scholarly journals An Evaluation of Dazomet Incorporation Methods on Soilborne Organisms and Pine Seedling Production in Southern Nurseries

2003 ◽  
Vol 27 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Stephen W. Fraedrich ◽  
L. David Dwinell
Keyword(s):  
Morphological Characteristics ◽  
High Rate ◽  
Parasitic Nematodes ◽  
Seedling Production ◽  
Seedling Density ◽  
The North ◽  
Nursery Plant ◽  
Shoot Weight ◽  
And Control

Abstract The use of dazomet as a fall and spring fumigant for pine seedling production and control of soilborne pests was evaluated at two southern nurseries. Dazomet was applied at low (280–325 kg/ha) and high (493–560 kg/ha) rates and incorporated with a rototiller or spading machine. Comparisons were made with methyl bromide/chloropicrin (MBC) fumigation and nonfumigated control treatments. Dazomet incorporation method had no effect on seedling density at either nursery, and often did not affect seedling morphological characteristics. At the Georgia (GA) nursery, seedling density and morphological characteristics did not differ among fumigant treatments except in the spring study area where shoot weight was greater in the MBC treatment than the dazomet or nonfumigated control treatments. In the fall study area at the North Carolina (NC) nursery, seedling density was greater in the high-rate dazomet treatment than the nonfumigated control. Seedlings were generally larger in MBC and dazomet treatments than the control. Seedling density and morphological characteristics did not differ among fumigation treatments in the spring study area. Fumigation with MBC or dazomet generally reduced the percentage of roots withPythium andFusarium spp. compared to controls at the GA nursery and the fall fumigation area in the NC nursery. Plant parasitic nematodes were found infrequently at both nurseries and did not differ among treatments. Nutsedge (Cyperus spp.) was the major problem at the GA nursery and was effectively controlled only with MBC. Compared to the MBC treatment, the abundance of soilborne fungi and the association of certain types ofTrichoderma with roots was often lower in the dazomet treatments. The importance of these differences for long term seedling production and management of soilborne diseases is not known at this time. South. J. Appl. For. 27(1):41–51.

History of Dlonguébougou and the wider region

2020 ◽  
pp. 29-49
Author(s):  
Camilla Toulmin
Keyword(s):  
Political Systems ◽  
Military Recruitment ◽  
The North ◽  
Political Events ◽  
History Of ◽  
Forced Labour ◽  
Village Life ◽  
And Control ◽  
The Village

Chapter 2 sets the village of Dlonguébougou within its wider region. Long-term shifts in rainfall have shaped the landscape and societies, from prehistory through to the emergence of the Ghana, Mali, and Songhai Empires, relying on trans-Saharan trade in gold, salt, and slaves. The Bambara kingdom of Ségou used warfare to exact tribute and control trade, but by the time of the French conquest, much of the region had been taken under the jihadist rule of El Hajj Oumar Tall. The colonial administration had profound, long-lasting impacts on village life, taxation, forced labour, military recruitment, and legal and political systems. Economic and political events since Independence in 1960 are described, including the growing conflict in the north and centre of the country, sparked by demands for Tuareg autonomy, but now spread into widespread instability.

Third World vulnerabilities and global negotiations

1983 ◽  
Vol 9 (4) ◽  
pp. 235-249 ◽  
Author(s):  
Stephen D. Krasner
Keyword(s):  
United States ◽  
Third World ◽  
Well Being ◽  
The United States ◽  
The North ◽  
Power And Control ◽  
The Common ◽  
Long Term Prognosis ◽  
And Control

What do Third World countries want? More wealth. How can they get it? By adopting more economically rational policies. What should the North do? Facilitate these policies. How should the North approach global negotiations? With cautious optimism. What is the long term prognosis for North–South relations? Hopeful, at least if economic development occurs. This is the common wisdom about relations between industrialized and developing areas in the United States and much of the rest of the North, Within this fold there are intense debates among adherents of conventional liberal, reformist liberal, and interdependence viewpoints. But the emphasis on economics at the expense of politics, on material well-being as opposed to power and control, pervades all of these orientations.

scholarly journals High Clonality and Geographically Separated Cryptic Lineages in the Threatened Temperate Coral, Acropora pruinosa

2021 ◽  
Vol 8 ◽  
Author(s):  
Supisara Pipithkul ◽  
Sota Ishizu ◽  
Akifumi Shimura ◽  
Hiroyuki Yokochi ◽  
Satoshi Nagai ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Clonal Diversity ◽  
Distribution Patterns ◽  
High Rate ◽  
Genetic Connectivity ◽  
Isolated Populations ◽  
Genetic Structuring ◽  
Genetic Lineages ◽  
Morphological Variations ◽  
The North

Acropora pruinosa is a threatened zooxanthellate scleractinian coral that is distributed in the temperate areas along the coastline of Japan and the northern area of the South China Sea. Since A. pruinosa propagates both asexually and sexually, assessing clonal diversity and genetic connectivity among populations is important for conservation. In addition, high morphological variations in the field create confusion during species identification. To examine the existence of hidden genetic lineages, clonality, and genetic connectivity of A. pruinosa for conservation, we applied microsatellite analysis. Clustering analysis indicated two distinct geographically separated genetic lineages: one is distributed in the west, and the other is distributed in the east. The two lineages co-existed in Nishidomari, Kochi. There was no obvious difference in morphological characteristics between the two lineages. Although the factors influencing the observed distribution patterns remain unknown, there is a possibility that the two lineages might have diverged somewhere in the north-western Kyushu and north-eastern Pacific coast habitats in the past, and then periodically colonized the current habitats. A low clonal diversity was observed in most of the populations, indicating a high rate of asexual reproduction associated with their branching morphologies. In addition, there are strong genetic structuring in this species, indicating weak connectivity among populations. These results indicated a low larval dispersal potential among populations and that populations are basically sustained by a high rate of clone propagation and self-seeding. The existence of cryptic lineages and genetically isolated populations with high clonality emphasized the importance of conservation of A. pruinosa.

Short-Term Increases in Aphid Dispersal From Defensive Dropping Do Not Necessarily Affect Long-Term Biological Control by Parasitoids

2019 ◽  
Vol 112 (4) ◽  
pp. 1552-1559
Author(s):  
Michelangelo La-Spina ◽  
Sarah E Jandricic ◽  
Rose Buitenhuis
Keyword(s):  
Biological Control ◽  
High Rate ◽  
Aphidius Ervi ◽  
Large Cage ◽  
Greenhouse Crops ◽  
Ornamental Crops ◽  
Foxglove Aphid ◽  
And Control ◽  
Over Time

Abstract Foxglove aphid (Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae)) is one of the principal aphid pests of greenhouse ornamental crops in North America. Biological control of foxglove aphid mostly relies on the use of Aphidius ervi Haliday (Hymenoptera: Braconidae). However, studies indicate that A. ervi may not be adapted to search for A. solani, and that in response to parasitoid attack aphids can drop and/or disperse, which may aggravate an infestation. Our goal was to further describe the searching behavior of A. ervi in the presence of foxglove aphids, the corresponding defensive behavior of foxglove aphid and the short- and medium-term effects on both pest dispersal and control by A. ervi. Behavioral observations were done on top and bottom leaves infested with foxglove aphid and a high release rate of A. ervi. Parasitoids tended to land on top leaves; however, more aphids were parasitized on bottom leaves, leading to equal numbers of parasitoid attacks in both locations. Most aphids dropped off the plant in the presence of a parasitoid. In large cage experiments, aphids were allowed to distribute naturally and A. ervi was released. The parasitoid still caused a high rate of aphid dropping. However, only a few aphids were able to successfully reach new plants, and most of these mummified over time. Our studies confirm that parasitoid-induced dispersal of foxglove aphid in greenhouse crops does occur, but also suggests this should not necessarily be a barrier to adoption of biological control, as A. ervi controls the aphids over time.

The effects of soil fumigation on pine seedling production, weeds, foliar and soil nutrients, and soilborne microorganisms at a south Georgia (U.S.A.) forest tree nursery

2003 ◽  
Vol 33 (9) ◽  
pp. 1698-1708 ◽  
Author(s):  
Stephen W Fraedrich ◽  
L David Dwinell
Keyword(s):  
Loblolly Pine ◽  
Morphological Characteristics ◽  
Cost Effective ◽  
Pinus Elliottii ◽  
Forest Tree ◽  
Slash Pine ◽  
Seedling Production ◽  
Trichoderma Spp ◽  
Nursery Plant ◽  
Pinus Taeda L

Pine seedling production and pest problems were evaluated in plots fumigated with methyl bromide and nonfumigated plots over a 6-year period at a Georgia nursery. Fumigation increased bed densities for loblolly pine (Pinus taeda L.) in 1996 and slash pine (Pinus elliottii Engelm. var. elliottii) in 1998; differences were not observed between treatments in other years. The root collar diameter, height, and root and shoot masses of loblolly pine seedlings were often greater in fumigated plots during the first 3 years. Morphological characteristics rarely differed between treatments for slash pine. The primary pest problem was nutsedge (Cyperus spp.); most other weeds were controlled with herbicides used operationally at the nursery. Plant-parasitic nematode populations did not increase over time and were not a problem. Although Fusarium and Pythium spp. were more common in soil and on roots in nonfumigated plots, evidence of disease was rare. Fumigation increased the abundance of and changed the composition of Trichoderma spp. in soil and on roots. Soil manganese and iron, and foliar manganese, phosphorus, and nitrogen were greater in the fumigation treatment in some years. A better understanding of the risks of soilborne diseases may facilitate the development of pest management programs that are more cost-effective.

scholarly journals Strengthening Resilience of Lithuania in an Era of Great Power Competition: The Case for Total Defence

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Liudas Zdanavičius ◽  
Nortautas Statkus
Keyword(s):  
International System ◽  
The United States ◽  
Great Power ◽  
Baltic Countries ◽  
The North ◽  
Rising China ◽  
The Baltic ◽  
And Control ◽  
Technical Measures

AbstractIn response to the power redistribution in the international system, the United States prepares for long-term Great power competition. It is aiming at strengthening America's network of alliances and partnerships in order to counter a rising China and revisionist Russia. The other states react to greater or lesser extent to the changing constraints and opportunities in the international system. The article examines how Lithuania, being a small state that belongs to the North Atlantic Alliance, is adapting to these systemic pressures. Current NATO's deterrence posture in the Baltic region is something akin to deterrence by the assured response – NATO is sending a signal that if the Russians attacked, NATO would respond in the Baltics. Lithuania, as well as other Baltic countries, has undertaken many legal, procedural, financial and technical measures to boost resilience and deterrence. However, there are not enough national or NATO military forces that would be able to counter conventional Russian forces deployed in the region. There are challenges such as air defence and control of the Baltic Sea. Also land forces are not present in adequate quantities. As a result, Lithuania has to strengthen its own capabilities with the help of the allied countries. It argued in the article that building up a total defence system in Lithuania would be a right effort in this regard.

Desiccation survival of parasitic nematodes

Parasitology ◽  
1999 ◽  
Vol 119 (S1) ◽  
pp. S19-S30 ◽  
Author(s):  
R. N. Perry
Keyword(s):  
Entomopathogenic Nematodes ◽  
Parasitic Nematodes ◽  
Effective Management ◽  
Term Survival ◽  
Morphological Adaptations ◽  
Before And After ◽  
Life Threatening ◽  
Low Levels ◽  
And Control

SUMMARYThe ability of certain species of parasitic nematodes to survive desiccation for considerable periods is a fascinating example of adaptation to the demands of fluctuating environments that occasionally can become extreme and life threatening. Behavioural and morphological adaptations associated with desiccation survival serve primarily to reduce the rate of drying, either to prolong the time taken for the nematode's water content to reach lethal low levels or, in true anhydrobiotes, to enable the structural and biochemical changes required for long-term survival to take place. Examples of these adaptations are reviewed, together with information on the factors involved in rehydration that ensure successful exit from the dormant state. Information on desiccation survival is central to effective management and control options for parasitic nematodes. It is also required to assess the feasibility of enhancing the longevity of commercial formulations of entomopathogenic nematodes, both before and after application; current research and future prospects for enhancing survival of these bio-insecticides are discussed.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

Suppressed, but Not Forgotten

2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke
Keyword(s):  
Memory Trace ◽  
Thought Suppression ◽  
Test Phase ◽  
Indirect Test ◽  
Final Test ◽  
Test Experiment ◽  
And Control ◽  
Cue Words ◽  
The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

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