376 research outputs found
Fertilizer Demand for Biofuel and Cereal crop Production in the United States
The emergence of biofuel production has impacted almost all sectors of the agricultural industry and the general economy and has produced a large body of research into how increased production of biofuels will impact the agricultural sector and the general economy. All research is in agreement that total biomass production will be required to increase to meet food and fuel demands. The increase in biomass will, of necessity, require increased use of fertilizers. Research on fertilizer demand has been scarce over the last decade. Because of the recent increase in the demand for grain crops and livestock in an era with little excess capacity in commodity production, the pressure to increase output will fall to increased use of fertilizers. In addition, there is some evidence of increasing scarcity in the principle macro nutrients (eg phosphorus, nitrogen and potassium). Thus, there is an urgent need to initiate research into the demand for fertilizers to determine the economic implications of expanded crop and livestock production. This analysis can provide crop producers and policy makers with important information on the role of nutrients in the economics of expanding uses for the major grain and forage crops. Most researchers have focused on total fertilizer (N.P.K) demand for total crop production which does not capture the effects of individual fertilizers on the individual crops. This study focuses on nitrogen demand for biofuel and cereal crop production and the impact on crop prices in the United States using the method of feasible generalized least squares (FGLS) estimation by weighted least squares regression. The results show that nitrogen fertilizer is very much responsive to corn price, wheat price, nitrogen price, phosphate price, and potash price. Results also indicate that increase in nitrogen price decreases nitrogen demand while increases in the price of corn, wheat, and other fertilizers increases the demand for nitrogen fertilizer.Nitrogen demand, corn production, fertilizer prices, biofuel production., Agricultural and Food Policy, Production Economics, Resource /Energy Economics and Policy,
The Impact of Biofuel Mandates and Switchgrass Production on Hay Markets
The Renewable Fuel Standard mandate in the Energy Independence and Security Act of 2007 requires 16 billion gallons out of 36 billion gallons of ethanol be produced from cellulosic feedstocks in 2022, but the mandate was apparently enacted without critical assessments of the agricultural impacts of attempting to achieve energy independence. The feedstock production will likely compete with lands currently used for producing other traditional crops of which hay is likely to be affected the most since it has comparatively lower net returns. Thus ruminant production will consequently be affected greatly. This study uses ordinary least squares (OLS) to estimate and predict Oklahoma hay price which is used as objective value in linear programming (LP) model that determines the profitability options between hay and switchgrass production. The OLS results show that Oklahoma hay price is fairly stable, and hay is shipped across adjoining states. The LP results show that switchgrass production would be more profitable than hay and that switchgrass for biofuel production likely will bid land away from hay if biofuel production becomes fully operational.biofuel mandates, switchgrass production, hay production, hay markets., Agricultural and Food Policy, Environmental Economics and Policy, Production Economics, Research and Development/Tech Change/Emerging Technologies, Resource /Energy Economics and Policy,
The Ghana Cocoa Board (COCOBOD) approved insecticides, imidacloprid, thiamethoxam and bifenthrin, for the control of cocoa mirids (Hemiptera: Miridae): Implications for insecticide-resistance development in Distantiella theobroma (Dist.) and Sahlbergella
The Ghana Cocoa Board (COCOBOD) in 2001 initiated a national Cocoa Diseases and Pest Control (CODAPEC) programme (popularly known as mass-spraying programme) against the cocoa mirids (Hemiptera: Miridae), which are predominantly Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl. The insecticides approved by COCOBOD for controlling the cocoa mirids under CODAPEC and for individual farmer applications are Confidor® (imidacloprid 200 g/l), Actara® (thiamethoxam 240 g/l) and Akate Master® (bifenthrin 27 g/l). Imidacloprid and thiamethoxam are both neonicotinoid insecticides with cross-resistance between them, while cross-resistance has been established between the neonicotinoids and bifenthrin, a pyrethroid insecticide. Using imidacloprid, thiamethoxam and bifenthrin singly or rotationally selects for genes that confer resistance to the approved insecticides. The detection of ɣ-BHC-resistant D. theobroma in Ghana after widespread use of the insecticide against mirids from the mid 1950s through early 1960s indicated the genetic ability of mirids to develop resistance to insecticides. The mass-spraying of imidacloprid, thiamethoxam or bifenthrin to control mirids is, therefore, increasing selection pressure on field populations of mirids, and escalating the risk of the mirids developing resistance to all three insecticides. Preventing resistance development in the cocoa mirids to the COCOBOD approved insecticides is crucial to avert resistance associated yield losses, reduce the risk of insecticide residues in cocoa beans and safeguards Ghana's foreign exchange earnings from cocoa. Measures for protecting imidacloprid, thiamethoxam and bifenthrin from mirid resistance development are recommended
Insecticide Use Practices in Cocoa Production in Four Regions in Ghana
Chemical control of insect pests of cocoa started in 1950, and insecticides from the various classes have been recommended and used by farmers since then. Presently, Imidacloprid (Confidor®), Bifenthrin (Akatemaster®) and Thiamethoxam (Actara®) are recommended by Ghana Cocoa Board (COCOBOD) for insect pest management. A survey was conducted in the Ashanti, Eastern, Volta and Western regions of Ghana using questionnaires and farm visits of 147 cocoa farmers’ fields to gather information on insecticide use practices by farmers. The survey showed that the farmers used mostly Imidacloprid and Bifenthrin insecticides and the frequency of application was more than that recommended by COCOBOD. Among the three recommended insecticides, 43% each of the farmers across the three regions used either Confidor® or Akatemaster® whilst the remaining 14% used Actara®. The number of years farmers had consistently used a particular insecticide ranged between 5 and 16 years. Whilst some cocoa farmers do not apply insecticides to their farms, others, however, do as many as 11 applications in a year. Most of the insecticides used are classified as class II under WHO Hazard category, and the farmers used very minimal protective clothing during pesticides application. The results of this study show that there is the need to intensify education on safe handling and use of pesticides to reduce pesticide abuse, especially by cocoa farmers, in order to sustain effective management of pests and protect farmers, consumers and the environment
Incipient bifenthrin-resistance in field populations of cocoa mirids, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl. (Hemiptera: Miridae)
Bifenthrin is one of the insecticides approved by the Ghana Cocoa Board (COCOBOD) for the control of cocoa mirids. Bifenthrin-resistance levels of D. theobroma and S. singularis collected from different locations in the Eastern Region (ER), Volta Region (VR) and Central Region (CR) were determined by calculating their resistance ratios (RRs). The highest RRs for S. singularis were recorded from New Tafo in the ER and Logba Alikpati in the VR, which displayed 6-fold and 6.2- fold bifenthrin-resistance, respectively. Populations of S. singularis from Pankese in the ER and Likpe in the VR also displayed 3.6-fold and 3.9-fold bifenthrin-resistance, respectively. The D. theobroma population that displayed the highest bifenthrin-resistance of 3.7-fold was from New Tafo. The results show incipient bifenthrin-resistance in field populations of D. theobroma and S. singularis, which requires the implementation of effective resistance management strategies to prevent full-blown resistance in the cocoa mirids
INSECTICIDE HANDLING IN COCOA PRODUCTION IN FOUR REGIONS IN GHANA
Management of insect pests of cocoa (Theobroma cacao L.) using insecticides began in 1950 and has since gone through various programmes with concomitant challenges and successes. Presently Imidacloprid (Confidor®), Bifenthrin (Akatemaster®) and Thiamethoxam (Actara®)are recommended by Ghana Cocoa Board (COCOBOD) for the management of insect pests. A survey was conducted in the Ashanti, Eastern, Volta and Western Regions of Ghana using questionnaires and farm visits of 147 cocoa farmers’ fields to gather information on the characteristics of the farmers and insecticide handling and use by respondents. The survey showed that males dominated cocoa farming (72.7%) and most of them aged between 50 and 60 years. About 44% have had basic education whilst 37.5% of them belonged to farmer based organizations. About 52.8% of the farmers own motorized mistblower but 47.2% of the farmers use knapsack in the absence of a mistblower. About 44.8% do their own spray application whereas 55.2% hire labour. About 60.9% of the population across the regions read the label on the insecticides before application. A few (31.6 %) of the respondents put on the full personal protective costume during insecticide application and 21.9% do not use any protection. There was a positive correlation between farmers’ membership of farmer-based organisation and the costume-wearing farmers in the Ashanti, Eastern and Volta Regions and it was significant in the Ashanti region. It isrecommended that training and monitoring programmes be organized for farmers on the need to handle pesticides properly for personal and environmental safety and consumer benefit.Keywords: Insecticides; pest management; cocoa farmers; safet
Survey of parasitoids and hyperparasitoids (Hymenoptera) of the green peach aphid, Myzus persicae and the foxglove aphid, Aulacorthum solani (Hemiptera: Aphididae) in British Columbia
We surveyed the parasitoids and hyperparasitoids of the green peach aphid, Myzus persicae, and the foxglove aphid, Aulacorthum solani in the lower Fraser Valley of British Columbia, Canada. Field surveys were conducted using isolated pepper plants, with aphids, as trap plants. Primary parasitoids recorded from field surveys were Aphidius ervi, A. matricariae, Praon gallicum, P. unicum, P. humulaphidis, Ephedrus californicus, Diaeretiella rapae, Monoctonus paulensis, Aphelinus abdominalis and A. asychis. Diaretiella rapae only emerged from green peach aphids, and Ephedrus californicus only emerged from foxglove aphids. Aphidius matricariae was the most abundant primary parasitoid species reared from both aphid species. Hyperparasitoid species collected belonged to the genera Dendrocerus, Asaphes, Alloxysta, Pachyneuron and Syrphophagous. In greenhouses, Dendrocerus carpenteri was the dominant hyperparasitoid species. Aphidius and Aphelinus spp. were attacked by hyperparasitoids at similar rates. In the field, Aphidius spp. were attacked by five species of hyperparasitoid, and Aphelinus spp. were attacked by one, Alloxysta ramulifera. In general, the rate of attack by hyperparasitoids was much lower in field surveys than in our collections from greenhouses
Transport Modelling During Preparation of General Plans in Big Cities: Reasons and Challenges
Rapidly growing mobility of people in European cities attaches greater importance to the sustainable developmentconcept. The dynamics of European cities are however different. Cites such as Lithuanian, Slovakian and Polishones will rapidly increase traffic flows and car ownership at fast pace. Also in most of Western Europe, even if at lowerrates, private mobility is increasing. In some cities, however, car use and car ownership are finally decreasing, alsothanks to policies implemented. Of course, an increase of traffic flows poses problems in terms of street space, pollutionand liveability of cities. Sustainable integration of all kinds of transport into the urban development process is one ofthe most effective actions in the hands of city planners. The coordination between the planning of residential and businessdevelopment areas and the expansion of public transport and its hierarchical integration is however a difficult butnecessary exercise. Transport modelling tools, in particular, need important advancements to integrate transport andland use in simulations. This article analyses the main challenges in the use of transport models to support the constructionof city plans by means of two case studies of Milan and Vilnius. The analysis deals both with traditional aspects,such as the proper simulation of multimodal choices, the level of detail of zoning, the issues associated to the simulationof traffic management policies. Then, we will focus on two aspects still open: the integration of transport modelling andeconomic assessment or ranking of actions, and the inclusion of land use changes in the modelling
Genetic analysis of heterogeneous subsets of circulating tumour cells from high grade serous ovarian carcinoma patients
Circulating tumour cells (CTCs) are heterogenous and contain genetic information from the tumour of origin. They bear specific intra- and extra-cellular protein markers aiding in their detection. However, since these markers may be shared with other rare cells in the blood, only genetic testing can confirm their malignancy. Herein, we analyse different CTC subsets using single cell whole genome DNA sequencing to validate their malignant origin. We randomly selected putative CTCs identified by immunostaining that were isolated from 4 patients with high grade serous ovarian cancer (HGSOC) and one with benign cystadenoma. We specifically targeted CTCs positive for epithelial (CK/EpCAMpos), mesenchymal (vimentinpos), and pseudoendothelial (CK/EpCAMpos plus CD31pos) markers. We isolated these cells and performed whole genome amplification (WGA) and low-pass whole-genome sequencing (LP-WGS) for analysis of copy number alterations (CNA). Of the CK/EpCAMpos cells analysed from the HGSOC patients, 2 of 3 cells showed diverse chromosomal CNAs. However, the 4 pseudoendothelial cells (CK/EpCAMpos plus CD31pos) observed in the HGSOC cases did not carry any CNA. Lastly, two of the clusters of vimentin positive cells sequenced from those found in the benign cystadenoma case had CNA. Despite the low number of cells analysed, our results underscore the importance of genetic analysis of putative CTCs to confirm their neoplastic origin. In particular, it highlights the presence of a population of CK/EpCAMpos cells that are not tumour cells in patients with HGSOC, which otherwise would be counted as CTCs
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