Flaxleaf fleabane (Conyza bonariensis (L.) Cronquist) has been considered a major weed in dryland... more Flaxleaf fleabane (Conyza bonariensis (L.) Cronquist) has been considered a major weed in dryland cropping systems in Australia. Resistance in populations of C. bonariensis to glyphosate has also been confirmed. The weed is very difficult to control with any single herbicide application especially when herbicides are applied after the bolting stage. Anecdotal evidence suggests that some chemicals might affect fleabane seed viability and/or dormancy based on the observations that seeds collected from certain paddocks did not germinate. Glasshouse experiments were conducted to investigate whether applications of glyphosate and paraquat could sterilise the weed seeds and affect seed dormancy of fleabane. Results showed that both herbicides affected the seed viability and dormancy, depending on the application timing and the herbicide. The herbicide-induced dormancy decreased during storage under laboratory conditions.
Weeds are a major impediment to crop and pasture production and profitability in Australian farmi... more Weeds are a major impediment to crop and pasture production and profitability in Australian farming systems, and knowledge of their occurrence is vital in devising weed management solutions. This study examined the relationships between weed and crop species from observations made during surveys of randomly selected fields in grain and/or pasture production. Between 2013 and 2017, 996 fields across New South Wales (NSW) were surveyed to record the occurrence and density of weed species. Annual ryegrass (Lolium rigidum) (69% of fields), wild oats (Avena spp.) (60%), and sowthistle (Sonchus oleraceus) (34%) were the most common species identified, with a total of 65 weed species recorded to be occurring in NSW cropping fields. Densities of occurring weeds were low, at one plant per square metre or less. Multiple species of wild oats were recorded, with their occurrence varying between survey regions; for example, Avena sterilis subsp. ludoviciana was more prevalent in the north and Av...
Bovine maternal behavior is known to be influenced by a variety of factors including hormonal med... more Bovine maternal behavior is known to be influenced by a variety of factors including hormonal mediation, breed, age, parity, host genetics and general management practices. Following centuries of varying levels of domestication processes, the behavior of the bovine cow has altered from that of her original wild ungulate ancestors, although many maternal instincts have remained unchanged. The influence of maternal behavior on calf health and performance is of interest to cow-calf beef production operations, as in most instances, the cow is solely responsible for rearing the calf until weaning. However, investigating the magnitude of this influence is challenging, in part because objective measurement of behavioral traits is difficult, particularly in extensive settings. In recent years, while a number of remote monitoring devices have been developed that afford opportunities for objective measurement of behavioral traits in livestock, characterization of physiological mechanisms that...
Barley grass (Hordeum spp.) is an annual weed of southern Australian mixed farming regions causin... more Barley grass (Hordeum spp.) is an annual weed of southern Australian mixed farming regions causing significant crop revenue loss and carcass damage in grazing sheep. Increased reliance on herbicides for management of barley grass has led to the development of herbicide resistance across southern Australia. Integrated weed management tactics have recently been used to manage barley grass populations, and have proven effective in reducing reliance on herbicides for management. Field studies performed in 2016 and 2017 examined the use of post-emergent herbicides and strategic defoliation through mowing on a barley grass infestation in a mixed legume pasture in Wagga Wagga, NSW. This paper presents data from the first year of the study. Significant differences between herbicide-only treatments revealed propaquizafop to be 99% effective in reducing barley grass survival and seed production in contrast to paraquat, which was generally ineffective. A significant interaction between mowing ...
Chaff lining and chaff tramlining are forms of Harvest Weed Seed Control (HWSC) that, owing to th... more Chaff lining and chaff tramlining are forms of Harvest Weed Seed Control (HWSC) that, owing to their low cost and ease-of-implementation, have potential for wide-spread adoption. The chaff environment is likely to be suboptimal (compacted soil and chaff covering) for seed persistence and seedling establishment, therefore, this practice has the potential to be as effective as other forms of HWSC in driving down weed seed banks. To examine the efficacy of chaff lining and chaff tramlining treatments, a series of field experiments were set up at three locations (Wagga Wagga, Narrabri and Irongate) during the 2017 harvest. The aim of these studies was to investigate the survival of 100 seed lots of annual ryegrass, brome grass, wild oats, wild radish, turnip weed, Impact of chaff lining/tramlining on the seed persistence and emergence of weeds
Grass seed contamination of sheep carcasses and skins results in significant losses across the Au... more Grass seed contamination of sheep carcasses and skins results in significant losses across the Australian lamb and mutton value chains. Seven grass species found across Victoria (VIC) and New South Wales (NSW) are known to significantly impact carcass quality, with barley grass and brome grass as key perpetrators. To evaluate current trends associated with carcass weed seed contamination, extensive abattoir datasets (2009–2014) provided by Animal Health Australia (AHA) were analysed by state and biogeographic region. Significant differences in regional infestation were noted, with reduced contamination observed in Tasmania (TAS) and VIC in contrast to other states. No significant differences were observed in contamination between NSW and Queensland (QLD). Highest contamination occurred throughout the mixed cropping and pastoral zones, with notable events also in the high rainfall zone. Sex and age of animal were identified to have impacted seed contamination. These findings have imp...
Flaxleaf fleabane (Conyza bonariensis (L.) Cronquist) has been considered a major weed in dryland... more Flaxleaf fleabane (Conyza bonariensis (L.) Cronquist) has been considered a major weed in dryland cropping systems in Australia. Resistance in populations of C. bonariensis to glyphosate has also been confirmed. The weed is very difficult to control with any single herbicide application especially when herbicides are applied after the bolting stage. Anecdotal evidence suggests that some chemicals might affect fleabane seed viability and/or dormancy based on the observations that seeds collected from certain paddocks did not germinate. Glasshouse experiments were conducted to investigate whether applications of glyphosate and paraquat could sterilise the weed seeds and affect seed dormancy of fleabane. Results showed that both herbicides affected the seed viability and dormancy, depending on the application timing and the herbicide. The herbicide-induced dormancy decreased during storage under laboratory conditions.
Weeds are a major impediment to crop and pasture production and profitability in Australian farmi... more Weeds are a major impediment to crop and pasture production and profitability in Australian farming systems, and knowledge of their occurrence is vital in devising weed management solutions. This study examined the relationships between weed and crop species from observations made during surveys of randomly selected fields in grain and/or pasture production. Between 2013 and 2017, 996 fields across New South Wales (NSW) were surveyed to record the occurrence and density of weed species. Annual ryegrass (Lolium rigidum) (69% of fields), wild oats (Avena spp.) (60%), and sowthistle (Sonchus oleraceus) (34%) were the most common species identified, with a total of 65 weed species recorded to be occurring in NSW cropping fields. Densities of occurring weeds were low, at one plant per square metre or less. Multiple species of wild oats were recorded, with their occurrence varying between survey regions; for example, Avena sterilis subsp. ludoviciana was more prevalent in the north and Av...
Bovine maternal behavior is known to be influenced by a variety of factors including hormonal med... more Bovine maternal behavior is known to be influenced by a variety of factors including hormonal mediation, breed, age, parity, host genetics and general management practices. Following centuries of varying levels of domestication processes, the behavior of the bovine cow has altered from that of her original wild ungulate ancestors, although many maternal instincts have remained unchanged. The influence of maternal behavior on calf health and performance is of interest to cow-calf beef production operations, as in most instances, the cow is solely responsible for rearing the calf until weaning. However, investigating the magnitude of this influence is challenging, in part because objective measurement of behavioral traits is difficult, particularly in extensive settings. In recent years, while a number of remote monitoring devices have been developed that afford opportunities for objective measurement of behavioral traits in livestock, characterization of physiological mechanisms that...
Barley grass (Hordeum spp.) is an annual weed of southern Australian mixed farming regions causin... more Barley grass (Hordeum spp.) is an annual weed of southern Australian mixed farming regions causing significant crop revenue loss and carcass damage in grazing sheep. Increased reliance on herbicides for management of barley grass has led to the development of herbicide resistance across southern Australia. Integrated weed management tactics have recently been used to manage barley grass populations, and have proven effective in reducing reliance on herbicides for management. Field studies performed in 2016 and 2017 examined the use of post-emergent herbicides and strategic defoliation through mowing on a barley grass infestation in a mixed legume pasture in Wagga Wagga, NSW. This paper presents data from the first year of the study. Significant differences between herbicide-only treatments revealed propaquizafop to be 99% effective in reducing barley grass survival and seed production in contrast to paraquat, which was generally ineffective. A significant interaction between mowing ...
Chaff lining and chaff tramlining are forms of Harvest Weed Seed Control (HWSC) that, owing to th... more Chaff lining and chaff tramlining are forms of Harvest Weed Seed Control (HWSC) that, owing to their low cost and ease-of-implementation, have potential for wide-spread adoption. The chaff environment is likely to be suboptimal (compacted soil and chaff covering) for seed persistence and seedling establishment, therefore, this practice has the potential to be as effective as other forms of HWSC in driving down weed seed banks. To examine the efficacy of chaff lining and chaff tramlining treatments, a series of field experiments were set up at three locations (Wagga Wagga, Narrabri and Irongate) during the 2017 harvest. The aim of these studies was to investigate the survival of 100 seed lots of annual ryegrass, brome grass, wild oats, wild radish, turnip weed, Impact of chaff lining/tramlining on the seed persistence and emergence of weeds
Grass seed contamination of sheep carcasses and skins results in significant losses across the Au... more Grass seed contamination of sheep carcasses and skins results in significant losses across the Australian lamb and mutton value chains. Seven grass species found across Victoria (VIC) and New South Wales (NSW) are known to significantly impact carcass quality, with barley grass and brome grass as key perpetrators. To evaluate current trends associated with carcass weed seed contamination, extensive abattoir datasets (2009–2014) provided by Animal Health Australia (AHA) were analysed by state and biogeographic region. Significant differences in regional infestation were noted, with reduced contamination observed in Tasmania (TAS) and VIC in contrast to other states. No significant differences were observed in contamination between NSW and Queensland (QLD). Highest contamination occurred throughout the mixed cropping and pastoral zones, with notable events also in the high rainfall zone. Sex and age of animal were identified to have impacted seed contamination. These findings have imp...
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