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Among the types of production systems applied in aquaculture, the biofloc culture system (BTF) has been gaining space due to its sustainable techniques. Noteworthy is the low or zero renewal of water, the formation of the microorganism population predominantly autotrophic and heterotrophic, resulting in microbial flakes. Taking into consideration the effectiveness of the system in tilapia farming, this work aimed at the fabrication, implementation, and analysis of the efficiency of a low-cost aerator. To evaluate and control the physical and chemical parameters of the water, 3,780 Nile tilapia fry were used with an initial average biomass of 3±0.5g, distributed in 24 rectangular tanks with a useful volume of 125 liters. The experiment included 6 treatments (T1: 360 fish m-3, T2: 1800 fish m-3, T3: 1080 fish m-3, T4: 1440 fish m-3, T5: 720 fish m-3 and T6: 2160 fish m-3) and four repetitions. The efficiency of the Venturi effect aerator and the water quality parameters were analyzed. Comparisons of the averages were performed using Tukey's test at 5% significance. From the dissolved oxygen analysis, it was possible to conclude that the aerator Venturi effect was efficient during the experiment, meeting the desired levels, also taking into consideration the ease of applicability and low cost for its development. Through the analysis of the physical-chemical parameters of the water and the mortality rates during the experiment, it can also be concluded that the safest density to operate using the bioflocci is up to 720 fish m-3. Entre los tipos de sistemas de producción aplicados en la acuicultura, el sistema biofloc ha ido ganando espacio debido a sus técnicas sostenibles. Destaca la escasa o nula renovación de agua, la formación de una población de microorganismos predominantemente autótrofos y heterótrofos, dando lugar a escamas microbianas. Teniendo en cuenta la efectividad del sistema en la creación de tilapia, este trabajo tuvo como objetivo construir, implementar y analizar la eficiencia de un aireador de bajo costo. Para evaluar y controlar los parámetros físicos y químicos del agua se utilizaron 3.780 alevines de tilapia del Nilo, con una biomasa promedio inicial de 3±0.5 g, distribuidos en 24 tanques rectangulares con un volumen útil de 125 litros. El experimento incluyó 6 tratamientos (T1: 360 peces m-3, T2: 1800 peces m-3, T3: 1080 peces m-3, T4: 1440 peces m-3, T5: 720 peces m-3 y T6: 2160 peces m-3) y cuatro repeticiones. Se analizaron la eficiencia del aireador de efecto venturi y los parámetros de calidad del agua. Las comparaciones de medias se realizaron mediante la prueba de Tukey al 5% de significancia. Del análisis de oxígeno disuelto se pudo concluir que el efecto aireador Venturi fue eficiente durante el experimento, cumpliendo con los niveles deseados, considerando también la facilidad de aplicabilidad y el bajo costo para su desarrollo. Mediante el análisis de los parámetros físico-químicos del agua y las tasas de mortalidad durante el experimento, también se puede concluir que la densidad más segura para operar con los bioflocs es hasta 720 peces m-3. Dentre os tipos de sistemas de produção aplicados na aqüicultura, o sistema de bioflocos vem ganhando espaço devido às suas técnicas sustentáveis. Destaca-se a baixa ou nula renovação de água, a formação da população de microrganismos predominantemente autotrófica e heterotrófica, resultando em flocos microbianos. Levando em consideração a eficácia do sistema na criação de tilápias, este trabalho teve como objetivo a construção, implantação e análise da eficiência de um aerador de baixo custo. Para avaliação e controle dos parâmetros físicos e químicos da água, foram utilizados 3.780 alevinos de tilápia do Nilo, com biomassa média inicial de 3±0,5 g, distribuídos em 24 tanques retangulares com volume útil de 125 litros. O experimento incluiu 6 tratamentos (T1: 360 peixes m-3, T2: 1800 peixes m-3, T3: 1080 peixes m-3, T4: 1440 peixes m-3, T5: 720 peixes m-3 e T6: 2160 peixes m-3) e quatro repetições. A eficiência do aerador de efeito Venturi e os parâmetros de qualidade da água foram analisados. As comparações das médias foram realizadas pelo teste de Tukey a 5% de significância. A partir da análise do oxigênio dissolvido, foi possível concluir que o efeito aerador Venturi foi eficiente durante o experimento, atendendo aos níveis desejados, considerando também a facilidade de aplicabilidade e o baixo custo para seu desenvolvimento. Por meio da análise dos parâmetros físico-químicos da água e das taxas de mortalidade durante o experimento, também pode-se concluir que a densidade mais segura para operar com os bioflocos é de até 720 peixes m-3.

The soxhlet oil extraction method provides a large amount of oil when compared to other methods, however the commonly used solvents are not always effective. The objective of this work was to compare the efficiency of two solvents in different moisture contents in the extraction of peanut oil (Arachis hypogaea L.), sunflower (Helianthus annuus L.), soybean (Glycine max), crambe (Crambe abyssinica) and canola (Brassica napus L.). The experiment was conducted in a 5 × 2×2 factorial scheme, and five grain moisture contents (9.44%, 7.76%, 6.68%, 6.82% and 7.77%) were tested for canola, crambe, peanut, sunflower and soybean, respectively, two solvents (petroleum ether and hexane) and four repetitions, totaling 80 experimental units. The solvents presented have no influence on the content of sunflower oil and soybean, while extractions of dry grains result in an increase in the content of sunflower oil, regardless of the solvent used. The interaction between the solvent of hexane (without moisture in the grains) optimizes the extraction of canola oil. It was also verified the highest percentage of peanut oil content (43.49%) extracted with petroleum ether with moisture in the grains (6.69%). For the grains of crambe, the humidity of (7.76%) presented the best percentage with 11.95% of oil.

A aplicação de serpentinito pode diminuir a acidez do solo aumentando a disponibilidade de Ca, Mg, P e Si às plantas. O Objetivo deste trabalho foi avaliar a influência do serpentinito na produção de matéria seca da parte aérea da forrageira Urochloa brizantha cv. Piatã e decomposição da fitomassa da forrageira. O delineamento experimental empregado foi blocos casualizados em parcelas sub-subdivididas no tempo, sendo as doses de serpentinito nas parcelas (0, 2, 4, 8 e 16 mg ha-1), o uso de bioativo nas subparcelas (com e sem o uso de bioativo) e as épocas de avaliação nas subsubparcelas (0, 30, 60, 90, 120 e 150 dias após o manejo). As variáveis analisadas foram: taxa de cobertura da fitomassa sobre o solo, massa remanescente, tempo de meia vida e constante de decomposição da fitomassa da forrageira. A aplicação do serpentinito proporcionou maior produtividade de matéria, aumentou a taxa de cobertura e massa remanescente da fitomassa da Urochloa brizantha sobre o solo. O uso do bioativo proporcionou maior produção de matéria seca da forrageira com menores doses de serpentinito.

An experiment was conducted at the Agronomic Institute of Parana – IAPAR, at the Experimental Station of the municipality of Santa Tereza do Oeste – PR, in Hapludox of clayey soil. Studies with the use of plants cover crops with vigorous root system in different systems of soil management systems are needed, in order to have a diversity of species capable of producing different amounts of crop residues which by decomposing, can alter the physical attributes and consequently, the productivity of the successor culture. The objective of this study was to evaluate the effect of crambe crop and plant cover crops in succession on the physical characteristics of a Haplortox under no-tillage system. The experimental area has been cultivated under no-tillage system for 18 years. The experimental area consisted of 15 plots, each plot with 20x25 m. In 12 plots, plant cover crops were planted, six species of summer and six of winter and the last three consisted of plots with no-tillage system with gypsum application, no-tillage system with scarification and traditional no-tillage (control) in a completely randomized design. The physical attributes of this soil were soil density (DS), total porosity (PT), microporosity (Micro), macroporosity (Macro) and saturated hydraulic conductivity (Ksat) of the soil in the periods of 2014 (initial characterization of the soil) and 2015 (after crambe culture). The microporosity (0.0-0.1 m layer) and Ksat (all soil layers) presented significant differences between treatments in the period of 2015. Microporosity was lower in the pigeon pea coverage (PP) (36.08%), while the largest occurred in the coverage of crambe C5 (45.38%). The Ksat was higher in the dwarf pigeon pea (DPP) (298.20 mm h-1) and sunn hemp (SH) (163.39 mm h-1) coverage in the 0.0-0.1 m layer. The highest Ksat was observed for crambe C9 (96.81 mm h-1), C8 (74.13 mm h-1), velvet bean (70.95 mm h-1) and C5 (53.94 mm h-1) respectively, in the soil layer of 0.1-0.2 m. Key words: Soil management, soil structure, residues.

1 recurso en línea (páginas 435-440) : ilustraciones color., This study verified the allelopathic influence of jack bean leaves (Canavalia ensiformis) on safflower cultures (Carthamus tinctorius), applied at different concentrations. Ten safflower genotypes were seeded in 20 containers, and a concentrate was prepared with jack bean leaves, crushed with water to make the extract. Five treatments were performed with four replicates, and this extract was applied at concentrations of 0%, 25%, 50%, 75% and 100%. The parameters were germination speed, percentage of germination, dry and fresh mass, leaf and root size. The jack beans influenced each evaluated treatment differently, presenting, at some times, neutral characteristics, inhibitory characteristics, or stimulating characteristics, varying according to the percentage of extract that was applied., Este estudio verificó la influencia alelopática del extracto de hojas del frijol canavalia (Canavalia ensiformis), sobre el cultivo de cártamo (Carthamus tinctorius) aplicado en diferentes concentraciones. Diez genotipos de cártamo fueron sembrados en 20 contenedores y la preparación del extracto acuoso fue a partir de la maceración de hojas de frijol canavalia con agua. Se aplicaron cinco tratamientos (0, 25, 50, 75 e 100%) del extracto de hoja con cuatro repeticiones. Se evaluaron los parámetros velocidad de germinación, porcentaje de germinación, masa seca y fresca, tamaño de hojas y raíces. Se encontró que el extracto acuoso de frijol canavalia influye de diferentes formas en los parámetros evaluados, presentando en algunos momentos características neutras, inhibitorias y estimulantes, variando de acuerdo al porcentaje del extracto aplicado., Bibliografía: página 440

The objective of this study was to assess the energy value of waste timber in the form of sawdust. Two types of wood: Araucaria (Araucaria angustifolia) and Pinus were evaluated with no defined species (Pinus sp). The sawdust was collected from a timber that receives wood from reforestation of these species in Southwestern Parana, Brazil. The material collected was evaluated with a calorimeter bomb to determine the gross and net calorific value. The main results obtained led to the conclusion that the sawdust of A. angustifolia showed gross calorific value of 17.32 MJ.kg-1 and net of 17.00 MJ.Kg-1, respectively, and Pinus sp. gross calorific value of 17.23 and net of 16.91 MJ.Kg-1, respectively. Key words: Wood energy, conifer of reforestation, gross calorific value.

The consolidation of crambe crops in the agricultural and industrial scenarios comes up against the lack of recommendations and technical information on their cultivation. Thus, this study aims to analyze the effects of boron fertilization on a crambe crop cultivated in two oxisols. The experiment was conducted in a greenhouse owned by the Agronomic Institute of Parana, in the city of Santa Tereza do Oeste - PR. The treatments were arranged in a 2×3 factorial scheme. Two oxisols with different textures (clayey and medium texture) were used, and three boron rates (0, 1, and 8 mg kg-1) were applied to the soil. A randomized complete block design with five replications was used. The experimental unit consisted of a vase containing 2.0 kg of soil with two crambe plants. Plant height, dry matter yield of roots, stems and fruit, number of fruit per plant, number of branches per plant, 100-seed weight and leaf boron content were assessed. Soil texture did not affect any variable. There was no significant interaction between the boron rates applied and soil texture. Plant heights, number of branches per plant and fruit dry matter were not influenced by the boron fertilizer. The number of fruit per plant as well as the dry matter yield of roots, stems and fruit was higher with the application of 1 mg B kg-1 of soil. The amount of boron in the leaves was proportional to the fertilizer rates applied. The application of 8 mg B kg-1 of soil caused toxicity symptoms on crambe leaves. Key words: Crambe abyssinica, fertilizing, nutrition of energy crops.

Crambe (Crambe abyssinica Hoschst) is a winter oilseed crop with yield potential of 1500 kg ha-1. It is indicated for crop rotation systems and tolerates moderate frost. However, crambe presents thermal and water limitations that influence sowing dates since it needs water at blooming and at least 200 mm rainfall until it reaches the flowering stage. This study aimed to assess the performance of a crambe crop in different sowing dates. The experiment was conducted on the experimental farm of Assis Gurgacz College (Faculdade Assis Gurgacz – FAG) Cascavel – Parana, at an altitude of 700 m, within latitudes 24°56’25.39” S and 24°56’45.39” S and longitudes 53°30'9.89" W and 53°31'17.01" W. The experimental design consisted of randomized blocks with three sowing dates (April, June and July) and five replications. Phenometric parameters such as plant height, dry mass, plants per meter, grain yield and mass of 1000 grains were assessed and data were subjected to Tukey’s test at 5% probability. Phenometric variables were influenced by sowing dates. Degree days and rainfall influenced the results. April has proven to be the best month for sowing. Key words: Winter oilseed crop, cycle, development, production, Crambe abyssinica Hoschst.

The aim of this study was to assess the decomposition rate of crambe straw under different soil management practices based on no-tillage system. The experiment was carried out at the experimental area of the Agronomic Institute of Parana - IAPAR, regional center of Santa Tereza do Oeste, Parana, Brazil. Treatments consisted of four soil management practices: Traditional No-tillage System - TNTS – Chisel Plowing Tillage System - CPTS – No-tillage System with Application of Gypsum - NTSG - and Quality No-tillage System - QNTS. The treatments were distributed in randomized order in parts subdivided on time with fifteen macro-plots of 20 m x 25 m. The assessments took place on 0 (zero), 7, 15, 30, 60, 90, and 120 days after crambe crop harvest. Decomposition was determined quantitatively through the analysis of the decomposition rate of crop residues using litter bags. Average loss of crambe phytomass was significantly different (p>0.05), mainly for CPTS and NTSG, around 0. 63% day-1 and 0. 71% day-1, respectively. The longest half-life period (66 days) was observed on QNTS with bristle oat and white lupin consortium, and the shortest half-life period (45 days) was observed on CPTS. Key words: Crambe abyssinica, litter bags, half-life period.

The objective of this work was to evaluate the phytotoxic effect of Brachiaria decumbens Stapf. on the morphometry of Eucalyptus urograndis plants, genetically modified hybrid of Eucalyptus urophylla S. T. Blake × Eucalyptus grandis W. Hill ex Maiden. Pots containing the eucalyptus plants were conditioned in protected environments in a completely randomized experimental design. The treatments were composed of aqueous extract of Brachiaria decumbens grass at different concentrations: 0% (control, distilled water only), 20%, 40%, 60%, 80% and 100% (g/L). On day 30 of the experiment, the following morphological parameters of the plants were evaluated: aerial part height, diameter of stem, aerial dry mass, root dry mass, total dry mass, and robustness index. The data were submitted to analysis of variance at the 5% level of significance, and a regression equation was constructed for the quantitative treatments. The results indicated that the Brachiaria decumbens grass extract did not have an inhibitory effect on aerial part height and robustness index. However, the extract at concentrations higher than 20% had negative effects on root dry mass, aerial dry mass, and total dry mass. For the diameter of the stem, only concentrations above 60% had an inhibitory effect.

The present study aimed to evaluate the initial development of safflower genotypes (Carthamus tinctorius) after different periods of seed hydration. For the study two experiments were evaluated. At first, an experiment was performed with 0, 24, 48, 72, 168 and 360 hours of seed hydration, and in the second moment, another with 0, 12, 24, 36, 48 and 60 hours of hydration. The experimental design for the two experiments was completely randomized, with four replicates and six treatments. After 30 days of conduction of the experiments were analyzed the percentage of emergency, index of emergency speed, average time of emergency and average speed of emergency. The evaluated morphological characteristics were plant height, stem diameter, root length, fresh shoot and root mass and dry shoot mass. Hydration of seeds in considerable proportions positively influences the emergence and development of safflower plants. The highest performance in the emergence of plants, size, accumulation of fresh and dry shoot mass and fresh root mass was obtained by the IAPAR genotype, which stood out in relation to the other. The greatest emergencies were obtained with seeds with 36 hours of hydration, and the lowest emergence was found after 72 hours under hydration.

This study aimed to evaluate the effect of soil compaction levels on initial development of safflower genotypes (Carthamus tinctorius). The experimental design was 2 × 2 × 6, composed of two sowing seasons (May and June 2017), two genotypes (IMA-2103 and IMA-4409) and six levels of soil density (1.0, 1.1, 1.2, 1.3, 1.4, and 1.5 g cm-3), with three replicates. After 30 days of planting, percentage of emergence, emergence speed index, mean time of emergence and mean speed of emergence were analyzed. Among the morphological characteristics, plant height, stem diameter, root length, shoot and root fresh mass, shoot dry mass and number of healthy and wilted leaves were evaluated. The compaction states did not significantly interfere in the emergence of the safflower seedlings that were sown in the uncompacted surface layer. As soil compaction increased, root length, shoot fresh mass, shoot dry mass and root fresh mass were reduced in both genotypes. Soil density considered critical to safflower root growth was 1.3 g cm-3. The IMA-4409 genotype, in relation to IMA-2103, was more tolerant to soil compaction levels.

The beneficial effects to the soil, when using cover crops, are numerous, such as nutrient cycling, nitrogen fixation, breaking of the cycle of pests and diseases, soil structuring and addition of dry matter. This makes the subsequent crop better able to express its productive potential. The nitrogen is a key element for any plant, especially in the early stages of crop development. In this way, the purpose of this study work was to evaluate the effect of nitrogen doses on the grain yield of soybeans grown on black oat and forage pea straw in a clayey Latosol in the western region of Paraná, Brazil. The experiment was conducted in the experimental area of the Agronomic Institute of Paraná (IAPAR), in the regional hub of Santa Tereza do Oeste. The local soil is classified as a typical Dystrophic Red Latosol. The experimental design consisted of a randomized complete block design with five replicates. The treatments consisted of nitrogen doses of 0, 25, 50, 75 and 100 kg ha-1 applied in a broadcasting cover, without incorporation, using urea as a nitrogen source, at 20 days after emergence when the plants were in stage V3. The soil physical attributes were bulk density, total porosity, microporosity, and macroporosity. In the soybean crop, the production components evaluated were: plant height, 100-grain weight, and grain yield of grains. The data were submitted to analysis of variance, in which, for the quantitative factors, a regression analysis was performed and, for the qualitative characteristics, the Tukey test (p < 0.05) was performed. The mineral addition of nitrogen did not lead to an increase in grain yield of the cultivated soybean on the species of oat or forage pea cover. Thus, it can be stated that in well-structured clayey Latosols with high fertility, the nitrogen present in the soil organic matter and what was fixed symbiotically is sufficient to supply the nitrogen demand for the soybean crop.

The inappropriate use of herbicides has increased the resistance of weeds; thus, the study of allelopathy becomes of paramount importance. The ability of certain plants to interfere with the metabolism of others by means of substances released into the environment, either by their aerial or roots system, becomes an alternative to combat invasive plants, dispensing with or reducing the use of herbicides. The objective of this work was to evaluate the plant species most sensitive to the allelopathic potential of aqueous extracts. One of the plant species studied was lettuce because it had a rapid response potential, thus showing the benefits obtained through allelopathy.

The crambe crop is an interesting option for the production of biodiesel, mainly due to the high oil content (35%) and the corn one of the most implanted crops in Brazil. Thus, the objective of this work was to evaluate the allelopathic effect of crambe in the initial development of maize. The experiment was carried out in the laboratory of seed and plant evaluation (LASP) and laboratory of soil physics (LAFIS) of UNIOESTE-Cascavel. The seeds of corn with germination of 93.5% were submitted to four concentrations plus the control in the different parts of the crambe plant, where the growth and mass of corn were valued. The experimental design was completely randomized with 4 replicates per treatment. The statistical analysis consisted of analysis of variance and the means of the treatments were compared by the Tukey test at 5% of significance. The extract of the whole crambe plant stimulated aerial length, root length, fresh and dry mass of corn shoot. Root, stem and leaf extracts inhibited the initial development of maize in relation to growth and fresh and dry shoot mass.

The intense agricultural machinery traffic over the plantation ground can lead the erosion and growth difficulty. The goal of this study was to evaluate the soya bean yield after the implantation of species named “recoverable”, of soil structure. The experiment was developed in plots of 20 m × 25 m, located in the Agronomic Institute of Parana (IAPAR), in Santa Tereza do Oeste, Paraná. The plots were cultivated by direct sowing of the following species, considered as treatments: sunn hemp (Crotalaria juncea), rattlebox (Crotalaria spectabilis), velvet bean (Mucuna aterrima), pearl millet (Pennisetum glaucum), pigeon pea (Cajanus cajan), dwarf pigeon pea (Cajanus cajan) beside them no-tillage and no-cover crop planting traditional system (control). Soil samples were collected from 0-10 cm, 10-20 cm, and 20-30 cm-layers with 4 repetitions on each treatment. Soil density and porous soil space were also determined. The plot yield of soybean grains was evaluated over an area of 4.5 m2 for each treatment and grain moisture corrected to 13%. The treatments’ mean yields were compared using the Tukey test at 5% probability. The dwarf pigeon pea and the rattlebox were the most efficient cover crops in the reduction of soil bulk density in 0-10 and 10-20 cm depths. The soybean grain yield did not differ between the evaluated treatments, possibly due to the good precipitation conditions during the soybean growing cycle.

The availability of water is one of the most important factors for the development of the seeds. Thus, studies related to adequate humidityfor germination, emergence and early development of safflowers, is necessary for the productive use of this culture. Thus, the objective of study was to evaluate the initial development of two varieties of seeds of Safflowers (IAPAR and IMA2103) in six levels of water availability in substrate: 0, 10, 20, 30, 40 and 50%. At 15 days the seedling emergence were evaluate. At 30 days were evaluate plant height, root length, stem diameter, number of leaves, fresh weight of the aerial part and root, dry weight of shoot and root. The treatment without irrigation, there was decrease the emergence, emergence speed for both genotypes. Treatments above 30% of water availability in the two varieties presented emergency superior to 50%. Lower irrigation rates favored root length and dry mass.

Nitrogen fertilization provides a great response in pasture productivity and quality but, after applied to the soil, this element undergoes several transformations, what increase its losses. To minimize this problem, a promising alternative currently suggested is diazotrophic bacteria use, which can contribute to a greater use of nitrogen by plants. This study aimed to evaluate the effect of nitrogen doses with and without inoculation of seeds with Azospirillum brasilense on the structural characteristics, chemical composition, and mass production of Urochloa decumbens cv. Basilisk. The experimental design was completely randomized, arranged in a 2 × 5 factorial scheme, with four replications. Treatments consisted of forage seed inoculation or not with Azospirillum and five nitrogen doses (0, 50, 100, 150, and 200 kg ha-1). The variables analyzed were plant height, number of tillers, shoot dry mass (SDM), root dry mass (RDM), SDM/RDM ratio, chlorophyll index, nutrient content in forage shoot, crude protein (CP), neutral detergent fiber (NDF), and nitrogen use efficiency. The inoculation of forage seeds with A. brasilense associated with nitrogen doses up to 100 kg ha-1 contributed positively to dry mass, plant-shoot nutrient content and bromatological composition of U. decumbens cv. Basilisk. The inoculation of seeds of U. decumbens cv. Basilisk, with A. brasiliense, is a viable alternative for partial substitution of nitrogen fertilization.

This work aimed to evaluate the dynamics of physical and hydric attributes of a clayey Latosol cultivated with different cover species. The experimental area was located in the Agronomic Institute of Paraná (IAPAR), in the regional hub of Santa Tereza do Oeste, Paraná, Brazil. The experiment was comprised of seven cover species also called treatments is the course of this work. Three of them were isolated summer species notably Crotalaria juncea, Crotalaria spectabilis, Cajanus cajan (pigeon pea), and the other four treatments winter species cultivated individually or in association including Avena strigosa (Black oat), + (Avena stirgosa + Raphamus sativus (radish), Avena strigosa + Lupinus albus (Lupin bean), and (Avena strigosa + Pisum sativum (pea). The treatments were distributed on a completely random plots of 20 m × 25 m without replication. Soil density, macroporosity, and saturated hydraulic conductivity were measured to follow the changes of the soil structure. Statistical analyses showed that cover crops species did not lead to a significant improvement in soil structural status. Soil density varied between 1.08 and 1.12 Mg m-3, macroporosity from 15.22 and 16.90%, and saturated hydraulic conductivity ranged from 28.83 to 45.07 mm h-1. Soybean grain yield were considered satisfactory in 2016 (mean = 1909.68 kg ha-1) and in 2017 (mean = 3355.30 kg ha-1) most probably due to the good initial structural conditions of the soil, alongside with the good climatic conditions during the two campaigns. Furthermore, the soybean grain yield was positively influenced by Ds which ranged from 1.0 to 1.17 Mg m-3.

The research was looking for the quick response of soil's microbiota to soil changes caused by management systems, changes to which biological indicators of soil quality are sensitive. In this context, this study aimed to evaluate the impacts of seven soil management systems, including in on hand covers of Pennisetum glaucum (PG), Avena strigosa (AS), Stizolobium aterrimum (SA), EF Pisum sativum (PS) + Avena strigosa (AS), and on the other hand, No soil tillage with gypsum application (NTSG), No soil tillage with scarification (NTSS) and No soil tillage (NTS), on soil quality bioindicators. The bioindicators recorded from top soil samples were collected from the first 10 cm at pre-planting, at pre-flowering and at post-harvest of the soybean, from July 2014 to March 2015 were Total organic carbon (TOC), Soil microbial biomass carbon (SMBC), Soil basal respiration, Respiratory coefficient (qCO2), Microbial coefficient (qMIC), and its relationship with soybean yields. The seven treatments were arranged in the field according to a completely randomized experimental, Analysis of variance (Anova) for each of the bioindicators and comparison of treatment mean values using Tukey test at 5% probability were carried out. SA, the AS+PS consortium and the no-tillage system led to significant improvement of the biological attributes of the soil. The management systems did not change the yield of soybean grain.

The objective is to evaluate the germination of four different safflower genotypes at six sowing depths. The study was carried out in the experimental field of the Western Paraná State University, in Cascavel, in two stages: in protected environment and in the field. In a protected environment, the experimental units were vessels with a 0.10 m diameter and a 0.20 m height, maintaining a 0.05 m water level. Using 10 seeds per vase, filled with substrate composed of vermiculite and macronutrients. For the field, the experimental units were divided in 3 blocks with 1.50 m rows, with 30 seeds spaced in 0.05 m, spacing between 0.30 m rows, totalizing blocks of 6 m by 1.8 m. For the analysis, we performed a 5 × 4 factorial, with four replicates being 5 depths (0.02; 0.04; 0.06; 0.08 and 0.10 m) and 4 genotypes, with analysis of percentage, speed index, mean time and average speed of emergence and morphometric characteristics of the plant. High emergence rates occurred for the lowest sowing depths, ranging from 60 to 80%. At the greatest depths, the averages were below 50%. At 0 m depth, there was no emergence for both sites. For the emergence speed index, the averages ranged from 0.47 to 1.34 seeds per day for the protected environment and 2.26 to 16.42 seeds per day for the field experiment. For both sites, the IMA-2103 genotype had the best performance for the evaluated indices. The depths indicated for planting are 2 and 4 cm.

This work evaluated the cover crop allelopathic potential of wheat, black oat, pearl millet, turnip and rape on the development of weed plants. It also verified which cover crop has larger control on the weed plants. The cover crop was implanted under conventional tillage (one disk plowing plus one disk harrowing) in the Experimental Nucleus of Agricultural Engineering (NEEA), of the State University of the West of Parana (Unioeste), Cascavel, Parana State. Monthly (from August 2000 to August 2001), weed plants identification in the cover crop area was made. Results showed that from the found species, the alexander grass was the one that presented larger allelopathic potential, and, the mexican-tea was the one that presented smaller control. The vegetable coverings that presented larger control of the total of weed plants in the experimental area, including those with recognized allelopathic potential, was black oat, rape, turnip and pearl millet.

Cover crop allelopathic potential in the development of corn seedlings. The objective of this work was to verify the allelopathic potential of aqueous extracts of wheat plants, black oat, pearl millet, turnip and rape on the germination of seeds, hypocotyl and radicle length, as well as dry weight of corn seedlings, using concentrations of 0%, 25%, 50%, 75% and 100%. The aerial part of the seedlings was used to obtain extracts in ten minutes and 24 hours periods of rest in distilled water. The experimental design was totally randomized, factorial 5x5. Germination percentage of the corn seed did not present interaction between the plants and the extracts concentrations by the test of Tukey (P≤ 0,05). Significant interactions were obtained in the ten minutes extracts for the length of the radicle, hypocotyl and seedling dry weight. In the 24 hours extracts, there was significant interaction in the length of the aerial part and seedlings dry weight. Results show that the extracts of the tested plants presented allelopathic effect on corn seedling, and it is larger on the 24 hours extracts, probably due to the presence of inhibited or retarded substances of the growth in larger quantity.