23 research outputs found
Antibiose e não preferência para oviposição de Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae) por cultivares de Vigna unguiculata (L.) Walp
Efeito inseticida sistêmico de nanoformulações à base de nim sobre Bemisia tabaci (Hemiptera: Aleyrodidae) biótipo B em tomateiro
A theory of texture controlled grain growth—II. Numerical and analytical treatment of grain growth in the presence of two texture components
Evolution of Recrystallization Texture in AISI300 Series Austenitic Stainless Steels After Cold Rolling to Large Strain
The present paper deals with the evolution of texture in austenitic stainless steels during annealing after 95% cold rolling. After 95% cold rolling, the texture is mainly of the brass type {110} along with a scatter towards the S orientation {123} and Goss orientation {011} . Weak evidence of Cu component is observed at this high deformation level. During annealing, recovery is observed before any detectable recrystallization. After recrystallization, the overall texture intensity was weak; however, there are some discernible texture components. There was no existence of the brass component at this stage. Major components are centered on Goss orientation and Cu component {112} as well as the BR component {236} . Also, there are some few orientations which come up after recrystallization i.e. {142} and {012} . With increase in annealing temperature the textural evolution shows emergence of weak texture with another new component i.e. {197} . The evolution of texture was correlated with the deformation texture through twin chain reaction
Evolution of Recrystallization Texture in AISI300 Series Austenitic Stainless Steels After Cold Rolling to Large Strain
Potencial biótico da mosca-branca Bemisia argentifolii a diferentes plantas hospedeiras Biotic potential of Bemisia argentifolii to different host plants
A mosca-branca Bemisia argentifolii Bellows & Perring, 1994 causa danos em diversas culturas de importância econ��mica no Brasil. Este trabalho teve o objetivo de avaliar o potencial biótico do inseto nas plantas de abobrinha, feijão, mandioca, milho, poinsétia, repolho e tomate. Os experimentos foram conduzidos na Embrapa Hortaliças, em Brasília-DF, em câmaras climatizadas, à temperatura de 28 ± 2ºC e casa de vegetação, à temperatura ambiente (25 ± 8ºC), partindo-se de uma população de B. argentifolii, criada em poinsétia desde 1995. Repolho e feijão foram as plantas hospedeiras que apresentaram períodos pré-imaginais mais curtos, respectivamente 20,5 e 21,9 dias. As maiores porcentagens de mortalidade nesses períodos foram observadas em mandioca (97,9%) e milho (94,2%). A razão sexual em geral foi favorável às fêmeas. O inseto apresentou valores muito próximos de r m (capacidade intrínseca de crescimento da população), variando de 0,18 em feijão a 0,13 em repolho, mostrando estar igualmente adaptado a estes hospedeiros. Resultados diversos foram observados em milho e mandioca, onde as fêmeas apresentaram alta mortalidade (> 90%), o que sugere baixa capacidade de utilização destes hospedeiros pela mosca-branca.<br>The whitefly Bemisia argentifolii Bellows & Perring, 1994 has been causing damage in several economically important crops in Brazil. The purpose of this research was to determine the biotic potential of the insect in zucchini, dry bean, cassava, corn, poinsettia, cabbage and tomato. The experiments were carried out at the Experimental Station of Embrapa Hortaliças, located in Brasilia, in BOD chamber (28°C ± 2°C) and greenhouse (25°C ± 8°C), with a whitefly population continuously reared on poinsettia plants since 1995. Cabbage and dry bean were the host plants with shorter pre-imaginal periods, 20.5 and 21.9 days respectively. The highest mortality in this periods was observed in cassava (97.9%) and corn (94.2%). Sexual ratio (female:male) favored females. The insect presented a small range for the intrinsic rate of increase (r m), 0.18 for dry bean and 0.13 for cabbage, reflecting the similar adaptability to both hosts. Lower intrinsic rates of increase were observed in corn and cassava, with high female mortality (> 90%), suggesting that these two species were less suitable hosts for this whitefly population