Revista Ceres

Isolamento, cultivo e esporulação de Microcyclus ulei, agente etiológico do mal-das-folhas da seringueira

Mon, 07 Apr 2025 00:00:00 -0300

This study was undertaken to evaluate several culture media to enhance spore production of Microcyclus ulei.

Influência do tamanho das partículas do fosfato de Araxá sobre a produção de matéria seca do sorgo

Mon, 07 Apr 2025 00:00:00 -0300

Experiments were carried out in pots, in the greenhouse, to evaluate the effects of particle size of Araxa phosphate rock (0-10; 10-20; 20-48; 48-100; 100-150; 150-200; 200-270 and larger than 400 mesh/inch), phosphorus sources (Araxa phosphate rock and triple superphosphate), phosphorus levels (25% and 75% of the maximum soil adsorption capacity), and liming (presence and absence) on dry matter production of two sorghum hybrids (CMSXS 136 and CMSXS 903, tolerant and sensitive to aluminum, respectively). The hybrids were seeded and harvested in the same pots three times, consecutively. At each time, the plants wereharvested 40 days after emergence and separated as to shoot and root, then dried and weighed.

Efeitos da densidade aparente e dos níveis de fósforo na solução do solo sobre o desenvolvimento de raízes e sobre a absorção de fósforo pelo tomateiro

Paulo Cezar Rezende Fontes, Francisco Morel Freire, Roberto Ferreira de Novais — Mon, 07 Apr 2025 00:00:00 -0300

An experiment was carried out in pots, in the greenhouse, to evaluate the effects of phosphorus levels in soil solution (0.62, 3.25, 6.50, 9.75 and 19.50 uM P) and soil bulk density (1.05, 1.25 and 1.45 g. cm-3) on root growth and phosphorus uptake by tomato seedlings, cultivar ‘Campbell-27".

Cargas elétricas de um latossolo vermelho-amarelo com diferentes coberturas florestais

Mon, 07 Apr 2025 00:00:00 -0300

The electrical charges of Red-Yellow Latosol samples, collected at six depths from areas covered with a sccond generation natural forest and 17-year old pine and eucalyptus plantations, at Vicosa, Minas Gerais, were evaluated in the laboratory by potentiometric titration. The samples showed a small net negative charge, correlated with their organic matter contents, which decreased with depth. The zero point of charge (ZPC) value did not vary among the covers and the net negative charge decreased in the following order: natural forest, pine and eucalyptus.

Produtividade e qualidade dos frutos de dez variedades de goiaba, em Visconde do Rio Branco, Minas Gerais, visando ao consumo ao natural e à industrialização

Mon, 07 Apr 2025 00:00:00 -0300

The perfomances-of 10 guava varieties were studied through evaluations of the following aspects: fruit weight produced per hectare; average fruit weight; pulp-seedpit ratio, based on weight and thickness of pulp; total titrable acids; Brix; total vitamin C and pectin content; dry matter; and, as to fitness for processing as adjudged by the preparation of the main types of processed products, such as: guava paste (known as «goiabada»), jelly, and stewed fruits in heavy syrup. The experiment was started in 1974, when the following varieties were planted: ‘Sao José Periforme’, ‘Tetraploide de Limeira’, ‘Brune Branca’, ‘Pirassununga Branca’, ‘Riverside Vermelha’, TAC+4', ‘Pirassununga Vermelha’, ‘Brune Vermelha', ‘Indus- trial de Montes Claros’, and ‘Péra’. This study of these varieties was conducted for three years, from August, 1977 through July, 1980. The physical and chemical parameters were determined during three harvest seasons. The tests for processing were made at the peak of harvest for each variety.

Modelos dinâmicos: uma aplicação ao mercado de soja do Brasil

Carlos Antônio Moreira Leite, Sonia Maria L Ribeiro do Vale — Mon, 07 Apr 2025 00:00:00 -0300

This work is concerned with an application of dynamic econometric models in policy analysis. For this purpose, an econometric model was employed for the soybean subsector and elasticities for the short and long runs were estimated.

Comparação da ação predatória de lambari-bocarra (Oligosarcus argentus) (Pisces-Characidae) e traíra (Hopilas malabaricus) Pisces-Erythrinidae) sobre as formas de jovens tilápia-nilótica (Oreochromis niloticus) (Pisces-Cichlidae)

José Rodrigues de Souza, Dálcio Ricardo de Andrade — Mon, 07 Apr 2025 00:00:00 -0300

This experiment was undertaken as a comparative study of the predation of Oligosarcus argenteus and Hoplias malabaricus on the juvenile stages of the Nile tilapia, Oreochromis niloticus.

Comparação de dois substratos para oviposição de tilápia-nilótica (Oreochromis niloticus) (Prisces: Cichlidae)

José Rodrigues de Souza, Dálcio Ricardo de Andrade — Mon, 07 Apr 2025 00:00:00 -0300

This experiment was implanted at the Hydrobiological and Fisheries Management Station at the Federal University Of Vicosa and was realized from October, 1981 to March, 1982. The objective was to determine the influence of bottom substrate on the reproductive sucess of Oreochromis niloticus. Concrete tanks (5x5x1 m) were used: one group of tanks with bottoms half concrete-half mud; and, one group with bottoms half concrete-half sand. There were three repli- cations each tank was stocked with 12 adult O. niloticus as 8 ¢ ¢ and 4 d d. Based on the number of fry produced, there was no great difference between substrates; however, the numbeér o1 nests was greater in the tanks with partial mud substrate than with sand.