scholarly journals Screening preemergence herbicides for weed control in cassava

2020 ◽  
Vol 34 (5) ◽  
pp. 735-747
Author(s):  
Friday Ekeleme ◽  
Alfred Dixon ◽  
Godwin Atser ◽  
Stefan Hauser ◽  
David Chikoye ◽  
...  
Keyword(s):  
Weed Control ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Root Yield ◽  
North Central ◽  
Herbicide Treatments ◽  
Sub Saharan ◽  
Cropping Seasons ◽  
Preemergence Herbicides ◽  
Grass Weed

AbstractWeed competition severely constrains cassava root yield in sub-Saharan Africa; thus, good weed control measures, including the use of herbicides, are increasingly important. Herbicide trials were conducted at five locations across eastern, western, and north-central Nigeria over two cropping seasons (2014 and 2015). Nineteen premixed PRE herbicides applied at different rates were evaluated for efficacy on weeds and selectivity on cassava. Manual hoe-weeding at 4, 8, and 12 wk after planting (WAP) and two S-metolachlor + atrazine treatments commonly used by cassava growers were included for comparison. Six of the 19 PRE herbicide treatments (indaziflam + isoxaflutole, indaziflam + metribuzin, flumioxazin + pyroxasulfone, isoxaflutole, acetochlor + atrazine + terbuthylazine, and terbuthylazine + S-metolachlor) consistently provided 80% to 98% broadleaf and grass weed control up to 8 wk after treatment. Overall, PRE herbicide treatments and cassava yield were significantly positively correlated. Herbicide treatments terbuthylazine + S-metolachlor, flumioxazin + pyroxasulfone, diflufenican + flufenacet + flurtamone (respectively, 60 + 60 + 60, 120 + 120 + 120, 90 + 360 + 120, and 135 + 360 + 180 g ha−1), acetochlor + atrazine + terbuthylazine (875 + 875 + 875 g ha−1), S-metolachlor + atrazine (870 + 1,110 g ha−1), oxyfluorfen (240 g ha−1), indaziflam + isoxaflutole (75 + 225 g ha−1), indaziflam + metribuzin (75 + 960 g ha−1), and aclonifen + isoxaflutole (500 + 75 g ha−1) contributed to yields exceeding twice the Nigerian national average of 8.76 tonnes ha−1. These treatments had root yields of 1.4 to 2 times higher than plots that had been hoe-weeded three times. There were some adverse herbicide treatment effects such as delayed cassava sprouting and temporary leaf bleaching observed in indaziflam and diflufenican + flufenacet + flurtamone treatments, whereas sulfentrazone caused prolonged leaf crinkling. The PRE applications alone at rates safe for cassava did not provide adequate season-long weed control; supplemental POST weed control is needed about 10 WAP for satisfactory season-long control.

Effects of Weed Control in Established Alfalfa (Medicago sativa) on Forage Yield and Quality

Weed Science ◽  
1987 ◽  
Vol 35 (4) ◽  
pp. 564-567 ◽  
Author(s):  
Dennis R. Cosgrove ◽  
Michael Barrett
Keyword(s):  
Medicago Sativa ◽  
Weed Control ◽  
Stand Density ◽  
Forage Yield ◽  
Control Measures ◽  
Acid Detergent Fiber ◽  
Yield And Quality ◽  
Herbicide Treatments ◽  
Forage Yields

The effects of weed control measures in established alfalfa (Medicago sativaL.) on forage yield and quality were investigated at three sites with varying alfalfa densities and weed populations. Herbicide treatments were 0.56 and 1.12 kg/ha metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] applied in fall or spring, respectively, 1.68 kg/ha pronamide [3,5-dichloro (N-1,1-dimethyl-2-propynyl)benzamide] applied in fall, and combinations of these treatments. First-harvest forage yields (weeds plus alfalfa) were either reduced or unchanged by herbicide treatments. Total forage yield was not altered by the herbicide treatments, but first-harvest and total alfalfa yield as well as first-harvest forage protein content were increased by several treatments, depending on stand density and weed pressure. Little effect was observed on in vitro digestible dry matter or acid detergent fiber content.

scholarly journals Biological Control of a Phytosanitary Pest (Thaumatotibia leucotreta): A Case Study

2021 ◽  
Vol 18 (3) ◽  
pp. 1198
Author(s):  
Sean D. Moore
Keyword(s):  
Biological Control ◽  
Systems Approach ◽  
Microbial Control ◽  
Codling Moth ◽  
Environmental Safety ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
The European Union ◽  
Thaumatotibia Leucotreta ◽  
Sub Saharan

Thaumatotibia leucotreta, known as the false codling moth, is a pest of citrus and other crops in sub-Saharan Africa. As it is endemic to this region and as South Africa exports most of its citrus around the world, T. leucotreta has phytosanitary status for most markets. This means that there is zero tolerance for any infestation with live larvae in the market. Consequently, control measures prior to exporting must be exemplary. Certain markets require a standalone postharvest disinfestation treatment for T. leucotreta. However, the European Union accepts a systems approach, consisting of three measures and numerous components within these measures. Although effective preharvest control measures are important under all circumstances, they are most critical where a standalone postharvest disinfestation treatment is not applied, such as within a systems approach. Conventional wisdom may lead a belief that effective chemical control tools are imperative to achieve this end. However, we demonstrate that it is possible to effectively control T. leucotreta to a level acceptable for a phytosanitary market, using only biological control tools. This includes parasitoids, predators, microbial control, semiochemicals, and sterile insects. Simultaneously, on-farm and environmental safety is improved and compliance with the increasing stringency of chemical residue requirements imposed by markets is achieved.

scholarly journals An afebrile heartwater-like syndrome in goats

2013 ◽  
Vol 84 (1) ◽  
Author(s):  
Rhoda Leask ◽  
Kenneth P. Pettey ◽  
Gareth F. Bath
Keyword(s):  
Clinical Signs ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Limiting Factor ◽  
Febrile Reaction ◽  
Presumptive Diagnosis ◽  
Appropriate Treatment ◽  
Sub Saharan ◽  
Characteristic Features ◽  
And Control

Heartwater is a serious limiting factor for sheep and goat production in the major endemic area of sub-Saharan Africa and therefore most knowledge, research and control methods originate from this region. Whilst the usual or common clinical presentations can be used to make a presumptive diagnosis of heartwater with a good measure of confidence, this is not always the case, and animals suffering from heartwater may be misdiagnosed because their cases do not conform to the expected syndrome, signs and lesions. One aberrant form found occasionally in the Channel Island breeds of cattle and some goats is an afebrile heartwaterlike syndrome. The most constant and characteristic features of this heartwater-like syndrome comprise normal temperature, clinical signs associated with generalised oedema, and nervous signs, especially hypersensitivity. The presumption that the disease under investigation is the afebrile heartwater-like syndrome entails a tentative diagnosis based on history and clinical signs and the response to presumed appropriate treatment (metadiagnosis). The afebrile heartwater-like syndrome presents similarly to peracute heartwater but without the febrile reaction. Peracute cases of heartwater have a high mortality rate, enabling confirmation of the disease on post-mortem examination. Recognition of the afebrile heartwater-like syndrome is important to prevent deaths and identify the need for appropriate control measures.

scholarly journals Characteristics of patients with acute heart failure in North Central Nigeria

2021 ◽  
Vol 9 (3) ◽  
pp. 221-235
Author(s):  
J.A. Ogunmodede ◽  
P.M. Kolo ◽  
M.O. Bojuwoye ◽  
B.F. Dele-Ojo ◽  
A.J. Ogunmodede ◽  
...  
Keyword(s):  
Heart Failure ◽  
New York ◽  
Heart Association ◽  
Public Health Education ◽  
Sub Saharan Africa ◽  
Aetiological Factor ◽  
Cross Sectional ◽  
Early Presentation ◽  
North Central ◽  
Sub Saharan

Objectives: Heart failure (HF) is an important cause of hospital admission in Nigeria. HF is increasingly prevalent because the population is aging and HF epidemiology is changing. We aimed at profiling the socio-demographic, clinical and echocardiographic (Echo)  characteristics of patients admitted for acute HF. This is one of the largest cohorts of HF patients profiled in Nigeria so far. Methods: Cross sectional design. Socio-demographic, clinical and Echo data were collected from 455 patients admitted for AHF at University of Ilorin Teaching Hospital, North central, Nigeria. Results: Mean age of patients was 58.9± 15.7years, (men were older than women, P= 0.006). 265(58.2%) were males, most patients were aged >60 years, 4.8% had pre-existing Type2 Diabetes mellitus. 53.2% of patients presented in New York Heart Association Stages III and IV. Median duration of admission was 11days (IQR, 6-17), intrahospital mortality- 11.6%. Hypertension was the commonest aetiological factor (62.4%), followed by dilated cardiomyopathy 17.6%, rheumatic heart disease (6.6%), Peripartum cardiomyopathy (5.3%), and others. Conclusion: AHF patients in our study are older than those in previous studies in Nigeria and sub-Saharan Africa. Hypertension is main driver of AHF, and patients largely present with clinically advanced disease necessitating stronger public health education about risk factors and early presentation.  

scholarly journals Contrasting Response Mechanisms of Maize Lines to Striga hermonthica

Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 485
Author(s):  
Nnanna N. Unachukwu ◽  
Abebe Menkir ◽  
Adekemi Stanley ◽  
Ebenezer O. Farombi ◽  
Melaku Gedil
Keyword(s):  
Cost Effective ◽  
Resistance Mechanisms ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Striga Hermonthica ◽  
Maize Line ◽  
Parasitic Weed ◽  
Resistant Lines ◽  
Sub Saharan ◽  
Better Than

Strigahermonthica (Del.) Benth is a parasitic weed that devastates cereals in Sub-Saharan Africa. Several control measures have been proposed for the parasite, of these, host plant resistance is considered the most cost-effective for poor farmers. Some tolerant/resistant lines have been developed and these lines display tolerance/resistance mechanisms to the parasite. A series of studies was done to investigate some of the mechanisms through which a resistant (TZISTR1108) and a susceptible (5057) maize line responds to S. hermonthica infestation, as well as the effects of parasitism on these lines. In this study, TZISTR1108 stimulated the germination and attachment of fewer S. hermonthica plants than 5057, both in the laboratory and on the field. In TZISTR1108, the growth of the S. hermonthica plants, that successfully attached, was slowed. When compared to the un-infested plants, the infested resistant plants showed fewer effects of parasitism than the infested susceptible plants. The infested TZISTR1108 plants were more vigorous, taller and resembled their un-infected counterparts. There were substantial reductions in the stomatal conductance and nitrogen content of the 5057 upon infestation. The resistant inbred line showed multiple mechanisms of resistance to S. hermonthica infestation. It thrives better than the susceptible line by reducing the attachment of S. hermonthica and it delays the parasite’s development.

scholarly journals Febrile Illness Evaluation in a Broad Range of Endemicities (FIEBRE): protocol for a multisite prospective observational study of the causes of fever in Africa and Asia

BMJ Open ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. e035632 ◽  
Author(s):  
Heidi Hopkins ◽  
Quique Bassat ◽  
Clare IR Chandler ◽  
John A Crump ◽  
Nicholas A Feasey ◽  
...  
Keyword(s):  
Social Science ◽  
Blood Sample ◽  
Venous Blood ◽  
Febrile Illness ◽  
Clinical Diagnostics ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Venous Blood Sample ◽  
Open Access Journals ◽  
Sub Saharan

IntroductionFever commonly leads to healthcare seeking and hospital admission in sub-Saharan Africa and Asia. There is only limited guidance for clinicians managing non-malarial fevers, which often results in inappropriate treatment for patients. Furthermore, there is little evidence for estimates of disease burden, or to guide empirical therapy, control measures, resource allocation, prioritisation of clinical diagnostics or antimicrobial stewardship. The Febrile Illness Evaluation in a Broad Range of Endemicities (FIEBRE) study seeks to address these information gaps.Methods and analysisFIEBRE investigates febrile illness in paediatric and adult outpatients and inpatients using standardised clinical, laboratory and social science protocols over a minimum 12-month period at five sites in sub-Saharan Africa and Southeastern and Southern Asia. Patients presenting with fever are enrolled and provide clinical data, pharyngeal swabs and a venous blood sample; selected participants also provide a urine sample. Laboratory assessments target infections that are treatable and/or preventable. Selected point-of-care tests, as well as blood and urine cultures and antimicrobial susceptibility testing, are performed on site. On day 28, patients provide a second venous blood sample for serology and information on clinical outcome. Further diagnostic assays are performed at international reference laboratories. Blood and pharyngeal samples from matched community controls enable calculation of AFs, and surveys of treatment seeking allow estimation of the incidence of common infections. Additional assays detect markers that may differentiate bacterial from non-bacterial causes of illness and/or prognosticate illness severity. Social science research on antimicrobial use will inform future recommendations for fever case management. Residual samples from participants are stored for future use.Ethics and disseminationEthics approval was obtained from all relevant institutional and national committees; written informed consent is obtained from all participants or parents/guardians. Final results will be shared with participating communities, and in open-access journals and other scientific fora. Study documents are available online (https://doi.org/10.17037/PUBS.04652739).

Sugarbeet tolerance when dimethenamid-P follows soil-applied ethofumesate and S-metolachlor

2019 ◽  
Vol 33 (03) ◽  
pp. 431-440
Author(s):  
Thomas J. Peters ◽  
Andrew B. Lueck ◽  
Aaron L. Carlson
Keyword(s):  
Control System ◽  
Weed Control ◽  
Field Experiments ◽  
Plant Density ◽  
Stand Density ◽  
Sucrose Content ◽  
Root Yield ◽  
Visible Injury ◽  
Herbicide Treatments

AbstractSugarbeet growers only recently have combined ethofumesate, S-metolachlor, and dimethenamid-P in a weed control system for waterhemp control. Sugarbeet plant density, visible stature reduction, root yield, percent sucrose content, and recoverable sucrose were measured in field experiments at five environments between 2014 and 2016. Sugarbeet stand density and stature reduction occurred in some but not all environments. Stand density was reduced with PRE application of S-metolachlor at 1.60 kg ai ha–1 and S-metolachlor at 0.80 kg ha–1 + ethofumesate at 1.68 kg ai ha–1 alone or followed by POST applications of dimethenamid-P at 0.95 kg ai ha–1. Sugarbeet visible stature was reduced when dimethenamid-P followed PRE treatments. Stature reduction was greatest with ethofumesate at 1.68 or 4.37 kg ha–1 PRE and S-metolachlor at 0.80 kg ha–1 + ethofumesate at 1.68 kg ha–1 PRE followed by dimethenamid-P at 0.95 kg ha–1 POST. Stature reduction ranged from 0 to 32% 10 d after treatment (DAT), but sugarbeet recovered quickly and visible injury was negligible 23 DAT. Although root yield and recoverable sucrose were similar across herbicide treatments and environments, we caution against the use of S-metolachlor at 0.80 kg ha–1 + ethofumesate at 1.68 kg ai ha–1 PRE followed by dimethenamid-P at 0.95 kg ha–1 in sugarbeet.

scholarly journals Status quo of chemical weed control in rice in sub-Saharan Africa

Food Security ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 69-92 ◽  
Author(s):  
Jonne Rodenburg ◽  
Jean-Martial Johnson ◽  
Ibnou Dieng ◽  
Kalimuthu Senthilkumar ◽  
Elke Vandamme ◽  
...  
Keyword(s):  
Weed Control ◽  
Status Quo ◽  
Sub Saharan Africa ◽  
Sub Saharan

scholarly journals Challenges and Economic Implications in the Control of Foot and Mouth Disease in Sub-Saharan Africa: Lessons from the Zambian Experience

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Y. Sinkala ◽  
M. Simuunza ◽  
D. U. Pfeiffer ◽  
H. M. Munang’andu ◽  
M. Mulumba ◽  
...  
Keyword(s):  
Economic Impact ◽  
Foot And Mouth Disease ◽  
Movement Control ◽  
Personal Communication ◽  
Mouth Disease ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Economic Implications ◽  
Foot And Mouth ◽  
Sub Saharan

Foot and mouth disease is one of the world’s most important livestock diseases for trade. FMD infections are complex in nature and there are many epidemiological factors needing clarification. Key questions relate to the control challenges and economic impact of the disease for resource-poor FMD endemic countries like Zambia. A review of the control challenges and economic impact of FMD outbreaks in Zambia was made. Information was collected from peer-reviewed journals articles, conference proceedings, unpublished scientific reports, and personal communication with scientists and personal field experiences. The challenges of controlling FMD using mainly vaccination and movement control are discussed. Impacts include losses in income of over US$ 1.6 billion from exports of beef and sable antelopes and an annual cost of over US$ 2.7 million on preventive measures. Further impacts included unquantified losses in production and low investment in agriculture resulting in slow economic growth. FMD persistence may be a result of inadequate epidemiological understanding of the disease and ineffectiveness of the control measures that are being applied. The identified gaps may be considered in the annual appraisal of the FMD national control strategy in order to advance on the progressive control pathway.

scholarly journals Labor-Saving Weed Technologies for Lowland Rice Farmers in sub-Saharan Africa

2015 ◽  
Vol 29 (4) ◽  
pp. 751-757 ◽  
Author(s):  
Jonne Rodenburg ◽  
Kazuki Saito ◽  
Runyambo Irakiza ◽  
Derek W. Makokha ◽  
Enos A. Onyuka ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Sub Saharan Africa ◽  
Herbicide Application ◽  
Control Efficacy ◽  
Rice Farmers ◽  
Time Requirements ◽  
Rice Yields ◽  
Sub Saharan ◽  
Hand Weeding

Time requirements, weed control efficacy, and yield effects of three labor-saving weed technologies were tested against hand weeding during three seasons in 2012 and 2013. The technologies included two hand-operated mechanical weeders, the straight-spike and the twisted-spike floating weeder, and the PRE application of oxadiazon. The straight-spike floating weeder reduced weeding time by 32 to 49%, the twisted-spike floating weeder reduced weeding time by 32 to 56%, and the application of herbicide required 88 to 97% less time than hand weeding. Herbicide application provided the best weed control in two of the three seasons. No differences in weed control efficacy were observed between mechanical and hand weeding. Yield differences were only observed in season 3 with higher rice yields after PRE application of oxadiazon compared with other weed management treatments.

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