905 resultados para Cotton gins and ginning.
Resumo:
Cotton production in the European Union (EU) is limited to areas of Greece and Southern Spain (Andalusia). The 2004 reform of the EU cotton policy severely affected the profitability of the crop. In this article we analyze how the introduction of genetically modified (GM), insect-resistant cotton varieties (Bt cotton) might help EU cotton farmers to increase profitability and therefore face the cotton policy reform. We first study farmers’ attitudes toward adoption of Bt cotton varieties through a survey conducted in Andalusia (Southern Spain). The results show a positive attitude of Andalusian cotton farmers toward the Bt cotton varieties. Second, we perform an ex-ante analysis of the effects of introducing Bt cotton in Andalusia. Finally, we integrate the analysis of the effects of Bt cotton with the analysis of the EU cotton reform. Our results show that despite the significant economic benefits of Bt cotton, the current policy reform is likely to jeopardize the profitability of cotton production in the EU.
Resumo:
In this paper, the yield increases resulting from the cultivation of Bt cotton in Maharashtra, India, are analysed. The study relies on commercial farm, rather than trial, data and is among the first of its kind to be based on real farm and market conditions. Findings show that since its commercial release in 2002, Bt cotton has had a significant positive impact on yields and on the economic performance of cotton growers in Maharashtra. This difference remains even after controlling for different soil and insecticide inputs in the production of Bt cotton. There is also significant spatial and temporal variation in this 'benefit', and much depends upon where production is taking place and on the season.
Resumo:
Entomopathogenic bacterial strains Pseudomonas (Flavimonas) oryzihabitans and Xenorhabdus nematophilus, both bacterial symbionts of the entomopathogenic nematodes Steinernema abbasi and S. carpocapsae have been recently used for suppression of soil-borne pathogens. Bacterial biocontrol agents (P. oryzihabitans and X nematophila) have been tested for production of secondary metabolites in vitro and their fungistatic effect,on mycelium and spore development of soil-borne pathogens. Isolates of Pythium spp. and Rhizoctonia solani, the causal agent of cotton damping-off, varied in sensitivity in vitro to the antibiotics phenazine-I-carboxylic acid (PCA), cyanide (HCN) and siderophores produced by bacterial strains shown previously to have potential for biological control of those pathogens. These findings affirm the role of the antibiotics PCA, HCN and siderophores in the biocontrol activity of these entomopathogenic strains and support earlier evidence that mechanisms of secondary metabolites are responsible for suppression of damping-off diseases. In the present studies colonies of R oryzihabitans showed production of PCA with presence of crystalline deposits after six days development and positive production where found as well in the siderophore's assay when X nematophila strain indicated HCN production in the in vitro assays. In vitro antifungal activity showed that bacteria densities of 101 to 10(6)cells/ml have antifungal activity in different media cultures. The results show further that isolates of Pythium spp. and R. solani insensitive to PCA, HCN and siderophores are present in the pathogen population and provide additional justification for the use of mixtures of entomopathogenic strains that employ different mechanisms of pathogen suppression to manage damping-off.
Resumo:
The economic benefits of Genetically Modified (GM) crops in developing countries have been well documented, but little research has been undertaken to date on the impacts of GM adoption on household livelihoods. The research reported here aimed to assess the livelihood impacts of the adoption of Bt cotton in South Africa., and involved 100 interviews of resource-poor farmers growing Bt cotton in Makhathini Flats, South Africa. Some 88% of respondents reported a higher income from Bt compared to non-Bt varieties previously grown by them, and this higher income was used primarily for greater education of their children (76%), more investment in growing cotton (46%), repaying debt (28%), investment in other crops (20%) and spending money on themselves. Some 89% had increased their asset base due to Bt cotton, primarily by increasing their cultivable land. These benefits of Bt adoption appeared widespread regardless of gender or farm size.
Resumo:
This paper presents the results of a large-scale study designed to monitor the impact arising from the introduction of insect-resistant Bt cotton in the Makhathini Flats, Republic of South Africa. Bt cotton provides a degree of resistance to cotton bollworm complex (Lepidoptera). Data were collected on the use of insecticides (type and quantity) as well as the farm-level economics of production from over 2200 farmers in three growing seasons (1998/1999, 1999/2000 and 2000/2001). and the results are discussed within the context of environmental impact brought about by insecticide. Over the three seasons of the study it was clear that Bt cotton provided benefits in terms of higher yield and gross margin relative to farmers growing conventional (non-Bt) cotton, and the benefits were particularly apparent for the smallest producers. Bt growers also used significantly less insecticide than growers of non-Bt cotton. Once quantities of insecticide applied to Bt and non-Bt cotton were converted into a Biocide Index and an Environmental Impact Quotient (EIQ) in order to allow for differences in terms of toxicity and persistence in the environment, it was apparent that the growing of Bt had a less negative impact on the environment. While this points to beneficial impacts on agricultural sustainability there are wider concerns regarding the vulnerability of resource-poor farmers in an area with limited (as yet) marketing options for their product and options for livelihood diversification both within and outside agriculture. Cotton producers in Makhathini are vulnerable as they rely on just One company for inputs (including, credit) and for their market. While Bt cotton provides benefits it does not in itself address some of the structural limitations that farmers face. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
The present paper explores the 'farmer' effect in economic advantages often claimed for Bt cotton varieties (those with the endotoxin gene from Bacillus thuringiensis conferring resistance to some insect pests) compared to non-Bt varieties. Critics claim that much of the yield advantage of Bt cotton could be due to the fact that farmers adopting the technology are in a better position to provide inputs and management and so much of any claimed Bt advantage is an artefact rather than reflecting a real advantage of the variety per se. The present paper provides an in-depth analysis of 63 non-adopting and 94 adopting households of Bt cotton in Jalgaon, Maharashtra State, India, spanning the seasons 2002 and 2003. Results suggest that Bt adopters are indeed different from non-adopters in a number of ways. Adopters appear to specialize more on cotton (at least in terms of the land area they devote to the crop), spend more money on irrigation and grow well-performing non-Bt varieties of cotton (Bunny). Taking gross margin as the basis for comparison, Bt plots had 2.5 times the gross margin of non-Bt plots in both seasons. If only adopters are considered then the gross margin advantage of Bt plots reduces to 1.6 times that of non-Bt plots. This is still a significant advantage and could well explain the popularity of Bt in Maharashtra. However, it is clear that great care needs to be taken with such comparative studies.
Resumo:
The paper explores the impact of insect-resistant Bacillus thuringiensis (Bt) cotton on costs and returns over the first two seasons of its commercial release in three sub-regions of Maharashtra State, India. It is the first such research conducted in India based on farmers' own practices rather than trial plots. Data were collected for a total of 7793 cotton plots in 2002 and 1577 plots in 2003. Results suggest that while the cost of cotton seed was much higher for farmers growing Bt cotton relative to those growing non-Bt cotton, the costs of bollworm spray were much lower. While Bt plots had greater costs (seed plus insecticide) than non-Bt plots, the yields and revenue from Bt plots were much higher than those of non-Bt plots (some 39% and 63% higher in 2002 and 2003, respectively). Overall, the gross margins of Bt plots were some 43% (2002) and 73% (2003) higher than those of non-Bt plots, although there was some variation between the three sub-regions of the state. The results suggest that Bt cotton has provided substantial benefits for farmers in India over the 2 years, but there are questions as to whether these benefits are sustainable. (c) 2004 Elsevier Ltd. All rights reserved.
Resumo:
Technology involving genetic modification of crops has the potential to make a contribution to rural poverty reduction in many developing countries. Thus far, pesticide-producing Bacillus thuringensis (Bt) varieties of cotton have been the main GM crops under cultivation in developing nations. Several studies have evaluated the farm-level performance of Bt varieties in comparison to conventional ones by estimating production technology, and have mostly found Bt technology to be very successful in raising output and/or reducing pesticide input. However, the production risk properties of this technology have not been studied, although they are likely to be important to risk-averse smallholders. This study investigates the output risk aspects of Bt technology by estimating two 'flexible risk' production function models allowing technology to independently affect the mean and higher moments of output. The first is the popular Just-Pope model and the second is a more general 'damage control' flexible risk model. The models are applied to cross-sectional data on South African smallholders, some of whom used Bt varieties. The results show no evidence that a 'risk-reduction' claim can be made for Bt technology. Indeed, there is some evidence to support the notion that the technology increases output risk, implying that simple (expected) profit computations used in past evaluations may overstate true benefits.
Resumo:
Various food and feed samples including groundnut seed, maize, sorghum, soyabean cake, groundnut cake, cotton cake, poultry feed, buffalo milk, cow milk and milk powders were collected from farmers' fields, farmer's stores, oil millers storage, traders' storage, retail shops and supermarkets. More than 2000 samples were analysed by ELISA and most of the commodities, with the exception of sorghum seed, contained high levels of aflatoxin. Groundnut cake was one of the major cattle feed ingredients in the peri-urban area of Hyderabad (Andhra Pradesh, India) and >75% of the samples contained >100 µg/kg aflatoxin, leading to a high level of aflatoxin M1, in milk samples. Strategies to reduce aflatoxin levels (especially in groundnut) by management interventions at preharvest, harvest and storage, are discussed.
Resumo:
Investigations were conducted during the 2003, 2004 and 2005 growing seasons in northern Greece to evaluate effects of tillage regime (mouldboard plough, chisel plough and rotary tiller), cropping sequence (continuous cotton, cotton-sugar beet rotation and continuous tobacco) and herbicide treatment on weed seedbank dynamics. Amaranthus spp. and Portulaca oleracea were the most abundant species, ranging from 76% to 89% of total weed seeds found in 0-15 and 15-30 cm soil depths during the 3 years. With the mouldboard plough, 48% and 52% of the weed seedbank was found in the 0-15 and 15-30 cm soil horizons, while approximately 60% was concentrated in the upper 15 cm soil horizon for chisel plough and rotary tillage. Mouldboard ploughing significantly buried more Echinochloa crus-galli seeds in the 15-30 cm soil horizon compared with the other tillage regimes. Total seedbank (0-30 cm) of P. oleracea was significantly reduced in cotton-sugar beet rotation compared with cotton and tobacco monocultures, while the opposite occurred for E. crus-galli. Total seed densities of most annual broad-leaved weed species (Amaranthus spp., P. oleracea, Solanum nigrum) and E. crus-galli were lower in herbicide treated than in untreated plots. The results suggest that in light textured soils, conventional tillage with herbicide use gradually reduces seed density of small seeded weed species in the top 15 cm over several years. In contrast, crop rotation with the early established sugar beet favours spring-germinating grass weed species, but also prevents establishment of summer-germinating weed species by the early developing crop canopy.
Resumo:
We have identified two mutations in the ace1 gene of Aphis gossypii that are associated with insensitivity of acetylcholinesterase (AChE) to carbamate and organophosphate insecticides. The first of these, S431F (equivalent to F331 in Torpedo californica), is associated with insensitivity to the carbamate insecticide pirimicarb in a range of A. gossypii clones. The S431F mutation is also found in the peach-potato aphid, Myzus persicae (Sulzer), and a rapid RFLP diagnostic allows the identification of individuals of both aphid species with a resistant genotype. This diagnostic further revealed the presence of S431 in several other pirimicarb-susceptible aphid species. The serine at this position in the wild-type enzyme has only been reported for aphids and provides a molecular explanation of why pirimicarb has a specific aphicidal action. A less specific insensitivity to a wide range of carbamates and organophosphates is associated with a second mutation, A302S (A201 in T. californica).
Resumo:
Four races of Xanthomonas campestris pv. mal-vacearum (Xcm) viz. races 23, 27 and 32 (isolated from Gossypium hirsutum) and race 23b (from Gossypium barbadense) were studied. The plasmid profile of the natural isolates showed four plasmids in races 23 and 23b (ca. 60, 40, 23, 8.2 kb), five in race 27 (ca. 60, 40, 23, 8.2 and 3.7 kb) and six in race 32 (ca. 60, 40, 23, 8.2, 3.7 and 1.6 kb). Continuously sub-cultured laboratory isolates of the Xcm races resulted in the loss of all but two plasmids, ca. 60 and 40 kb in size. When the laboratory isolates were passed through cotton (Gossypium hirsutum), they regained certain plasmids so that four plasmids were found in race 23 and 23b (ca. 60, 40, 23 and 8.2 kb), five in race 27 (ca. 60, 40, 23, 8.2 and 3.7 kb) and six in race 32 (ca. 60, 40, 23, 8.2, 3.7 and 1.6 kb), which was more or less similar to the original isolates. The isolates recovered from cotton maintained their plasmid profile (except for minor changes in the miniplasmids) after storage for six months at -70degreesC in 50% glycerol. It is suggested that plasmid profiles among highly virulent races of Xcm are unstable during repeated sub-culturing at room temperature, resulting in rapid loss of some plasmids. However, when the cultures were sub-cultured and stored at -70degreesC the plasmid profile was fairly stable except for the miniplasmids (ca. 3.7 and 1.6 kb).