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Effects of Hemizygia welwitschii leaf extract fractions on postharvest infestation of maize by Sitophilus zeamais Motsculsky (Coleoptera: Curculionidae): Presentation
Get PDFAs part of on-going efforts to use eco-friendly alternatives to chemical pesticides, leaf powder of Hemizygia welwitschii was sequentially extracted in hexane, acetone and methanol. Bioassays were carried out to establish the most active fraction(s) against Sitophilus zeamais in maize. Maize grains (50 g) were treated with concentrations within the range 2, 4, 6, and 10 g/kg of extract and Azadirachta indica seed oil (positive control) in the laboratory. The total number of progeny emerging from grains infested separately with S. zeamais eggs, larvae and pupae were recorded. Adult mortality counts were carried out 1, 3, 7 and 14 d post-exposure. Acetone extract was more toxic to the eggs, larvae and pupae than the other extracts, inhibiting progeny production by 90.90%, 88.10% and 100%, respectively, at the concentration 10 g/kg. For the same concentration, A. indica seed oil reduced progeny production by 100% for eggs, 96.08% for larvae and 70.93% for pupae. Hexane extract was more potent to the adult weevil than the other extracts, recording 100% mortality for the concentration 10 g/kg within 14 d. LC50 values were 0.78 (Hexane), 5.52 (acetone) and 1.69 g/kg (methanol). Extracts of H. welwitschii leaves had sufficient efficacy to be a component of storage pest management package for S. zeamais.As part of on-going efforts to use eco-friendly alternatives to chemical pesticides, leaf powder of Hemizygia welwitschii was sequentially extracted in hexane, acetone and methanol. Bioassays were carried out to establish the most active fraction(s) against Sitophilus zeamais in maize. Maize grains (50 g) were treated with concentrations within the range 2, 4, 6, and 10 g/kg of extract and Azadirachta indica seed oil (positive control) in the laboratory. The total number of progeny emerging from grains infested separately with S. zeamais eggs, larvae and pupae were recorded. Adult mortality counts were carried out 1, 3, 7 and 14 d post-exposure. Acetone extract was more toxic to the eggs, larvae and pupae than the other extracts, inhibiting progeny production by 90.90%, 88.10% and 100%, respectively, at the concentration 10 g/kg. For the same concentration, A. indica seed oil reduced progeny production by 100% for eggs, 96.08% for larvae and 70.93% for pupae. Hexane extract was more potent to the adult weevil than the other extracts, recording 100% mortality for the concentration 10 g/kg within 14 d. LC50 values were 0.78 (Hexane), 5.52 (acetone) and 1.69 g/kg (methanol). Extracts of H. welwitschii leaves had sufficient efficacy to be a component of storage pest management package for S. zeamais
Evaluation of two new insecticide formulations based on inert dusts and botanicals against four stored-grain beetles: Poster
Get PDFToxicity of extracts derived from different parts of cassava plant, Manihot esculenta Crantz to four major coleopteran pests of stored-products: Poster
Get PDFFumigant toxicity of insecticidal principles extracted from tuber rind, fresh leaf, fresh leaf with petiole, and dried leaf of cassava (var. M4) was studied against four major stored-product insect pests viz. Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Tribolium castaneum (Herbst) and Callosobruchus chinensis (L.) under laboratory conditions (28±2ºC, Rh. 75±5%). Mortality of the test insects varied with respect to extracts collected from different parts of the plant, and time of exposure. Extract collected from cassava rind recorded the highest toxicity. Callosobruchus chinensis was highly susceptible and showed immediate knockdown effect to the active principles extracted from tuber rind, fresh leaf, fresh leaf with petiole, twig and semi-dried leaf. The extract collected from various parts of plant caused 100% mortality of R. dominica at 1 hour after treatment (HAT), but the same collected from tuber and dried leaves did not show any toxic effect. Mortality of S. oryzae was 100% at 1 HAT with tuber rind extract, but no response was observed from the extract collected from semi-dried leaf, twig, and leaf with petiole. No fumigant action was observed in all the four coleopteran pests exposed to the extract collected from dried leaves. The study revealed that fresh leaf and tuber rind are good sources for the extraction of biofumigant against major coleopteran pests, however dried leaves are unfit for same purpose.Fumigant toxicity of insecticidal principles extracted from tuber rind, fresh leaf, fresh leaf with petiole, and dried leaf of cassava (var. M4) was studied against four major stored-product insect pests viz. Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Tribolium castaneum (Herbst) and Callosobruchus chinensis (L.) under laboratory conditions (28±2ºC, Rh. 75±5%). Mortality of the test insects varied with respect to extracts collected from different parts of the plant, and time of exposure. Extract collected from cassava rind recorded the highest toxicity. Callosobruchus chinensis was highly susceptible and showed immediate knockdown effect to the active principles extracted from tuber rind, fresh leaf, fresh leaf with petiole, twig and semi-dried leaf. The extract collected from various parts of plant caused 100% mortality of R. dominica at 1 hour after treatment (HAT), but the same collected from tuber and dried leaves did not show any toxic effect. Mortality of S. oryzae was 100% at 1 HAT with tuber rind extract, but no response was observed from the extract collected from semi-dried leaf, twig, and leaf with petiole. No fumigant action was observed in all the four coleopteran pests exposed to the extract collected from dried leaves. The study revealed that fresh leaf and tuber rind are good sources for the extraction of biofumigant against major coleopteran pests, however dried leaves are unfit for same purpose
Postharvest knowledge, perceptions and practices of African small-scale maize and sorghum farmers: Presentation
No full textDue to a single annual food production season in southern Africa, small-scale maize and sorghum farmers store grain until the next harvest. The farmers’ postharvest knowledge, perceptions and practices (KPP) is important in reducing postharvest losses (PHLs); a key component of household food and nutritional security. Using random sampling, 310 farmers from two districts of Zimbabwe with contrasting agroecologies and agricultural systems (maize and sorghum) were interviewed to assess their KPP on post-production aspects. Maize and sorghum grain were stored in new and recycled polypropylene bags (93.5% and 42.6%) placed in ordinary rooms (44.5% and 27.1%), brick store houses (28.4% and 54.2%) and traditional huts (23.2% and 16.1), respectively. Farmers recognised field infestation as important source of insect infestation in sorghum (60%) but not in maize (21.3%). Synthetic commercial grain protectants were used more on maize (90.2%) than on sorghum grain (63.2%). Majority of farmers (> 75%) perceived these insecticides as both effective and safe to use. Farmers’ household reserved grain ran out before the next harvest and was supplemented through buying grain or mealie-meal with cash, or exchanging grain with labour or livestock. Postharvest information and training were scarce in both systems. The study provides important information to extensionists, policy makers, development agents and researchers for reviewing and benchmarking extension services and farmer training requirements to effectively accelerate progress towards PHL reduction and contribute to household and national food and nutritional security.Due to a single annual food production season in southern Africa, small-scale maize and sorghum farmers store grain until the next harvest. The farmers’ postharvest knowledge, perceptions and practices (KPP) is important in reducing postharvest losses (PHLs); a key component of household food and nutritional security. Using random sampling, 310 farmers from two districts of Zimbabwe with contrasting agroecologies and agricultural systems (maize and sorghum) were interviewed to assess their KPP on post-production aspects. Maize and sorghum grain were stored in new and recycled polypropylene bags (93.5% and 42.6%) placed in ordinary rooms (44.5% and 27.1%), brick store houses (28.4% and 54.2%) and traditional huts (23.2% and 16.1), respectively. Farmers recognised field infestation as important source of insect infestation in sorghum (60%) but not in maize (21.3%). Synthetic commercial grain protectants were used more on maize (90.2%) than on sorghum grain (63.2%). Majority of farmers (> 75%) perceived these insecticides as both effective and safe to use. Farmers’ household reserved grain ran out before the next harvest and was supplemented through buying grain or mealie-meal with cash, or exchanging grain with labour or livestock. Postharvest information and training were scarce in both systems. The study provides important information to extensionists, policy makers, development agents and researchers for reviewing and benchmarking extension services and farmer training requirements to effectively accelerate progress towards PHL reduction and contribute to household and national food and nutritional security
Temporal and spatial patterns in aerosol insecticide droplet distribution: Modifying application strategies to improve coverage and efficacy
Get PDFWith the phase-out of methyl bromide, treatment of food facilities with aerosol insecticides as part of management programs has increased. The physical layout of the structure, the distribution of equipment and other items within the space, and the application method and location may all cause spatial variation in how the insecticide is deposited, which can result in areas with insufficient or excessive amounts of insecticide applied. The impact of aerosol insecticide application position and dispersal method/formulation on the distribution of droplets was evaluated using a series of applications within the same flour mill room. The spatial pattern of droplet distribution and the effect of treatment on bioassay insects (Tribolium confusum Jacquelin DuVal) was evaluated. There was variation in aerosol concentration and droplet size distributions within room and application position had an impact on the spatial pattern of aerosol droplets. The further away and more obstructed by structural features a location was the lower the aerosol concentration, but concentration was also lower to the side and behind the release point. Evaluation of the temporal pattern in droplet deposition shows that most larger droplets settle out of the air relatively quickly, supporting that idea that shorter shutdown times are be possible. Efficacy was correlated with droplet concentration. The overall conclusion is that there can be considerable variation in distribution of aerosol insecticides and as a result considerable potential for improvement in the effectiveness of these applications.With the phase-out of methyl bromide, treatment of food facilities with aerosol insecticides as part of management programs has increased. The physical layout of the structure, the distribution of equipment and other items within the space, and the application method and location may all cause spatial variation in how the insecticide is deposited, which can result in areas with insufficient or excessive amounts of insecticide applied. The impact of aerosol insecticide application position and dispersal method/formulation on the distribution of droplets was evaluated using a series of applications within the same flour mill room. The spatial pattern of droplet distribution and the effect of treatment on bioassay insects (Tribolium confusum Jacquelin DuVal) was evaluated. There was variation in aerosol concentration and droplet size distributions within room and application position had an impact on the spatial pattern of aerosol droplets. The further away and more obstructed by structural features a location was the lower the aerosol concentration, but concentration was also lower to the side and behind the release point. Evaluation of the temporal pattern in droplet deposition shows that most larger droplets settle out of the air relatively quickly, supporting that idea that shorter shutdown times are be possible. Efficacy was correlated with droplet concentration. The overall conclusion is that there can be considerable variation in distribution of aerosol insecticides and as a result considerable potential for improvement in the effectiveness of these applications
Mites in aromatic, condiment and medicinal dehydrated plants in bulk sale in the city of São Paulo.: Poster
Get PDFProceedings of the12th International Working Conference on Stored Product Protection (IWCSPP) in Berlin, Germany, October 7-11, 2018
Get PDFInnovation Ecosystems to Promote the Establishment of Complex Bio-Technologies in Distant Markets – The Case of Fucoidan
Get PDFFucoidane bilden eine Stoffgruppe sulfatisierter Polysaccharide, die auch in Braunalgen in Nord- und Ostsee vorkommen. Trotz eines breiten Spektrums gesundheitsfördernder und bioaktiver Eigenschaften, die diverse Forschungsteams verschiedener Fachrichtungen über die letzten Jahrzehnte identifiziert haben, werden Marktpotenziale der vielfältigen Anwendungsgebiete heute meist noch nicht ausgenutzt. Die Nutzung von Fucoidanen für Anwendungen wie die Kosmetik und die Medizin bedarf der Integration vielfältiger Technologien entlang der Wertschöpfungskette von der Kultivierung, der nachhaltigen Ernte, Extraktion, Separierung und ggf. Synthese, Kombination mit anderen z.B. Medizintechnologien und Technologien zur Applikation der Wirkstoffe. Hinzu kommen regulative, ökologische und gesellschaftliche Aspekte die im Innovationsprozess beachtet werden müssen. Daher erfordert die Entstehung und Anwendung solch komplexer Technologiefelder das Mitwirken einer Vielzahl von Experten unterschiedlicher wissenschaftlicher Fachrichtungen. Deren kontinuierliches Mitwirken an der Exploration neuer technologischer Komponenten und Systemlösungen und der Exploitation der Technologien in Form von Produktinnovationen ist entscheidend für den Erfolg. Daher ist es notwendig, wichtige Stakeholder einer Technologie und angrenzender Anwendungsfelder zu identifizieren und ein multidisziplinares Innovationsökosystem aufzubauen und zu koordinieren, welches die Technologieentwicklung durch interdisziplinare Zusammenarbeit auch jenseits etablierter Technologie- und Marktgrenzen vorantreibt. Die Entwicklung und Anwendung eines derartig komplexen und entlang der Wertschöpfungskette intergierten technologischen Systems werden aus der Perspektive der Innovationsökosysteme am Beispiel des Braunalgenextrakts „Fucoidan“ untersucht. Als Grundlage dienen Patent- & Publikationsdaten sowie qualitative Interviews mit Akteuren des Innovationsökosystems.Fucoidans are a group of sulfated polysaccharides mainly found in various brown algae species that also exist in the North and the Baltic Sea. Despite a broad range of beneficial and bioactive characteristics that have been identified by numerous research teams of diverse professional backgrounds over the last decades the market opportunities in distant application fields of fucoidans have not been exploited yet. The use of fuciodans in application fields of the dietary, cosmetic or medical branch requires the integration of multiple technologies along the supply chain – cultivation, harvesting, extraction, separation, characterization, synthesis and possible combinations with adjacent technologies such as medical technologies for the application of the active ingredient. Additionally, regulatory, ecological and social aspects of the innovation process need to be considered. Consequently, the evolution of such complex technology domains including the applications requires the knowledge of a diverse group of professions. Their continuous collaboration exploring new technological components and system solutions and exploiting technologies in the shape of product innovations is a crucial factor of success. Therefore, it is necessary to identify key stakeholders of a technology and adjacent application fields to create and coordinate a multidisciplinary innovation ecosystem. Such an ecosystem supports the ability to collectively promote the technological evolution by interdisciplinary collaboration beyond established technological and market boundaries. On the example of the brown algae extract fucoidan the development and application of such a complex and supply chain integrated technological system will be analyzed from the perspective of innovation ecosystems. The results are based on patent and publication data as well as qualitative interviews with actors of the ecosystem
