Optimising woody-weed control

Woody weeds pose significant threats to the 12.3 billion dollar Australian grazing industry. These weeds reduce stocking rate, increase mustering effort, and impede cattle access to waterways. Two major concerns of woody-weed management are the high cost of weed management with respect to grazing gross margins, and episodic seedling recruitments due to climatic conditions. This case study uses a Stochastic Dynamic Programming (SDP) model to determine the optimal weed management decisions for chinee apple (Ziziphus mauritiana) in northern Australian rangelands to maximise grazing profits. Weed management techniques investigated include: no-control, burning, poisoning, and mechanical removal (blade ploughing). The model provides clear weed management thresholds and decision rules, with respect to weed-free gross margins and weed management costs.woody weeds, weed control, chinee apple, rangelands, grazing, stochastic dynamic programming, Livestock Production/Industries,

Bio-economic evaluation of pasture-cropping, a novel system of integrating perennial pastures and crops on crop-livestock farms

Pasture-cropping is a novel approach to increase the area of perennial crops in mixed sheep and cropping systems. It involves planting annual cereals directly into a living perennial pasture. There is interest in subtropical grasses as they are winter dormant and their growth profile is potentially well suited to pasture-cropping. However, a wide range of factors can affect the uptake of such systems. This paper assesses the relative importance of factors that can influence decisions to introduce pasture-cropping. In this paper the research question is: what factors predispose a farm to take up a new technology such as (1) subtropical grass and (2) subtropical grass that is pasture-cropped. The analysis uses the MIDAS model of a central wheatbelt farm in Western Australia. The results suggest the adoption of subtropical grasses is likely to be strongly influenced by soil mix; feed quality; and whether the farm is predominantly grazing or cropping and by the presence of meat versus wool producing animals. The same factors are relevant for subtropical grass that is pasture-cropped but in addition yield penalties due to competition between the host perennial and the companion cereal become important. The results suggest the level of forage production by subtropical grass is less important but this factor is likely to become more important if feed quality can be improved.Environmental Economics and Policy,

Crop Updates 2009 - Genetically Modified Crops, Nutrition, Soils, & Others

This session covers fifteen papers from different authors: 1. Performance of Canola Breeders Roundup Ready® canola hybrid CHYB-166 in 2008, Wallace Cowling, Canola Breeders Western Australia Pty Ltd 2. The implications of GM glyphosate resistant lupin, Art Diggle, Caroline Peek, Frank D’Emden, Fiona Evans, Bob French, Rob Grima, Sam Harburg, Abul Hashem,, John Holmes, Jeremy Lemon, Peter Newman, Janet Paterson, Steve Penny,Department of Agriculture and Food, Peter Portmann, Agriconnect 3. Nufarm Roundup Ready® Canola Systems Trials— 2008 Mark Slatter, Research and Development Officer, Victoria, Nufarm (0438 064 845) Angus MacLennan, Business Development Manager, New South Wales, Nufarm (0408 358 024) Cooperators: Monsanto, Nuseed, Pacific Seeds, Pioneer Seeds 4. Roundup Ready® canola—2008 Limited Commercial Release. Getting the system right, Andrew Wells and Mark Slatter, Nufarm Australia Limited (Reprint from 2008 GRDC Cropping Updates with Introductory note) NUTRITION 5. Fertilising in a changing price environment, Bill Bowden1, Wayne Pluske2 and Jeremy Lemon1, 1Department of Agriculture and Food, 2Back Paddock Company 6. Making better fertiliser for Western Australian cropping systems, Wen Chen1 2, Geoff Anderson1, Ross Brennan1and Richard Bell2 1Department of Agriculture and Food, 2School of Environmental Science, Murdoch University 7. The nitrogen fertiliser replacement value of biosolids from wastewater treatment, Hannah Rigby1, Deborah Pritchard1, David Collins1, Katrina Walton2, David Allen2 and Nancy Penney31School of Agriculture and Environment,Curtin University of Technology, Muresk Campus, 2Chemistry Centre of Western Australia 3Water Corporation of Western Australia 8. Fertilising to soil type (usually) pays, Michael Robertson, Bill Bowden and Roger Lawes, CSIRO, Floreat and Department of Agriculture and Food SOILS 9. Management of subsoil acidity and compaction using a combination of lime, deep ripping and controlled traffic, Stephen Davies, Chris Gazey, Breanne Best and David Gartner, Department of Agriculture and Food 10. Optimising gypsum applications through remote sensing and Variable Rate Technology, Frank D’Emden, Department of Agriculture and Food and Quenten Knight,Precision Agronomics Australia 11. Case study of a 17 year agricultural lime trial, Chris Gazey1, Joel Andrew2and Ryan Pearce3 1Department of Agriculture and Food; 2Precision SoilTech; 3ConsultAg 12. Soil organic carbon in WA agricultural soils, FC Hoyle and A Bennett, Department of Agriculture and Food OTHER 13. Is the no-till revolution complete in WA? Frank D’Emden1, Rick Llewellyn2 and Ken Flower3 1Department of Agriculture and Food, 2CSIRO Sustainable Ecosystems, 3University of Western Australia 14. Progression Planning (The Concept), Julian Krieg and Owen Catto, Wheatbelt Men’s Health 15. Is the Department of Agriculture and Food still a primary source of cropping information? Cindy Parsons, Department of Agriculture and Foo

Hypertension persisting after pre-eclampsia: a prospective cohort study at Mulago Hospital, Uganda.

BACKGROUND: Pre-eclampsia/eclampsia usually resolves after delivery but sometimes hypertension persists and cardiovascular disease develops later. Our objective was to determine the incidence and maternal socio-demographic and obstetric risk factors for persistence of hypertension in women with pre-eclampsia/eclampsia. METHODS: This was a prospective cohort study conducted from July 2009 to June 2011 at Mulago Hospital labour ward and postnatal clinics. We followed up 188 women admitted with pre-eclampsia/eclampsia until 3 months after delivery. Data was collected using interviewer-administered questionnaires, examination of participants and review of medical records. Stata (version12) software was used for data analysis. Univariable analysis was used to compute the relative risk of persistent hypertension at the 95% confidence level. This was followed by multivariable logistic regression analysis to determine factors independently associated with persistence of hypertension. RESULTS: 64 (34%) out of the 188 women analysed had persistent hypertension three months after delivery. Maternal age, gestational age at delivery and parity were predictors of persistent hypertension. CONCLUSION: The proportion of women with pre-eclampsia/eclampsia at risk of persistent hypertension at three months after delivery was high, with nearly one of three mothers remaining hypertensive. Follow up of mothers who develop pre-eclampsia is important so that early diagnosis and management of chronic hypertension can be made to avoid long term morbidity and mortality

An analysis of sugarcane harvesting options in the Tully mill area using dynamic and linear programming

Sugarcane in a perennial crop harvested annually over a six-month season from June to December. Each crop cycle consists of a plant crop followed by several ratoon crops. Time of harvest influences both commercial cane sugar (CCS) content in the current season and yield in the following season. Legislative requirements force growers to harvest some of their cane during sub-optimal periods and growers have to decide the order in which to harvest blocks when both yield and sugar content that determine block returns are uncertain. Industry data about yield and (CCS) stored in a MS Access database were used in a dynamic programming analysis of potential harvest sequences. Optimal harvest patterns were identified given industry constraints on cane harvested in several equal time periods during the season

Optimising woody-weed control

Woody weeds pose significant threats to the 12.3 billion dollar Australian grazing industry. These weeds reduce stocking rate, increase mustering effort, and impede cattle access to waterways. Two major concerns of woody-weed management are the high cost of weed management with respect to grazing gross margins, and episodic seedling recruitments due to climatic conditions. This case study uses a Stochastic Dynamic Programming (SDP) model to determine the optimal weed management decisions for chinee apple (Ziziphus mauritiana) in northern Australian rangelands to maximise grazing profits. Weed management techniques investigated include: no-control, burning, poisoning, and mechanical removal (blade ploughing). The model provides clear weed management thresholds and decision rules, with respect to weed-free gross margins and weed management costs

Farming practices at the landscape scale: a novel approach investigating rotations in the WA wheatbelt

International audienc

Bio-economic evaluation of pasture-cropping, a novel system of integrating perennial pastures and crops on crop-livestock farms

Pasture-cropping is a novel approach to increase the area of perennial crops in mixed sheep and cropping systems. It involves planting annual cereals directly into a living perennial pasture. There is interest in subtropical grasses as they are winter dormant and their growth profile is potentially well suited to pasture-cropping. However, a wide range of factors can affect the uptake of such systems. This paper assesses the relative importance of factors that can influence decisions to introduce pasture-cropping. In this paper the research question is: what factors predispose a farm to take up a new technology such as (1) subtropical grass and (2) subtropical grass that is pasture-cropped. The analysis uses the MIDAS model of a central wheatbelt farm in Western Australia. The results suggest the adoption of subtropical grasses is likely to be strongly influenced by soil mix; feed quality; and whether the farm is predominantly grazing or cropping and by the presence of meat versus wool producing animals. The same factors are relevant for subtropical grass that is pasture-cropped but in addition yield penalties due to competition between the host perennial and the companion cereal become important. The results suggest the level of forage production by subtropical grass is less important but this factor is likely to become more important if feed quality can be improved

Positioning in political marketing: How Semiotic Analysis Can Support Traditional Survey Approaches

The 2010 British election particularly focused on the party leaders' images - a departure in fifty years of British elections. The principal contribution of the article is to illustrate how a combined approach to assessing leadership positioning using both the traditional survey and semiotic analysis can provide insights into what image attribute dimensions end up in the minds of members of the public (actual positioning) and on what image attribute dimensions party marketers are trying to position themselves (intended positioning). Using data from the 2010 British general elections, our findings indicate that the combined methodological approach would be particularly useful for brands that need repositioning, those whose image attribute positions change dramatically over time, and those who wish to target previously unresponsive target audience segments