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Evaluation of herbaceous legumes for crop-livestock systems in eastern Indonesia
No full textThe sale of cattle presents a significant opportunity to improve livelihoods for smallholder farmers in eastern Indonesia. An opportunity was identified to grow herbaceous forage legumes either in rotation with, or sown within, staple grain crops (maize, rice) to use surplus soil moisture to produce a feed bank for (mostly penned) cattle and potentially increase nitrogen supply to the grain crops. A series of experiments was conducted on Vertisol, Alfisol and Inceptisol soils in lowland and upland districts of eastern Indonesia to identify legumes from 18 taxa suitable for integrated crop-forage systems. Clitoria ternatea and Centrosema pascuorum were found to have best potential for these systems as they established reliably using local methods, consistently ranked highly for herbage yields 2–4 months after sowing and were relatively easy to harvest. Yields were highest on the Vertisol (greatest number of sites) and Inceptisol soils. Lablab purpureus, Macroptilium bracteatum and Mucuna pruriens also ranked high for yield on Vertisol soils. Clitoria ternatea regrew consistently after cutting and forage removal providing potential for extended forage production as growing conditions allow
Evolution and objectives of diverse Australian recreational fisheries monitoring programs
No full textApproximately half a billion people engage in recreational fishing, and are estimated to capture at least 10 million tons of fish annually, equivalent to 12% of the global fish catch. However, the recreational fishing sector can be difficult to monitor due to the lack of mandatory reporting of catch and participation. Australia, where one in five adults, or 4.2 million people, participate in recreational fishing annually, highlighted the need to collect information and monitor recreational fishing activity, catch, fish biology, and economic and social values in its 1994 ‘National Policy for Recreational Fishing.’ Here, we identify past and present Australian recreational fisheries monitoring programs (RFMPs) and provide a comprehensive overview of their objectives and methodologies, specifically considering their alignment with the four key research foci identified in the ‘National Policy for Recreational Fishing in Australia.’ We identified 40 unique marine state-wide multi-species RFMPs across all Australian states and territories. Most RFMPs focus on collecting catch, fishing activity and social and economic values information, and rarely contribute information on fish biology. However, there has been ongoing expansions in the number and scope of RFMPs, and an increasing proportion of offsite (i.e., information collected outside the fishing location) programs. While offsite monitoring programs are often cost-effective, we emphasize the crucial role played by onsite monitoring surveys. Results from this review can be used in plans for further expanding recreational monitoring programs towards a more comprehensive and in depth understanding of the recreational fisheries sector in Australia
Cold storage conditions affect ‘Shepard’ avocado fruit ripening and quality
Full text linkThere has been little research into long storage of ‘Shepard’ avocado. Simulated conditions for sea freight of Australian-grown fruit to key Asian markets were investigated. Thirteen storage treatments were applied to fruit of premium quality sourced from two commercial farms. Compared with the generally recommended 7°C, fruit stored at 5.5°C for up to 28 days were firmer at removal, slow to ripen, and had less severe flesh rots at the ripe stage. Compared with regular air storage (Air), controlled atmosphere (CA; 2% O2 and 5% CO2) decreased weight loss at removal, retarded ripening and, after 28 days of storage, reduced discrete patches on the skin of ripe fruit. However, CA storage also resulted in ripe fruit with more severe shrivel, stem end rot, and vascular browning. For 14 or 21 days at 5.5°C, Air resulted in the best overall quality of ‘Shepard’ fruit. CA was comparatively advantageous after a 28-day storage in improving external quality at ripe. There was considerable variation between both farms in storage effects on fruit ripening and quality. Given the high variability in fruit chilling responses apparently dependent on preharvest factors, further research is warranted to elucidate these results and better evaluate risks under commercial sea freight conditions
Fumigant toxicity of allyl isothiocyanate against phosphine-resistant populations of five major stored-grain insect pests
No full textGiven the development of resistance in stored-grain insect pests to phosphine (PH3), the grain industry is seeking alternative methods for effective pest and resistance management. We evaluated the efficacy of allyl isothiocyanate (AITC), a potential alternative fumigant against adults of phosphine-susceptible (PH3-S) and resistant strains (PH3-R) of five major grain insect pests, including Sitophilus oryzae (Linnaeus), Tribolium castaneum (Herbst), Rhyzopertha dominica (Fabricius), Oryzaephilus surinamensis (Linnaeus), and Cryptolestes ferrugineus (Stephens). Adult dose-mortality response curves were established for each species, and the mortality endpoints of post-fumigated adult S. oryzae and T. castaneum were compared. The effect of commodities on the efficacy of AITC was briefly investigated from the perspective of adult insect mortality. The PH3-R strain of S. oryzae was the most tolerant and required the highest dose, LC50: 1.75 µL a.i. L-1, whereas the PH3-R strain of C. ferrugineus was the most susceptible to AITC, requiring the lowest LC50: 0.59 µL a.i. L-1. Comparisons of LC99.9 across the species and strains confirmed that AITC at 2.59 µL a.i. L-1 was adequate in achieving complete control of adults across all five insect species tested, irrespective of their resistance status to phosphine. These results suggest that phosphine-resistant insects fail to confer cross-resistance to AITC. Post-exposure endpoint mortality studies revealed a steady increase in mortality in S. oryzae (from 18% at 24 h to 100% at 168 h). In contrast, no such changes were recorded with T. castaneum, suggesting the existence of species-specific differences in responding to AITC. The presence of insect-infested commodities, such as rolled oats and cracked sorghum, reduced the efficacy of AITC, indicating that this fumigant could be sorptive
Relationship between Key Aroma Compounds and Sensory Attributes of Australian Grown Commercial Pineapple Cultivars
No full textThe intricate relationship between the chemical composition and sensory attributes of various pineapple (Ananas comosus var. comosus) cultivars was investigated using multivariate statistical analysis. Our findings revealed that high hedonic ratings for pineapples are partially attributed to their distinct flavor profiles such as tropical fruit, sweetness, coconut, and floral aroma and flavor and textural qualities like juiciness and fibrousness. Aroma emerged as a pivotal criterion for evaluating pineapple flavor, with positive sensory experiences linked to volatile compounds such as several methyl and ethyl esters and terpenoid-like compounds such as alpha-terpineol, limonene, and damascenone. Notably, the high °Brix to % titratable acidity ratio further contributes to the overall appeal. Conversely, less favorable green and acidic flavors correlate with lower hedonic liking and align with higher acidity levels. Importantly, our results highlight the complex interplay among individual chemical components within pineapple cultivars, offering valuable insights into selecting and developing improved pineapple varieties in the future
Mobilisation and replenishment of phosphorus reserves in Bos indicus cows. 2. Mature lactating cows fed diets deficient or adequate in phosphorus
No full textContext
Pastures growing on low phosphorus (P) soils are often P deficient, particularly for lactating cows.
Aim
To examine the effects of P-deficient diets on the performance of lactating multiparous cows.
Methods
From parturition, mature Bos indicus cross cows (n = 32, initially 474 kg liveweight (LW) and body condition score 3.5) were fed ad libitum for 14 weeks one of four diets: (i) high P (HP-HCa), (ii) low P with low calcium (LP-LCa), (iii) low P with high Ca (LP-HCa), or (iv) the LP-LCa diet with ammonium chloride (LP-LCa+ac).
Results
Voluntary feed intakes were higher for cows fed the HP-HCa than the three LP diets (23.1 vs 17.4–19.6 g DM/kg LW.day; P < 0.001). The HP-HCa cows gained 0.15 kg LW/day, whereas LP cows lost 0.14–0.51 kg LW/day; P < 0.05). The cows fed LP diets generally maintained milk production and calf growth comparable to that of HP-HCa cows (5.8 kg/day and 0.70 kg/day). The HP-HCa cows retained 6.0–6.4 g P/day from weeks 1–8, but P retention was negligible at week 14. The LP cows mobilised 4.9–9.1 g body P/day. Rib cortical bone shortly after parturition was 634 ± 127 (337–848) μg P/mm2 in the 12th rib, and indicated that the bone P reserves were deficient, marginal and adequate in 27, 37 and 37% of the cows, respectively. During lactation, rib bone P increased 23% in HP-HCa cows, changed little in the LP-LCa and LP-HCa cows (−4 and +7%), and decreased 13% (P < 0.05) in LP-LCa+ac cows. The change in rib cortical bone P during lactation was correlated with this measurement at parturition; the P per unit surface area of rib cortical bone of cows with low bone P at parturition did not change, but in cows with high bone P it decreased up to 16%. Plasma inorganic P averaged 1.49 mmol/L in the HP-HCa cows and <0.8 mmol/L in the LP cows. Plasma Ca, Ca/inorganic P ratio, 1,25-dihydroxy vitamin D3, bone alkaline phosphatase, and carboxy-terminal telepeptides of type 1 collagen increased during lactation (P < 0.05 to P < 0.001) in the LP cows.
Conclusions
When fed acutely P-deficient diets, mature cows of moderate LW and with body condition scores at parturition generally maintained milk secretion and calf growth by mobilisation of body reserves.
Implications
The capacity of beef cows to maintain lactation when ingesting P-deficient diets provides opportunities for improved herd management
Predicting the potential distribution of the invasive weed Mikania micrantha and its biological control agent Puccinia spegazzinii under climate change scenarios in China
No full textResearch on the potential distribution of invasive plants and their biological control agents under climate change is critical for informing strategies in invasive species management. The rust fungus Puccinia spegazzinii shows significant potential as a biological control agent for the invasive weed Mikania micrantha. The MaxEnt (Maximum Entropy) model was used to simulate the distribution of M. micrantha and P. spegazzinii under current and future climate scenarios. The models achieved excellent prediction performance, with M. micrantha and P. spegazzinii having area under the curve values of 0.921 and 0.978 respectively, and true skill statistics values of 0.886 and 0.902 respectively. Precipitation is the primary factor influencing the distributions of M. micrantha, while P. spegazzinii is determined by both temperature and precipitation. The suitable areas for the two species are concentrated in southern China, with M. micrantha exhibiting broader adaptability compared to P. spegazzinii. Under future climate scenarios, the suitable areas for M. micrantha in China will expand northward, with a maximum projected growth rate of 84.6 % in the 2070 s, whereas P. spegazzinii exhibits a contracting trend (with a projected reduction of 40.8 % in the 2050 s). Under the current climate scenario, the overlapping suitable areas between the two species account for 25.2 % of the total suitable area for M. micrantha and 100 % of that for P. spegazzinii and both remain relatively stable under future climate scenarios. This work can provide guidance for the application of biological control, and serves as a valuable reference for developing early warning and management response strategies for invasive species in China
Lethal and sublethal effects of cotton expressing single and pyramided proteins of Bacillus thuringiensis (Bt) on Helicoverpa armigera (Lepidoptera: Noctuidae), Spodoptera litura (Lepidoptera: Noctuidae), and Spodoptera frugiperda (Lepidoptera: Noctuidae)
No full textThe susceptibility to proteins from Bacillus thuringiensis (Bt) can vary among lepidopteran pest species. While Bollgard 3 cotton (BG3) effectively controls the primary pest Helicoverpa armigera (Hübner) in Australia, its effectiveness against other pests, such as Spodoptera litura (Fabricius) and Spodoptera frugiperda (J. E. Smith), is unknown. This laboratory study assessed the survival and development of H. armigera, S. litura, and S. frugiperda larvae when fed foliage from a non-transgenic cotton variety (CC) and 3 transgenic cotton varieties: Bollgard (BG1) expressing Cry1Ac, Bollgard II (BG2) expressing Cry1Ac and Cry2Ab, and Bollgard 3 (BG3) expressing Cry1Ac, Cry2Ab, and Vip3A. Pyramided Bt cotton had greater negative effects on survival and development of all species compared with CC or BG1. The proportion of H. armigera that eclosed as adults was very low when larvae fed on BG2 or BG3 compared with BG1. Eclosion rates of S. litura and S. frugiperda on BG3 were much lower compared with BG2 and BG1. This study demonstrates that BG3 has greater efficacy against a wider lepidopteran pest complex compared with previous Bt cotton products. Despite efficacy in the laboratory, S. litura larvae are reported to be surviving in BG3 fields, suggesting other factors are influencing field efficacy. As BG3 production expands across tropical northern Australia, preserving the susceptibility of S. litura and S. frugiperda to BG3 proteins is crucial. This study identifies the need for further research on field survival and resistance management strategies for secondary pest species
Narrow mango canopies have more even light distribution and more efficient light use
No full textThe intensity of light and the ability of leaves to e iciently use light are key determinants of the productivity of tree canopies. Temperate tree crops research has shown that the distribution of light within the canopy and the ability of leaves to adapt to light availability are a ected by genetics, pruning and canopy architecture. We tested the e ect of canopy width on light distribution within the canopy at two key phenological stages, and leaf functionality and morphology across a light intensity gradient. We then combined this understanding in virtual canopies to examine the e ect of canopy width on the net primary productivity per leaf area of wide and narrow Calypso® mango trees. We found the light extinction rate did not di er between narrow espalier training systems and wide conventional mango canopies, but the proportion of the tree’s leaf area in a high to moderate light intensity was greater with a narrow canopy. We also found that leaf morphology, productivity and stress tolerance are driven by light availability. When these e ects are modelled in digital canopies, narrow canopies have greater net primary productivity per leaf area than wide canopies at certain phenological stages. Our findings suggest that intensified mango orchards with narrow canopies benefit from more e icient use of light, but further research is needed to model this across an entire growth cycle
Utilising unmanned aerial vehicles (UAV) for remotely assessing and effectively controlling emergent weeds in aquatic systems using herbicides
No full textThe use of emerging Unmanned Aerial Vehicle (UAV) technologies in weed control has been readily adopted as a complementary new tool by land managers. The functionality, availability and affordability of UAV’s has meant that their use is no longer restricted to highly skilled research and commercial operators but accessible to farmers, local councils and Government agencies. There remain questions about the value and efficacy of herbicide treatments when applied by UAVs in terrestrial and more specifically aquatic situations. Of equal importance, from an assessment perspective, is the ability to assess herbicide efficacy remotely using UAVs. In this paper, we use the latest photogrammetry software to assess a previously captured data set to assess the efficacy of several herbicides applied by UAV to an infestation of the invasive ponded pasture species Aleman grass (Echinochloa polystachya) in North Queensland. The entire process of pre-mapping, treating and assessing efficacy by UAV proved the validity of this approach for use in emergent aquatic weed control