3D weed management

Onopordum Thistles Case Studies Four Case Studies of Farmers Managing Onopordum Thistles in Grazing Systems

HELPING PRODUCERS TO MANAGE WEEDS IN GRAZING SYSTEMS Introduction

Contents: Page

Case Study 1 - Rick Hutchinson, “Rosemount”, Jugiong, New South Wales 3 - 5

Case Study 2 - Dougald and Lachlan Campbell, “Burrendong”, Wellington, New South Wales 6 - 8

Case Study 3 - Tony and Pattianne Gay, “Clonalton”, Reid’s Flat, New South Wales 9 - 11

Case Study 4 - Bob and Elizabeth Douglas, “Cobargo”, Kyneton, Victoria 12 - 14

Onopordum thistle refers Onopordum thistles are either annual or biannual to any species of the genus weeds that affect around a million hectares of eastern Australia. They compete directly with Onopordum, including Scotch autumn, winter, spring and sometimes early thistle (Onopordum acanthium), summer growing pastures for moisture, sunlight Illyrian thistle (Onopordum and nutrients. ), stemless thistle illyricum Onopordum thistle seeds can persist for (Onopordum acaulon) and several seasons and are spread by animals, Taurian thistle (Onopordum birds, vehicles and water. These weeds have tauricum). a tendency to form dense stands, smothering desirable vegetation with their rosette leaves, reducing pasture stocking rates and excluding livestock from heavily infested areas.

Stock poisoning as a result of eating Onopordum thistles is possible. Physical damage to grazing animals and contamination of wool can also be a significant issue. Case Study 1 - Jugiong, New South Wales

Case Study 1 - Rosemount Rick Hutchinson, “Rosemount”, Jugiong, New South Wales

The Hutchinsons invested in Rosemount at Jugiong six years ago. The farm operation has now amalgamated three neighbouring properties, bringing it to 1,440 ha. The property is managed by Phil Campbell.

The production system Onopordum thistles of actions, both to lift the farms’ carrying capacity, and to make the properties a The emphasis of the grazing enterprise Two of the farms already had a better place to live and work. on Rosemount has shifted from wool moderate level of thistle infestation production to cattle. From 300 cows, when they were purchased by the 130 steers are sold at 450 kg, and Hutchinsons. The third farm (about With neighbours who shared his heifers not retained for breeding are sold 230 ha) was heavily infested with philosophy on weed control and offered at 380‑400 kg. thistles and, as means of control, helpful advice, Rick began to address goats were run on the property by the the problem immediately. Thistles are the number one weed. Rosemount ran 7,000 wethers in previous owner. 1990, but the sheep enterprise is now primarily lamb production. 1,000 prime Today all three farms have low lambs are produced each year, with infestations of Onopordum thistles in Deliberation wool now a by-product of the sheep terms of groundcover. Finding information about thistles was enterprise. relatively easy. Rick spoke with a friend Since buying the property, Rick and in another area who had success with Water is reticulated into 40 troughs Phil have made a concerted effort to control and also with a local agronomist. across the property and pastures are effectively control the thistles. Rick said He was aware of others successfully set stocked. The carrying capacity of the that he has hit them hard but realises dealing with thistles in the Boorowa property has been lifted by fertilising that the control efforts will need to area, so he visited them to gather pastures with superphosphate and continue into the future. information about different strategies. sowing introduced pastures under an expanded cropping program. The incentive to act Rick also spoke with his neighbours Rick’s goal is to turn off high quality to ask them what worked in the area A small block of lucerne is grown on the livestock. Good genetics, well bred and and to facilitate a common approach to river flats for hay. About 160 hectares well grown animals are important to thistle control. of fodder crops are grown each year him. for grazing and, in a good year, grain production. When Rick bought the properties, he was well aware of the Onopordum Typically, 490 ha of the property is thistle problem. Control of thistles and cropped but approximately 15% of the other weeds was high on his initial list land is too hilly or rocky for cropping.

3 Case Study 1 - Jugiong, New South Wales

Rick ensured that he cross referenced Grazing management each piece of information. Actions that Grazing is managed to maintain passed his common sense test and groundcover. fitted the labour and financial capacity were implemented. Grazing management changed with the shift towards more cattle and less The key message that he took on board sheep. Cattle are grazed in paddocks early was that “it takes a while, but first, followed by sheep when the grass don’t panic as they can be controlled. A is shorter. rushed job is not necessarily the right way to go”. Biological control Biological control has been discussed Diversity in the by other people and Rick has heard that some other farmers are relying approach on biological control solely to control thistles. Rick doesn’t rely on this. Rick approached the control of this weed as an investment to improve carrying capacity. His program focuses on cropping to remove heavy infestations, Diligence establishing competitive pastures, and The key to ongoing control has been to concentrated spot spraying to control get on top of the problem early and to infestations in non-arable areas. dedicate particular effort to the control of thistles. Crops and pastures Cropping, at a cost of around $140/ha, Commitment, diligence, a planned is part of the change in management approach and a thistle control budget to lift the productive capacity of the have been pivotal. whole farming enterprise. Arable land Herbicides is sprayed with herbicides and direct The thistle control effort has dominated drilled to cereal crops for four years. Once a pasture is established, thistles farm operations over time. People Oats and wheat are sown on around are controlled by monitoring and working with Rick on the farm know that 35% (490 ha) of the total farm area each spot spraying with herbicide. Seeds August/September is the time for thistle year. are brought in by water and birds so control, before flowering. ongoing monitoring and treatment is Even with the poor seasonal conditions essential. Rick and Phil are constantly checking over the past five years, cropping has the areas where thistles have been had an overall positive return. A team of spray contractors are controlled in the cropping operation. brought in during August to clean They also have the team looking for new A pasture mix is undersown with the up rocky outcrops and inaccessible weeds to spot spray and contractors are fourth crop. Phalaris and clovers are areas to reduce the risk of significant brought in to help with the effort. included, and ryegrass and chicory have reinfestation. Particular attention is paid also been tried recently. to creeklines, under trees and fencelines Rick said that if he missed one year, he near infested areas or rocky outcrops. would be right back where he started. Rick said that the key to success is good The country has a lot of rocky outcrops pasture establishment. In some cases, so this work does take significant time pastures are re-sown if conditions did and effort. not allow a good establishment. Rick knows that some farmers do not In the first three years of the program, worry if the thistles take over non-arable superphosphate was spread over the areas. In the long run he feels that this whole property, making the existing will cost time and money. Rick said pastures more competitive against that it is important to set a clear control thistles. objective so that everyone is working towards one goal.

4 Case Study 1 - Jugiong, New South Wales

Benefits and costs Keys to success Summary Rick is certain that the thistles would Rick believes that the critical factor Rick has managed thistles by: have taken over the whole farm area if in their success was taking account nothing had been done to reduce their of a number of different views when ✔✔Using a four-year cropping program impact on the farm carrying capacity. developing the control strategy. to establish competitive pastures, reduce large stands of thistles and maintain Having decided to control thistles, Rick Rick spoke to friends who had past has invested significantly in his control success, local agronomists, and carrying capacity. strategy. He is confident that, even neighbours. He cross referenced the ✔✔Spot spraying gullies, creek lines, over six years, there have been huge information these sources gave him, fence lines and rocky areas with improvements. He is much less worried then applied the common sense options herbicide to keep pasture country clean. about thistles now than he was when that fitted with the labour and financial ✔ he began the program. capacity of the farm operation. ✔Grazing appropriately – shifting the balance to more cattle and less sheep By controlling the thistles, Rick said he It remains important that he and his and maintaining groundcover. has maintained the property’s original neighbours have a similar philosophy for ✔✔With significant investment and stocking rate for the past six years, even managing the weed. effort, thistles are being effectively through drought. controlled to minimise the impact they Rick has leaned toward more rapid Rick estimates that he has spent about means of controlling the weed, but have on carrying capacity. $10,000 a year in herbicides, and all thinks that the key strategies of pasture up, there is about two months thistle establishment and ongoing persistence control work for two workers each year. would have the same outcome in the long run. Top tips ✔ Thistles had reduced carrying capacity Rick’s key messages for managing by 20-25%. The change in management Rick knows he has invested significant Onopordum thistles are: to include cropping and control the effort in control. He is confident that thistles has improved overall farm the tools exist to control thistle and he ✔✔Don’t panic! Thistles can be productivity. will achieve long-term success through controlled with a budget and diligence. ongoing control. ✔✔Budget for a sustained effort. The combination of cropping, spot spraying and the increased carrying ✔✔Use herbicides and cropping in capacity under the new farming system heavily infested areas to establish are returning significant benefits pasture. for the outlay. Using NSW DPI farm ✔✔Focus on an initial control program, budgets, the net benefit of controlling as it will save money and effort in the Onopordum thistles on Rosemount is around $8,000 per year for the grazing long run. operation alone. ✔✔Monitor and treat inaccessible areas as they can be a source of reinfestation. The cropping enterprise provides additional feed and direct returns, along with greater flexibility and thistle control options.

Annual costs and benefits of weed management

Costs Direct costs of spot spraying 490 ha $12,000

Benefits Avoided 20% loss of carrying capacity $20,000 Annual net benefit $8,000

5 Case Study 2 - Wellington, New South Wales

Case Study 2 - Burrendong Dougald and Lachlan Campbell, “Burrendong”, Wellington, New South Wales

Burrendong is a 1,800 ha dryland grazing property in the Dripstone district, near Wellington in central west NSW. The Campbell family purchased the farm in the 1870s. Dougald and Lachlan are the fifth generation to manage the farm.

The production system a pioneer of pasture improvement, While Onopordum thistles had been using superphosphate and sub clover. treated regularly with herbicides as The main enterprises at Burrendong are It is therefore likely that reasonable part of the weed control program, the a self-replacing Merino breeding flock accumulation of sulphur and phosphorus Campbells felt that no real progress was of 6,000 ewes and a 5,000-head Merino is helping to maintain soil fertility being made. wether flock. Trade sheep and cattle are across the property. The Campbells also part of the business, depending plan to fertilise again when production on seasonal and market conditions. The The incentive to act is observed to be limited by mineral Campbells currently have 70 cows plus Burrendong has always been a profitable deficiencies. calves. and well run property. However, after attending a grazing management course, Despite a run of difficult seasons, Since 2000, most of the property has the Campbells realised that both the carrying capacity has increased and both undergone significant structural change, profitability and long-term sustainability livestock and pasture have performed with the introduction of modified of their property could be improved by above expectations. cell grazing. Work involved major a more holistic approach to pasture and subdivision, upgrading water supplies, livestock management. and fencing off 7 km of an 11 km river Onopordum thistles frontage to improve river and stock Onopordum thistles, principally Scotch The family set a goal to holistically water management. thistle, have been a troublesome weed manage their property to achieve at Burrendong for as long as Dougald profitability, repair and enhance the The pasture base is native perennial and Lachlan can remember. landscape, and to allow for an enjoyable grasses with winter annuals such as lifestyle. sub clover, and annual grasses such as The weed dominated sheep camps and ryegrass, complementing the winter gullies, and had spread to dominate It became clear to the Campbells feed. These pastures respond effectively many parts of the pasture. They that the Onopordum thistle problem to rain at any time of year, which is an estimate that, through lost pasture throughout Burrendong was a result of essential feature for the variable rainfall production, the weed reduced stock the way they managed grazing on the patterns in the area. numbers by up to 10% across the farm. property. In addition, thistles often made stock No fertiliser has been used on the handling difficult, had the potential property since a cell grazing program to cause stock poisoning (especially commenced. However, Dougald and in cattle) and contributed to wool Lachlan’s late father, Malcolm, was contamination.

6 Case Study 2 - Wellington, New South Wales

Deliberation The strategy maintains good Despite a run of very difficult years, groundcover levels with around including drought, livestock productivity Thistles began to be seen as part of 1,000 kg/ha dry matter or better left to has increased. an overall imbalance in the pasture protect the soil, build soil organic matter on Burrendong. Sheep camps and and ensure better rainfall capture. The competitive pastures resulting from extended grazing periods thinned out the Campbell’s management system native perennials, and winter annuals Dougald and Lachlan have observed are the key to controlling weeds like occasionally smothered perennial that the perennial grasses are surviving Onopordum thistles at Burrendong. The pastures just as they were beginning to and regenerating well, as they have the family believes weeds are no longer grow. opportunity to replenish root and seed an issue when the farm is managed reserves. to achieve productive perennial-based They believed a competitive, well pastures, the species grown (mainly populated, perennial-based pasture Paddocks are set stocked during winter natives) suit the area, and plant density would out-compete the weeds. lambing to minimise lamb losses from ensures almost complete groundcover. mismothering. There is little impact This led to a new approach - higher on the perennial pasture base, which Herbicides stock density grazing for shorter is mainly dormant during winter. Set Before the Campbells developed their periods. Paddocks were subdivided and stocking in winter also helps annuals management strategy, an enormous new watering points were created to like sub clover perform optimally, by amount of time and money was devoted implement cell grazing. preventing them from accumulating too to spraying weeds like Onopordum much dry matter. thistle. Today, weed spraying is no longer Athough this approach was initially necessary on Burrendong. costly, the Campbells believed that Pasture recovery periods vary according this new approach would help them to rainfall received and pasture growth preserve groundcover, more evenly patterns. For example, 35 days after Biological control distribute nutrients (animal waste) summer rain, the summer perennials Biological control agents have across a paddock, and ensure all plants are commonly approaching flowering, never been deliberately released at were grazed equally for short periods, which is an ideal time to graze them. Burrendong but are present throughout with good opportunities to recover from The grazing rotation may be adapted to the district. Dougald and Lachlan think grazing. make better use of this. they probably contribute to control, but they believe that biological controls Dougald and Lachlan believed that a The number of grazing days spent in shouldn’t be the sole method of weed reduction in weed infestations, and each paddock varies according to feed management. improvements in productivity and availability and stock requirements. sustainability, could be achieved by fostering perennial pastures (especially The system has worked well over the native species), improving groundcover, past six years, with perennial plant and integrating the management of both density building and weed densities animal and plants. gradually declining.

Diversity in the approach The Campbells’ weed management strategy is embedded in the changes made to their grazing management practices.

Grazing and pasture management Dougald and Lachlan use a flexible grazing strategy with up to 70 paddocks per system. The duration of grazing in each paddock ranges from one to three days, followed by resting the paddock for up to 100 days.

7 Case Study 2 - Wellington, New South Wales

Summary Diligence Annual benefits of weed management The Campbells are controlling Onopordum Dougald and Lachlan say that the keys thistles at Burrendong as a result of to success in agriculture, including weed Benefits adopting holistic property management, control are understanding the property Reduced herbicide costs $10,000 including flexible cell grazing. The system environment, continuous and careful Reduced spraying labour has delivered more productive pastures monitoring of pastures and livestock, costs (200 hrs @ $30/hr) $6,000 and livestock, improved groundcover, a and management that suits the overall larger area of native perennial grasses, well being of the property. 10% production increase $30,000 and ultimately, greater profitability. Annual net benefit $46,000 In contrast to a lot of other weed control Production has increased 10%, which programs, the Campbells’ approach There are additional costs and benefits is worth around $30,000 each year. The relies on getting the overall property associated with holistic management on greatest expense has been additional management right, with positive flow- Burrendong. fencing and water, at a total one-off cost on effects for weed management. In of $200,000. The system has reduced this sense, weeds are regarded as a The Campbells have been able to keep herbicide use and application costs by symptom of other problems, such as $16,000/year. ahead financially, as well as dramatically overgrazing, lack of suitable perennials improve their property’s natural and poor groundcover. resources, despite some very poor seasonal conditions and comparatively Maintaining competitive, perennial- low wool prices. Top tips ✔ based pastures across the entire Dougald and Lachlan recommend that property also prevents potential weed With young families, Dougald and other people: incursions from adjoining properties and Lachlan also enjoy a reduced work load public areas. and additional time with their families ✔✔Examine why Onopordum thistles are under the new management system. a problem. In all probability, it is because Benefits and costs of grazing management practices that Since adopting a whole-of-property Keys to success discourage a strong perennial-based management approach, weed Dougald and Lachlan feel the keys to pasture, result in low groundcover, and fail densities have dramatically declined on their success have included: to target highly fertile areas such as sheep Burrendong. The level of Onopordum thistles is now so low that it is no longer camps. ➜➜Education – attending a grazing regarded as a major problem. ✔✔Develop a grazing system that management course provided encourages a strong perennial pasture, Overall, the property is now in much knowledge and motivation for changing always retains good groundcover, and that better condition. The perennial pasture to a more sustainable and profitable avoids creating areas like sheep camps. base has greatly improved (and is still management system. improving), ground cover is always ✔ Consider adopting holistic property ➜➜Planning, undertaking and following ✔ adequate, soil quality has improved and through with the new approach – even management, including flexible cell productivity has increased. grazing. in difficult times it is important to remain The change to a holistic system of focused and stay with the program. grazing cost around $200,000 for the ➜➜Fully understanding the dynamics of new watering system and subdivision overall property management, so that fencing. decisions are based on logic and sound knowledge. With a reduction in herbicide costs of around $10,000 per year, reduced labour requirements for spraying and 10% higher production, the Campbells’ investment has already paid for itself and will continue to provide benefits into the future.

8 Case Study 3 - Reid’s Flat, New South Wales

Case Study 3 - Clonalton Tony and Pattianne Gay, “Clonalton”, Reid’s Flat, New South Wales

Clonalton is a 2,000 ha property at Reid’s Flat, south-east of Cowra in Central NSW. The property is owned by Tony and Pattianne Gay. Tony has lived on Clonalton all his life.

The production system only moving stock when sheep are to be Paterson’s curse, cape weed and saffron sold. In dry times, wethers are the first thistle are the other problem weeds The property is primarily used for to be sold. on Clonalton. Paterson’s curse is more grazing around 12,000 Merino sheep, prolific and has a bigger negative effect comprising 6,000 ewes, 3,000 wethers on grass production. and 3,000 hoggets. Over time, Tony has Onopordum thistles adapted his wool enterprise to achieve a Tony has always recognised Onopordum finer micron. thistle and the potential problems it can The incentive to act cause. The primary goal for Tony and Pattianne’s Around 20% of the land is arable and a farm is to maintain a profitable business. small area of grazing oats is grown each To Tony’s knowledge, it has always been They want to produce lower micron year. 280 ha is timbered. present on the property. wool, maintain a good wool flock, and keep the property in good condition. Tony recently purchased a second About 20 years ago the flock had a property, where he joins Merino ewes significant footrot outbreak. During this The spread of Onopordum thistles to crossbred rams for prime lamb time, the management focus shifted whilst Tony was busy managing the production. from weed management to eradicating footrot outbreak prompted him to take footrot. As a consequence, the thistle action against them. The pasture is dominated by native problem became more than just isolated species such as microlaena, with some pockets across the property. The main impact of Onopordum thistle sub clover. Phalaris and clovers have on Tony’s Merino wool enterprise is been sown over time, and fertiliser During this period, when thistles were increased vegetable matter in the wool, is applied each year – typically single at their worst, 10% of the property was which attracts a price discount. The superphosphate. heavily infested by thistles, 35% with extent of this discount is influenced by moderate infestations and 55% with market conditions and the quality of In the past few years, Tony has used low infestations. other wool on the market. MCPA as a ground spray to control annual weeds such as Paterson’s curse, Tony estimates that this has been The thistle can also increase the risk of saffron thistle and cape weed. reduced to 5% of the property being scabby mouth, particularly in lambs. Tony heavily infested with Onopordum thistle, vaccinates against this when necessary. Tony has increased the stocking 30% with a moderate infestation and rate over the past ten years, running 65% with a low infestation.Heavy Onopordum thistle becomes a bigger approximately 8.5 DSE/ha. He has infestations also vary with seasonal problem in dry times, when sheep push made few other changes to his grazing conditions. into thistle areas for feed. Thick stands management, using a set stocking, and are a nuisance during mustering.

9 Case Study 3 - Reid’s Flat, New South Wales

Tony does not believe that thistles have The second phase, which began had a significant impact on his carrying 10 years ago, targeted Paterson’s curse capacity, as pastures tend to grow right and involved spraying MCPA over up around the base of thistle plants and 300-400 ha, and MCPA plus chlorpyralid sheep will graze in thistle patches. over 40-50 ha, both at a cost of around $12/ha. Tony understands that thistles don’t like competition, which further motivates Boom spray applications of either him to maintain good pastures. MCPA, at a rate of 800 mL/ha, or terbutryn, at 250 mL/ha, have effectively The management of Onopordum thistles controlled the thistle on Clonalton. is an ongoing process, to avoid the potential economic impact on the farm This later approach was chosen because enterprise, and to reduce the risk of the it was relatively simple and effective. weed taking over if left unmanaged. The weed is now at a level where its economic impact does not warrant an Overall, the effort made to control increase in the area sprayed. thistles is driven by seasonal conditions and the impact on both farm returns and Tony has also used a mix of MCPA and day-to-day farm management activities. chlorpyralid to kill mature weeds that survived an application of regular MCPA.

Deliberation Biological control Tony mainly relied on discussions with CSIRO Entomology released crown his peers to obtain information about weevils at Clonalton six years ago. The how to manage the weed. weevils eat the seeds within the head of the plant, reducing seed production. He does not see their goal as The weevils persisted and increased eradication of Onopordum thistle. He in numbers, expanding their area of aims to keep the weed at a level that Diversity in the influence. minimises the economic impact of approach thistle-based vegetable matter in the Over time, stem weevils have also made wool clip. Selective herbicide application and their way onto the property, from other biological control are the two main thistle infestations in the area. Tony’s weed control tactics are linked methods that Tony uses to manage to seasonal conditions and the weed’s Onopordum thistles. While these biological measures have impact on economics and management. been an important component of the The effort made to control the weed Managing for competitive pastures weed management program, Tony each year is determined by the effect is also part of the overall weed believes they should not be viewed that each of these three factors is having management approach on the farm. as independent methods of control. on the farm system. Rather, they work best when used Other weed management approaches, together with herbicides and pasture When the economic costs of the weed other than very labour intensive chipping management. (lost pasture production and vegetative out of the weeds more than 20 years contamination of wool) increase ago, have not been attempted. significantly, or when the seasonal Diligence conditions are favourable for weed Herbicides Tony attributes his success in managing growth, a more concerted effort is made The first phase in weed management Onopordum thistles to maintaining to spray thistles and keep them under (around 20 years ago) targeted the a consistent approach to control the control. thickest patches scattered over an weed. area of around 200 ha with MCPA and chlorpyralid. Areas such as sheep Persistence in spraying plants early has camps, which are often harder to access helped to reduce the number of plants with a boom spray, were also targeted. reaching maturity and the potential for seed production.

10 Case Study 3 - Reid’s Flat, New South Wales-

On reflection, Tony said that if he had his Annual costs and benefits of Summary time again, he would pay more attention weed management early on to the lighter infestations, as Tony and Pattianne Gay have effectively these areas can quickly spread. Costs managed Onopordum thistles at Spraying thistles with Clonalton by: herbicides $2,640 Benefits and costs ✔✔Actively spraying thistle patches Tony and Pattianne have significantly Benefits early each year. reduced the area of the farm that is Avoid 20% discount for heavily infested by thistles. Over the ✔✔Focusing on larger infestations and VM in wool $6,600 past 20 years, this area has halved from susceptible areas such as sheep camps. around 10% of the farm to just 5%. Annual net benefit $3,960 ✔✔Trying to keep the weed at a manageable level, rather than trying to Control of Onopordum thistle at Keys to success eradicate it. Clonalton reduces vegetable matter Tony does not believe that his current (VM) in the wool clip, makes mustering ✔✔Maintaining good pastures that weed strategy will eradicate the of sheep easier, and reduces the compete with weeds. weed but it is keeping the weed at a incidence of scabby mouth in lambs. manageable level. ✔✔Encouraging biological controls to complement the other tools. The level of VM in the wool clip still He commented that being successful tends to fluctuate seasonally. In drier ”depends on your definition of success”. Tony and Pattianne have significantly years, when feed becomes scarce, His indicators of success include no reduced the area of the farm that is sheep push into thistle patches for feed new areas being invaded by thistles and heavily infested by thistle. Over the past and in doing so, increase the amount of declining VM levels in his wool clip. 20 years, heavily infested areas have VM in the wool. halved from around 10% of the farm to Tony lists two key factors critical to the just 5%. This has reduced vegetative The primary economic benefit from success of his strategy over the past matter contamination in their wool clip, controlling the thistle is a reduction of 20 years. giving a benefit worth around $6,600 VM in the wool. A higher VM content each year. in the wool clip can typically reduce The first is perseverance - “keep on the price Tony receives by 50‑60 c/kg of chipping away at it” with a consistent wool. Managing Onopordum thistle over approach. ✔ the last 20 years has avoided a Top tips 20% discount on the wool price due Tony and Pattianne’s suggestions to The second is getting the timing right for to VM, delivering a benefit of around farmers managing Onopordum thistle herbicide applications, especially MCPA. $6,600 per year. are: He said “the earlier you can spray, the better” because it is easier to kill the ✔ The costs of Onopordum thistle ✔It is more cost efficient and effective immature seedlings, thereby reducing management are largely integrated with to spray thistles in conjunction with other the number of plants maturing and the control of other broad leaf weeds, weeds. setting seed. such as Paterson’s curse. Annual weed ✔✔It is best to hit the largest and worst spraying costs have been estimated to The greatest challenge to success is patches with a boom spray of selective be $4,200 to treat 300 - 400 ha of the getting to the weed. For example, rocky property for broadleaf weeds each year. herbicide. outcrops and tree patches prevent About half of this, or $2,100 could be ✔✔Thistles need to be managed when spraying with the boom. Sheep camps solely attributed to thistle control. Tony they are impacting on production. are also problematic for access, as also uses MCPA plus chlorpyralid to these particularly fertile areas often ✔✔Keep thistles at a manageable level control large thistle plants, and based around rocks and trees. on treating 40-50 ha per year, this is - it may not be cost effective to try and estimated to cost a further $540. eradicate them, but it is too costly to let Tony believes that his weed them go. management strategy would apply in other regions. ✔✔Manage pastures to encourage competitiveness. ✔✔Biological controls are useful when combined with herbicides and pasture improvement in an overall weed management program, but don’t rely on them as the sole method.

11 Case Study 4 - Kyneton, Victoria

Case Study 4 - Cobargo Bob and Elizabeth Douglas, “Cobargo”, Kyneton, Victoria

The Douglas family has held Cobargo, a 123 ha grazing property near Kyneton in the Macedon Ranges of central Victoria, since 1970. Bob took over the management of the property from his parents in 1993.

The production system Prior to 1993, there were low to The incentive to act moderate infestations of Scotch thistles Prior to 1993, the property carried about Although small in scale, the property has on the property. The naturalised pastures 35 cows plus some cattle for fattening. been developed and managed to a set on the property at the time provided No pastures were sown, fertiliser use of commercial objectives since 1993. some competition to the thistles. was limited and there was a heavy Chipping of thistles was done on an reliance on bought in feed and fodder. The Douglas’ aim to improve the annual basis to achieve partial control. productivity of the property in a Since 1993, Bob has considerably lifted financially and environmentally The commencement of the pasture farm productivity. sustainable manner. introduction program increased the number of thistles and therefore the The property currently carries 80 spring Achieving this objective commenced need for a more strategic approach to calving cows plus progeny. The progeny with the preparation of a whole farm control. Thistles took advantage of the are carried through and sold at plan that identified drainage lines and cultivation, increased soil fertility and 18 months. In addition, the property three soil types on the property, and low plant populations in the newly sown runs a flock of 250 spring lambing plotted the location of existing and pasture - all a part of the early stages of Suffolk ewes. future infrastructure including laneways, pasture improvement. fencing and stock watering points. Remnant vegetation and the location of Onopordum thistles Even though systematic control of shelter belts were also incorporated into The two main weed species in the area Scotch thistles has been practiced the whole farm plan. are scotch thistles and gorse. When at Cobargo for many years, soil seed left uncontrolled, both species provide reserves are activated by cultivation, The desire to control thistles was habitat for vermin including rabbits and airborne seed is blown in by the driven by a number of factors including and foxes. Both weeds compete with wind. These infestations could quickly profitability, management and personal pasture, reducing carrying capacity. dominate in the absence of a control satisfaction. The prime driver was the Wool can also be contaminated by the program. commitment to improve profitability weed seeds and with resulting price through pasture introduction, increased discounts. fertility and increased carrying capacity. In the absence of weeds, pastures can be grazed more effectively and there is less contamination of fodder and livestock products.

12 Case Study 4 - Kyneton, Victoria

A key driver was also the personal satisfaction of being able to work and live in a weed free environment. Scotch thistles germinate on the property each year mainly from airborne seed landing on the property. Unless these germinations are controlled annually, the extent of Scotch thistle on the property would quickly increase.

Since 1993, the objective for Cobargo has been to achieve a property free of weeds. The specific objective is to be weed free at the end of each year. The key to achieving this has been the implementation of an annual control program that aims to prevent any Scotch thistle plants on the property from seeding. Bob has adopted an integrated approach Herbicides and chipping to weed control that involves pasture Weed control aims to prevent seed introduction, grazing management and set on the property each year through Deliberation annual eradication to prevent Scotch a combination of spot spraying with Bob’s desire has always been to improve thistles seeding on the property. MCPA and hand chipping. This is done the productivity and profitability of the mainly in the spring though it is an property and to enhance the “presence” ongoing activity whenever weeds are of the property. Introduced pastures and Diversity in the found. the eradication of weeds were seen as being integral to achieving this objective. approach The weed management strategy Diligence Bob is an active member of the Kyneton focuses on healthy pastures that The success of the strategy relies on Prime Livestock Group. The group freely compete with thistles. It includes persistence. In addition to promoting exchanges information on all aspects of introduced pasture, cultivation for fodder introduced pastures and practising livestock production including pasture crops, increased fertiliser use, grazing rotational grazing, the strategy is to improvement and management, weed management, and weed control. prevent any weeds from setting seed, control, husbandry and marketing. Bob then germinating on the property each also obtains information from rural Pastures and cropping year. publications, suppliers and his own A pasture introduction program has research. been progressively implemented with This requires constant surveillance, and approximately 10 ha sown each year. eradication by spot spraying or hand This information, combined with a The designated area is cultivated in chipping wherever thistles are found. general awareness of the benefits of spring prior to sowing a summer fodder introduced pastures and the costs of crop, usually turnips. This is followed by The main source of any new infestations weed-infested pastures, drove Bob to introduced pastures, sown in autumn. is airborne seed from neighbouring embark on a control strategy. areas. It is not possible to prevent these On the higher areas, which tend to have airborne seeds settling and germinating lighter soils, the pasture mix includes on the property, but encouraging perennial ryegrasses, cocksfoot, white competitive pastures reduces the clover and a mix of sub clovers. Fescue opportunity for thistles to germinate and is substituted for cocksfoot on the lower establish. areas of the farm where the soils tend to be heavier.

Soil tests results help to determine the fertiliser program and lime is routinely applied when sowing new pastures. In addition, all established pastures receive annual applications of superphosphate.

13 Case Study 4 - Kyneton, Victoria

Summary Benefits and costs Keys to sucess Bob Douglas has effectively managed There is currently very little Scotch The key to the effective implementation Scotch thistles at Cobargo by implementing thistle on Cobargo, but seeds still of this strategy has been persistence, a control program focused on competitive germinate from airborne seed landing on particularly: pastures that includes: the property. ➜➜Identifying weeds during routine inspections of the property. ✔✔Boom spraying cultivated areas. An aggressive approach towards control ✔✔Sowing introduced pastures. in the early years reduced the Scotch ➜➜Carrying a spray unit and hoe on the thistle population on the property and farm utility so that identified weeds can ✔✔Spot spraying and chipping annual lowered the ongoing costs of control. be controlled immediately. infestations. ➜➜Ground spraying cultivated areas In recent years control has been Bob has adopted an integrated approach achieved mainly by chipping and limited or newly established pastures where to controlling weeds in general, involving spot spraying. infestations are most likely. pasture introduction, grazing management ➜➜Establishing introduced pastures and annual weed eradication. The combination of pasture introduction, and using rotational grazing to provide grazing management and weed control competition for weeds. The property is now relatively free of has increased the carrying capacity by scotch thistles and net farm returns have 250%. ➜➜Attending to annual infestations doubled to $325/ha. Without effective from airborne seed to prevent seed set. weed control, farm carrying capacity may Financial returns from the property By preventing seed set, infestations have reduced by 30% which would have have increased with the increase in in subsequent years are reduced and reduced the farm’s net income by around productivity. Cobargo now generates a ongoing control costs are lowered. $20,000 each year. net margin of around $325/ha. Without effective weed control, it is estimated that the carrying capacity would be reduced by 30%, which would reduce Top tips ✔ net income by around $20,000 each Bob recommends to someone else in this year. situation: Although all of the financial gain cannot ✔✔Don’t rely on a single tool – monitor the be attributed to the removal of thistles needs of the soils, the pastures and the from the property, thistles certainly livestock. provided the impetus to implement an integrated approach to weed ✔✔Be alert for weeds when routinely management focused on the pastures, inspecting the property soils and livestock. Bob and Elizabeth ✔✔Carry a spray unit and a hoe on the now have the personal satisfaction and farm utility or the motorbike so that any reward of being able to live and work on infestations can be treated when they are a productive, weed-free property observed during routine inspections of the property ✔✔Ground spray cultivated areas or newly established pastures ✔✔Establish and maintain productive mixed pastures in order to provide as much competition as possible for the weeds. ✔✔Control any annual infestations each year by spot spraying or chipping in order to prevent any seed being set on the property ✔✔Use appropriate grazing management to balance the needs of the pastures and livestock.

14 Other publications from AWI and MLA:

3D Weed Management: Onopordum thistles

Tips & Tools: Weed removers, pasture improvers – Effective weed control

For more information contact: AWI www.wool.com.au Care is taken to ensure the accuracy of the information or 1800 070 099 contained in this publication. However MLA and AWI cannot accept responsibility for the accuracy or completeness of the information or opinions contained MLA in the publication. You should make your own enquiries www.mla.com.au before making decisions concerning your interests. or 1800 023 100

15 Tel 1800 023 100 Tel 1800 070 099 www.mla.com.au www.wool.com.au