ABSTRACT Irrigated agriculture is considered one of the most important techniques for agricultural production in the world, despite being the sector that uses water resources the most. Thus, technological advances have been constantly developed and applied in the sector as a way to improve water management and reduce its consumption, considering that some cultures are affected by economic costs and feasibilities of production, because the water cost has increased significantly in recent years. Remote sensing is a technology that has provided good results for estimating evapotranspiration (ETr) in producing areas, enabling more efficient irrigation management for low costs. This study aimed to answer the question about how the generation of irrigation management zones (IMZs) can be used to optimize water use and improve irrigation systems and which ETr models are better for it. Three ETr estimation models (Surface Energy Balance Algorithm for Land [SEBAL], Mapping Evapotranspiration at High Resolution and with Internalized Calibration [METRIC] and Simple Algorithm for Evapotranspiration Retrieving [SAFER]) were used to design IMZs in center pivot cultivated with cotton. The design of IMZs with ETr data proved to be a viable alternative, making it possible to improve water management in irrigated systems, reducing costs with viability irrigation for cotton and others cultures. The METRIC method displayed the greatest ease in obtaining the data used in the ETr estimation for generating the IMZs.

ABSTRACT Furrowing shank horizontal strength and working depth can be correlated with soil compaction in a no-till sowing. This study aimed to evaluate the correlation of furrowing shank strength and working depth with soil physical properties at two working speeds (1.58 and 1.87 m s-1) and four compaction levels induced by an agricultural tractor (0P, 1P, 3P, and 5P+Ballast), with four repetitions in an RBD. Thereby, we aimed to verify a potential increase in sampling density of soil compaction data. Horizontal strength at 1.58 m s-1 had Pearson correlations ranging from 0.74 to 0.73 with soil penetration resistance (SPR), and from 0.57 to 0.72 with some soil properties collected by volumetric ring. Working depth also correlated with several parameters ranging from 0.49 to 0.81. The highest correlations were verified for the speed of 1.58 m s-1, at which shanks maintained greater depth. This increased soil contact with the shank, hence sensitivity to compaction. Our findings show that furrowing shank horizontal strength and working depth can be used to monitor soil compaction.

ABSTRACT The aim was to evaluate the diseases severity on corn second crop. The research was conducted on the agricultural year of 2013 and 2014, evaluating the application quality over the fungicide spraying. The hybrid used was PIONEER 30k75 BT HERCULEX, evaluating the diseases severity previously and after the fungicide spraying, spray deposition on the culture and productivity. The aerial application was carried out with solution volume of 7.5, 13.5, 20 and 30.3 L ha-1, using automatic rotating nozzles, and the ground application with 90, 110, 130 and 150 L ha-1, uniform flat spray tips. As control a non-fungicide treatment was used. The aerial and soil treatment showed diseases control from the corn crop, being the biggest cover of drops acquired at the volumes 30.30 L ha-1 for aerial and 150 L ha-1 for soil, with no significant change on the productivity of the corn harvest for both forms of spraying: aerial or soil.

O objetivo da pesquisa foi estudar os efeitos do manejo com diferentes formas de preparo do solo, tipos de resteva e infestação do solo com o fungo Trichoderma harzianum Rifai sobre as características de componentes do dossel vegetativo da cultura da batata. O experimento foi desenvolvido em Guarapuava-PR, em delineamento inteiramente casualizado, com parcelas subsubdivididas, em um esquema fatorial 4 x 5 x 2, com quatro repetições. Para o fator 1, foram avaliadas quatro formas de mecanização do preparo do solo (P): preparo-base (escarificação e sulcamento) - P1; preparo-base mais grade niveladora - P2; preparo-base mais enxada rotativa - P3 preparo-base mais grade niveladora e enxada rotativa - P4. No fator 2, utilizaram-se restevas de aveia, milho, trigo, feijão e uma testemunha sem resteva. O fator 3 constitui-se da infestação ou não infestação do solo com o fungo T. harzianum. As variáveis comprimento da maior haste e índice de área foliar (IAF) foram afetadas pelo tratamento com o fungo T. harzianum. O IAF apresentou também comportamento diferenciado ao longo do ciclo em relação à cobertura do solo com resteva de milho. O maior revolvimento do solo no preparo inicial reduz a produção de massa seca da parte aérea da cultura da batata.

The objective was to study the effects of management with different forms of tillage, reservoir types and soil infestation with the fungus Trichoderma harzianum Rifai over the characteristics of canopy components of potato. The experiment was structured in a completely randomized design with split plots in a 4 x 5 x 2 factorial with four replications. For factor 1 it was evaluated four types of tillage - (P): base tillage (scarifiation and harrowing furrowing) - P1, base tillage plus disc harrow - P2, rotary hoe plus basic tillage - P3 and base tillage plus disc harrow and rotary hoe - P4 . In Factor 2 it was used the stubble of oats, corn, wheat, beans and a control without stubble. The Factor 3 was constituted by no infestation or infestation of soil with the fungus T. harzianum. The variable length of the longest stem and index of leaf area (IAF) were affected by the treatment with the fungus T. harzianum. IAF presented also different length over the cycle in relation to the soil cover with corn stubble. The highest soil inversion in the initial tillage reduces the production of dry matter of the potato crop shoot.

Com este trabalho objetivou-se estimar o potencial médio de produção da cultura do milho em função das variações da disponibilidade hídrica considerando-se a realização da semeadura em diferentes momentos dentro do período recomendado para o município de Guarapuava, Estado do Paraná. Os estudos foram realizados com base na série ininterrupta de dados climáticos do período de 1984 a 2007. A duração do ciclo da cultura foi calculada pelo acúmulo de soma térmica e a disponibilidade de água avaliada pelo balanço hídrico da cultura, ponderando-se a distribuição da precipitação pluvial e a evapotranspiração da cultura. A probabilidade de redução de produtividade de grãos por deficiência hídrica foi estimada considerando-se a porcentagem de redução de produção de grãos a partir da ocorrência de deficiência hídrica nos diferentes estádios do ciclo de desenvolvimento no campo. Verificou-se que a cultura do milho é afetada pela distribuição da disponibilidade hídrica ao longo do ciclo, sendo que a maior probabilidade de perdas de produção por deficiência hídrica ocorre no estádio da antese-fecundação. As semeaduras mais tardias no período recomendado tendem a ocasionar menores riscos de obtenção de produtividade de grãos abaixo da média regional.

This study aimed to estimate the average potential of production of the corn crop in consequence of the variation of the water availability and the planting performed at different dates within the recommended period for Guarapuava, Paraná State, Brazil. The study was conducted considering uninterrupted series of climate data for the period from 1984 to 2007. The duration of the crop cycle was calculated by the accumulation of the thermal sum and the availability of water evaluated by the water balance of the crop considering the distribution of the precipitation and the evapotranspiration of the crop. The probability of reduction of the grain yield due to shortage of water was estimated considering the percentage of the reduction of grain production with the occurrence of water deficiency in the different stages of the crop cycle. It was verified that the corn crop is affected by the distribution of the water availability along the crop cycle, with the highest probability of production losses for water deficiency occurring at the stage of anthesis-fecundation. Late planting in the recommended period tend to cause less risks of having grain productivity below the regional average.

O objetivo da pesquisa foi estudar os efeitos do manejo com diferentes formas de preparo do solo, tipos de resteva e infestação do solo com Trichoderma harzianum sobre a produtividade e as características dos tubérculos da cultura da batata. O experimento foi estruturado em delineamento inteiramente casualizado, em parcelas subsubdivididas, em um esquema fatorial 4 x 5 x 2, com quatro repetições. Foram avaliadas, na parcela, as seguintes formas de preparo do solo: preparo-base (escarificação e sulcamento) - P1; preparo-base mais grade niveladora - P2; preparo-base mais enxada rotativa - P3, e preparo-base mais grade niveladora e enxada rotativa - P4. Na subparcela, utilizaram-se as restevas de aveia, milho, trigo, feijão e uma testemunha sem resteva. A subsubparcela constitui-se da infestação ou não infestação de T. harzianum no solo. Concluiu-se que a menor mobilização do solo ocasiona maior produtividade da cultura. O preparo convencional do solo para o cultivo da batata pode ser reduzido, eliminando-se as operações com enxada rotativa ou grade niveladora. A aplicação das restevas exerceu efeito positivo para o incremento da produtividade de tubérculos. O efeito da presença do fungo T. harzianum afetou negativamente a qualidade do tubérculo, sem exercer efeito significativo sobre a produtividade da cultura, demonstrando a necessidade de ser mais bem estudado.

The aim of the research was to study the effects of management with different forms of tillage, stubble and types of infestation of soil with Trichoderma harzianum on the characteristics of components of the canopy of the potato crop, production and characteristics of tubers produced. The experiment was structured in a randomized design in split plots in a factorial 4 x 5 x 2 with four replications. It was evaluated, in plots, the following forms of tillage: tillage base (and chisel plowing) - P1, base tillage more harrowing - P2, rotary hoe most basic preparation and P3 base most harrowing and rotary hoe - P4. In the subsections it was used the stubble of oats, corn, wheat, beans and a control without stubble. The sub subplot constitutes of no infestation or infestation of T. harzianum in soil. It was concluded that less tillage causes greater crop yield, and that the application of stubble positive effect for increasing productivity, especially corn and wheat. The effect of T. harzianum to the potato yield was not significant, demonstrating the need for further studies.

Tendo em vista o propósito de se avaliar épocas de semeadura para maximizar a produção de arroz de terras altas e de milho e sorgo em sucessão e avaliar o retorno econômico desse sistema de produção irrigado, na região de Santa Maria, RS, conduziu-se este trabalho em área experimental do Departamento de Engenharia Rural da Universidade Federal de Santa Maria, no ano agrícola 2001/2002. Conduziu-se dois experimentos em delineamento experimental de blocos ao caso, com quatro repetições. O primeiro experimento constituiu-se de quatro datas de semeadura do arroz (18 de setembro, 4 de outubro, 19 de outubro e 5 de novembro); no segundo experimento foram utilizadas as seguintes datas de semeadura do milho e do sorgo, semeados após a colheita do arroz, em 28 de janeiro, 8 de fevereiro, 20 de fevereiro e 5 de março. As datas de semeadura do arroz ocasionaram diferenças no rendimento de grãos, apresentando a máxima eficiência técnica (5,80 Mg ha-1) na semeadura estimada de 13 de outubro. Na sucessão de culturas irrigadas de arroz de terras altas para produção de grãos e sorgo para produção de silagem, a maior receita líquida foi observada com a semeadura do arroz, na segunda quinzena de setembro.

The objective of this work was to evaluate different sowing dates to maximize double-cropping (upland rice followed by either maize or sorghum) and evaluate the economica practicability of this production system in the region of Santa Maria, in the State of Rio Grande do Sul. Two experiments were conducted in the experimental field of the Agricultural Engineering Department of the Federal University of Santa Maria - RS, Brazil, during the 2001/2002 growing season. A randomized block design was used with four replications. Treatments of the first experiment were constituted of four sowing dates of upland rice: September 18, October 4, October 19 and November 5. The treatments of the second experiment were constituted of four sowing dates of maize and sorghum (after the harvest of the upland rice): January 28, February 8, February 20 and March 5. The upland rice sowing dates caused differences in grain yield and the maximum technical efficiency (5.80 Mg ha-1) was observed for the rice sown on October 13. The use of double-cropping cultivation in the southern half of Rio Grande do Sul the State upland rice followed by sorghum for the production of silage, for maximum retnans, the upland rice should be sown during de second half of September.