Palavras-chave -Milho hibrido. Plantio direto. Componentes de rendimento.Abstract -Corn plant arrangement is one of the most important management tool to improve solar radiation interception and it can be done through changes in plant density, row spacing, distribution of plants in the row and plant variability aiming to optimize its use and maximize the yield. Due to it, the objective of this work was to study the effects of different corn hybrids and row spacing over the corn development cultivated in a no-tillage system in the Southwest of Paraná. The experiment was carried out at the experimental area of the UTFPR Agronomy Course located in Pato Branco -Pr, following a complete randomized block design factorial (3 x 3), with four replications. The treatments consisted of combinations among three hybrids (DKB 240, Pioneer 30R50 and SG 6010) and three row spacing (0.45; 0.70 and 0.90 m). After seeding, were evaluated: plant height, stem diameter, grain yield and its components. According to the results, there were no interaction among hybrids and row spacing, the row spacing reduction promoted greater number of spikes per plant and increased corn grain yield.

The sowing process for annual no-till crops affects the physical soil conditions around the seeds by exposing them to adverse conditions that may limit initial plant development and reduce potential yield. The use of seed drills that are not compatible with field conditions and the use of inappropriate seed drill speeds affect sowing performance. Therefore, this study aims to evaluate the effect of different seed drill types and operating speeds on soybean quality parameters and yield components. Two furrow opener (double disc and chisel) and four operating speed (0.86; 1.22; 1.47 and 1.94 m s -1 ) treatments were used. The following variables were evaluated: mean number of days until emergence, plant distribution uniformity, sowing depth, area of the soil disturbed, crop stand and grain yield. Overall, the chisel furrow opener provided a greater sowing depth and increased the disturbed soil area more than the double disc furrow opener. Increased operating speeds reduced crop stands and yields and increased the disturbed soil area. Key words: No-tillage, sowing performance, no-tillage quality ResumoEm culturas anuais submetidas ao sistema plantio direto o processo de semeadura afeta o condicionamento físico do solo ao redor das sementes expondo as mesmas a condições adversas, podendo limitar o desenvolvimento inicial das plantas e minimizar o potencial produtivo. O uso de sulcadores não condizentes com a situação de campo e de velocidades inadequadas são fatores que afetam o bom desempenho da semeadura. Nesse contexto, este trabalho teve por objetivo, avaliar o efeito de diferentes sulcadores e velocidades de operação sobre parâmetros de qualidade de semeadura e componentes de produtividade da cultura da soja. Os tratamentos foram compostos pela combinação entre dois sulcadores (disco e haste) e quatro velocidades de operação (0,86; 1,22; 1,47 e 1,94 m s -1 ). Foram avaliados: o número médio de dias para a emergência, a uniformidade de distribuição de plantas, a profundidade de semeadura, a área de solo mobilizado, o estande de plantas e a produtividade de grãos. De acordo com os resultados, o sulcador tipo haste proporcionou maior profundidade de semeadura e área de solo mobilizada, quando comparado ao disco duplo defasado. O aumento da velocidade reduziu o estande de plantas e a produtividade da cultura e aumentou a área de solo mobilizada. Palavras-chave: Semeadura direta, desempenho de semeadura, plantio direto com qualidade

A integração lavoura-pecuária pode ser definida como o sistema que integra duas atividades, visando a maximizar racionalmente o uso da terra e a minimizar os custos de produção. Objetivou-se, com este trabalho, avaliar os efeitos de diferentes alturas remanescentes de pastagem e de mecanismos sulcadores sobre o desenvolvimento inicial e a produtividade da cultura do milho semeado em sequência. Os tratamentos foram compostos pela combinação de quatro intensidades de pastagem (0,05; 0,15; 0,30 m e sem pastejo) e de dois mecanismos sulcadores (haste e disco), utilizados na semeadura pós-pastejo. Após a semeadura, foram avaliados a profundidade de deposição das sementes, o índice de velocidade de emergência de plântulas, o estande final de plantas, a altura inicial e de inserção de espigas e o rendimento de grãos. As diferentes intensidades de pastagem influenciaram significativamente a profundidade de deposição de sementes, a altura inicial de plantas e de inserção da primeira espiga e a produtividade, sendo que a altura de pasto remanescente de 0,05 m apresentou os menores valores de profundidade de deposição de sementes, quando comparada com os demais níveis. Os diferentes mecanismos sulcadores influenciaram apenas a profundidade de deposição de sementes.

As épocas utilizadas nos manejos de plantas de cobertura podem prejudicar o desempenho das semeadoras e a produtividade de culturas subsequentes, uma vez que propiciam diferentes condições quali e quantitativas de palhada. Nesse contexto, o objetivo do trabalho foi verificar a influência das épocas de dessecação da aveia preta e mecanismos sulcadores na plantabilidade, desenvolvimento e produtividade da cultura do milho. O experimento foi conduzido no delineamento de blocos ao acaso, em esquema fatorial 4 x 2, com 4 repetições. Os tratamentos foram constituídos de quatro épocas de dessecação da aveia, sendo elas 0, 15, 30 e 45 dias antes da semeadura do milho e dois mecanismos sulcadores (haste e disco duplo). A antecipação da dessecação da aveia preta melhora as condições de plantabilidade, mas não proporciona aumento na produtividade de grãos. Apesar de o sulcador tipo haste apresentar maior estande de plantas, ele mobiliza muito solo e não apresenta ganho na produtividade em relação ao disco.

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Times and methods of black oat management on corn plantability 1The importance of maintaining straw on the soil surface is a subject widely discussed and proven in the literature. However, the effects of this straw on planting efficiency and quality still lack information. In this sense, both time and method of the black oat management influence the permanence of the straw on the soil and, thus, can interfere in the next crop's germination and plantability of the seed drill. This study aimed to evaluate methods and times of black oat management and their implications on the plantability and development of the corn crop in succession in two harvests. A randomized block design with twelve treatments was used, consisting of the combination of three methods of management (crushed, rolled, and desiccated) and four times of management (0, 10, 20, and 30 days before the corn sowing) of black oat straw, arranged in a 3 x 4 factorial scheme, with four replications. The black oat management carried out 30 days before the corn sowing provides the highest corn emergence rate. Management methods that promote greater fragmentation of straw tend to offer less mechanical impediment to seedling development and result in a greater initial and final plant population.

Direct onion sowing under soil tillage methods 1Onion production is conditioned to the adopted techniques during the cultivation. Sowing depth, soil preparation and cultivars are determinant factors for productivity to be increased. Two experiments were developed, the first with the objective of evaluating the effect of sowing depths and soil preparation methods on the germination and development of onion seedlings, while the objective of the second was to evaluate the productivity of onion cultivars as a soil preparation function. In experiment I, the split plot scheme was adopted, where the main plots consisted on soil tillage methods (total area and bed) and in the subplots, the sowing depths (0.5; 1.0; 1.5 and 2.0 cm), with six replicates. Experiment II was carried out in a split plot scheme, in which the main plots consisted on soil tillage methods (total area and bed) and in the subplots, such as onion cultivars (Itajubá, Rainha, Salto Grande, Ômega, Mulata and BR29), with four replicates. The 1.5 cm sowing depth provided greater speed of germination and plant stand. Raising beds offers the best initial seedling development. The onion cultivation under beds offers the highest vegetative development and productivity.

There is some doubt about the influence of seed size among soybean producers, who often believe that larger seeds produce more vigorous plants. There is also some debate regarding the furrow opener, as it influences the depth of the fertilizer in relation to the seed. This study aimed to evaluate seeding parameters and the development and productivity of the soybean in regard to seed size and employing fertilizer furrow opener. The experiment was conducted in a typical distroferric red nitisol with very clayey texture in two crop seasons 2014/2015 and 2015/2016. The experiment adopted a randomized block design in a factorial structure, with five replications. Treatments consisted of the combination of two seed sizes of Nidera ® NS 4823 RR cultivar (large-6.5 mm, and small-5.5 mm in diameter) and two types of furrow opener (shank and double disc). The use of shank-type furrower resulted in a greater mobilized area and a greater sowing depth in both seasons. Due to environmental conditions, smaller seeds resulted in lower plants, 30 days after sowing and fewer pods per plant in the first studied season. In turn, seeds with larger diameter resulted in higher productivity in the second season, although in the first year there was no significant difference.