Microcosm assessment of potential molluscicides for control of the rice snail Isidorella newcombi sens. lat. (Gastropoda: Basommatophora: Planorbidae)

1996 ◽  
Vol 47 (5) ◽  
pp. 673 ◽  
Author(s):  
MM Stevens ◽  
RJ Faulder ◽  
NE Coombes
Keyword(s):  
Field Conditions ◽  
Initial Screening ◽  
Screening Rate ◽  
Irrigated Rice ◽  
Fish Toxicity ◽  
Further Development ◽  
Over Time ◽  
Delayed Exposure

Twenty-seven pesticides were evaluated for their toxicity to mature Isidorella newcombi (Adams & Angas), a serious pest of irrigated rice in NSW, Australia. Evaluations were conducted using microcosms in which typical field conditions were simulated. Only 3 compounds, niclosamide, n-tritylmorpholine, and nicotinanilide, provided >95% mortality at an initial screening rate of 3 mg/L. These compounds were assessed at a range of rates using both immediate and delayed-exposure bioassays to determine LC values and comparative persistence. Niclosamide (as Bayer Bayluscide� 250 g/L EC) and n-tritylmorpholine (as Shell FresconB 165 g/L EC) were the most toxic (LC90, immediate exposure, 0.19 mg/L for both compounds), whilst the corresponding LC90 value for nicotinanilide (laboratory grade in DMSO) was 0.53 mg/L. Persistence (reflected by a slower increase in LC90 values over time in delayed exposure bioassays) was strongest in nicotinanilide and weakest in n-tritylmorpholine. Although niclosamide is the most promising compound for the control of I. newcombi, further development of nicotinanilide is also recommended, as it represents a potentially valuable tool for use in situations where low fish toxicity is required.

Response of seashore paspalum and bermudagrass to topramezone and triclopyr mixtures

2020 ◽  
pp. 1-8
Author(s):  
Clebson G. Gonçalves ◽  
Austin M. Brown ◽  
Suma Basak ◽  
J. Scott McElroy
Keyword(s):  
Field Conditions ◽  
Single Application ◽  
Seashore Paspalum ◽  
Application Timing ◽  
Application Programs ◽  
Over Time

Abstract Few options are available for controlling bermudagrass invasion of seashore paspalum. Bermudagrass and seashore paspalum tolerance to topramezone, triclopyr, or the combination of these two herbicides were evaluated in both greenhouse and field conditions. Field treatments included two sequential applications of topramezone (15.6 g ai ha−1) alone and five rates of topramezone + triclopyr (15.6 + 43.2, 15.6 + 86.3, 15.6 + 172.6, 15.6 + 345.2, or 15.6 g ai ha−1 + 690.4 g ae ha−1). Secondary greenhouse treatments included a single application of topramezone (20.8 g ha−1) or triclopyr (258.9 g ha−1) alone, or in combination at 20.8 + 258.9 or 20.8 + 517.8 g ha−1, respectively. Greenhouse and field results showed that topramezone applications in combination with triclopyr present opposite responses between bermudagrass and seashore paspalum. Topramezone increased bermudagrass injury and decreased seashore paspalum bleaching injury compared to topramezone alone. In field evaluations, topramezone + triclopyr at 15.6 + 690.4 g ha−1 used in sequential applications resulted in >90% injury to bermudagrass, however, injury decreased over time. Furthermore, sequential applications of topramezone + triclopyr at 15.6 + 690.4 g ha−1 resulted in >50% injury to seashore paspalum. Application programs including topramezone plus triclopyr should increase bermudagrass suppression and reduce seashore paspalum injury compared to topramezone alone. However, additional studies are needed because such practices will likely require manipulation of topramezone rate, application timing, application interval, and number of applications in order to maximize bermudagrass control and minimize seashore paspalum injury.

scholarly journals Globe fringerush (Fimbristylis miliacea) cross resistance to als-inhibitor herbicides under field conditions in irrigated rice in the south of Brazil

2013 ◽  
Vol 31 (4) ◽  
pp. 893-902 ◽  
Author(s):  
C.E. Schaedler ◽  
J.A. Noldin ◽  
D.S. Eberhardt ◽  
D. Agostinetto ◽  
N.R. Burgos
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Rice Fields ◽  
Field Conditions ◽  
Cross Resistance ◽  
Herbicide Application ◽  
The South ◽  
Santa Catarina ◽  
Irrigated Rice ◽  
South Of Brazil

ALS-inhibiting herbicides usually provide adequate weed control in irrigated rice fields. After consecutive years of use, the Cyperaceae species, globe fringerush (Fimbristylis miliacea) began to show resistance to ALS (acetolactate synthase) inhibitors. Globe fringerush is one of the most problematic herbicide-resistant weeds in irrigated rice in the state of Santa Catarina in the South of Brazil. The objective of this research was to examine cross resistance of globe fringerush to ALS inhibitors, under field conditions. Two experiments were conducted in a rice field naturally infested with ALS-resistant globe fringerush in Santa Catarina, in the 2008/09 and 2009/10 cropping seasons. The experimental units were arranged in randomized complete block design, with five replicates, consisting of two factors (herbicide and dose) in a 4 x 5 factorial arrangement. ALS herbicides included bispyribac-sodium, ethoxysulfuron, pyrazosulfuron-ethyl and penoxsulam. Six-leaf globe fringerush was sprayed with herbicide doses of 0, 0.5, 1, 2 and 4X the recommended doses in a spray volume of 200 L ha-1. The number of rice culm, filled and sterile grains, plant height, dry shoot biomass and grain yield were recorded. Globe fringerush control was evaluated 28 and 70 days after herbicide application (DAA); shoots were harvested at 13 weeks after herbicide application and dry weight recorded. Competition with globe fringerush reduced the number of culm and rice grain yield. The globe fringerush biotype in this field was resistant to all ALS herbicides tested. Penoxsulam had the highest level of activity among treatments at 28 and 70 DAA, but the control level was only 50% and 42%, respectively, in the second year of assessment. This was not enough to prevent rice yield loss. Alternative herbicides and weed control strategies are necessary to avoid yield losses in rice fields infested with ALS-resistant biotypes of globe fringerush.

scholarly journals Attributes of irrigated rice and soil solution as affected by salinity levels of the water layer

2010 ◽  
Vol 34 (4) ◽  
pp. 1049-1057 ◽  
Author(s):  
Thiago Isquierdo Fraga ◽  
Felipe de Campos Carmona ◽  
Ibanor Anghinoni ◽  
Elio Marcolin
Keyword(s):  
Soil Solution ◽  
Water Layer ◽  
Vegetative Stage ◽  
Patos Lagoon ◽  
Irrigated Rice ◽  
Flooded Rice ◽  
Salinity Levels ◽  
Growth Attributes ◽  
Water Transpiration ◽  
Over Time

In the State of Rio Grande do Sul, Brazil, flooded rice fields using Patos Lagoon as the source of water for irrigation are subject to be damaged by salinity, since this source is bound to the sea on its southern end. The sensitivity of rice is variable during plant development, being higher in the seedling and reproductive periods. However, there is not enough information about the behavior of plants under salt stress during the course of its development, especially in the vegetative stage. This study evaluated the effect of different levels of salinity of irrigation water on the salinity of soil solution over time and on some plant attributes, during the vegetative stage of rice. The study was conducted in a greenhouse, where seeds of the variety IRGA 424 were sown in pots and irrigated with water with electrical conductivity (ECi) levels of: 0.3, 0.75, 1.5, 3.0 and 4.5 dS m-1; from the tillering initiation (V4) until the panicle initiation (PI). The evaluations made were the electrical conductiviy of soil solution (ECe), the dry biomass of plants and stems, tillering, height and the transpiration of plants. The ECe increased with the ECi over time, and was determined by water transpiration flux in pots. The ECe values at the end of the experiment were high and, in most cases, higher than the critical values for flooded rice. The growth attributes of rice were negatively affected from ECi of 2.0 dS m-1 and ECe of 4.0 dS m-1.

scholarly journals The development of a model for assessing the level of impact of information and library services

2009 ◽  
Vol 29 (93) ◽  
pp. 43-49 ◽  
Author(s):  
Peter Brophy
Keyword(s):  
Library Services ◽  
Community Or ◽  
Further Development ◽  
Over Time

This paper describes the background to the development and application of a model of Levels of Impact of innovations in information and library services. The model is based on earlier work in the eLearning field and provides a tool for comparing the different effects of a service on individuals, either within a particular community or over time. The paper suggests that there is scope for further development and testing of the model to refine its application.

scholarly journals GEOECONOMIC ASPECTS OF THE MONETARY GLOBALIZATION

2020 ◽  
Vol 19 (Vol 19, No 3 (2020)) ◽  
pp. 395-408
Author(s):  
Oleksandr SHAROV
Keyword(s):  
Economic Globalization ◽  
International Level ◽  
Historical Process ◽  
Bretton Woods ◽  
Monetary System ◽  
The World ◽  
Further Development ◽  
Over Time ◽  
Qualitative Changes

Author defines monetary globalization and examines the historical process of spreading money and cash nexus across the globe. It is stated that money developed almost simultaneously in three great civilizations (Europe, India, China), but over time the Hellenistic form of money absorbed and universalized all other forms of money. The author examines in detail the process of distribution of metallic and then credit form of money and their impact on economic globalization. All these processes occurring both in the markets of separate countries or small regions and at the international level (where money started to act as global currency almost immediately after its appearance) constitute the essence of the monetary globalization. The author dwells on the post-Bretton Woods period of development of the World Monetary System, believing that the extensive phase of monetary globalization has come to an end at this stage and its further development will be caused by fundamental qualitative changes.

Peaceful Revolutions in Algeria and Sudan: the Factor of the Coronavirus Pandemic

2021 ◽  
pp. 37-46
Author(s):  
Nailia Fakhrutdinova
Keyword(s):  
Driving Forces ◽  
Arab Countries ◽  
African Studies ◽  
Long Period ◽  
First Time ◽  
Further Development ◽  
Over Time

The article deals with the problem of the post Arabic spring situation. Only three Arab countries remained unchanged in Africa: Morocco, Algeria and Sudan. After a long period of time their protesters remained outside the zone of active action, but over time they appeared in the streets again. The circumstances forced people to take to the streets. Moroccans were in a better situation, but gradually the population of Algeria and Sudan where the situation was especially serious began to criticize the policy of the authorities, although they did it exclusively peacefully. For the first time in Russian African studies, the author assesses all the driving forces of the events at the end of 2020 and early 2021 and, emphasizing the complications brought by the coronavirus pandemic, makes an analytical forecast for the further development of the situation.

The Topography of Historical Contingency

2012 ◽  
Vol 6 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Rob Inkpen ◽  
Derek Turner
Keyword(s):  
Initial Conditions ◽  
Historical Contingency ◽  
Scaling Effects ◽  
Historical Events ◽  
Change Over Time ◽  
Complex Landscape ◽  
Definition Of ◽  
Further Development ◽  
Over Time

Abstract Starting with Ben-Menahem’s definition of historical contingency as sensitivity to variations in initial conditions, we suggest that historical events and processes can be thought of as forming a complex landscape of contingency and necessity. We suggest three different ways of extending and elaborating Ben-Menahem’s concepts: (1) By supplementing them with a notion of historical disturbance; (2) by pointing out that contingency and necessity are subject to scaling effects; (3) by showing how degrees of contingency/necessity can change over time. We also argue that further development of Sterelny’s notion of conditional inevitability leads to our conclusion that the topography of historical contingency is something that can change over time.

The Application of Modern Metallurgical Principles And Knowledge to the Manufacture of Mokumé Gane (Wood-Grain Metal) Decorative Alloy

2004 ◽  
Vol 852 ◽  
Author(s):  
Ian T. Ferguson ◽  
Brian Derby ◽  
G. E. Thompson
Keyword(s):  
Aluminium Alloys ◽  
Success Rates ◽  
Hot Press ◽  
Visual Effects ◽  
Roll Bonding ◽  
Solid State Bonding ◽  
New Type ◽  
Wood Grain ◽  
Further Development ◽  
Over Time

ABSTRACTMokumé Gane layered metal is a 300-year old decorative metal laminate technique peculiar to the isolated culture of the Japanese Shogunate. Like many complex craft practices handed down through individual experience, the manufacture and development of Mokumé Gane has changed minimally over time. The application of contemporary metallurgical knowledge and solid state bonding techniques such as Hot Press Diffusion Bonding and Hot Roll Bonding provide for further development of Mokumé Gane: bonding success rates are improved, and manufacturing times are reduced. In addition, the range of possible metal combinations is substantially increased; 42 different combinations to date have been successfully bonded, including a new type of Mokumé Gane employing aluminium alloys. This research has allowed a very large increase in the variety of colours, patterns, and visual effects, available to contemporary metalsmiths and jewellers.

The Atlantic Slave Trade: A tentative economic model

1974 ◽  
Vol 15 (2) ◽  
pp. 223-246 ◽  
Author(s):  
Henry A. Gemery ◽  
Jan S. Hogendorn
Keyword(s):  
New World ◽  
Labour Supply ◽  
Slave Trade ◽  
Necessary Conditions ◽  
Labour Shortage ◽  
Supply Pattern ◽  
Derived Demand ◽  
Further Development ◽  
Over Time

Two necessary conditions for the existence of New World slavery and the slave trade are an acute labour shortage and an elastic supply of coerced labour. Though the former condition has been the mainstay of hypotheses on slavery where high land/labour ratios were viewed as causal determinants, less attention has been given to the role of labour supply responses. This paper joins these conditions in a model which postulates that labour demand stemming from open resource pressures induced a politico–economic supply response in West Africa. The model shows a derived demand for labour evolving over time into a specific demand for slaves as entrepreneurs sought the lowest cost method of expanding the production of agricultural staples. Free and indentured labour were both characterized by inelastic supply, but the supply of slaves was elastic due to factors discussed within a vent for surplus framework. African governments and private traders responded to the new effective demand from the Americas with improved organization which widened the pre-existing market for slaves. The desire for imported goods, with firearms especially significant, plus various technical changes in transport, money, and credit all combined to ensure the further development of the slave trade and the continued maintenance of a longrun elastic supply pattern

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