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).

Identification of QTL for sugar-related traits in a sweet x grain sorghum (Sorghum bicolor L. Moench) recombinant inbred population

QTL for stem sugar-related and other agronomic traits were identified in a converted sweet (R9188) × grain (R9403463-2-1) sorghum population. QTL analyses were conducted using phenotypic data for 11 traits measured in two field experiments and a genetic map comprising 228 SSR and AFLP markers grouped into 16 linkage groups, of which 11 could be assigned to the 10 sorghum chromosomes (SBI-01 to SBI-10). QTL were identified for all traits and were generally co-located to five locations (SBI-01, SBI-03, SBI-05, SBI-06 and SBI-10). QTL alleles from R9188 were detected for increased sucrose content and sugar content on SBI-01, SBI-05 and SBI-06. R9188 also contributed QTL alleles for increased Brix on SBI-05 and SBI-06, and increased sugar content on SBI-03. QTL alleles from R9403463-2-1 were found for increased sucrose content and sucrose yield on SBI-10, and increased glucose content on SBI-07. QTL alleles for increased height, later flowering and greater total dry matter yield were located on SBI-01 of R9403463-2-1, and SBI-06 of R9188. QTL alleles for increased grain yield from both R9403463-2-1 and R9188 were found on SBI-03. As an increase in stem sugars is an important objective in sweet sorghum breeding, the QTL identified in this study could be further investigated for use in marker-assisted selection of sweet sorghum.

Molecular characterisation, pathogenesis and fungicide sensitivity of Pythium spp. from table beet (Beta vulgaris var. vulgaris) grown in the Lockyer Valley, Queensland

Table beet production in the Lockyer Valley of south-eastern Queensland is known to be adversely affected by soilborne root disease from infection by Pythium spp. However, little is known regarding the species or genotypes that are the causal agents of both pre- and post-emergence damping off. Based on RFLP analysis with HhaI, HinfI and MboI of the PCR amplified ITS region DNA from soil and diseased plant samples, the majority of 130 Pythium isolates could be grouped into three genotypes, designated LVP A, LVP B and LVP C. These groups comprised 43, 41 and 7% of all isolates, respectively. Deoxyribonucleic acid sequence analysis of the ITS region indicated that LVP A was a strain of Pythium aphanidermatum, with greater than 99% similarity to the corresponding P. aphanidermatum sequences from the publicly accessible databases. The DNA sequences from LVP B and LVP C were most closely related to P. ultimum and P. dissotocum, respectively. Lower frequencies of other distinct isolates with unique RFLP patterns were also obtained with high levels of similarity (>97%) to P. heterothallicum, P. periplocum and genotypes of P. ultimum other than LVP B. Inoculation trials of 1- and 4-week-old beet seedlings indicated that compared with isolates of the LVP B genotype, a higher frequency of LVP A isolates caused disease. Isolates with the LVP A, LVP B and LVP C genotypes were highly sensitive to the fungicide Ridomil MZ, which suppressed radial growth on V8 agar between approximately four and thirty fold at 5 μg/mL metalaxyl and 40 μg/mL mancozeb, a concentration far lower than the recommended field application rate.

Fruit traits of vertebrate-dispersed alien plants: smaller seeds and more pulp sugar than indigenous species

Vertebrates play a major role in dispersing seeds of fleshy-fruited alien plants. However, we know little of how the traits of alien fleshy fruits compare with indigenous fleshy fruits, and how these differences might contribute to invasion success. In this study, we characterised up to 38 fruit morphology, pulp nutrient and phenology traits of an assemblage of 34 vertebrate-dispersed alien species in south-eastern Queensland, Australia. Most alien fruits were small (81%\15 mm in mean width), and had watery fruit pulps that were high in sugars and low in nitrogen and lipids. When compared to indigenous species, alien fruits had significantly smaller seeds. Further, alien fruit pulps contained more sugar and more variable (and probably greater) nitrogen per pulp wet weight, and species tended to have longer fruiting seasons than indigenous species. Our analyses suggest that fruit traits could be important in determining invasiveness and could be used to improve pre- and post-border weed risk assessment.

Increased profitability through product diversification and improved sugar quality.

The proposed simplified Integrated Sugar Production Process (ISPP) using membrane technology would allow the sugar industry to produce new product streams and higher quality mill sugar with increased sugar extraction efficiency. Membrane filtration technology has proven to be a technically sound process to increase sugar quality. However commercial viability has been uncertain partly because the benefits to crystallisation and sugar quality have not outweighed the increased processing cost. This simplified ISPP produces additional value-added liquid streams to make the membrane fractionation process more financially viable and improve the profitability of sugar manufacture. An experimental study used pilot scale membrane fractionation of clarified mill juice confirmed the technical feasibility of separating inorganic salt and antioxidant rich fractions from cane juice. The paper presents details on the compositions of the liquid streams along with their potential uses, values and challenges in getting these products out to market.

Membrane fractionation technologies for high quality mill sugar and value-added by products - an integrated sugar production process concept model.

Membrane filtration technology has been proven to be a technically sound process to improve the quality of clarified cane juice and subsequently to increase the productivity of crystallisation and the quality of sugar production. However, commercial applications have been hindered because the benefits to crystallisation and sugar quality have not outweighed the increased processing costs associated with membrane applications. An 'Integrated Sugar Production Process (ISPP) Concept Model' is proposed to recover more value from the non-sucrose streams generated by membrane processing. Pilot scale membrane fractionation trials confirmed the technical feasibility of separating high-molecular weight, antioxidant and reducing sugar fractions from cane juice in forms suitable for value recovery. It was also found that up to 40% of potassium salts from the juice can be removed by membrane application while removing the similar amount of water with potential energy saving in subsequent evaporation. Application of ISPP would allow sugar industry to co-produce multiple products and high quality mill sugar while eliminating energy intensive refining processes.

SRDC-Manufacture of a new beverage base from sugar depleted cane juice

The overall objective of the proposed project is to increase profitability through application of membrane technology.

Remote Sensing - based precision agriculture tool for the sugar industry

The project will produce practical and relevant benchmarks, protocols and recommendations for the adoption of remote sensing technologies for improved in season management and therefore production within the Australian sugar cane industry.

Soil C stocks in grains and sugar farming systems

Quantify soil C stocks in grains and sugarcane cropping systems of Queensland, including impacts of management practices.

Spatially based data delivery and recording sys-Aust Sugar Cane industry

Establish an internet platform where spatially referenced data can be viewed, entered and stored.

Improved sugar-cane farming systems

This project - Improved Sugarcane Farming Systems (BSS286) - was designed to build on the outcomes of phase 1 and 2 or the Sugar Yield Decline Joint Venture (STDJV). Thus its main focus was on issues that had been identified in the SYDJV that were not fully researched in the earlier programs and/or required further development.

Increased profitability through product diversification and improved sugar quality.

The proposed simplified Integrated Sugar Production Process (ISPP) using membrane technology would allow the sugar industry to produce new product streams and higher quality mill sugar with increased sugar extraction efficiency. Membrane filtration technology has proven to be a technically sound process to increase sugar quality. However commercial viability has been uncertain partly because the benefits to crystallisation and sugar quality have not outweighed the increased processing cost. This simplified ISPP produces additional value-added liquid streams to make the membrane fractionation process more financially viable and improve the profitability of sugar manufacture. An experimental study used pilot scale membrane fractionation of clarified mill juice confirmed the technical feasibility of separating inorganic salt and antioxidant rich fractions from cane juice. The paper presents details on the compositions of the liquid streams along with their potential uses, values and challenges in getting these products out to market. This paper was presented at the 2010 Australian Society of Sugar Cane Technologists annual conference.

Economic evaluation of precision controlled traffic farming in the Australian sugar industry: a case study of an early adopter

Controlled traffic has been identified as the most practical method of reducing compaction-related soil structural degradation in the Australian sugarcane industry. GPS auto-steer systems are required to maximize this potential. Unfortunately there is a perception that little economic gain will result from investing in this technology. Regardless, a number of growers have made the investment and are reaping substantial economic and lifestyle rewards. In this paper we assess the cost effectiveness of installing GPS guidance and using it to implement Precision Controlled Traffic Farming (PCTF) based on the experience of an early adopter. The Farm Economic Analysis Tool (FEAT) model was used with data provided by the grower to demonstrate the benefits of implementing PCTF. The results clearly show that a farming system based on PCTF and the minimum tillage improved farm gross margin by 11.8% and reduced fuel usage by 58%, compared to producers' traditional practice. PCTF and minimum tillage provide sugar producers with a tool to manage the price cost squeeze at a time of low sugar prices. These data provide producers with the evidence that investment in PCTF is economically prudent.

More fertile florets and grains per spike can be achieved at higher temperature in wheat lines with high spike biomass and sugar content at booting

An understanding of processes regulating wheat floret and grain number at higher temperatures is required to better exploit genetic variation. In this study we tested the hypothesis that at higher temperatures, a reduction in floret fertility is associated with a decrease in soluble sugars and this response is exacerbated in genotypes low in water soluble carbohydrates (WSC). Four recombinant inbred lines contrasting for stem WSC were grown at 20/10 degrees C and 11 h photoperiod until terminal spikelet, and then continued in a factorial combination of 20/10 degrees C or 28/14 degrees C with 11 h or 16 h photoperiod until anthesis. Across environments, High WSC lines had more grains per spike associated with more florets per spike. The number of fertile florets was associated with spike biomass at booting and, by extension, with glucose amount, both higher in High WSC lines. At booting, High WSC lines had higher fixed C-13 and higher levels of expression of genes involved in photosynthesis and sucrose transport and lower in sucrose degradation compared with Low WSC lines. At higher temperature, the intrinsic rate of floret development rate before booting was slower in High WSC lines. Grain set declined with the intrinsic rate of floret development before booting, with an advantage for High WSC lines at 28/14 degrees C and 16 h. Genotypic and environmental action on floret fertility and grain set was summarised in a model.

Applications of a sugar-based surveillance system to track arboviruses in wild mosquito populations

Effective arbovirus surveillance is essential to ensure the implementation of control strategies, such as mosquito suppression, vaccination, or dissemination of public warnings. Traditional strategies employed for arbovirus surveillance, such as detection of virus or virus-specific antibodies in sentinel animals, or detection of virus in hematophagous arthropods, have limitations as an early-warning system. A system was recently developed that involves collecting mosquitoes in CO2-baited traps, where the insects expectorate virus on sugar-baited nucleic acid preservation cards. The cards are then submitted for virus detection using molecular assays. We report the application of this system for detecting flaviviruses and alphaviruses in wild mosquito populations in northern Australia. This study was the first to employ nonpowered passive box traps (PBTs) that were designed to house cards baited with honey as the sugar source. Overall, 20/144 (13.9%) of PBTs from different weeks contained at least one virus-positive card. West Nile virus Kunjin subtype (WNVKUN), Ross River virus (RRV), and Barmah Forest virus (BFV) were detected, being identified in 13/20, 5/20, and 2/20 of positive PBTs, respectively. Importantly, sentinel chickens deployed to detect flavivirus activity did not seroconvert at two Northern Territory sites where four PBTs yielded WNVKUN. Sufficient WNVKUN and RRV RNA was expectorated onto some of the honey-soaked cards to provide a template for gene sequencing, enhancing the utility of the sugar-bait surveillance system for investigating the ecology, emergence, and movement of arboviruses. © 2014, Mary Ann Liebert, Inc.