Weed Science Commons^™

Towards Effective Management: Toxicity, Causal Mechanism And Controlling Strategy Of Toxic Rangeland Weeds In Western China, Wei He, Yongmei Liu, Hao Lu, Baoyu Zhao, Chonghui Mo, Juying Wu, Nengtai Da, Yahui Wei

IGC Proceedings (1977-2023)

Toxic rangeland weeds (TRWs) pose a great threat to animal husbandry. Currently, an estimated 33 million hectares of pasture (10%) in western China is infested by a variety of toxic weeds, including Stellera chamaejasme, Oxytropis spp., Astragalus spp., Achnatherum inebrians. The spread of these toxic weeds results in huge annual economic losses of more than $2.4 billion USD (direct and indirect). A combination of ecology, molecular biology, biochemistry and field practise methods will be used to identify and evaluate TRWs, explore the mechanism of toxicity, and more importantly, understand the causal mechanism by which TRWs flourish. The knowledge …

Effect Of Sample Handling And Storage On Ergovaline Concentration In Fresh Tall Fescue Samples, Krista L. Cotten, Lori Smith, Cynthia L. Gaskill, Robert Coleman, S. Ray Smith

IGC Proceedings (1977-2023)

Ergovaline is an ergot alkaloid produced by an endophyte (Neotyphodium coenophialum Morgan-Jones and Gams), found in tall fescue (Schedonorus arundinacea=Festuca arundinacea Schreb.) and causes a range of disorders across livestock species. The concentration of ergovaline within a plant can vary by variety, management, time of year, location and weather conditions (Smith et al. 2009). Due to the significant economic impact of fescue toxicity in livestock, many samples are tested every year in research and diagnostic laboratories. Ergovaline is known to be unstable and affected by many variables; therefore sample handling is critical to obtaining accurate and consistent …

Effectiveness Of Tronador To Control Brittlebush In Buffelgrass Pastures At Central Sonora, México, Fernando Ibarra-Flores, Martha Martin, Salomón M. Moreno, Fernando Ibarra Jr., Jared Atondo, Francisco B. Denogean, Alfredo V. Aguilar, Rafael Retes

IGC Proceedings (1977-2023)

Buffelgrass (Cenchrus ciliaris L.) is an introduced species which is planted in low productive semi-arid rangelands in northern Mexico to increase productivity and ranchers profit. Brittlebush (Encelia farinosa) is a native half size shrub of low forage value that invades buffelgrass stands. Buffelgrass pastures lose productivity as brittlebush densities increase.

Once brittlebush infestations occur plant densities do not decline unless brush control practices are applied. Mechanical treatments are mainly used when grass seeding is needed. Prescribed burning and manual control as well as granular herbicides have resulted on good plant control. Most liquid herbicides are either not …

A Guide To Noxious Plants As An Educational Resource Of Veterinary Medicine Students, M. G. Klich, G. Atencio, N. Autalán, C. Busson, M. Chazarreta, G. Estevanacio, B. Fernández, G. Lucero, E. Moscovakis, S. Peña, B. Shaap, D. Vallejo

IGC Proceedings (1977-2023)

The School of Veterinary UNRN is located in the town of Choele Choel (39° 17'S, 65° 39'W), in Northern Patagonia, Argentina. The climate is semi-arid with a historical average annual continental rainfall of 303 mm, with marked daily and seasonal temperature ranges. However, the type of vegetation that can be found in the area ranges fromxerophytic shrubs to hydrophytic vegetation because the arid plateau is crossed by the broad valley of Río Negro. Due to the topographic distribution of agricultural and livestock farms, the toxic plants for livestock may be found in the irrigated valleys or arid shrubby camps.

Integrating Mechanical And Cultural Control Treatments To Manage The Invasive Shrub Chromolaena Odorata In Grassland Areas, Muhammad Rusdy, E. K. Budiman

IGC Proceedings (1977-2023)

Chromolaena odorata (L.) King and H. Robinson, is a major invasive weed of pastures and plantation crops in many countries and has become one of the worst invasive plants in grassland areas in Indonesia. Chromolaena can grow rapidly and form infestations that can suppress pasture by competing for nutrients and water, and by over-shading. Its allelopathic effect lowers productivity of desirable forage species with a concomitant loss of livestock production. Chromolaena leaves, especially when young, are toxic to animals due to high levels of nitrate (5 - 6 times above toxic level) (Sajise 1974).

Control of Chromolaena is difficult due …

Dynamic Of Soil Mesofauna Of Fixed Sand Dunes On The Songnen Grasslands, Northeastern China, Xiuqin Yin, Zhenhai Wang, Dandan Zhang

IGC Proceedings (1977-2023)

Grasslands cover vast land areas in semi-arid and semi-humid regions. Sand dunes, most of which are fixed sand dunes, form a large portion of grasslands. Vegetation on fixed sand dunes is an important part of grassland ecosystem productivity, and topographic position is one of the important factors resulting in the differences among vegetation, soil, etc. (Sakai and Ohsawa, 1994; Nagamatsu and Miura, 1997).

An important component of soil fauna ecology is to analyze the distribution of soil fauna and its influencing factors. On the small scale, the ozone factors become the dominant factor affecting the soil fauna (Frouz et al., …

Fodder Yield Of Baby Corn (Zea Mays L.) As Influenced By Mulching, Liming And Integrated Nutrition Management Under Foot Hill Condition Of Nagaland, Rakesh Kumar, Bidyut C. Deka, Manoj Kumar, Neivah Hansing

IGC Proceedings (1977-2023)

Baby corn (Zea mays L.) being one of the most important dual purpose crop is grown widely round the year for its cob as well as green fodder in India. It has an edge over the other cultivated fodder crops due to its higher production potential, wider adaptability, fast growing nature and excellent fodder quality free from toxicants. Baby corn production has been directly integrated with dairying farms in different countries because only 13-20% of fresh ear weight is used as human food and the rest (silk, husk and green stalk) can be used as excellent feed materials for …

Effects Of Abscisic Acid On Alleviation Of Aluminum Toxicity In Alfalfa, Yuan An, Shengyin Wang, Peng Zhou

IGC Proceedings (1977-2023)

On a global scale, acidic soils cover an estimated 37.8 million km² of the earth's surface, and up to 50% of the world’s potentially arable soils are acidic. Aluminum (Al) is highly abundant in acid soil conditions. At low (< 5.5) pH, a toxic form of aluminum, Al³⁺, is solubilized from aluminosilicate clay minerals into soil solutions. High concentrations of Al³⁺ in soil solutions caused seriously damage to plants by inhibiting cell elongation and division in roots, leading to swollen root apices with poor or no root-hair development, and decreasing plant growth (Kochian et al., 2005). Al toxicity represents one of the most important …

Effect Of Arbuscular Mycorrhize On Growth And Productivity Of Stylosanthes Seabrana, Neha Chakravarty, Ashok Shukla, Anil Kumar, S. K. Dhyani, Taru Nagori

IGC Proceedings (1977-2023)

Stylosanthes seabrana, an important range legume was introduced in India in the year 1998 through ACIAR-ICAR joint project. It has given good results under agroforestry/silvopastoral systems and can be grown as sole pasture crop or along with compatible grasses/legumes on a variety of soils. For its year round production, intensive cutting approach is generally employed. Under such conditions, plant demands large amount of soil nutrients for better productivity, which are generally applied as inorganic fertilizers (Chandra et al., 2006).

In soils with low nutrient contents especially phosphorus (P), large amount of phosphatic fertilizers are required for establishment and growth …

Anatomical Characteristics And Leaf Blade Digestibility Of Five Panicum Genotypes Under Integrated Crop-Livestock-Forest System, Mariana Pereira, Roberto G. Almeida, Maria Da Graça Morais, Beatriz Lempp, Davi José Bungenstab

IGC Proceedings (1977-2023)

Integrated crop-livestock-forest systems (ICLF) are intended to increase land use efficiency and to harvest benefits from interactions among the components involved. Thus, cattle husbandry success on such systems depends on the suitability and adaptability of the forages used. Shadow causes stress to plants growing in the understory of ICLF systems due to limitation of photo synthetically active radiation, whose intensity varies with location, time of the year and the tree component.

Reduction of light incidence on forage leads to limited growth rates as a function of energy restriction necessary to the photosynthetic processes, requiring a number of morphological, physiological, structural …

Radiation Use Efficiency On Campos Grasslands With Contrasting Grazing Methods, Patricia Basile, Oscar Blumetto, Daniel Formoso, Guadalupe Tiscornia

IGC Proceedings (1977-2023)

In Uruguay, natural grasslands cover about 67% of the lands of the country. The Basaltic region occupies 4 millions of hectares and it has the highest proportion of natural grasslands of the country. In these pastures, livestock management is applied traditionally associated with intense grazing, with high loads, high sheep / cattle relations, with long periods of occupation and continuous grazing or with short rest periods. This livestock management is the main reason of degradation of natural grasslands. In Basaltic deep soils, it results in the loss of high value species with a decrease in productivity (Millot et al., …

Plant And Animal Responses To Different Grazing Regimes On A Meadow Steppe In Northeast China, Deli Wang, Zhiming Yang, Ling Wang

IGC Proceedings (1977-2023)

Grazing by domestic herbivores is often considered to be an essential factor governing grassland vegetation and animal production (Hodgson and Illius 1996). During recent decades, there is increasing interest as a fundamental interaction between plant-animal interface, especially for the simultaneous or interactive responses of plants and animals to grassland grazing regimes (Liu et al., 2015), which benefits on improving the efficiency of grazing or grassland resource management. To achieve sustainable animal productivity and maintain the stability of grasslands, farmers or stakeholders need to employ optimal grazing strategies or regimes based on practical grassland vegetation and environments. Unfortunately, up to date …

Effect Of Sheep Grazing And Rainfall On The Ecology Of Lasiurus Sindicus-Dominated Grassland In Hot Arid Zone Of India, Suresh Kumar, J. P. Singh, K. Venkatesan

IGC Proceedings (1977-2023)

Thar Desert in India is very fragile owing to frequent drought and low rainfall which causes extreme stress on biodiversity of region especially on livestock due to limited seasonal grazing resources. Despite inhospitable and harsh climate, as well as anthropogenic pressures, Indian arid zone has 682 species belonging to 352 genera and 87 families. Some 63 species are introduced belonging to 37 genera and 9 families. Compared to other deserts of the world, this desert has higher number of endemic species, i.e. 6.4%. Poaceae and Leguminosae are the largest species. All these species have typical habitat-plant cover …

Changes In Stable Fraction Of Soil Organic Carbon And Microbial Structure In Response Of Grazing Intensity, Wenjie Lu, Yingjun Zhang, Liu Nan

IGC Proceedings (1977-2023)

Carbon sequestration is one of the most important ecological function of the grassland. Soils contain more carbon than in vegetation in the form of soil organic matter (SOM). But grassland soils are vulnerable to disturbances caused by human activities. Grazing may result in various disturbances to both soil and vegetation under different grazing intensities (Bai et al., 2012). Grazing led to the shifts in amount and composition of soil organic matter. In previous studies, the chemical methods were used to separate soil into the different pools according to the stability of SOM (Carvalho Leite et al., 2004), but they cannot …

Chemical Composition Of Woody Species At Browsed Caatinga Under Different Forage Allowance, Osniel F. De Oliveira, Mércia V. F. Dos Santos, Márcio V. Da Cunha, James P. Muir, Evaristo J. Oliveira De Souza, Felipe M. Saraiva

IGC Proceedings (1977-2023)

Native rangelands are essential for Brazilian livestock production in the northeast Caatinga because they are abundant and inexpensive. Greater knowledge of nutritive values of these native plants is a needed because they fit well in prevailing edapho-climatic conditions. The chemical composition of plants, however, may differ according to ontogeny, elevation, soil, climate, plant community and human actions. Caatinga plants usually have high crude protein (CP) although some of this is fiber-bound (Santos et al., 2009). Browse can therefore become a key livestock diet component.

Condensed tannins (CT) in browse can provide benefits, including anthelmintic activity greater amino acid absorption, …

In Search Of An Alternative To Fire For Manipulating Bush Encroachment In The Arid Karoo Region Of South Africa, S. Theron, J. C. Botha, A. Marais

IGC Proceedings (1977-2023)

Burning of natural rangeland in order to rejuvenate and increase palatability of grazing is a common practice in parts of South Africa. Concern about the long-term effects on biodiversity and the depletion of much-needed soil car-bon led to this investigation.

Aminopyralid + Metsulfuron-Methyl For Cost-Effective Control Of Hard To Kill Pasture Weeds, Gregory S. Wells, Christopher O. Love, Natalie V. Elias, Colin L. Plater, Robert A. Annetts

IGC Proceedings (1977-2023)

This paper summarises research trials conducted from 2010 to 2013 to determine speed of brownout and efficacy of an aminopyralid + metsulfuron-methyl herbicide product in pastures compared to metsulfuron alone and current commercial standards.

Methods For Estimating Seed Production Of Two Summer-Active Grass Weeds, Setaria Pumila And Digitaria Sanguinalis, In New Zealand Dairy Pastures, Katherine N. Tozer, Catherine A. Cameron

IGC Proceedings (1977-2023)

Undesirable C4 annual grasses such as summer grass (Digitaria sanguinalis, (L.) Scop., SG) and yellow bristle grass (Setaria pumila (Poir.) Roem. et Schult., YBG) are prevalent in dairying regions in the North Island of New Zealand. Field surveys of 39 dairy pastures in the central North Island demonstrated that their percentage ground cover has tripled over the last four years (Tozer et al. 2012). The prolific seed production of these species is thought be facilitating this increase in ground cover. However, little information is available on their fecundity in dairy pastures. Counting the number of seeds …

Foragemax® Herbicide–A New Product For Weed Management In Forage Brassicas In Australia, Gregory S. Wells, Peter J. Nott

IGC Proceedings (1977-2023)

ForageMax Herbicide (50 g/L Aminopyralid + 100 g/L ARYLEX^TM, active ingredient Halauxifen-methyl) is a new herbicide product for selective weed control in rape or turnips in Australia. ARYLEX (development code XDE-729 methyl) is a novel arylpicolinate synthetic auxin herbicide being developed by Dow AgroSciences for post-emergence broadleaf weed in cereals and several other crops. This paper describes the research conducted by Dow AgroSciences that support the application to register the product in Australia.

Unpalatable Perennial Grass Invasion In Central-East Argentina Native Grasslands: Processes, Implications And Recovery, Roberto A. Distel

IGC Proceedings (1977-2023)

In temperate semiarid central-east Argentina, unpalatable perennial grasses (UPG) have been steadily invading native grasslands formerly dominated by palatable perennial grasses (PPG). The objective of this contribution is to provide a synthesis of underlying processes and implications of UPG invasion, as well as recovery strategies. Results have shown that heavy selective grazing on PPG reduces their superior competitive ability. Gaps formed due to reduced competition by PPG provide safe sites for UPG establishment. The development of large, long-lived tussock of UPG, in combination with high standing crop accumulation, impairs PPG establishment even in absence of grazing. UPG produce sclerophyllous tissues, …