The study was conducted during the summer of 2002. The treatments were monocropping and intercropping the common bean Canario 107, Bayomex (determinate type), Michoacan (indeterminate type), and sunflower cv. Victoria. Sowing took place on May 25, 2002 at a population density of 4.2 (bean) and 8.3 (sunflower) plants m(-2), respectively, in a clay texture soil, with a pH of 7.8 and was fertilized with 100-100-00 of NPK. The experimental design was randomized blocks with four replications. In neither of the crops the phenology, heat units nor evapotranspiration were affected by the sowing system. The heat units (HU) and evapotranspiration (ETc) of de sown crops at physiological maturity were 1521 HU and 279.6 mm for cv. Victoria, 658 HU and 201.3 mm for Canario 107, 811 HU and 213.7 for Bayomex, and 1041 HU and 241.7 mm for Michoacan. The combined agrosystem of sunflower and bean was more efficient in the use of resources in agricultural production. The combination of the Victoria sunflower and the Michoacan bean showed higher efficiency in the use of water and in the use of radiation and, as a result, greater production of biomass and yield. The land equivalent ratio for seed yield obtained with the combination of Victoria plus Canario 107, Victoria plus Michoacan, and Victoria plus Bayomex was 1.6, 1.9, and 3.0, respectively. This shows an advantage for the yield of combined crops over monocrops by 60, 90, and 200%, respectively.

En el presente trabajo se presentan los resultados de ensayos conducidos en condiciones de invernadero con un suelo Typic Haplustolls de Chaguaramas, Estado Guárico. En dicho suelo se sembró sorgo con una densidad de 300.000 - 350.000 plantas/Ha y fue sometido a dos tratamientos de aplicación de lluvia simulada. i) 24.3 mm cada cinco días (lluvias distribuidas), y ii) 48,6 mm cada 10 días (lluvias concentradas) y a tres tratamientos de cobertura: R-C: Colocación de 5 ton/Ha de residuos de ';cadillo bobo'; (Cenchrus ciliaris) + cultivo. A-C: aplicación de 1,5 ton/Ha de emulsión asfáltica catiónica diluida en agua (1:6) + cultivo. D-C: Suelo desnudo + cultivo. T.: Suelo desnudo sin cultivo (testigo). Los resultados permiten evidenciar la efectividad de las coberturas de residuos y emu1sión asfá1tica para reducir la escorrent1a y favorecen 1a infiltración de agua en el suelo, encontrándose que di­ coberturas redujeron las perdidas de agua por escurrimiento superficial hasta un 59,6% y 45%, respectivamente, mientras que el cultivo por si solo logra reducir las perdidas de agua sólo hasta un 9,4% en relación a1 testigo. Se concluye que las coberturas de residuos y emulsión asfáltica, al mejorar la disponibilidad de agua, especialmente de las etapas iniciales del cultivo facilitan la absorción de nutrimientos por parte del cultivo, permitiendo de esta forma un mayor crecimiento y desarrollo del cultivo, tanto en la parte aérea como del sistema radical

Este trabalho teve como objetivo estudar os efeitos da combinação entre teores de água do solo e cargas aplicadas pela roda compactadora da semeadora-adubadora sobre o índice de velocidade de emergência de plântulas de soja, em sistema de plantio direto.Utilizou-se o esquema de parcelas subdivididas, em que as parcelas constituíram os três teores de água do solo (U1, U2 e U3), correspondentes a 0,27; 0,31 e 0,36 kg kg-1, respectivamente, e as subparcelas os quatro níveis de carga aplicada pela roda compactadora(C1, C2, C3 e C4), correspondentes a 0, 50, 90 e 140 N, respectivamente, no delineamento em blocos ao acaso, com quatro repetições. Foram avaliados o diâmetro médio ponderado dos agregados na linha de semeadura, a porcentagem de finos < 2,0 mm e o índice develocidade de emergência de plântulas. A combinação entre cargas aplicadas pela roda compactadora e teores de água no solo não influenciaram a porcentagem de finos < 2,0 mm. A velocidade de emergência das plântulas de soja foi afetada pelas cargas aplicadas epelos teores de água do solo. A carga máxima de 140 N aplicada pela roda compactadora sobre a semente causou encrostamento superficial do solo.<br><br>The aim of this work is to study the effects of soil water contents combined with press wheel loads of a seed drill on the emergence velocity index of soybean plants, in direct drilling systems. The experiment was a subdivided design where each unit corresponded to a different soil water content (U1, U2 e U3): 0.27; 0.31 and 0.36 kg kg-1, and the sub-portions stood four charge levels applied bythe press wheel (C1, C2, C3 e C4): 0, 50, 90 and 140 N, respectively, in a randomized block design with four repetitions. Parameters evaluated were: pondered medium diameter of the aggregates in the planted line, percentage of thin ones < 2.0 mm, plants velocity emergence index. The combination between the charges applied by the press wheel and the soil water contents did not influenced the thin percentage < 2.0 mm. The soybean plants emergence velocity was affected by the applied charges and the water contents. The maximum charge of 140 N applied by the press wheel on the seed caused a superficial incrusting of the soil.

The ability of a plant to extract soil water during water deficit affects growth and grain yield crop. Experiments were conducted to evaluate the water extraction and rooting patterns of three genotypes (Arawaca, Acarigua and Piritu) of Sesame (Sesamum indicum L.) during periods of water deficit imposed at productive stage of growth, on a Fluventic Haplustolls, Maracay-Venezuela, during period of January-April of 1994 and 1995. Profiles of volumetric water content of the soil were measured with a neutron moisture meter, root, biomass and leaf area samples were taken at ending of water deficit period. There are differences in water extraction to drought, among genotypes, Arawaca showed significantly greatests water extraction (53.6 mm) at root zone of crop (0.15 -0.55 m) during the early water deficit period (CST). While the genotypes Acarigua and Piritu showed similar extractable water (40.0 y 39.1 mm respectively). The differences of soil water extraction among genotypes were related to root system patterns and canopy cover of each genotype. Piritu developed the 60% of its root system on the first O.25 m of soil profile and showed the less root length density (0.41 cm cm -3 respectively). A greater root system, with a better capacity to explore the soil, of Acarigua and Arawaca allows a greater amount of water uptake from soil profile. The minor water extraction by Arawaca during CSTR was correlated to its smaller canopy cover (0.65 M2 M2) during this period. The root characteristics of the genotypes suggest its better adaptative value in cropping areas with high risk of water deficit.

The perfomance of wheat cultivated under rainfed condition during 3 years using five sowing systems and four sowing densities was evaluated. The variables measured were: grain yield, yield components and water consumption. Rainfall intensity affected the grain yield and some yield components. The sowing systems: furrow, comercial machine and broadcasted were more productive. Water consumption was not influenced by the sowing system. The best sowing densities were 100, 150 and 50 kg/ha due to a larger water consumption and to an increment of the yield components. | Se presenta la informacion de 3 ciclos de evaluacion de 5 formas de siembra y 4 densidades de siembra en trigo de temporal. Se evaluo el rendimiento de grano, componentes del rendimiento y el consumo de agua por etapas fenologicas. El rendimiento del grano fue afectado por la precipitacion pluvial en cada ciclo y por algunos componentes del rendimiento. Los sistemas de siembra: surcos dobles, siembra en plano en hileras o al voleo presentaron los rendimientos mas altos, debido al incremento de los componentes del rendimiento. El consumo de agua no fue influenciado por los sistemas de siembra. Las mejores densidades de siembra fueron 100, 150 y 50 kg/ha, debido a los incrementos en los componentes del rendimiento y al mayor consumo de agua.

O presente trabalho foi conduzido na Pista de Ensaios de Semeadura do Laboratório de Máquinas e Mecanização Agrícola (LAMMA) da UNESP/Jaboticabal - SP, para o estudo da ação da roda compactadora de semeadoras sob cargas verticais, na deformação do solo, com dois teores de água. Os tratamentos consistiram da combinação de dois teores de água e seis cargas verticais, totalizando 12 tratamentos, com três repetições, em dois ensaios, analisando-se a resistência mecânica do solo à penetração e a deformação do solo provocada pela roda compactadora. A roda compactadora utilizada era de alumínio, com massa de 6,4 kg, 40 cm de diâmetro e 10 cm de largura, sob a ação de cargas verticais de 63; 161; 259; 357; 455 e 553 N, obtidas acoplando-se lastros de chumbo sobre a roda compactadora, sendo os teores de água do solo de 15,4 e 9,2%. Os resultados permitem concluir que o teor de água do solo tem grande influência na deformação e compactação do solo, que aumentam proporcionalmente com as cargas verticais sobre a roda compactadora, e que, quanto maior o teor de água do solo, mais suscetível o mesmo fica à compactação e deformação. | The present work was leading in the sowing assays track at the Laboratório de Máquinas e Mecanização Agrícola (LAMMA), UNESP/Jaboticabal-SP, Brazil, where it was studied the press wheel action under loads in soil deformation with two moisture contents. The treatments consisted in the combination of two moisture contents, and six loads, totalizing twelve treatments with three repetitions. The following parameters were analyzed: soil mechanical resistance to penetration and the analysis of the soil deformation caused by the press wheel in static and dynamic testing. The press wheel used was of aluminum, with 6.4 kg mass, 40 cm diameter and 10 cm width. The load used was of 63; 161; 259; 357; 455 e 553 N, gotten by the connection of ballasts on the press wheel. The tested soil moisture was 15.4%, and 9.2%. The results allow concluding that the soil moisture has great influence on the soil deformation and compacting. The increase of the loads on the press wheel is directly proportional to soil deformation and compacting, and the bigger the soil moisture is, more susceptible is the soil to the compacting and deformation.

O maracujazeiro está entre as principais fruteiras cultivadas no País, sendo semeadura o método predominante na produção de mudas. Objetivou-se com este trabalho avaliar o efeito do pH da água de embebição e do trincamento das sementes nos processos de germinação e desenvolvimento inicial do maracujazeiro amarelo, cultivar IAC 277. O trabalho foi realizado no Departamento de Fitotecnia, da Universidade Federal de Viçosa (MG). Os tratamentos foram constituídos de sementes trincadas e não trincadas embebidas durante 24 horas em solução de água destilada com pHs 3,0; 4,0; 5,0; 6,0 e 7,0. Posteriormente, no interior da casa-de-vegetação, as sementes foram semeadas em caixas plásticas contendo areia fina lavada. Foi utilizado o delineamento experimental em blocos casualizados, num fatorial 5 x 2 (pH da solução x trincamento da semente), com quatro repetições, considerando como unidade experimental, um lote de 50 sementes. Após 28 dias da semeadura, foram analisadas: porcentagem de germinação e sobrevivência; índice de velocidade de emergência; comprimento total; altura e comprimento da raiz primária e, massa da matéria seca total das plântulas. Concluiu-se que, os valores de pH das soluções de embebição foram favoráveis com os pHs de 3,81 e 6,14, para sementes não trincadas e trincadas, respectivamente. Os valores de pH das soluções de embebição não influenciaram no desenvolvimento inicial do maracujazeiro amarelo. As sementes não trincadas apresentaram os melhores resultados, não sendo aconselhável o trincamento das mesmas nos processos de germinação e desenvolvimento inicial do maracujazeiro amarelo.<br>The passion fruit plant is among the main fruits cultivated in the country, being the sowing of seeds the predominant method in the production of seedlings. The aimed of this work was to evaluate the effect of the water pH of soaking and of the cracking of the seeds on the germination and initial development processes of the yellow passion fruit, cv. IAC 277. The work was carried out at the Department of Plant Science, of the Federal University of Viçosa (MG), Brazil. The treatments were constituted of cracking and no cracking seeds soaked for 24 hours into solution of distilled water at pHs 3.0; 4.0; 5.0; 6.0 and 7.0. After, at the greenhouse, the seeds were sowed in plastic boxes being used as fine substrate washed sand. The experiment was designed in a completely randomized blocks, in a factorial 5 x 2 (pH of the solution x cracking of the seed), with four replications, where each plot constituted of 50 seeds. After 28 days of sowing, the following characteristics were evaluated: germination and survival percentages; emergence speed; total plantlet length; plantlet height; first root length and plantlet mass total drought. It was concluded that, pH values of the soaking solutions were favorable at the pHs of 3.81 and 6.14, for no cracking and cracking seeds, respectively. The pH values of the soaking solutions did not influence on the initial development of the yellow passion fruit. The no cracking seeds presented the best results, not being recommended the cracking of the seeds for the germination and initial development processes of the yellow passion fruit.

O maracujazeiro está entre as principais fruteiras cultivadas no País, sendo semeadura o método predominante na produção de mudas. Objetivou-se com este trabalho avaliar o efeito do pH da água de embebição e do trincamento das sementes nos processos de germinação e desenvolvimento inicial do maracujazeiro amarelo, cultivar IAC 277. O trabalho foi realizado no Departamento de Fitotecnia, da Universidade Federal de Viçosa (MG). Os tratamentos foram constituídos de sementes trincadas e não trincadas embebidas durante 24 horas em solução de água destilada com pHs 3,0; 4,0; 5,0; 6,0 e 7,0. Posteriormente, no interior da casa-de-vegetação, as sementes foram semeadas em caixas plásticas contendo areia fina lavada. Foi utilizado o delineamento experimental em blocos casualizados, num fatorial 5 x 2 (pH da solução x trincamento da semente), com quatro repetições, considerando como unidade experimental, um lote de 50 sementes. Após 28 dias da semeadura, foram analisadas: porcentagem de germinação e sobrevivência; índice de velocidade de emergência; comprimento total; altura e comprimento da raiz primária e, massa da matéria seca total das plântulas. Concluiu-se que, os valores de pH das soluções de embebição foram favoráveis com os pHs de 3,81 e 6,14, para sementes não trincadas e trincadas, respectivamente. Os valores de pH das soluções de embebição não influenciaram no desenvolvimento inicial do maracujazeiro amarelo. As sementes não trincadas apresentaram os melhores resultados, não sendo aconselhável o trincamento das mesmas nos processos de germinação e desenvolvimento inicial do maracujazeiro amarelo. | The passion fruit plant is among the main fruits cultivated in the country, being the sowing of seeds the predominant method in the production of seedlings. The aimed of this work was to evaluate the effect of the water pH of soaking and of the cracking of the seeds on the germination and initial development processes of the yellow passion fruit, cv. IAC 277. The work was carried out at the Department of Plant Science, of the Federal University of Viçosa (MG), Brazil. The treatments were constituted of cracking and no cracking seeds soaked for 24 hours into solution of distilled water at pHs 3.0; 4.0; 5.0; 6.0 and 7.0. After, at the greenhouse, the seeds were sowed in plastic boxes being used as fine substrate washed sand. The experiment was designed in a completely randomized blocks, in a factorial 5 x 2 (pH of the solution x cracking of the seed), with four replications, where each plot constituted of 50 seeds. After 28 days of sowing, the following characteristics were evaluated: germination and survival percentages; emergence speed; total plantlet length; plantlet height; first root length and plantlet mass total drought. It was concluded that, pH values of the soaking solutions were favorable at the pHs of 3.81 and 6.14, for no cracking and cracking seeds, respectively. The pH values of the soaking solutions did not influence on the initial development of the yellow passion fruit. The no cracking seeds presented the best results, not being recommended the cracking of the seeds for the germination and initial development processes of the yellow passion fruit.