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251.
Rafael Antonio Pasini Anderson Dionei Grützmacher Juliano de Bastos Pazini Franciele Silva de Armas Flávio Amaral Bueno Stefânia Nunes Pires 《Phytoparasitica》2018,46(1):115-125
In Brazil, chemical control is one of the main tools to manage insect pests in wheat. However, this kind of management can impair the biological control provided by the predators Chrysoperla externa and Eriopis connexa. The present study evaluated the side effects on C. externa and E. connexa of 15 insecticides registered for wheat. Insecticides were sprayed on eggs and pupae via Potter tower at the maximum recommended dose. We evaluated the viability of eggs and pupae as well as the sub-lethal effects on fecundity and fertility of the adults emerged from treated pupae. The insecticides were classified according to the scale of toxicity proposed by IOBC. Regarding the eggs, the insecticide etofenprox was classified as slightly harmful (class 2) to C. externa. Imidacloprid + beta-cyfluthrin, diflubenzuron WG, thiamethoxam + lambda-cyhalothrin A and B, gamma-cyhalothrin, and etofenprox were also classified as slightly harmful (class 2) to E. connexa, while methomyl was classified as moderately harmful (class 3) for the eggs of the predator. The insecticide imidacloprid + beta-cyfluthrin was considered slightly harmful (class 2) to pupae of C. externa, while imidacloprid + beta-cyfluthrin, thiamethoxam + lambda-cyhalothrin A and B, and lufenuron were classified as slightly harmful (class 2) to the pupae of E. connexa. The insecticides beta-cyfluthrin, diflubenzuron SC, lambda-cyhalothrin, permethrin, thiamethoxam, triflumuron, and zeta-cypermethrin were harmless to eggs and pupae of both predators and should therefore be prioritized in the control of insect pests in wheat, thus preserving the natural biological control provided by C. externa and E. connexa. 相似文献
252.
Functional integration between semiconductors and ferromagnets was demonstrated with the spin-valve transistor. A ferromagnetic multilayer was sandwiched between two device-quality silicon substrates by means of vacuum bonding. The emitter Schottky barrier injected hot electrons into the spin-valve base. The collector Schottky barrier accepts only ballistic electrons, which makes the collector current very sensitive to magnetic fields. Room temperature operation was accomplished by preparing Si-Pt-Co-Cu-Co-Si devices. The vacuum bonding technique allows the realization of many ideas for vertical transport devices and forms a permanent link that is useful in demanding adhesion applications. 相似文献
253.
Over the past 70 years, numerous gas-surface adsorption studies have indicated the existence of a weakly bound, mobile intermediate that is a precursor to chemical bond formation. The direct observation and characterization of such a species are presented. Precursor and chemisorbed benzene on a silicon surface were clearly distinguished with the use of a tunable-temperature scanning tunneling microscope. Precursor decay to chemisorption was observed, allowing the salient features of the potential energy surface to be determined. 相似文献
254.
Antnio L. Amaral Orlando Rocha Cristina Gonalves Antnio A. Ferreira Eugnio C. Ferreira 《Industrial Crops and Products》2009,30(3):366-371
It is known that the barley kernel size is an important factor regarding the uniformity of the malting and brewery processes, barley valuation, approval and market value. In order to facilitate the barley purchasing process, a fast field technique for kernel size evaluation, such as the image analysis technique proposed in this work, would be greatly appreciated as a fast and simple procedure for barley selection. In this study a close correlation between the image analysis and the standard EBC was obtained with a correlation factor of 0.999 and a regression coefficient of 0.991 between the two methodologies. The proposed IA methodology was found to accurately predict the Scarlett and Prestige barley varieties weight distribution especially when considering the crucial ‘business transactions selection’ classes. 相似文献
255.
Felipe Oliveira Vilela Antonio Teixeira do Amaral Júnior Silvério de Paiva Freitas Júnior Alexandre Pio Viana Messias Gonzaga Pereira Marcelo Geraldo de Morais Silva 《Euphytica》2009,165(1):21-26
With the objective of selecting superior recombinant lines of snap bean, four segregating F2 populations were selected by early generation testing and advanced by single seed descent. In a randomized complete block
design with two replications within sets 120 F6:7 lines were obtained and evaluated for seven traits of agronomic interest. The mean pod yield of the F6:7 generation was 72% higher than in generation F2, confirming the efficiency of early selection. There was genetic variability in the F6:7 lines within the sets. The selection of superior genotypes was possible by the high estimates of narrow-sense heritability.
Highest gains in simultaneous selection of traits were expressed by the indices proposed by Mulamba & Mock for the genetic
standard deviation and by Williams, based on tentatively attributed arbitrary weights. Line 3 of the F6:7 generation, with a yield of 8,050.0000 kg ha−1 and pod fiber content of 0.3650% is highly promising to be release as new cultivar. 相似文献
256.
257.
Tatiane da Costa Barbé Antonio Teixeira do Amaral Júnior Leandro Simões Azeredo Gonçalves Rosana Rodrigues Carlos Alberto Scapim 《Euphytica》2010,171(3):337-343
Genetics of resistance to ascochyta blight was studied using different generations of fifteen crosses of chickpea (Cicer arietinum L.). Six parents comprising two susceptible varieties GL 769, C 214 and four resistant lines GG 1267, GL 90168, GL 96010
and GL 98010 were used to develop one S × S, eight S × R and six R × R crosses and some of the back crosses and F3 generations were developed. Field screening technique was used to evaluate the different generations for disease reaction
using mixture of ten prevalent isolates (ab1–ab10) of ascochyta blight (Ascochyta rabiei). Inheritance study showed digenic recessive control of resistance in the cross GL 769 × C 214, whereas monogenic recessive
control of resistance was found in the crosses GL 769 × GL 98010 and C 214 × GL 98010. Digenic dominant and recessive control
of resistance was found in the crosses GL 769 × GG 1267 and C 214 × GG 1267 while the crosses GL 769 × GL 90168 and C 214 × GL
96010 showed the monogenic dominant control of resistance. Trigenic dominant and recessive control of resistance was observed
in the crosses GL 769 × GL 96010 and C 214 × GL 90168. Allelic relationship studies showed that three resistant parents viz.,
GG 1267, GL 96010 and GL 90168 possessed allelic single dominant gene for resistance. Besides, GG 1267 possessed two minor
recessive genes for resistance, one of them was allelic to the minor recessive gene possessed by GL 90168 and other with GL
96010. The resistant parents GL 90168 and GL 96010 possessed non-allelic minor gene for resistance. The resistant parent GL
98010 possessed two minor recessive genes for resistance which were allelic to respective single recessive gene for resistance
possessed by the susceptible parents GL 769 and C 214. The susceptible parents GL 769 and C 214 also possessed single independent
inhibitory dominant susceptibility gene. The inhibitory gene was epistatic to the corresponding recessive gene for resistance. 相似文献
258.
A. S. Bhering M. G. F. Carmo I. S. Coelho E. S. A. Lima C. F. de Carvalho A. L. R. F. Saraiva S. R. Passos N. M. B. Amaral Sobrinho 《Plant pathology》2020,69(2):302-309
Clubroot, caused by Plasmodiophora brassicae, is a disease limiting the production of Brassica species. Its severity varies according to the density of the pathogen's resting spores and environmental conditions. Although the soil environment (including its physical, chemical and biological characteristics) is determinant in the development of the disease, little is known regarding these characteristics in tropical regions, such as Brazil. The objective of this study was to investigate the relationships between soil attributes, bacterial population composition and clubroot intensity in a tropical mountain agroecosystem. Soil and plant samples were collected from 17 cauliflower-producing localities in Nova Friburgo, Brazil. The physical and chemical attributes, the bacterial population composition, the number of pathogen resting spores in the soil samples, and the clubroot severity were evaluated. Based on bacterial population composition, two distinct groups of soils were identified, which varied in attributes such as organic matter, potential acidity, pH and disease severity. The organic matter level was associated with differences in soil acidity, bacterial population composition and disease intensity, but there was not a cause and effect relationship between bacterial population composition and clubroot severity. Under the conditions of this agroecosystem, soils with increased organic matter presented higher acidity potential (H + Al), which was strongly correlated to clubroot severity. Thus, high acidity potential could be a key factor leading to clubroot development in mountain regions of Brazil. 相似文献
259.
Camila Baptista do Amaral Gustavo Hugo Ferreira de Oliveira Gustavo Vitti Môro 《Archives of Agronomy and Soil Science》2018,64(10):1465-1472
The high nitrogen nutrient requirement of maize is a major production constraint in areas that have a low availability of soil nitrogen. A 2-year field experiment was conducted to characterize open-pollinated varieties of maize by identifying possible sources of variability targeting low N environments. Twelve experimental varieties and two checks, AL Avaré and Ipanema, were cultivated under high and low nitrogen levels and evaluated for chlorophyll content index, lodging, prolificacy and grain yield. The results indicate that the applied nitrogen resulted in differences in the chlorophyll content index between environments. Nitrogen level affected the percentage of lodged plants of varieties K and L. Grain yield and lodging were the traits that most affected genotypic variability, and 17% of the studied varieties were considered as superior due to higher lodging-resistance and higher grain yield. 相似文献
260.
Colla E do Amaral Sobral PJ Menegalli FC 《Journal of agricultural and food chemistry》2006,54(18):6645-6653
Films forming solutions composed of Amaranth (Amaranthus cruentus) flour (4.0 g/100 mL), stearic acid (5-15 g/100 g of flour), and glycerol (25-35 g/100 g of flour) were prepared by an emulsification process, with varying stirring speed values (6640-13360 rpm). The influence of these parameters (stearic acid and glycerol concentrations and stirring speed) on the water vapor barrier and mechanical properties of films was evaluated using the response surface methodology (RSM). Other characterizations, including microstructure, water solubility, and oxygen permeability, were performed in optimized films. According to statistical analysis results, the optimized conditions corresponded to 10 g of stearic acid/100 g of flour, 26 g of glycerol/100 g of flour, and a stirring speed of 12 000 rpm. The films produced under these conditions exhibited superior mechanical properties (2.5 N puncture force, 2.6 MPa tensile strength, and 148% elongation at break) in comparison to those of other protein and polysaccharide composite films, low solubility (15.2%), and optimal barrier properties (WVP of 8.9 x 10(- 11) g m(- 1) s(- 1) Pa(- 1) and oxygen permeability of 2.36 x 10(- 13) cm3 m(-1) s(-1) Pa(-1)). 相似文献