948 resultados para Nematodes -- Cereals
Resumo:
This study aimed to propose methods to identify croplands cultivated with winter cereals in the northern region of Rio Grande do Sul State, Brazil. Thus, temporal profiles of Normalized Difference Vegetation Index (NDVI) from MODIS sensor, from April to December of the 2000 to 2008, were analyzed. Firstly, crop masks were elaborated by subtracting the minimum NDVI image (April to May) from the maximum NDVI image (June to October). Then, an unsupervised classification of NDVI images was carried out (Isodata), considering the crop mask areas. According to the results, crop masks allowed the identification of pixels with greatest green biomass variation. This variation might be associated or not with winter cereals areas established to grain production. The unsupervised classification generated classes in which NDVI temporal profiles were associated with water bodies, pastures, winter cereals for grain production and for soil cover. Temporal NDVI profiles of the class winter cereals for grain production were in agree with crop patterns in the region (developmental stage, management standard and sowing dates). Therefore, unsupervised classification based on crop masks allows distinguishing and monitoring winter cereal crops, which were similar in terms of morphology and phenology.
Resumo:
The purpose of this study was to evaluate the efficacy of orally administered albendazole sulphoxide and pour-on ivermectin for the treatment of bovine parasitic otitis caused by rhabditiform nematodes. Eighteen Gyr cows presenting clinical otitis were divided in three groups with six animals each. The first one did not receive any treatment (control group). The second one was treated with 0.5% pour-on ivermectin, 500µg/kg of body weight, and the third group was treated with oral 6% albendazole sulphoxide, at 6.0mg/kg. Both ear canals of each animal were reexamined on days 7 and 21 post treatment. The animals in the control group remained infected throughout the days of observation. Ivermectin treatment did not show effectiveness on days 7 or 21 post treatment. The albendazole sulphoxide treatment had an efficacy of 16.7 and 25% on days 7 and 21, respectively. Further studies are required to assess an effective treatment for this parasitic disease, especially via alternative administration routes, because of its significant impact on Bos taurus indicus cattle breeding in Tropical and Subtropical Regions.
Resumo:
The aim was to evaluate for 75 days the impact on production of the remaining burden of ivermectin (IVM)-resistant parasites in naturally infected feedlot calves. The herds came from tick-infested areas of cattle breeding where the systematic use of IVM to control tick increases the gastrointestinal parasites resistant to this drug. This investigation was carried out in two commercial feedlots in Buenos Aires province. In feedlot A, two groups of 35 animal each received IVM 1% and the other received ricobendazole (RBZ) 10% respectively. The same was done in feedlot B. On day 0, two groups of 35 animals were made in feedlots A and B. Fecal samples were taken on days 0, 22, 54 and 75 pos-treatment (PT), and body weight was registered, from each animal. Fecal samples were processed for individual count of eggs per gram (EPG) and pooled fecal culture was carried out for identification of the parasite genus in each sampling. Fecal egg count reduction test (FECR) was calculated on day 22 PT. The study design used was a totally randomized block, with commercial feedlot and sex as block variables. For data analysis, a mixed model of the SAS statistical program was used. The FECR average on day 22 was 28.4% in the IVM group, and 94,2 % in the RBZ group . From this date on, significant differences in EPG were kept until day 54. EPG counts were only equal near the end of the trial, on day 75 (p=0.16). In both commercial feedlots, especially in the IVM group, Cooperia spp. was the most prevalent parasite in the fecal cultures. Significant differences in weight (P<0.01) on post-treatment day 75 was found between the average weight in the RBZ and the IVM group (246 vs. 238 kg respectively), what means a difference of 8.3% in gains. The importance for production in the antiparasite failure treatment in commercial feedlots was demonstrated, and the need of pos-treatment controls to evaluate the efficacy of the antiparasitic administered is emphasized.
Resumo:
In vitro tests were carried out on the pathogenicity of nine isolates of the predatory fungi of the genus Monacrosporium (5 M. sinense isolates, 3 M. appendiculatum and 1 M. thaumasium isolate) for a phytonematode (second stage juveniles from Meloidogyne incognita, race 3), a free-living nematode (Panagrellus spp), and two gastrointestinal parasitic nematodes of cattle (infective larvae of Cooperia punctata and Haemonchus placei). A suspension containing 2,000 nematodes from each species was added to Petri dishes containing fungi and grown on 2% water-agar medium at 25oC in the dark for up to 7 days. The dishes were examined every other day for 7 days and predation-free nematodes were counted. The results showed that the free-living nematodes, Panagrellus spp, were the most susceptible (P<0.05), followed by the phytonematode M. incognita, while the controls were ³98.5% viable. However, a variable susceptibility of the nematodes to different fungi was observed. This indicates that the use of predatory fungi for the environmental control of nematodes will be limited by the multiplicity of nematodes in the environment and their differential susceptibility to fungal isolates of the same genus.
Resumo:
Iron bioavailability was evaluated in three mixtures of cereals, seeds, and grains ("Human Ration"): light, regular, and homemade provided to rats. The animals received an iron depletion diet for 21 days, followed by a repletion diet containing 12 mg·kg-1 of iron for 14 days. The hemoglobin regeneration efficiency and the relative biological value did not differ between the light mixture and control group. The iron bioavailability of the light mixture of cereals, seeds, and grains and the control group were 99.99±27.62 and 80.02±36.63, respectively, while the regular and homemade mixtures of cereals, seeds, and grains showed lower iron bioavailability, 50.12±35.53 and 66.66±15.44, respectively; the iron content of the diet with light cereal mixture light was statistically similar to that of the control (ferrous sulfate 99.99±27.62). The high content of tannin (202.81±19.53 mg·100-1) in the diet with the regular cereal mixture may have contributed to its low iron bioavailability. The higher intake of soluble fiber by the animals fed the light mixture (21.15±0.92 g) was moderately correlated (r=0.5712, p=0.0018) with the concentration of propionate in the caecal bulk (65.49±11.08 µmol/g). The short chain fatty acids produced by soluble fiber fermentation, associated with the low-content of tannin may have improved iron solubility and absorption in the light cereal mixture diet. The iron bioavailability in the light mixture of cereals, seeds, and grains was similar to that of ferrous sulfate.
Resumo:
Department of Marine Biology, Microbiology and Biotechnology, Cochin University of Science and Technology
Resumo:
A field experiment with millet (Pennisetum glaucum L.), sorghum [Sorghum bicolor (L.) Moench], cowpea (Vigna unguiculata L.) and groundnut (Arachnis hypogeae L.) was conducted on severely P-deficient acid sandy soils of Niger, Mali and Burkina Faso to measure changes in pH and nutrient availability as affected by distance from the root surface and by mineral fertiliser application. Treatments included three rates of phosphorus (P) and four levels of nitrogen (N) application. Bulk, rhizosphere and rhizoplane soils were sampled at 35, 45 and 75 DAS in 1997 and at 55 and 65 DAS in 1998. Regardless of the cropping system and level of mineral fertiliser applied, soil pH consistently increased between 0.7 and two units from the bulk soil to the rhizoplane of millet. Similar pH gradients were observed in cowpea, but pH changes were much smaller in sorghum with a difference of only 0.3 units. Shifts in pH led to large increases in nutrient availability close to the roots. Compared with the bulk soil, available P in the rhizoplane was between 190 and 270% higher for P-Bray and between 360 and 600% higher for P-water. Exchangeable calcium (Ca) and magnesium (Mg) levels were also higher in the millet rhizoplane than in the bulk soil, whereas exchangeable aluminium (Al) levels decreased with increasing pH close to the root surface. The results suggest an important role of root-induced pH increases for crops to cope with acidity-induced nutrient deficiency and Al stress of soils in the Sudano-Sahelian zone of West Africa.
Resumo:
A more widespread use of cereal/legume rotations has been suggested as a means to sustainably meet increasing food demands in sub-Saharan West Africa. Enhanced cereal yields following legumes have been attributed to chemical and biological factors such as higher levels of mineral nitrogen (Nmin) and arbuscular mycorrhizae (AM) but also to lower amounts of plant parasitic nematodes. This study was conducted under controlled conditions to examine the relative contribution of AM, plant parasitic nematodes and increased nitrogen (N) and phosphorus (P) availability to cereal/legume rotation effects on two West African soils. Sample soils were taken from field experiments at Gaya (Niger) and Fada (Burkina Faso) supporting continuous cereal and cereal/legume rotation systems and analysed for chemical and biological parameters. Average increases in cereal shoot dry matter (DM) of rotation cereals compared with continuous cereals were 490% at Gaya and 550% at Fada. Shoot P concentration of rotation millet was significantly higher than in continuous millet and P uptake in rotation cereals was on average 62.5-fold higher than in continuous cereals. Rotation rhizosphere soils also had higher pH at both sites. For the Fada soil, large increases in Bray1-P and organic P were observed in bulk and rhizosphere soils. Plant parasitic nematodes in roots of continuous cereals were 60–80-fold higher than in those of rotation cereals. In both cropping systems mycorrhizal infection rates were similar at 37 days after sowing (DAS) but at 57 DAS AM infection was 10–15% higher in rotation sorghum than in continuous sorghum. This study provides strong evidence that cereal/legume rotations can enhance P nutrition of cereals through improved soil chemical P availability and microbiologically increased P uptake.
Resumo:
On-farm experiments and pot trials were conducted on eight West African soils to explore the mechanisms governing the often reported legume rotation-induced cereal growth increases in this region. Crops comprised pearl millet (Pennisetum glaucum L.), sorghum (Sorghum bicolor Moench), maize (Zea mays L.), cowpea (Vigna unguiculata Walp.) and groundnut (Arachis hypogaea L.). In groundnut trials the observed 26 to 85% increases in total dry matter (TDM) of rotation cereals (RC) compared with continuous cereals (CC) in the 4th year appeared to be triggered by site- and crop-specific early season differences in nematode infestation (up to 6-fold lower in RC than in CC), enhanced Nmin and a 7% increase in mycorrhizal (AM) infection. In cowpea trials yield effects on millet and differences in nematode numbers, Nmin and AM were much smaller. Rhizosphere studies indicated effects on pH and acid phosphatase activity as secondary causes for the observed growth differences between RC and CC. In the study region legume-rotation effects on cereals seemed to depend on the capability of the legume to suppress nematodes and to enhance early N and P availability for the subsequent cereal.
Resumo:
Ziel der vorliegenden Arbeit war es, den Mischfruchtanbau von Sommer- oder Wintererbsen und Getreide zu bewerten und die Eignung einer flachwendenden Bodenbearbeitung im ökologischen Erbsenanbau zu ermitteln. Weiterhin war im Rahmen dieser Arbeit beabsichtigt, den Einfluss einer mechanischen Bodenbelastung zur Saat auf die Leistungsfähigkeit von Sommererbsen in Reinsaat und Gemenge nach tief- (Pflug, 25-30 cm) und flachwendender (Stoppelhobel, 7-12 cm) Bodenbearbeitung zu untersuchen. Zu diesem Zweck wurden Feldversuche mit den Versuchsfaktoren Anbauform (Sommererbsen und Hafer in Reinsaat oder Gemenge), Pflugsystem (flach- und tiefwendend), mechanische Bodenbelastung (0 t; 2,6 t; 4,6 t Hinterradlast) und Standort (Köllitsch, Trenthorst) in 2009 und 2010 durchgeführt. Der Mischfruchtanbau zweier Wintererbsen-Sorten (E.F.B. 33: normalblättrig, buntblühend; James: halbblattlos, weißblühend) nach flach- und tiefwendender Bodenbearbeitung wurde am Standort Trenthorst in den Jahren 2009/10 und 2010/11 untersucht. Zur Untersuchung der Vorfruchtwirkung wurde im Anschluss an die Wintererbsen-Versuche Winterweizen angebaut. Ein Gefäßversuch und ein Bioassay wurde ergänzend zu den Mischfruchtversuchen mit Sommererbsen durchgeführt, um die Ursachen eines unterschiedlichen Unkrautunterdrückungsvermögens in Reinsaaten und Gemenge von Sommererbsen und Hafer bestimmen zu können. Mischfruchtbestände von Erbsen und Getreide unterdrückten annuelle Unkräuter stärker als Erbsen-Reinsaaten, was insbesondere bei halbblattlosen Erbsen zu beobachten war. Die Ergebnisse weisen darauf hin, dass eine stärkere unterirdische Interaktion zwischen Kulturpflanzen und Unkräutern für die stärkere Unkrautunterdrückung in Erbsen-Hafer-Gemengen im Vergleich zu Erbsen-Reinsaaten verantwortlich war. Die flachwendende Bearbeitung führte in Sommererbsen-Reinsaaten zu einem signifikant höheren Unkrautaufkommen, wohingegen in den Erbsen-Hafer-Gemengen eine vergleichbare (Köllitsch) oder signifikant höhere (Trenthorst) Verunkrautung nach flachwendender Bearbeitung vorhanden war. In den Wintererbsen-Versuchen waren keine signifikanten Unterschiede hinsichtlich des Unkrautaufkommens zwischen den Pflugsystemen festzustellen. Der Mischfruchtanbau von Wintererbsen und Triticale reduzierte den Befall mit der Grünen Erbsenblattlaus und verbesserte die Standfestigkeit der normalblättrigen Wintererbse, wohingegen kein positiver Effekt des Mischfruchtanbaus in Hinsicht auf Auswinterungsverluste der Wintererbsen und einen Befall mit dem Erbsenwickler festgestellt werden konnte. Die Mischfruchtbestände von Sommer- oder Wintererbsen und Getreidepartnern wiesen unter der Voraussetzung, dass keine Ertragsbildungsprobleme beim Getreide auftraten, höhere Gesamterträge im Vergleich zu den entsprechenden Erbsen-Reinsaaten auf. Die Getreidepartner unterdrückten in den Mischfruchtbeständen insbesondere die halbblattlosen Erbsen. Die flachwendende Bodenbearbeitung führte im Vergleich zur tiefwendenden Bearbeitung zu einer vergleichbaren oder signifikant besseren Ertragsleistung der Rein- und Mischfruchtbestände von Erbsen und Getreide. Die mechanische Bodenbelastung hat die Ertragsleistung und die Kornqualität der Kulturen im Jahr 2009 nicht beeinflusst. Im Jahr 2010 führte die mechanische Bodenbelastung, im Gegensatz zum Hafer, zu einer Reduzierung der Erbsen-Erträge um 12,1 % (2,6 t) und 20,8 % (4,6 t). Zudem nahmen der Rohproteingehalt der Erbsen und die Gesamterträge mit zunehmender mechanischer Bodenbelastung nach tiefwendender Bodenbearbeitung kontinuierlich ab, wohingegen nach flachwendender Bearbeitung keine signifikanten Unterschiede festgestellt wurden. Der Winterweizen, der nach den Rein- und Mischsaaten von E.F.B. 33 angebaut wurde (2010/11: 35,9; 2011/12: 20,1 dt TM ha-1), war dem Winterweizen nach den Rein- und Mischsaaten von James (2010/11: 23,8; 2011/12: 16,7 dt TM ha-1) ertraglich überlegen. Während im Jahr 2010/11 kein signifikanter Unterschied der Ertragsleistung der Nachfrucht Winterweizen in den beiden Pflugsystemen festgestellt wurde, führte die flachwendende Bodenbearbeitung im Jahr 2011/12 zu signifikant geringeren Winterweizen-Erträgen (12,9 dt TM ha-1) im Vergleich zur tiefwendenden Bodenbearbeitung (20,5 dt TM ha-1). Der metabolische Energiegehalt der weißblühenden Winter- (15,2 MJ kg-1) und Sommererbsen (15,7 MJ kg-1) lag signifikant über demjenigen der buntblühenden Wintererbsen-Sorte E.F.B. 33 (13,3 MJ kg-1). Das Pflugsystem hatte nur geringe Auswirkungen auf die Kornqualität und den energetischen Futterwert.
Resumo:
Una sitja és una cavitat subterrània destinada a emmagatzemar la collita, especialment de cereals. Amb el manteniment d'unes condicions ideal de temperatura i humitat els cereals s'hi poden conservar durant un llarg període de temps, que segons Varró podria arribar als 50 anys. Aquestes excepcionals possibilitats han possibilitat que l'emmagatzematge en sitges fos un dels mètodes de conservació de cereals a llarg termini més utilitzat en les societats pre-industrials de tot el món. La sitja estàndard del nord-est de Catalunya és aquella que era excavada a l'argila, no portava revestiment i tenia la boca en forma de tub, de 0,77 m de diàmetre màxim per 0,42 de profunditat. El perfil era de tipus còncau, amb el diàmetre màxim situat en el terç central de la sitja, i un fons indistintament còncau o pla. La profunditat i el diàmetre màxim es situarien entre 1,75 i 2 m., amb un marge de diferència reduïdíssim entre ambdues mesures. La capacitat resultant d'aquestes dimensions se situaria entre 1 i 3 tones de cereals, que en termes estàndards de producció seria el resultat de la collita d'una extensió d'entre 1,5 i 4 hectàrees de terreny. ASBTRACT: A silo is an underground cavity designed to store the harvest, especially grain. With the maintenance of ideal conditions of temperature and moisture grains can be preserved for a long period of time, according to Varró it could reach 50 years. These exceptional opportunities have enabled the storage silos to be one of the methods of long-term conservation of grain used in most pre-industrial societies around the world. The standard silo from the North-East of Catalonia was excavated in clay,it had no siding and its mouth was tube-shaped, up to 0.77 m of maximum diameter to 0.42 deep. The profile was concave, with maximum diameter located in the central third of the silo, and a background either concave or flat. The depth and maximum diameter are located between 1.75 and 2 m, with a very little margin of difference between the two measures. The capacity resulting from these dimensions would be located between 1 and 3 tons of cereals, which in terms of production standards it would mean a harvest of between 1.5 and 4 hectares of ground.