Showing papers by "Universidade Federal de Viçosa published in 1981"

Effect of soil temperature, moisture, and nitrogen on competitive saprophytic ability of Macrophomina phaseolina

Abstract: The effect of soil temperature, moisture and nitrogen on saprophytic colonization of bean or wheat stems by Macrophomina phaseolina was studied in two soils. Maximum colonization of the substrate units occurred at 15–20° and decreased with increasing soil temperature. At 15° more wheat than bean stems were colonized whereas at higher temperatures the reverse occurred. Maximum colonization of substrates occurred at 15–25% of moistureholding capacity, and percentage colonization decreased with increasing soil moisture. Addition of nitrogen to soil completely inhibited saprophytic colonization.

Erwinia amylovora cell wall receptor for apple agglutinin

Abstract: Lipopolysaccharide (LPS) was isolated from an acapsular strain of Erwinia amylovora . This “crude LPS” was divided into 2 fractions by elution from a Sepharose CL-6B column. These were designated the low molecular weight form (retained by the column) and the high molecular weight form (not retained by the column). When assayed by rocket electrophoresis, only the low molecular weight form served as a receptor for the apple agglutination factor (AF) and cross-reacted with antiserum prepared to E. amylovora . Mild acid hydrolysis of crude LPS gave a milky suspension that was divided into a pellet (Lipid A) and a supernate (O-side chain plus core) by centrifugation. The supernate, which contained all of the receptor for AF, was further divided into O-side chain and core by elution from a Bio-Gel P-30 column. Only those fractions which would be expected to contain core region of LPS interacted with AF in agarose gel to form precipitant peaks.

Effects of Cooking and/or Processing Upon Levels of Aflatoxins in Meat from Pigs Fed A Contaminated Diet

Abstract: Pork loins, bellies and hams from pigs fed a diet containing 571 and 386 Mg of aflatoxins B1 and B2 per kg of feed, respectively, for 42 days were analyzed for aflatoxins in the fresh, fresh-cooked, cured smoked (hams only) and cured-smoked-cooked states. Although some destruction of aflatoxins B1 and B2 occurred during cooking and/or processing, the maximum amount of inactivation did not exceed 41% of the total, and was generally in the range of 15–30%. Thus, results suggest that aflatoxins are quite stable during cooking and/or processing.

Korunomyces, a new genus of fungi imperfecti from Brazil.

Abstract: A new disease was observed on the foliage of seedlings of Terminalia ivorensis seedlings and young plantation trees of T. ivorensis and Bouchenavia sp. in the lower Amazon region of Brazil. The dis...

Tolerância do tamanho da semente de soja (Glycine max (L.) Merr.) ao metribuzin

Abstract: Este experimento foi instalado em casa-de-vegetacao com o objetivo de avaliar a tolerância de tres tamanhos de sementes de soja (Glycine max (L.) Merr.), cv. UFV-1 classificadas nas peneiras de 10/64" x 3/4", 13/64" x 3/4" e 15/64 x 3/4", a diferentes doses de metribuzin (4-amino-6-tertbutil-3-(metiltio-as-triazina-5(4H) ona ). As doses de 0, 300, 600, 900 e 1.200g do i.a./ha foram aplicadas nos materiais do solo de Ponta Nova-MG classificado como franco-argilo-arenoso, e as doses de 0, 50, 100, 150, 200, 250, 300, 350 e 600g do i.a./ha em areia lavada. Nos materiais de solo de Ponte Nova, a inibicao de 50% do crescimento (I50) das plantas de soja correspondeu a aplicacao de 600, 1050 e 1150 g/ha de metribuzin, enquanto em areia lavada os I-,,, foram de 150, 210 e 265g/ha de metribuzin para as sementes retidas nas peneiras 10/64" x 3/4", 13/64" x 3/4" e 15/64" x 3/4", respectivamente. O aumento do tamanho da semente aumentou a tolerancia da soja ao metribuzin.

Lixiviação e inativação do metribuzin em dois tipos de solos

Abstract: Com o objetivo de avaliar a lixiviacao e a inativacao do herbicida metribuzin (4-amino-6-tertbutil-3-(metiltio)-as-triazina-5-(4H)ona) em materiais de um solo franco-argiloso e de outro solo franco-argilo-arenoso de duas regioes de Minas Gerais, um em laboratorio e outro em casa de vegetacao O solo franco-argiloso era um Latossolo Roxo, com 2,8% de materia organica e o solo franco-argilo-arenoso era um Podzolico Vermelho-Amarelo; fase terraco, em 2,17% de materia orgânica Em laboratorio estudou-se a lixiviacao do metribuzin em colunas de 5, 10 e 15 cm de altura, com 7,5 cm de diâmetro, enchidas com materiais dos solos franco-argiloso e do solo franco-argiloarenoso Usou-se o ensaio biologico de discos de cotiledones de melancia para detectar o metribuzin no lixiviado Em casa de vegetacao, estudou-se a inativacao do metribuzin com materiais dos mesmos solos utilizados para o estudo de lixiviacao Para este ensaio foram utilizadas as doses de 0, 50, 80, 110, 140, 170 e 200g do ia/ha do produto, e em areia lavada, as doses foram de 0, 4, 6, 8, 10, 12 e 16 g do ia/ha do metribuzin, usando o pepino como planta teste, que foi cortado rente ao solo e pesado aos 14 dias apos o plantio Informacoes adicionais sao necessarias para explicar porque o solo franco -argiloso inativa mais o metribuzin que o solo franco-argilo-arenoso