Página 15 dos resultados de 1947 itens digitais encontrados em 0.003 segundos

Utilização de oleaginosas em dietas de vacas leiteiras; Use of oilseeds in diets of dairy cows

Bonfim Júnior, Silvano
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Dissertação
POR
Relevância na Pesquisa
16.87%
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia Veterinária, 2014.; O Brasil é destaque na produção agrícola, principalmente em produtos como a soja e o algodão, que são produzidos em grande parte do território nacional. A soja tem como função primária a produção de óleo. Seu principal coproduto é o farelo de soja, amplamente utilizado como fonte de proteína para a nutrição animal. Situação que lhe confere um alto preço de mercado, sendo maior até que a soja grão. A produção de plumas de algodão tem como coproduto o caroço de algodão que, em partes, é absorvido como semente para a nova safra e o restante destinado a nutrição animal, principalmente para ruminantes. A soja grão e o caroço de algodão apresentam teores de extrato etéreo próximos a 20%, o que torna sua utilização interessante para vacas de leite, principalmente no terço inicial da lactação, quando os animais se encontram em balanço energético negativo. Esta suplementação lipídica as dietas confere uma maior densidade energética as mesmas corrigindo, em partes, a deficiência apresentada pelos animais. O presente trabalho comparou a inclusão de 1 kg de soja grão crua com 1,2 kg de caroço de algodão com línter...

Availability of heavy metals in contaminated soil evidenced by chemical extractants

Silva,Maria Ligia de Souza; Levy,Camila de Carvalho Braga; Vitti,Godofredo Cesar
Fonte: Universidade Federal de Viçosa Publicador: Universidade Federal de Viçosa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
Relevância na Pesquisa
16.87%
Heavy metals have been accumulating in Brazilian soils, due to natural processes, such as atmospheric deposition, or human industrial activities. For certain heavy metals, when in high concentrations in the soil, there is no specific extractant to determine the availability of these elements in the soil. The objective of the present study was to evaluate the availability of Cd, Cu, Fe, Mn, Pb and Zn for rice and soybeans, using different chemical extractants. In this study we used seven soil samples with different levels of contamination, in completely randomized experimental design with four replications. We determined the available concentrations of Cd, Cu, Fe, Mn, Pb and Zn extracted by Mehlich-1, HCl 0.1 mol L-1, DTPA, and organic acid extractants and the contents in rice and soybeans, which extracts were analyzed by ICP-OES. It was observed that Mehlich-1, HCl 0.1 mol L-1 and DTPA extractants were effective to assess the availability of Cd, Cu, Pb and Zn for rice and soybeans. However, the same was not observed for the organic acid extractant.

Weeds infestation in corn intercropped with forages at different planting densities

Concenço,G.; Ceccon,G.; Fonseca,I.C.; Leite,L.F.; Schwerz,F.; Correia,I.V.T.
Fonte: Sociedade Brasileira da Ciência das Plantas Daninhas Publicador: Sociedade Brasileira da Ciência das Plantas Daninhas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 EN
Relevância na Pesquisa
16.87%
Corn is planted in the Center West region of Brazil as a second crop, following soybeans or beans. Intercropping of Brachiaria species with corn as a second crop increases the mulching in the cropping system. This study aimed to evaluate the weeds infestation in soybeans following corn/forages intercrop, as a function of corn plant structure, forage species and density. Experiments were conducted in a completely randomized blocks design with four replications, in Ponta Porã and Dourados municipalities, Mato Grosso do Sul state, Brazil, in 2010/2011. Treatments consisted of three corn hybrids with distinct plant architectures intercropped with three forage species: Brachiaria ruziziensis, B. brizantha and B.decumbens, at five densities, and the resulting dry mass was maintained throughout the winter. During the following cropping season, forages were desiccated prior to planting soybeans, and the dry mass of weeds, dry mass of the mulching, soil coverage by weeds, and the broadleaf/grass weed species index (WPI) were determined 15 days after soybean emergence, submitted to an F-test, and analyzed either by regression or by multiple mean comparison, according to the nature of the data. When intercropping corn with species of Brachiaria...

Hedging with futures contracts in the Brazilian soybean complex: BM&F vs. CBOT

Silva,Andréia Regina O. da; Aguiar,Danilo R. D.; Lima,João Eustáquio de
Fonte: Sociedade Brasileira de Economia e Sociologia Rural Publicador: Sociedade Brasileira de Economia e Sociologia Rural
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2003 EN
Relevância na Pesquisa
16.87%
This article analyzes the effectiveness of hedging Brazilian soy oil, soy meal, and soybeans in the Chicago Board of Trade (CBOT) and in the Brazilian Commodities and Futures Exchange (BM&F) to reduce the risk of financial loss due to commodity price fluctuations. The econometric results show that a cross-hedging strategy using the BM&F soybean futures contract is an instrument of low effectiveness for managing soy oil and soy meal price risk. Despite low effectiveness, the estimates demonstrate total advantage for soy meal hedging operations using CBOT soy meal futures contracts rather than cross-hedging using BM&F soybean futures contracts. With some exceptions, the results are also more favorable for hedging soy oil with soy oil futures contracts at the CBOT rather than cross hedging with soybeans at the BM&F. Conversely, Brazilian traders hedging soybeans receive more effective risk protection by trading soybean futures contracts at the BM&F than by trading soybean futures contracts at the CBOT.

Performance, carcass characteristics and non-carcass components of Texel × Santa Inês lambs fed fat sources and monensin

Soares,Sandro Braga; Furusho-Garcia,Iraides Ferreira; Pereira,Idalmo Garcia; Alves,Danilo de Oliveira; Silva,Guilherme Rodrigues da; Almeida,Amélia Katiane de; Lopes,Clenardo Macedo; Sena,Janaina Adna Barbosa
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 EN
Relevância na Pesquisa
16.87%
Performance, carcass, non-carcass and commercial cuts and components of Texel × Santa Inês crossbred lambs, managed in confinement and fed diets based on soybean oil, soybeans and a conventional diet, with or without the use of monensin (78 ppm dry matter basis) were evaluated. Thirty-six Texel × Santa Inês lambs (18 males and 18 females) were managed in intensive systems. Animals were slaughtered after 87 days of confinement, and performance, carcass characteristics, weight and percentages of carcass and non-carcass components were evaluated. The animals fed the control diet had heavier carcass and parts than animals fed soybean, while the oil diet did not differ from the controls in most parameters. The animals fed soybean showed lower intake kg dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and metabolizable energy (ME) compared with animals fed the control diet, increased ether extract (EE) intake in kg, % body weight (BW) and metabolic weight (MW) and did not differ from the soybean oil diet. Animals receiving monensin had lower DM intake, OM, CP, EE, NDF, gross energy (GE) regardless of the expression, % kg BW, or % PM, than the animals that did not receive the additive. Males produced better and had heavier cuts than the females; the latter deposited subcutaneous fat earlier. Animals that received oil or soybean showed greater body weight and small intestine percentage. Soybean oil intake did not improve performance...

Lipid and selenium sources on fatty acid composition of intramuscular fat and muscle selenium concentration of Nellore steers

Pereira,Angélica Simone Cravo; Santos,Marcos Veiga dos; Aferri,Gabriela; Corte,Rosana Ruegger Pereira da Silva; Silva,Saulo da Luz e; Freitas Júnior,José Esler de; Leme,Paulo Roberto; Rennó,Francisco Palma
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2012 EN
Relevância na Pesquisa
16.87%
The objective of this study was to evaluate the effect of lipid and selenium sources in diets for finishing Nellore steers on the fatty acid composition and selenium concentration of the longissimus muscle. Fifty Nellore steers (body weight = 458±39 kg) were assigned to one of six dietary treatments: 1) diet containing sunflower seed and inorganic selenium; 2) sunflower seed and organic selenium; 3) whole cottonseed and inorganic selenium; 4) whole cottonseed and organic selenium; 5) soybeans and inorganic selenium; and 6) soybeans and organic selenium. Diets were formulated with the same amount of nitrogen and calories and supplied once daily to steers in collective pens, with three animals per pen, for 120 d. At the end of the trial, steers were slaughtered and samples of the longissimus muscle were collected for fatty acid and selenium analysis. Effect of selenium sources was detected for selenium concentration in the longissimus muscle. Organic selenium had higher concentrations in the meat compared with inorganic selenium. The total saturated, monounsaturated and polyunsaturated fatty acids did not differ between the sources of lipids and selenium. For selenium sources, no differences were observed between the concentrations of polyunsaturated fat. Also...

Rice-Grown Rhizopus oligosporus Inoculum for Tempeh Fermentation

Rusmin, Simon; Ko, Swan Djien
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1974 EN
Relevância na Pesquisa
16.87%
A method of growing Rhizopus oligosporus on cooked rice as the inoculum for the fermentation of soybeans into tempeh was described and evaluated. Isolated R. oligosporus spores on glass beads survived best at low temperature and intermediate humidity. The activity of the rice-grown inoculum to ferment soybeans into tempeh did not decrease appreciably when stored desiccated for one year at 4 C or room temperature. Bacterial contaminants as high as 108 counts per g of cooked soybeans did not seem to affect the fermentation.

Production of vitamin B-12 in tempeh, a fermented soybean food.

Liem, I T; Steinkraus, K H; Cronk, T C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1977 EN
Relevância na Pesquisa
16.87%
Several varieties of soybeans contained generally less than 1 ng of vitamin B-12 per g. It was found that use of a lactic fermentation typical of tropical conditions during the initial soaking of the soybeans did not influence the vitamin B-12 content of the resulting tempeh. Pure tempeh molds obtained from different sources did not produce vitamin B-12. It was found that the major source of vitamin B-12 in commercial tempeh purchased in Toronto, Canada, was a bacterium that accompanies the mold during fermentation. Reinoculation of the pure bacterium onto dehulled, hydrated, and sterilized soybeans resulted in the production of 148 ng of vitamin B-12 per g. The presence of the mold, along with the bacterium, did not inhibit or enhance production of vitamin B-12. Nutritionally significant amounts of vitamin B-12 were also found in the Indonesian fermented food, ontjom.

Influence of Maize Rotations on the Yield of Soybean Grown in Meloidogyne incognita Infested Soil

Kinloch, Robert A.
Fonte: Society of Nematologists Publicador: Society of Nematologists
Tipo: Artigo de Revista Científica
Publicado em /07/1983 EN
Relevância na Pesquisa
16.87%
A replicated field study was conducted from 1972 to 1980 involving soybeans grown in 2-, 3-, and 4-year rotations with maize in soil infested with Meloidogyne incognita. Monocultured soybeans were maintained as controls. Cropping regimes involved root-knot nematode susceptible and resistant soybean cultivars and soybeans treated and not treated with nematicides. Yields of susceptible cultivars declined with reduced length of rotation. Nematicide treatment significantly increased yields of susceptible cultivars when monocultured, but bad little influence on yield when susceptible cultivars were grown in rotation. Yields of monocultured resistant cultivars were significantly lower than yields of resistant cultivars grown in rotation. However, yields of resistant cultivars grown in rotation were not influenced by the length of the rotation. Nematicide treatment significantly increased yields of monocultured resistant cultivars over the latter years of the study.

Multiple Pest Interactions in Soybean: Effects on Heterodera glycines Egg Populations and Crop Yield

Alston, D. G.; Schmitt, D. P.; Bradley, J. R.; Coble, H. D.
Fonte: Society of Nematologists Publicador: Society of Nematologists
Tipo: Artigo de Revista Científica
Publicado em /03/1993 EN
Relevância na Pesquisa
16.87%
Population changes of Heterodera glycines eggs on soybean in small field plots were influenced by the lepidopterous insect pest, Helicoverpa zea; however, few effects on eggs due to the presence of annual weeds were detected. Soybeans defoliated 15-35% by H. zea during August remained green and continued to produce new flowers and pods later into the season than soybeans without H. zea, resulting in higher numbers of H. glycines eggs at harvest on insect-defoliated soybeans. Final H. glycines populations also were influenced by soil population density (Pi) of the nematode at planting. Fecundity of H. glycines was generally greater at the undetected and low Pi than at high Pi levels. Soybean yields were suppressed 12, 22, and 30% by low, moderate, and high H. glycines Pi, respectively. When weed competition and H. zea feeding damage effects were added, yields were suppressed 34, 40, and 57% by the three respective nematode Pi levels. Effects among the three pests on soybean yield were primarily additive.

Evaluating the Allergic Risk of Genetically Modified Soybean

Kim, Sang-Ha; Kim, Hyun-Mi; Ye, Young-Min; Kim, Seung-Hyun; Nahm, Dong-Ho; Park, Hae-Sim; Ryu, Sang-Ryeol; Lee, Bou-Oung
Fonte: Yonsei University College of Medicine Publicador: Yonsei University College of Medicine
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
16.87%
Genetically modified (GM) soybean (carrying the EPSPS transgene) is the most common GM food in Korea. In order to assess whether genetic modification increases the allergenic risk of soybeans, the allergenicity and IgE-reactive components of wild-type and GM soybean extracts were compared in allergic adults who had been sensitized to soybeans. We enrolled 1,716 adult allergy patients and 40 healthy, non-atopic controls. Skin prick tests and IgE enzyme linked immunosorbent assays (ELISAs) were performed using wild-type and GM soybean extracts, along with other common inhaled allergens. The specificities of serum IgE antibodies from allergic patients and the identities of the IgE-reactive components of the soybean extracts were compared using ELISA inhibition testing, 2-dimensional gel electrophoresis, and IgE immunoblotting. To evaluate the effects of digestive enzymes and heat treatment, the soybean extracts were heated or pre- incubated with or without simulated gastric and intestinal fluids. The IgE sensitization rates to wild-type and GM soybeans were identical (3.8% of allergic adults), and circulating IgE antibodies specific for the two extracts were comparable. The results of the ELISA inhibition test, SDS-PAGE, and IgE immunoblotting showed a similar composition of IgE-binding components within the wild-type and GM extracts...

Evaluation of soybean germplasm conserved in NIAS genebank and development of mini core collections

Kaga, Akito; Shimizu, Takehiko; Watanabe, Satoshi; Tsubokura, Yasutaka; Katayose, Yuichi; Harada, Kyuya; Vaughan, Duncan A.; Tomooka, Norihiko
Fonte: Japanese Society of Breeding Publicador: Japanese Society of Breeding
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
16.87%
Genetic variation and population structure among 1603 soybean accessions, consisted of 832 Japanese landraces, 109 old and 57 recent Japanese varieties, 341 landrace from 16 Asian countries and 264 wild soybean accessions, were characterized using 191 SNP markers. Although gene diversity of Japanese soybean germplasm was slight lower than that of exotic soybean germplasm, population differentiation and clustering analyses indicated clear genetic differentiation among Japanese cultivated soybeans, exotic cultivated soybeans and wild soybeans. Nine hundred ninety eight Japanese accessions were separated to a certain extent into groups corresponding to their agro-morphologic characteristics such as photosensitivity and seed characteristics rather than their geographical origin. Based on the assessment of the SNP markers and several agro-morphologic traits, accessions that retain gene diversity of the whole collection were selected to develop several soybean sets of different sizes using an heuristic approach; a minimum of 12 accessions can represent the observed gene diversity; a mini-core collection of 96 accession can represent a major proportion of both geographic origin and agro-morphologic trait variation. These selected sets of germplasm will provide an effective platform for enhancing soybean diversity studies and assist in finding novel traits for crop improvement.

A GmRAV Ortholog Is Involved in Photoperiod and Sucrose Control of Flowering Time in Soybean

Lu, Qingyao; Zhao, Lin; Li, Dongmei; Hao, Diqiu; Zhan, Yong; Li, Wenbin
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 14/02/2014 EN
Relevância na Pesquisa
16.87%
Photoperiod and sucrose levels play a key role in the control of flowering. GmRAV reflected a diurnal rhythm with the highest expression at 4 h after the beginning of a dark period in soybean leaves, and was highly up-regulated under short-day (SD) conditions, despite of not following a diurnal pattern under long-day (LD) conditions. GmRAV-i (GmRAV-inhibition) transgenic soybean exhibited early flowering phenotype. Two of the FT Arabidopsis homologs, GmFT2a and GmFT5a, were highly expressed in the leaves of soybeans with inhibition (-i) of GmRAV under SD conditions. Moreover, the transcript levels of the two FT homologs in GmRAV-i soybeans were more sensitive to SD conditions than LD conditions compared to the WT plant. GmRAV-i soybeans and Arabidopsis rav mutants showed more sensitive hypocotyl elongation responses when compared with wild-type seedlings, and GmRAV-ox overevpressed in tobacco revealed no sensitive changes in hypocotyl length. These indicated that GmRAV was a novel negative regulator of SD-mediated flowering and hypocotyl elongation. Although sucrose has been suggested to promote flowering induction in many plant species, high concentration of sucrose (4% [w/v]) applied into media defer flowering time in Arabidopsis wild-type and rav mutant. This delayed flowering stage might be caused by reduction of LEAFY expression. Furthermore...

Potential of essential oils for protection of grains contaminated by aflatoxin produced by Aspergillus flavus

Esper, Renata H.; Gonçalez, Edlayne; Marques, Marcia O. M.; Felicio, Roberto C.; Felicio, Joana D.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 04/06/2014 EN
Relevância na Pesquisa
16.87%
Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean) treated with Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) essential oils. Samples with 60 g of the grains were treated with different volumes of essential oils, 200, 100, 50, and 10 μL for oregano and 50, 30, 15, and 10 μL for mentrasto. Fungal growth was evaluated by disk diffusion method. Aflatoxin B1 production was evaluated inoculating suspensions of A. flavus containing 1.3 × 105 spores/mL in 60 g of grains (corn and soybeans) after adjusting the water activity at 0.94. Aflatoxin was quantified by photodensitometry. Fungal growth and aflatoxin production were inhibited by essential oils, but the mentrasto oil was more effective in soybeans than that of oregano. On the other hand, in corn samples, the oregano essential oil was more effective than that of mentrasto. Chemical compositions of the essential oils were also investigated. The GC/MS oils analysis showed that the main component of mentrasto essential oil is precocene I and of the main component of oregano essential oil is 4-terpineol. The results indicate that both essential oils can become an alternative for the control of aflatoxins in corn and soybeans.

Gel-free proteomic analysis of soybean root proteins affected by calcium under flooding stress

Oh, MyeongWon; Nanjo, Yohei; Komatsu, Setsuko
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 20/10/2014 EN
Relevância na Pesquisa
16.87%
Soybean is sensitive to flooding stress and exhibits reduced growth under flooding conditions. To better understand the flooding-responsive mechanisms of soybean, the effect of exogenous calcium on flooding-stressed soybeans was analyzed using proteomic technique. An increase in exogenous calcium levels enhanced soybean root elongation and suppressed the cell death of root tip under flooding stress. Proteins were extracted from the roots of 4-day-old soybean seedlings exposed to flooding stress without or with calcium for 2 days and analyzed using gel-free proteomic technique. Proteins involved in protein degradation/synthesis/posttranslational modification, hormone/cell wall metabolisms, and DNA synthesis were decreased by flooding stress; however, their reductions were recovered by calcium treatment. Development, lipid metabolism, and signaling-related proteins were increased in soybean roots when calcium was supplied under flooding stress. Fermentation and glycolysis-related proteins were increased in response to flooding; however, these proteins were not affected by calcium supplementation. Furthermore, urease and copper chaperone proteins exhibited similar profiles in 4-day-old untreated soybeans and 4-day-old soybeans exposed to flooding for 2 days in the presence of calcium. These results suggest that calcium might affect the cell wall/hormone metabolisms...

Reduced Fitness of Virulent Aphis glycines (Hemiptera: Aphididae) Biotypes May Influence the Longevity of Resistance Genes in Soybean

Varenhorst, Adam J.; McCarville, Michael T.; O’Neal, Matthew E.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 15/09/2015 EN
Relevância na Pesquisa
16.87%
Sustainable use of insect resistance in crops require insect resistance management plans that may include a refuge to limit the spread of virulence to this resistance. However, without a loss of fitness associated with virulence, a refuge may not prevent virulence from becoming fixed within a population of parthenogenetically reproducing insects like aphids. Aphid-resistance in soybeans (i.e., Rag genes) prevent outbreaks of soybean aphid (Aphis glycines), yet four biotypes defined by their capacity to survive on aphid-resistant soybeans (e.g., biotype-2 survives on Rag1 soybean) are found in North America. Although fitness costs are reported for biotype-3 on aphid susceptible and Rag1 soybean, it is not clear if virulence to aphid resistance in general is associated with a decrease in fitness on aphid susceptible soybeans. In laboratory assays, we measured fitness costs for biotype 2, 3 and 4 on an aphid-susceptible soybean cultivar. In addition, we also observed negative cross-resistance for biotype-2 on Rag3, and biotype-3 on Rag1 soybean. We utilized a simple deterministic, single-locus, four compartment genetic model to account for the impact of these findings on the frequency of virulence alleles. When a refuge of aphid susceptible was included within this model...

Comparison of Sweep-net and Ground-cloth Sampling Methods for Estimating Arthropod Densities in Different Soybean Cropping Systems

Deighan, John; McPherson, Robert M.; Ravlin, William F.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
EN
Relevância na Pesquisa
16.87%
Methods involving a sweep net, ground cloth, and ground cloth plus visual observation were evaluated for sampling arthropod pests and predators in three soybean cropping systems. The ground-cloth technique provided a good estimate of absolute density for most of the species sampled. In conventionally planted soybeans with rows spaced 81 cm apart, the ground cloth alone sampled from 82 to 97% of the true arthropod density as measured by the ground cloth plus visual observation method. In drill-planted soybeans and soybeans planted in small grain stubble, these ranges in efficiency were 75 to 96% and 73 to 90%, respectively. The lower percentages in ground-cloth sampling were primarily due to individuals remaining on the soybean foliage after the plants had been shaken. A power model was used to transform sweep-net counts to equivalent ground-cloth counts using regression analyses on mean densities of nine arthropod species encountered in 150 fields. In 11 of the 27 species/cropping system combinations, a linear model adequately described the relationship between the two methods. In those regressions that showed nonlinear relationships, the sweep net was more efficient than the ground cloth at high pest densities. Our equations provide estimates of absolute densities of arthropods in different cropping systems using different sampling methods and can be used to convert action thresholds between systems and methods.

Free Flight of Western Corn Rootworm (Coleoptera: Chrysomelidae) to Corn and Soybean Plants in a Walk-In Wind Tunnel

Spencer, Joseph L.; Isard, Scott A.; Levine, Eli
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
EN
Relevância na Pesquisa
16.87%
Oviposition in soybean fields by western corn rootworm, Diabrotica virgifera virgifera LeConte, is threatening the effectiveness of crop rotation in east-central Illinois and adjoining counties in northwestern Indiana. Attraction to soybean, Glycine max L., plants has been hypothesized as a mechanism underlying rootworm oviposition in soybean fields. In this study, female western corn rootworms were allowed to fly freely for 0.5 h within a wind tunnel array of potted soybean and corn, Zea mays L., plants before rootworm distribution patterns on corn and soybeans were determined. Test insects were collected in corn and soybean plantings from both within and outside of areas where adults oviposit in soybean fields. We found no evidence of an increased tendency for rootworms from various populations to be associated with soybeans regardless of collection location, cropping history at the collection site, or the area’s status with respect to western corn rootworm oviposition in soybean fields. The difference between corn and soybean plant height influenced postflight distribution of adults in the wind tunnel. More rootworms accumulated on plants whose foliage projected above the height of the insect release platform. Distance moved during a 0.5-h period of free flight was greatest when the foliage of nearby plants did not extend above the level of the insect release platform. Regardless of how corn and soybean plants were configured in the wind tunnel...

Influence of Tillage Practices and Row Spacing on Soybean Insect Populations in Louisiana

Troxclair, Noel N.; Boethel, David J.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
EN
Relevância na Pesquisa
16.87%
Insects were monitored by the sweep-net method for 2 years in conventionally tilled and no-till soybeans planted in narrow and wide row spacings to determine the effects of different cultural practices on soybean insect populations. Season-long differences in population densities due to the influences of tillage practices were detected for several species at each of three locations. However, the banded cucumber beetle, Diabrotica balteata (LeConte), was the only species whose populations showed a consistent response at each location. Differential emergence of teneral adults of the banded cucumber beetle and bean leaf beetle, Cerotoma trifurcata (Forster), between conventional tillage and no-till culture at one location indicated an ovipositional preference for the tilled soybeans or a higher egg/larval mortality in the no-till soybeans. A leafhopper, Scaphytopius acutus (Say), an important vector implicated in the transmission of two soybean diseases in Louisiana, was the insect species most affected by differences in row spacings, with larger populations found on the narrower row spacing.

Mapeamento agrícola com imagens de sensores remotos orbitais para apoio ao gerenciamento de recursos hídricos; Agricultural mapping with remotely sensed images to support water resources management

Carmo, Nadyelle Curcino do
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Engenharia do Meio Ambiente (EEC); Escola de Engenharia Civil - EEC (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Engenharia do Meio Ambiente (EEC); Escola de Engenharia Civil - EEC (RG)
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
16.87%
The catchment areas of water are extremely important because they have the function of providing water for public supply, and its occupation should be monitored to avoid damage to its environmental quality. Currently, most of the mappings of use and occupation of land classified as agriculture evenly, not discriminate their crops, which could help more effectively in the planning and management of natural resources. This work aims at mapping the major crops of the state of Goiás, using GIS tools and remote sensing in order to provide support for managing water resources in the region. Vegetation indices produced from data collected by MODIS the years 2007-2013 to map cane sugar, corn and soybeans and winter corn were used. The methodology proved feasible, cost effective and promising for mapping corn and soybeans results, but the similarities obtained in relation to official data, for mapping of cane sugar and winter corn were not satisfactory. In a second step was quantified occupation of catchment basins of water for public supply for corn and soybeans in the state. The results showed that of the 183 catchment basins, 100 have these crops and that the basins of southern Goiás have densified occupation. The main conclusion of the paper is that the use and occupation of land in the catchment should be systematically monitored...