Detection and prevention of the dispersal of the seeds of Chilean needle grass (Nassella neesiana Trin. & Rupr. (Barkworth)) in hay bales
- Authors: Weller, Sandra
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: Invasive and noxious weeds are well known as a pervasive problem, imposing significant economic burdens on all areas of agriculture, and thus their control and eradication are of central concern to the industry. Whilst there are multiple possible pathways of weed dispersal in this industry, of particular interest to this discussion is how the unintended dispersal of Chilean needle grass (Nassella neesiana) weed seeds, within emergency fodder, may be prevented. Periodic drought is a feature of the Australian climate, which, together with natural disasters of flood and bushfire, necessitates the urgent provision of emergency fodder for maintenance of livestock production. However, previous investigations into weed seed dispersal by this fodder type have revealed a significant risk for the dispersal of a number of noxious weeds well beyond their current range. Because preventive work, relating to detection and eradication of noxious species, is at an early stage of development, the development of faster, more reliable, and non-destructive sampling methods for seed species has become essential. In addition to prevention of weed seed dispersal in fodder, the use of appropriate methods of controlling troublesome pasture weeds in situ is of relevance for addressing established infestations. Whilst silage preservation is one such typical method that can reduce weed seed input into the soil seed bank, there is currently little data on the absolute effectiveness of this method for control of N. neesiana. To investigate whether rapid detection of seeds in bales is possible and how the numbers of seeds in a pasture are linked to the numbers of seeds that may be incorporated into hay bales made from an infested pasture, an investigation of a rapid, non-destructive technique to detect seeds in bales, together with an examination of a pasture to estimate seed density and dispersal prior to baling, were carried out. Additionally, since pastures infested with this weed are of no use for producing hay and little use for grazing, a third experiment was devised, which was an investigation of silaging for preventing inadvertent seed input into pasture soil seed banks. This thesis has shown that this approach of non-destructive core sampling of bales to detect the seeds of N. neesiana, and possibly others, which can be visually recognised, shows promise for those involved in weed control. Similarly, the simultaneous demonstration that silage fermentation is an efficient viable method for both eliminating viability of mature (germinable) seeds of this species while also reducing the probability of injury to livestock from these seeds, confirms that reducing the impact of this weed in agro-ecological systems and on livestock during emergency situations is possible.
- Description: Doctor of Philosophy
- Authors: Weller, Sandra
- Date: 2016
- Type: Text , Thesis , PhD
- Full Text:
- Description: Invasive and noxious weeds are well known as a pervasive problem, imposing significant economic burdens on all areas of agriculture, and thus their control and eradication are of central concern to the industry. Whilst there are multiple possible pathways of weed dispersal in this industry, of particular interest to this discussion is how the unintended dispersal of Chilean needle grass (Nassella neesiana) weed seeds, within emergency fodder, may be prevented. Periodic drought is a feature of the Australian climate, which, together with natural disasters of flood and bushfire, necessitates the urgent provision of emergency fodder for maintenance of livestock production. However, previous investigations into weed seed dispersal by this fodder type have revealed a significant risk for the dispersal of a number of noxious weeds well beyond their current range. Because preventive work, relating to detection and eradication of noxious species, is at an early stage of development, the development of faster, more reliable, and non-destructive sampling methods for seed species has become essential. In addition to prevention of weed seed dispersal in fodder, the use of appropriate methods of controlling troublesome pasture weeds in situ is of relevance for addressing established infestations. Whilst silage preservation is one such typical method that can reduce weed seed input into the soil seed bank, there is currently little data on the absolute effectiveness of this method for control of N. neesiana. To investigate whether rapid detection of seeds in bales is possible and how the numbers of seeds in a pasture are linked to the numbers of seeds that may be incorporated into hay bales made from an infested pasture, an investigation of a rapid, non-destructive technique to detect seeds in bales, together with an examination of a pasture to estimate seed density and dispersal prior to baling, were carried out. Additionally, since pastures infested with this weed are of no use for producing hay and little use for grazing, a third experiment was devised, which was an investigation of silaging for preventing inadvertent seed input into pasture soil seed banks. This thesis has shown that this approach of non-destructive core sampling of bales to detect the seeds of N. neesiana, and possibly others, which can be visually recognised, shows promise for those involved in weed control. Similarly, the simultaneous demonstration that silage fermentation is an efficient viable method for both eliminating viability of mature (germinable) seeds of this species while also reducing the probability of injury to livestock from these seeds, confirms that reducing the impact of this weed in agro-ecological systems and on livestock during emergency situations is possible.
- Description: Doctor of Philosophy
An investigation of the effects of stage of ensilage on Nassella neesiana seeds, for reducing seed viability and injury to livestock
- Weller, Sandra, Florentine, Singarayer, Sillitoe, Jim, Grech, Charles, McLaren, David
- Authors: Weller, Sandra , Florentine, Singarayer , Sillitoe, Jim , Grech, Charles , McLaren, David
- Date: 2016
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 6, no. (2016), p. 1-7
- Full Text:
- Reviewed:
- Description: The noxious weed Nassella neesiana is established on a wide range of productive land throughout southeastern Australia. N. neesiana seeds, when mature, are sharp, causing injury to livestock, thus posing a problem in fodder bales. To reduce infestations of agricultural weeds in situ, production of silage from weed-infested pastures is practised as part of integrated weed management (IWM). However, there is little data to demonstrate whether this process is useful to reduce infestations or the harmful properties of N. neesiana. Therefore, the minimum duration of ensilage required to reduce the viability of N. neesiana seeds was investigated, both with and without addition of ensilage inoculants in this process. Also, the decreasing propensity of the seeds to injure livestock, after various times and conditions of ensilage, was assessed. Ensilage inoculant reduced seed germination probability to zero after 35 days. When no inoculant was added, zero viability was achieved after 42 days. A qualitative assessment of the hardness of ensilaged seeds found seed husks were softer (and therefore safer) after 42 days, whether inoculant was used or not. Therefore, we suggest that both the viability of N. neesiana seeds and hardness of seed casings are significantly reduced after 42 days, thereby reducing the risks of seed dispersal and injury to livestock.
- Authors: Weller, Sandra , Florentine, Singarayer , Sillitoe, Jim , Grech, Charles , McLaren, David
- Date: 2016
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 6, no. (2016), p. 1-7
- Full Text:
- Reviewed:
- Description: The noxious weed Nassella neesiana is established on a wide range of productive land throughout southeastern Australia. N. neesiana seeds, when mature, are sharp, causing injury to livestock, thus posing a problem in fodder bales. To reduce infestations of agricultural weeds in situ, production of silage from weed-infested pastures is practised as part of integrated weed management (IWM). However, there is little data to demonstrate whether this process is useful to reduce infestations or the harmful properties of N. neesiana. Therefore, the minimum duration of ensilage required to reduce the viability of N. neesiana seeds was investigated, both with and without addition of ensilage inoculants in this process. Also, the decreasing propensity of the seeds to injure livestock, after various times and conditions of ensilage, was assessed. Ensilage inoculant reduced seed germination probability to zero after 35 days. When no inoculant was added, zero viability was achieved after 42 days. A qualitative assessment of the hardness of ensilaged seeds found seed husks were softer (and therefore safer) after 42 days, whether inoculant was used or not. Therefore, we suggest that both the viability of N. neesiana seeds and hardness of seed casings are significantly reduced after 42 days, thereby reducing the risks of seed dispersal and injury to livestock.
Finding needles in a haystack: an investigation of non-destructive method to detect the seeds of Chilean needle grass (Nassella Neesiana (Trin. & Rupr.) Barkworth) in round hay bales
- Weller, Sandra, Florentine, Singarayer, Ambrose, Graeme, Grech, Charles, McLaren, David
- Authors: Weller, Sandra , Florentine, Singarayer , Ambrose, Graeme , Grech, Charles , McLaren, David
- Date: 2012
- Type: Text , Conference paper
- Relation: 18th Australasian Weeds Conference p. 222-240
- Full Text: false
- Reviewed:
- Description: Preserved fodder is a key component in modern agricultural practice. Hay bales are commonly provisioned for livestock. Unfortunately this is also a significant source of new weed infestations, including those of noxious species. Because hay bales may be of a low absolute value the usual approaches for weed control, for example herbicide treatment, may be expensive to apply and therefore not justified by the expected economic returns for this commodity. The methods of detecting weed seeds in bales that have been employed to date suffer from several deficiencies. These include the inefficiently long time needed for testing, loss of the commodity by overly destructive sampling methods and a serious potential for a lack of ecological representation for the presence of weeds. It is proposed that an alternative method, which is both potentially more rapid and more ecologically representative for detecting the presence of the seeds of noxious weeds in hay bales should be devised.
- Authors: Weller, Sandra , Florentine, Singarayer , Ambrose, Graeme , Grech, Charles , McLaren, David
- Date: 2012
- Type: Text , Conference paper
- Relation: 18th Australasian Weeds Conference p. 222-240
- Full Text: false
- Reviewed:
- Description: Preserved fodder is a key component in modern agricultural practice. Hay bales are commonly provisioned for livestock. Unfortunately this is also a significant source of new weed infestations, including those of noxious species. Because hay bales may be of a low absolute value the usual approaches for weed control, for example herbicide treatment, may be expensive to apply and therefore not justified by the expected economic returns for this commodity. The methods of detecting weed seeds in bales that have been employed to date suffer from several deficiencies. These include the inefficiently long time needed for testing, loss of the commodity by overly destructive sampling methods and a serious potential for a lack of ecological representation for the presence of weeds. It is proposed that an alternative method, which is both potentially more rapid and more ecologically representative for detecting the presence of the seeds of noxious weeds in hay bales should be devised.
- «
- ‹
- 1
- ›
- »