating biomass and therefore a method to estimate canopy N remotely. Future research will explore this and the use of active and passive sensor technologies for use in precision farming for targeted N management.

RIRDC PRJ000044 - Folate content of Asian vegetables

This study will first institute an improved methodology for folate content and folate isomer composition which will then be used to provide information on the folate content and composition of a range of Asian vegetables. This will allow the development of improved production and processing approaches as well as generate promotional material to increase consumer awareness and knowledge and increase sales of these products.

Improving the quality of kikuyu by reducing the lignin content

Development of improved pasture grass via chemical mutagenesis and selection of mutations in lignin genes.

Participatory adaptation and mitigation strategies for climate change on mixed farms

The project uses participatory methods to engage primary producers and advisers in central Queensland, southern Queensland, and north east New South Wales on-farm trials and demonstrations to adapt mixed farming systems to changed climate conditions. The focus is adaptation to climate change but will support abatement of greenhouse gas emissions by building soil carbon, better managing soil nitrogen and soil organic carbon. Data will be collected and integrated with data from Round 1 of the Climate Change Research Program to extend industry understanding beyond a general awareness of ‘climate change’. Nitrous oxide and soil carbon data will help farmers/advisers understand the implications of climate change and develop adaptation strategies for a more sustainable, climate sensitive future.

Folate Content of Asian Vegetables

Folates are one of the most nutritionally significant vitamins. Natural sources of folate are reportedly more effective than supplementation or fortification with folic acid. Green leafy vegetables are excellent sources of folates which occur naturally in many forms or vitamers. With an expanding range of Asian vegetables and increasing consumer awareness and acceptance, it is timely to present information on the health attributes of these vegetables.

Cat's claw creeper vine, Macfadyena unguis-cati (Bignoniaceae), invasion impacts: comparative leaf nutrient content and effects on soil physicochemical properties

Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) is a major environmental weed in coastal Queensland, Australia. There is a lack of quantitative data on its leaf chemistry and its impact on soil properties. Soils from infested vs uninfested areas, and leaves of M. unguis-cati and three co-occurring vine species (one exotic, two native) were collected at six sites (riparian and non-riparian) in south-eastern Queensland. Effects of invasion status, species, site and habitat type were examined using univariate and multivariate analyses. Habitat type had a greater effect on soil nutrients than on leaf chemistry. Invasion effect of M. unguis-cati on soil chemistry was more pronounced in non-riparian than in riparian habitat. Significantly higher values were obtained in M. unguis-cati infested (vs. uninfested) soils for ~50% of traits. Leaf ion concentrations differed significantly between exotic and native vines. Observed higher leaf-nutrient load (especially nitrogen, phosphorus and potassium) in exotic plants aligns with the preference of invasive plant species for disturbed habitats with higher nutrient input. Higher load of trace elements (aluminium, boron, cadmium and iron) in its leaves suggests that cycling of heavy-metal ions, many of which are potentially toxic at excess level, could be accelerated in soils of M. unguis-cati-invaded landscape. Although inferences from the present study are based on correlative data, the consistency of the patterns across many sites suggests that M. unguis-cati may improve soil fertility and influence nutrient cycling, perhaps through legacy effects of its own litter input.