WHIPPET: a novel tool for prioritizing invasive plant populations for regional eradication

Large geographic areas can have numerous incipient invasive plant populations that necessitate eradication. However, resources are often deficient to address every infestation. Within the United States, weed lists (either state-level or smaller unit) generally guide the prioritization of eradication of each listed species uniformly across the focus region. This strategy has several limitations that can compromise overall effectiveness, which include spending limited resources on 1) low impact populations, 2) difficult to access populations, or 3) missing high impact populations of low priority species. Therefore, we developed a novel science-based, transparent, analytical ranking tool to prioritize weed populations, instead of species, for eradication and tested it on a group of noxious weeds in California. For outreach purposes, we named the tool WHIPPET (Weed Heuristics: Invasive Population Prioritization for Eradication Tool). Using the Analytic Hierarchy Process that included expert opinion, we developed three major criteria, four sub-criteria, and four sub-sub-criteria, taking into account both species and population characteristics. Subject matter experts weighted and scored these criteria to assess the relative impact, potential spread, and feasibility of eradication (major criteria) for 100 total populations of 19 species. Species-wide population scores indicated that conspecific populations do not necessarily group together in the final ranked output. Thus, priority lists based solely on species-level characteristics are less effective compared to a blended prioritization based on both species attributes and individual population and site parameters. WHIPPET should facilitate a more efficacious decision-making process allocating limited resources to target invasive plant infestations with the greatest predicted impacts to the region under consideration.

Effect of irrigation amounts applied with subsurface drip irrigation on corn evapotranspiration, yield, water use efficiency, and dry matter production in a semiarid climate

Quantifying the local crop response to irrigation is important for establishing adequate irrigation management strategies. This study evaluated the effect of irrigation applied with subsurface drip irrigation on field corn (Zea mays L.) evapotranspiration (ETc), yield, water use efficiencies (WUE = yield/ETc, and IWUE = yield/irrigation), and dry matter production in the semiarid climate of west central Nebraska. Eight treatments were imposed with irrigation amounts ranging from 53 to 356 mm in 2005 and from 22 to 226 mm in 2006. A soil water balance approach (based on FAO-56) was used to estimate daily soil water and ETc. Treatments resulted in seasonal ETc of 580-663 mm and 466-656 mm in 2005 and 2006, respectively. Yields among treatments differed by as much as 22% in 2005 and 52% in 2006. In both seasons, irrigation significantly affected yields, which increased with irrigation up to a point where irrigation became excessive. Distinct relationships were obtained each season. Yields increased linearly with seasonal ETc (R 2 = 0.89) and ETc/ETp (R 2 = 0.87) (ETp = ETc with no water stress). The yield response factor (ky), which indicates the relative reduction in yield to relative reduction in ETc, averaged 1.58 over the two seasons. WUE increased non-linearly with seasonal ETc and with yield. WUE was more sensitive to irrigation during the drier 2006 season, compared with 2005. Both seasons, IWUE decreased sharply with irrigation. Irrigation significantly affected dry matter production and partitioning into the different plant components (grain, cob, and stover). On average, the grain accounted for the majority of the above-ground plant dry mass (≈59%), followed by the stover (≈33%) and the cob (≈8%). The dry mass of the plant and that of each plant component tended to increase with seasonal ETc. The good relationships obtained in the study between crop performance indicators and seasonal ETc demonstrate that accurate estimates of ETc on a daily and seasonal basis can be valuable for making tactical in-season irrigation management decisions and for strategic irrigation planning and management.

The impact of dry matter, ripeness and internal defects on consumer perceptions of avocado quality and intentions to purchase.

Insights into the relative importance of various aspects of product quality can be provided through quantitative analysis of consumer preference and choice of fruit. In this study, methods previously used to establish taste preferences for kiwifruit (Harker et al., 2008) and conjoint approaches were used to determine the influence of three key aspects of avocado quality on consumer liking and willingness to purchase fruit: dry matter percentage (DM), level of ripeness (firmness) and internal defects (bruising). One hundred and seven consumers tasted avocados with a range of DM levels from ~20% (minimally mature) to nearly 40% (very mature), and at a range of fruit firmness (ripeness) stages (firm-ripe to soft-ripe). Responses to bruising, a common quality defect in fruit obtained from the retail shelf, were examined using a conjoint approach in which consumers were presented with photographs showing fruit affected by damage of varying severity. In terms of DM, consumers showed a progressive increase in liking and intent to buy avocados as the DM increased. In terms of ripeness, liking and purchase intent was higher in avocados that had softened to a firmness of 6.5 N or below (hand-rating 5). For internal defects, conjoint analysis revealed that price, level of bruising and incidence of bruising all significantly lowered consumers' future purchase decision, but the latter two factors had a greater impact than price. These results indicate the usefulness of the methodology, and also provide realistic targets for Hass avocado quality on the retail shelf.

Non-destructive prediction of 'Hass' avocado dry matter via FT-NIR spectroscopy.

BACKGROUND: The inability to consistently guarantee internal quality of horticulture produce is of major importance to the primary producer, marketers and ultimately the consumer. Currently, commercial avocado maturity estimation is based on the destructive assessment of percentage dry matter (%DM), and sometimes percentage oil, both of which are highly correlated with maturity. In this study the utility of Fourier transform (FT) near-infrared spectroscopy (NIRS) was investigated for the first time as a non-invasive technique for estimating %DM of whole intact 'Hass' avocado fruit. Partial least squares regression models were developed from the diffuse reflectance spectra to predict %DM, taking into account effects of intra-seasonal variation and orchard conditions. RESULTS: It was found that combining three harvests (early, mid and late) from a single farm in the major production district of central Queensland yielded a predictive model for %DM with a coefficient of determination for the validation set of 0.76 and a root mean square error of prediction of 1.53% for DM in the range 19.4-34.2%. CONCLUSION: The results of the study indicate the potential of FT-NIRS in diffuse reflectance mode to non-invasively predict %DM of whole 'Hass' avocado fruit. When the FT-NIRS system was assessed on whole avocados, the results compared favourably against data from other NIRS systems identified in the literature that have been used in research applications on avocados.

Negligible evidence for regional genetic population structure for two shark species Rhizoprionodon acutus (Rüppell, 1837) and Sphyrna lewini (Griffith & Smith, 1834) with contrasting biology

Biodiversity of sharks in the tropical Indo-Pacific is high, but species-specific information to assist sustainable resource exploitation is scarce. The null hypothesis of population genetic homogeneity was tested for scalloped hammerhead shark (Sphyrna lewini, n = 237) and the milk shark (Rhizoprionodon acutus, n = 207) from northern and eastern Australia, using nuclear (S. lewini, eight microsatellite loci; R. acutus, six loci) and mitochondrial gene markers (873 base pairs of NADH dehydrogenase subunit 4). We were unable to reject genetic homogeneity for S. lewini, which was as expected based on previous studies of this species. Less expected were similar results for R. acutus, which is more benthic and less vagile than S. lewini. These features are probably driving the genetic break found between Australian and central Indonesian R. acutus (F-statistics; mtDNA, 0.751–0.903, respectively; microsatellite loci, 0.038–0.047 respectively). Our results support the spatially homogeneous monitoring and management plan for shark species in Queensland, Australia.

Phenotypic and genotypic variation within populations of kikuyu (Pennisetum clandestinum) in Australia.

Experiments at 2 sites in subtropical eastern Australia investigated the variation in agronomic attributes, quality and genetic structure existing within: naturally-occurring populations of kikuyu ( Pennisetum clandestinum) from within Australia; selections produced from the treatment of Whittet seed with mutagenic chemicals; and available cultivars. Runners were collected from coastal areas extending from Western Australia to the Atherton Tableland in north Queensland. One experiment evaluated 10 mutagenic selections and 4 cultivars in a lattice design and the other evaluated 12 ecotypes and 3 cultivars in a randomised block design. The experimental unit was single plants, which were sown on a 1.5 m grid into a weed-free seed-bed (Mutdapilly) or a killed kikuyu stand (Wollongbar), both of which were kept clear of weeds and other kikuyu plants for the duration of the experiments. Foliage height, forage production and runner yield were assessed. Leaf material was analysed for concentrations of crude protein (CP), acid detergent fibre (ADF) and neutral detergent fibre (NDF) and for in vitro dry matter digestibility (IVDDM) in autumn, winter and spring. DNA was extracted from each plant in the ecotype comparison and subjected to a modified DAF (DNA amplification fingerprinting) analysis to determine the level of genetic relatedness. In the first experiment, none of the mutagenic lines derived from Whittet yielded significantly more or was more digestible than commercial Whittet material, although some selections were superior to the other commercial kikuyu cultivars, Noonan and Crofts, and 'common' kikuyu. However, there were significant differences in plant height and runner expansion. In the second experiment, significant differences in plant height, foliage yield, runner development, and leaf CP, ADF, NDF and IVDDM concentrations were demonstrated between the ecotypes, mutagenic selections and cultivars. There was a 4- to 6-fold difference in plant yield and a 6- to 10-fold difference in runner production between the ecotypes at the 2 sites. Quality of the leaf ranged from 200 to 270 g/kg (CP), from 700 to 770 g/kg (IVDDM), from 170 to 250 g/kg (ADF) and from 470 to 550 g/kg (NDF). Improvements in quality and agronomic attributes were not mutually exclusive. Genetic fingerprint analysis of the kikuyu lines indicated that they formed 2 broad groupings. Most of the regional ecotypes were grouped with 'common' kikuyu as represented by the material collected from Wollongbar, and the Beechmont, Atherton Tableland and Gympie ecotypes were grouped with the registered cultivars Whittet, Noonan and Crofts. Two lines produced by mutagenesis from Whittet remained closely linked to Whittet. These results suggest that there was variation between populations of kikuyu in yield, quality and genetic diversity but that mutagenesis by treating seed with sodium azide and diethylene sulphide did not achieve a significant change in the digestibility of leaf over cv. Whittet.

Developing a dynamic regional brand - focus on flavour.

This project has delivered technical sensory language that accurately and precisely describes the flavour and texture of key seafood species to the seafood industry of the Eyre Peninsula. Industry members and producers have been trained on the sensory properties of their products and are equipped with knowledge of how to apply sensory language to their products for their customers. The seafood industry of the Eyre Peninsula has embraced the “Eyre Peninsula Seafood Flavour wheel” and is already using it in the promotion of their products. In addition local, national and international seafood producers and end-users have indicated a strong interest in the results and outputs of this project and the potential application of the seafood flavour wheel in their respective businesses.

Regional development, commercialisation and target adoption of new integrated management techniques for Sheep industry

This Sheep CRC2 project is directed towards regional development of, support for, commercialisation and target adoption of, new integrated management techniques, which will lift productivity and better match product with market specification. The outputs and benefits will help support and improve the productivity and profitability of producers remaining in the industry, and support industry in the current move towards one in which both meat and wool will be joint drivers of industry productivity.

Campylobacter genotypes in chickens - national and regional

An understanding of whether Campylobacter are linked to particular companies and/or particular regional areas. An improved industry ability to respond to food-borne outbreaks associated with Campylobacter.

Northern Grazing Systems Bioeconomic analysis and regional assessment

This project is part of the Northern Grazing Systems (NGS) projects which aim to increase adoption of innovative best-practice grazing management by beef producers throughout Queensland, Northern Territory and the Kimberley and Pilbara regions of Western Australia.

Area Wide Integrated Pest Management for Bundaberg regional production horticulture

Regional implementation of Integrated Pest Management (IPM) in Bundaberg production horticulture providing a unified approach to pest and disease control on an area-wide basis. This is aimed at reducing chemical dependency, increasing sustainability, profitability and enhancing biodiversity through detailed investigations, technology application, coordination, monitoring, communication and education.

Macadamia Regional Variety Trials Series 3 - Phase 2

Regional variety trials (RVT) established in 1983 and again in 1997 identified superior varieties for the macadamia industry. From the 1983 trials, guidelines were developed to assist growers to select the most appropriate new varieties for their particular orchards and many of these superior varieties have been enthusiastically adopted by industry. This is also being done for varieties in the 1997 trials. Many of the best cultivars have already been adopted by growers on the basis of annual reports of yield and quality. Industry development over the next 10 to 20 years will be largely dependent on new, superior varieties selected in these RVT5, including new selections from the macadamia industry breeding program.

Delivering Regional Extension Cotton/Grains Farming Systems on the Darling Downs and Border Rivers

New regional extension project for the cotton/grains farming systems on the Darling Downs and Border Rivers with CRDC and Cotton CRC based on the CRDC/Agri-Science Queensland discussion paper.

Effects of seasonal variability on FT-NIR prediction of dry matter content for whole Hass avocado fruit

Fourier Transform (FT)-near infra-red spectroscopy (NIRS) was investigated as a non-invasive technique for estimating percentage (%) dry matter of whole intact 'Hass' avocado fruit. Partial least squares (PLS) calibration models were developed from the diffuse reflectance spectra to predict % dry matter, taking into account effects of seasonal variation. It is found that seasonal variability has a significant effect on model predictive performance for dry matter in avocados. The robustness of the calibration model, which in general limits the application for the technique, was found to increase across years (seasons) when more seasonal variability was included in the calibration set. The R-v(2) and RMSEP for the single season prediction models predicting on an independent season ranged from 0.09 to 0.61 and 2.63 to 5.00, respectively, while for the two season models predicting on the third independent season, they ranged from 0.34 to 0.79 and 2.18 to 2.50, respectively. The bias for single season models predicting an independent season was as high as 4.429 but <= 1.417 for the two season combined models. The calibration model encompassing fruit from three consecutive years yielded predictive statistics of R-v(2) = 0.89, RMSEP = 1.43% dry matter with a bias of -0.021 in the range 16.1-39.7% dry matter for the validation population encompassing independent fruit from the three consecutive years. Relevant spectral information for all calibration models was obtained primarily from oil, carbohydrate and water absorbance bands clustered in the 890-980, 1005-1050, 1330-1380 and 1700-1790 nm regions. These results indicate the potential of FT-NIRS, in diffuse reflectance mode, to non-invasively predict the % dry matter of whole 'Hass' avocado fruit and the importance of the development of a calibration model that incorporates seasonal variation. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.

Separating grazing and rainfall effects at regional scale using remote sensing imagery: A dynamic reference-cover method

Remote detection of management-related trend in the presence of inter-annual climatic variability in the rangelands is difficult. Minimally disturbed reference areas provide a useful guide, but suitable benchmarks are usually difficult to identify. We describe a method that uses a unique conceptual framework to identify reference areas from multitemporal sequences of ground cover derived from Landsat TM and ETM+ imagery. The method does not require ground-based reference sites nor GIS layers about management. We calculate a minimum ground cover image across all years to identify locations of most persistent ground cover in years of lowest rainfall. We then use a moving window approach to calculate the difference between the window's central pixel and its surrounding reference pixels. This difference estimates ground-cover change between successive below-average rainfall years, which provides a seasonally interpreted measure of management effects. We examine the approach's sensitivity to window size and to cover-index percentiles used to define persistence. The method successfully detected management-related change in ground cover in Queensland tropical savanna woodlands in two case studies: (1) a grazing trial where heavy stocking resulted in substantial decline in ground cover in small paddocks, and (2) commercial paddocks where wet-season spelling (destocking) resulted in increased ground cover. At a larger scale, there was broad agreement between our analysis of ground-cover change and ground-based land condition change for commercial beef properties with different a priori ratings of initial condition, but there was also some disagreement where changing condition reflected pasture composition rather than ground cover. We conclude that the method is suitably robust to analyse grazing effects on ground cover across the 1.3 x 10(6) km(2) of Queensland's rangelands. Crown Copyright (c) 2012 Published by Elsevier Inc. All rights reserved.