Abstract Root growth is crucial in crop production and is influenced by soil attributes, but also affects soil chemical, physical and biological quality, along with management and conservation practices. In this paper, soybean root growth data from a field study at Guarapuava, Paraná State, Brazil are examined. In 2019, at a farm with over 35 years of no-tillage system (NT) adoption, three management sets were established in 1,1 ha macroplots: 1) farmer's NT standard (FNT), without terraces, with downhill farming and with autumn fallow; 2) autumn cover crops and contour farming added to FNT, as best management practices (BMP); 3) terraces and contour farming (TC) added to FNT. Soybean was sowed in November 2020 and 2021, and minirhizotron tubes (1 m long, 7 cm wide) were installed into the soil just after soybean emerged in 2020. Root length, area, volume, and diameter were evaluated with the help of a root scanner. Data were submitted to descriptive statistics. The added conservation practices improved root length, area and volume, significantly for BMP in the subsoil (40-60 cm) compared to FNT standard. Minirhizotron enabled the study of roots in the field, but data variability was high, so that for annual crops with pivoting roots like soybean, root observation points (6 per plot) must be increased, and crop stand close to the observation points is a critical font of error. attributes chemical quality paper Guarapuava State examined 2019 3 notillage no tillage (NT adoption 11 1 1, macroplots farmers farmer s , (FNT) fallow 2 (BMP) TC (TC 202 2021 ( long wide length volume scanner statistics 4060 40 60 (40-6 high 6 plot increased error 201 (FNT (BMP 20 406 4 (40- (40 (4

ABSTRACT The effects of machinery traffic and cover crops on soil physical properties have been underexplored under no-till agricultural production in subtropical environments. The objective of this study was to quantify the soil water infiltration rate and related soil physical properties in response to tractor traffic levels (0, 2, 5, and 20 passes) and the presence or absence of cover crops in a Xanthic Hapludox soil over two growing seasons under no-till conditions. The experiment was carried out in a randomized block design arranged in a factorial scheme with four replications. The traffic factor was constituted by the number of passes with a 6 Mg weight tractor. The winter crop management practices factor consisted of the cover crops (i) black oat (Avena strigosa) in 2017 and turnip (Raphanus sativus var. oleiferus) in 2018 compared with (ii) fallow with spontaneous vegetation. The soil water infiltration rate increased with cover crops when compared to fallow. Regarding tractor traffic levels, shortly after soil compaction, there was a lower water infiltration rate at 20 passes, 45 mm h-1 lower than the absence of tractor traffic. The soil water infiltration rate was positively correlated with macroporosity and negatively correlated with soil bulk density. After 14 months of soil compaction caused by tractor traffic, an improvement in the soil physical properties and the water infiltration rate was found, which were enhanced by the inclusion of cover crops. notill no till environments 0, 0 (0 2 5 conditions replications i (i Avena strigosa 201 Raphanus var oleiferus ii (ii vegetation 4 h1 h 1 h- density found (

ABSTRACT No-tillage system (NTS) plays a prominent role in conservation agriculture, however, its benefits can be further improved by adopting complementary soil management and conservation practices, such as using autumnal cover crops, contour seeding, and terraces. This study aimed to evaluate how soil biological activity responds to soil management and conservation systems. The treatments consisted of three macroplots with an area of 11.000 m2 each, as follows: a) Non-Terraced catchment (NTC), cultivated in NTS similar to most farmers of the region, in which the agricultural operations are carried out in the direction of the slope and without terraces used; b) Best Management Practices (BMPs) were adopted in NTS with additional autumnal cultivation of cover crops, and also the direction of machine traffic was transverse to the slope direction; and c) Terraced catchment (TC), cultivated in NTS was associated to mechanical practices to erosion control, using wide base terrace on level. Soil microbial properties sampled in the 0.00-0.10 m layer were evaluated during 2019, 2020, and 2021, all shortly after the summer crop harvest. Natural inoculum potential of arbuscular mycorrhizal fungi (AMF), respirometry, metabolic coefficient, acid phosphatase activity, and organic carbon and nitrogen in the microbial biomass were assessed. Averages of each microbiological properties were compared through the confidence intervals (p<0.05). The results showed a greater potential for AMF inoculum in BMPs and TC systems. The NTC showed the highest values of respirometry and metabolic quotient, releasing 31.7 and 27.3 % more CO2 compared to BMPs and TC, respectively. The BMPs and TC were able to retain 13.8 and 16.5 % more carbon in the microbial biomass and 8.0 and 8.8 % more nitrogen in the biomass than NTC, respectively. Adopting soil management and conservation practices such as autumn cover crops, level seeding, and wide base terrace on level improved the soil microbial properties, with an increase in AMF inoculum potential, higher levels of acid phosphatase activity, and increment of carbon and nitrogen in microbial biomass. Notillage No tillage (NTS agriculture however crops seeding systems 11000 11 000 11.00 follows NonTerraced Non , (NTC) region used b (BMPs c (TC) control 0.000.10 000010 0.00 0.10 0 00 10 0.00-0.1 2019 2020 2021 harvest AMF, (AMF) coefficient assessed p<0.05. p005 p p<0.05 . 05 (p<0.05) quotient 317 31 7 31. 273 27 3 27. CO respectively 138 13 8 13. 165 16 5 16. 80 8. 88 1100 1 11.0 (NTC (TC 0.000.1 00001 0.0 010 0.1 0.00-0. 201 202 (AMF p00 p<0.0 (p<0.05 2 110 11. 0.000. 0000 0. 01 0.00-0 20 p0 p<0. (p<0.0 0.000 0.00- p<0 (p<0. p< (p<0 (p< (p

RESUMO A compactação do solo pode reduzir a produtividade potencial das culturas e é frequentemente encontrada no sistema plantio direto, mas há pouca informação sobre os limites críticos das propriedades físicas do solo nessas condições, especialmente em solos subtropicais. Os objetivos deste estudo foram avaliar a influência do tráfego de tratores nas propriedades físicas do solo e identificar limites críticos de densidade do solo, grau de compactação do solo, macro e microporosidade no rendimento das culturas de milho e aveia preta avaliados in situ em um Latossolo Bruno no Sul do Brasil. O tráfego de trator agrícola (0, 2, 5 e 20 passagens) foi estabelecido em sistema plantio direto para criar diferentes níveis de compactação do solo. Amostras indeformadas de solo foram coletadas em profundidades de 0,00-0,05; 0,07-0,12 e 0,17-0,22 m logo após o tráfego do trator em dois momentos: antes do cultivo de milho e, antes do cultivo de aveia preta. Nas condições deste experimento, os rendimentos 10% maiores de milho e aveia preta foram obtidos com macroporosidade acima de 0,10 m3 m-3 e 0,13 m3 m-3, respectivamente. Da mesma forma, o grau de compactação do solo de 90% e 86% foi considerado crítico para o milho e aveia-preta, respectivamente. Além disso, a compactação do solo pelo tráfego de máquinas reduziu o rendimento do milho em até 33% e o rendimento da biomassa de aveia preta em até 44%. Nossos resultados demonstram que os produtores devem estar atentos às consequências do tráfego de máquinas nas propriedades do solo, pois pode comprometer severamente o rendimento a produtividade das culturas, principalmente do milho e da aveia preta cultivados em solo muito argiloso como o avaliado neste estudo.

ABSTRACT Soil compaction can decrease potential crop yield and is frequently found in no-till cultivation systems, but there is little information on the critical limits of soil physical properties in these conditions, especially in subtropical soils. The objectives of this study were to evaluate the influence of tractor traffic on soil physical properties and identifies critical limits of soil bulk density, soil compaction degree, macro, and microporosity on crop yield of corn and black oat assessed in situ in a Xanthic Hapludox in Southern Brazil. Tractor machine traffic (0, 2, 5 and 20 passes) was established in no-till soil to create different soil compaction levels. Undisturbed soil samples were collected at depths of 0.00-0.05, 0.07-0.12 and 0.17-0.22 m just after tractor traffic in two moments: before corn cultivation, and then before black oat cultivation. Under the conditions of this experiment, the 10% higher yields of corn and black oats were obtained with macroporosity above 0.10 m3 m-3 and 0.13 m3 m-3, respectively. Similarly, the soil compactness degrees of 90% and 86% were considered critical for the corn and black oat, respectively. In addition, soil compaction by machine traffic reduced maize yield up to 33% and black oat biomass yield up to 44%. Our results demonstrate that growers should be aware of the consequences of machine traffic on soil properties, as it can severely compromise crop yields, especially of corn and black oats cultivated in very clayey soil like the one evaluated in this study.

ABSTRACT The objective of this study was to evaluate the effect of harvesting corn at different maturity stages for silage production combined with four storage periods, considering nutrient loss and the chemical composition of silage of the whole plant and also of grainless plants. The experiment was performed in a completely randomized design with a factorial arrangement of six maturity stages of corn [reproductive (R); R1 to R6] and four periods of silage storage (30, 60, 90, and 120 days). At stages R1 and R2, losses by effluents occurred more intensely when compared with the more advanced stages, whereas losses by gases showed the opposite behavior, with stage R6 responsible for the greatest losses. Stage R4 showed a stable dry matter (DM) content during the storage period, 42.08%, and had the lowest levels of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) for the whole plant silage. The ADL in the silage of grainless plant of stage R4 was not the lowest, but it was close to the first reproductive stages, being an important point, since the first reproductive stages can present a vegetative fraction of better quality. The highest DM volumes produced by area occurred in the most advanced stages; however, R5 obtained a greater reduction in volume over the days of storage (20.66 kg day −1 ). The production cost was lower at the advanced stages (R4, R5, and R6) when compared with the first reproductive stages (R1, R2, and R3), and in general, during the storage period the costs did not have great variations. Based on the chemical composition of the silages, DM losses during the storage period, the stability in the costs of DM ton over the days of storage, the R4 stage was the most suitable for silage production.

RESUMO O zinco (Zn) é um dos micronutrientes mais deficientes em solos agrícolas no Brasil. Objetivou-se nesse estudo avaliar a nutrição, produção de grãos e exportação de nutrientes em função da fertilização de Zn em feijoeiro-comum (Phaseolus vulgaris L.) cultivado sob sistema de plantio direto. Dois experimentos de campo foram conduzidos usando a cultivar IPR Campos Gerais (feijão carioca) e a cultivar BRS Esteio (feijão preto). Os tratamentos foram compostos pela aplicação de Zn no solo durante a semeadura e pela pulverização foliar de Zn no estádio fenológico de florescimento. A aplicação de Zn no solo teve efeito sobre o teor foliar de Zn da IPR Campos Gerais, mas não afetou a produtividade de grãos. Entretanto, a pulverização foliar de Zn elevou consideravelmente o teor foliar de Zn, resultando em aumento e redução na produtividade de grãos da IPR Campos Gerais e BRS Esteio, respectivamente. Os teores foliares de N, Ca, S e Mn foram afetados pela aplicação de Zn no solo e/ou foliar, enquanto que os teores foliares de P, K, Mg, Cu e Fe não foram influenciados pelos tratamentos. Considerando os tratamentos que não receberam Zn, as exportações de nutrientes obedeceram à ordem para os macronutrientes N > K > P > Ca ≈ S > Mg e à ordem para os micronutrientes Fe > Mn > Cu > Zn. A pulverização foliar de Zn elevou as exportações de Zn, P, Ca, Mg, S, Mn, Cu e Fe na IPR Campos Gerais, enquanto que a aplicação de Zn no solo resultou em maior exportação de P, K e Mn na BRS Esteio.

ABSTRACT Zinc (Zn) is one of the most deficient plant micronutrients in agricultural crops. The objective of this study was to evaluate plant nutrition, grain yield and nutrient export rate in response to soil and foliar Zn fertilization in common bean (Phaseolus vulgaris L.). Two field experiments in no-till system were carried out using two common bean cultivars, BRS Esteio (black bean) and IPR Campos Gerais (Carioca bean). Treatments were composed of soil Zn application during sowing and foliar Zn spray at flowering stage. Soil Zn application had effect on leaf Zn concentration in IPR Campos Gerais and did not affect grain yield of both cultivars. Foliar Zn spray increased leaf Zn concentration by approximately two times in both cultivars, but negatively affected the grain yield in BRS Esteio. Leaf concentration of N, Ca and S were affected by soil Zn application and leaf concentration of Mn was affected by foliar Zn spray, while leaf concentration of P, K, Mg, Cu and Fe were not influenced by the soil and foliar Zn treatments. In treatments without Zn, the descending order of nutrient export rate from the experimental site was as follows: N > K > P > Ca ≈ S > Mg for macronutrients and Fe > Mn > Cu > Zn for micronutrients. Foliar Zn spray increased the export rate of Zn, P, Ca, Mg, S, Mn, Cu and Fe in IPR Campos Gerais, while soil Zn application resulted in higher export rate of P, K and Mn in BRS Esteio.

RESUMO A utilização de protetores físicos é uma técnica eficiente na semeadura direta de espécies nativas. Devido à importância da espécie Peltophorum dubium para a utilização no repovoamento de áreas degradadas, arborização e paisagismo, determinou-se o comportamento fisiológico das plantas com a análise da influência de um protetor físico com diferentes taxas de luminosidade no processo das trocas gasosas das plantas. O experimento foi conduzido em vasos com o solo Latossolo Vermelho Distroférrico, típico da região, em vasos com solo. As plantas de Peltophorum dubium foram avaliadas aos 30, 50, 70, 90, 110 e 130 dias após a semeadura (DAS) com os tratamentos: T1, ausência de protetor físico (APF); T2, protetor físico transparente (PFT); T3, protetor físico transparente + celofane azul (PFA) e T4, protetor físico transparente + celofane vermelho (PFV). Foram avaliadas as seguintes características: condutância estomática, transpiração, assimilação de CO2, concentração de CO2 no interior da câmara subestomática e eficiência do uso de água. Os resultados obtidos mostraram que o protetor físico independentemente de sua coloração promoveu aumento dos valores médios de trocas gasosas durante a permanência dos protetores físicos no ponto de semeadura 70 DAS, exceto para assimilação líquida de CO2. No entanto, a eficiência do uso de água foi maior com APF 70 DAS.

ABSTRACT The utilization of physical protectors has been considered an efficient technique for direct sowing of different species, mainly native ones. Based on the importance of the species Peltophorum dubium for revegetation of degraded areas, tree planting and landscaping, this study evaluated gas exchanges in canafistula seedlings under the influence of physical protectors subjected to different luminosity rates. The experiment was carried out in pots a Dystropheric Red Latosol, a typical soil of the study region. Seedlings of Peltophorum dubium were evaluated at 30, 50, 70, 90, 110, and 130 days after sowing (DAS). Thus, the following treatments were adopted: T1, absence of physical protector (APP); T2, transparent physical protector (TPP); T3, transparent physical protector + blue cellophane (BPP) and T4, transparent physical protector + red cellophane (RPP). The evaluated characteristics were: stomatal conductance, transpiration, CO2 assimilation, CO2 concentration inside the substomatal chamber and water use efficiency. In general, all types of physical protectors led to higher mean values of gas exchanges during their permanence in the sowing site until 70 DAS, except for CO2 assimilation. However, water use efficiency was higher in APP seedlings at the same period.

Resumo O objetivo deste trabalho foi avaliar a qualidade do solo a partir das frações químicas e oxidáveis da matéria orgânica (MOS) em áreas com diferentes sistemas de manejo. O trabalho foi realizado no Município de Guaíra, no Oeste do Paraná, em áreas com diferentes tempos de adoção do sistema plantio direto (SPD, 6, 14 e 22 anos), com sucessão das culturas soja (verão) e milho/trigo (inverno), além de áreas com 12 anos de SPD - no mesmo arranjo de sucessão - mais quatro anos de cultivo de braquiária (Urochloa ruziziensis) consorciada com milho (M+B) e com pastagem e mata nativa. As frações químicas de ácido fúlvico (AF), ácido húmico (AH) e humina (HUM) foram avaliadas, bem como as frações oxidáveis da MOS (F1, F2, F3 e F4), o carbono total (CT) e o estoque de carbono (C) nas frações húmicas. Os teores de CT aumentaram com o tempo de adoção do SPD, principalmente entre SPD6 e SPD22. Verificou-se predomínio da fração HUM e movimentação de AH e AF na camada de 0,0-0,4 m de profundidade. As frações oxidáveis apresentaram equilíbrio na distribuição do conteúdo de C, com maiores teores nas frações mais lábeis, em superfície. O cultivo com sucessão de culturas contribui para o aumento das frações mais lábeis, mas não para o aumento das frações mais recalcitrantes do C.

Abstract The objective of this work was to evaluate soil quality from soil organic matter (SOM) chemical and oxidizable fractions in areas with different management systems. The study was carried out in the municipality of Guaira, in the west of the state of the Paraná, Brazil, in areas with different adoption times of the no-tillage system (NT; 6, 14, and 22 years), with succession scheme of soybean (summer) and corn/wheat (winter) crops, besides areas with 12 years under NT - in the same succession scheme - plus four years of Urochloa ruziziensis intercropped with maize (M+U), and with pasture and native forest. The chemical fractions of fulvic acid (FA), humic acid (HA), and humin (HUM) were evaluated, as well as the oxidizable fractions of MOS (F1, F2, F3, and F4), total carbon (TC), and carbon storage (C) in the humic fractions. Total carbon contents increased with the increasing adoption of time of SPD, especially from NT6 to NT22. Humin fraction predominance was observed, with movement of HA and FA in the 0.0-0.4 m soil depth. The oxidizable C fractions showed equilibrium in the distribution of C contents, with higher levels in the more labile fractions, at surface. The cultivation with succession of crops contributes to the increase in labile fractions, but not to the increase of the more recalcitrant fractions of C.

Resumo: O presente trabalho teve por objetivo avaliar os componentes de produção e produtividade de dois genótipos de soja cultivados em casa de vegetação e submetidos à inoculação com bactérias diazotróf icas do gênero Bradyrhizobium e Azospirillum. Adotou-se delineamento em blocos ao acaso com quatro repetições, em esquema fatorial 2×4; no fator 1 foram testados: dois genótipos de soja (BMX Turbo e Coodetec 250) e no fator 2 foram avaliadas quatro combinações de inoculação (sementes não inoculadas mas que receberam 200 kg ha-1 de N na semeadura; sementes inoculado com Bradyrhizobium japonicum; sementes inoculadas com Azospirillum brasilense; sementes com inoculação de B. japonicum e A. brasilense). No estádio R8 foi avaliado as variáveis biométricas: diâmetro de coleto (DC); altura de planta (ALP); número de vagens (NVS); número de grãos por vagem (NGV); massa seca de parte aérea (MPA); massa seca de vagens (MSV); produtividade por planta (PPP); teor de N na parte aérea (TNA) e teor de N nos grãos (TNG). Foi observado resposta diferenciada dos genótipos de soja BMX Turbo e Coodetec 250 à inoculação de sementes com bactérias diazotróf icas do gênero B. japonicum ou A. brasilense na altura de plantas e nitrogênio na parte aérea. A inoculação conjunta de B. japonicum e A. brasilense em sementes intensif ica o desempenho produtivo da cultura da soja no genótipo BMX Turbo.

Summary: This study aimed to evaluate the productivity and yield components of two soybean genotypes grown in a greenhouse and inoculated with diazotrophic bacteria of the genera Bradyrhizobium and Azospirillum. We adopted a complete randomized block design with four replications in a factorial 2 × 4; factor 1 was two genotypes of soybean (BMX Turbo and Coodetec 250) and factor 2 was four combinations of inoculation (seeds not inoculated but fertilized with 200 kg ha-1 N at sowing, seed inoculation with Bradyrhizobium japonicum; seeds inoculated with Azospirillum brasilense; seeds inoculated with B. japonicum and A. brasilense). At stage R8, the following biometric variables were assessed: diameter collect (DIC); plant height (ALP); number of pods (NVS); number of seeds per pod (NGV); shoot dry mass (MPA); pod dry mass (MSV); yield per plant (PPP); N content in shoots (TNA) and N content in grains (TNG). Dif ferential response of soybean genotypes BMX Turbo and Coodetec 250 and of seed inoculated with diazotrophic bacteria B. japonicum and A. brasilense in plant height and nitrogen in the shoots was observed. The combined inoculation of B. japonicum and A. brasilense seed enhanced the productive performance of soybean genotype in BMX Turbo.

Este trabalho teve por objetivo avaliar a influência da densidade do solo no desenvolvimento inicial da cultura do pinhão-manso. O experimento foi realizado em vasos de 10,6 dm³, em casa de vegetação. O solo utilizado foi o Latossolo Vermelho eutroférrico de textura argilosa, coletado em Marechal Cândido Rondon - PR. O delineamento experimental utilizado foi o de blocos casualizados, composto por cinco níveis de densidade do solo (1,08; 1,22; 1,36; 1,50 e 1,64 kg dm-3), com quatro repetições. Após 120 dias da emergência das plantas, foram efetuadas as avaliações biométricas e as relativas ao do tecido vegetal. Houve redução de 25% da altura das plantas, na densidade de 1,64 kg dm-3, quando,comparada com a da densidade de 1,08 kg dm-3. Para o comprimento radicular, a redução foi de aproximadamente 24 , 35 , 54 e 66 % para as densidades de 1,22; 1,36; 1,50 e 1,64 kg dm-3 respectivamente, quando comparadas com o da densidade de 1,08 kg dm-3. A limitação do desenvolvimento da parte aérea ocorreu a partir da densidade estimada de 1,26 kg dm-3, com redução do número de folhas, da área foliar e da produção de matéria seca da parte aérea. O desenvolvimento do sistema radicular e o conteúdo de P e K nas plantas de pinhão-manso reduziram-se linearmente com o aumento da densidade do solo.

The objective of this work was to evaluate theinfluence of soil densities on the early growth ofthephysic nut(JatrophacurcasL.). The experiment wascarried out in 10.6 dm³pots in a greenhouse.The soilused in the experiment wasa clay-texture Oxisolcollected in Marechal Cândido Rondon, Paraná State, Brazil. The experimental designwas randomized blockswith five levels ofsoil density (1.08, 1.22, 1.36, 1.50and 1.64kg dm-3) with four repetitions. Biometric and plant tissue evaluations were performed 120 days after plant emergence.It was found a reduction by 25% in plant heightat a density of1.64kg dm-3when compared todensity of1.08kg dm-3. For root length, the reduction was approximately 24%, 35%, 54% and 66%at the densities of1.22,1.36,1.50 and1.64 kg dm-3, respectively, when compared with density of1.08kg dm-3. Limitation of shoot development was found from the estimated density of 1.26 kg dm-3, with a reduction in the number of leaves, leaf area and dry weight of shoots. The root system development and content of P and K in plants of physic nut decreased linearly as the density increased.

O objetivo deste trabalho foi avaliar os componentes de produção, teor de nitrogênio (N) no tecido foliar e produtividade de grãos na cultura do milho em função de diferentes espaçamentos entre linhas, densidade populacional e doses de adubação nitrogenada em cobertura. O experimento foi conduzido no município de Toledo-PR, no ano agrícola de 2005/2006, em área de Latossolo Vermelho Eutroférrico sob sistema de semeadura direta, com o híbrido simples AG 8021. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições e tratamentos dispostos em parcelas subsubdivididas. Nas parcelas foram alocados os espaçamentos entre linhas (0,45 e 0,90 m), nas subparcelas foram alocadas as populações de plantas de milho (60 mil e 80 mil plantas ha-1) e nas subsubparcelas foram alocadas as doses de nitrogênio em cobertura (80, 100, 120 e 140 kg ha-1 de N), utilizando-se como fonte de nitrogênio a ureia. A elevação da população de plantas de 60 mil para 80 mil plantas ha-1, assim como a aplicação de doses crescentes da adubação nitrogenada em cobertura proporcionaram incremento nos componentes de produção. A aplicação de N em cobertura proporciona incremento no teor de N foliar e na produtividade de grãos para o espaçamento 0,45 m e 0,90 m. O espaçamento de 0,45 m alcançou produtividade superior ao espaçamento 0,90 m. Com 60 mil plantas a produtividade foi maior do que com 80 mil plantas no espaçamento de 0,90 m, enquanto que com 0,45 m não houve diferença quanto à densidade populacional.

The objective of this study was to evaluate yield components, leaf nitrogen content and grain yield in corn as affected by row spacing, plant density and nitrogen topdressing. The experiment was conducted with the single-cross hybrid AG 8021, in the municipality of Toledo-PR, in an Oxisoil under no-tillage system, in the crop year 2005/ 2006. The experiment was arranged in a randomized block design and treatments in split-split-plots, with four replications. The two row spacings (0.45 and 0.90 m) were allocated in the main plots, the two plant densities (60,000 and 80,000 plants ha-1) were allocated in the subplots and the three nitrogen rates (80, 100, 120 and 140 kg ha-1 N) were allocated in the sub-subplots. Topdress nitrogen was applied using urea as N source. The rise of the plant population from 60,000 to 80,000 plants ha-1 and the application of topdress nitrogen resulted in increased production components. The application of topdress fertilization provided increase in leaf N content and grain yield for the spacings 0.45 m and 0.90 m. Yield was higher in the spacing 0.45 m than 0.90 m. Yield was higher with 60,000 plants than with 80,000 plants at 0.90 m, while at 0.45 m there was no difference in relation to the plant density.

Objetivou-se avaliar a qualidade fisiológica de sementes de trigo submetidas aos tratamentos com bioestimulante, triadimenol e Azospirillum brasilense. O delineamento utilizado foi inteiramente casualizado, quatro repetições, esquema fatorial 3x8, três cultivares de trigo e oito tratamentos de sementes. As cultivares foram CD-150, CD-116 e CD-104, e os tratamentos foram obtidos da combinação entre: 150 g.L-1 de triadimenol (TRI); 90 mg.L-1 de cinetina + 50 mg.L-1 de ácido giberélico + 50 mg.L-1 de ácido indolbutírico (CGA) e estirpes Ab-V5 e Ab-V6 de A. brasilense na concentração de 2,0 x 10(8) células viáveis mL-1 (AZO), organizados da seguinte forma: testemunha; TRI; CGA; AZO; TRI+CGA; TRI+AZO; CGA+AZO e TRI+CGA+AZO. Foi avaliada a germinação e plântulas anormais (%); comprimento da parte aérea, hipocótilo e raiz; diâmetro do hipocótilo; número de raiz; massa seca da parte aérea e raiz, e a relação raiz/parte aérea. Os resultados evidenciaram que: os tratamentos não influenciaram a germinação; o bioestimulante e Azospirillum brasilense isolados ou em associação proporcionaram incrementos no desenvolvimento inicial de plântulas de trigo, e o triadimenol isolado ou associado com bioestimulante ou A. brasilense proporcionou menores valores de comprimento da parte aérea, hipocótilo, raiz e número de raiz, independente da cultivar testada.

The objective of this study was to evaluate the physiological quality of wheat seed treated with plant growth regulators, triadimenol and Azospirillum brasilense. The experimental design was completely randomized with four replications in a 3x8factorial: three wheat cultivars and eight seed treatments. The cultivars used were CD-150, CD-116 and CD-104, and the treatments were a combination of three different substances: 150 g.L-1 triadimenol (TRI), 90 mg.L-1 kinetin + 50 mg.L-1 giberellic acid + 50 mg.L-1 indolebutyric acid (CGA) and strains Ab-V5 and Ab-V6 of A. brasilense at a concentration of 2.0 x 10(8) viable cells mL-1 (AZO), as follows: control, TRI, CGA, AZO, TRI+CGA, TRI+AZO, AZO+CGA and TRI+CGA+AZO. Germination and abnormal seedlings (%), shoot and hypocotyl length and the diameter, length and number of roots, dry weight of shoot and root/shoot were determined. The results showed that: the treatments did not affect seed germination; the treatments did not increases the early development of wheat seedlings and triadimenol alone or in combination with A. brasilense plant growth regulator resulted in lower values for shoot, root and hypocotyl length and root number for all the cultivars.

A aplicação de gesso para tornar o Al indisponível, assim como para suprir nutrientes do solo para as plantas, pode proporcionar condições para a obtenção de elevada produtividade das culturas. Este trabalho teve como objetivo avaliar o efeito do gesso (0, 1.000, 2.000, 3.000, 4.000 e 5.000 kg ha-1) nas características químicas de duas áreas com Latossolo Vermelho eutroférrico de textura argilosa, com ou sem Al trocável, e na nutrição mineral e produtividade das culturas de trigo e soja em sistema semeadura direta. As doses de gesso foram aplicadas em superfície seis meses após a calagem. Aos seis e 12 meses após a aplicação do gesso, foram coletadas amostras de solo nas profundidades de 0-0,10; 0,10-0,20 e 0,20-0,40 m. O uso de até 5.000 kg ha-1 de gesso resultou em aumento dos teores de Ca2+ e SO4(2-) e lixiviação de K+ até 0,20 m e Mg2+ até 0,40 m de profundidade, um ano após a aplicação, sendo a dose de 3.000 kg ha-1 a que proporcionou maior redução do Al trocável. A aplicação de gesso implicou aumento dos teores foliares de Ca e Mg na cultura da soja, redução dos teores de Ca e Mg na cultura do trigo e aumento no teor de S em ambas as culturas, enquanto o teor de K aumentou até a dose de 3.170 kg ha-1 de gesso na cultura da soja. A utilização do gesso eleva a produtividade do trigo, cultivar CD 104, em solo com presença de Al trocável, mas não influencia a produtividade da soja em ambas os solos, com ou sem Al.

The application of gypsum can make Al unavailable to plants and provide soil nutrients, improving conditions for high crop yields. This study evaluated the chemical characteristics of Red Latosol, with or without exchangeable Al as influenced by gypsum rates (0, 1000, 2000, 3000, 4000, and 5000 kg ha-1) applied to the soil surface, and the effect of gypsum on mineral nutrition and wheat and soybean yields under no-tillage. Gypsum was applied to the surface six months after liming. Six and twelve months after gypsum application, soil samples were collected from the layers 0-0.10, 0.10-0.20 and 0.20-0.40 m. The use of up to 5000 kg ha-1 gypsum resulted in increased levels of Ca2+ and SO4(2-) and leaching of K+ to a depth of 0.20 m and Mg2+ down to 0.40 m, one year after gypsum application. The rate of 3000 kg ha-1 resulted in greatest Al3+ level reduction. The application of gypsum induced increased Ca and Mg contents for soybean and reduced Ca and Mg content in wheat and increased contents of S in both crops, while K contents increased in soybean up to the 3170 kg ha-1 gypsum rate. Gypsum increased wheat yields (cultivar CD 104), in soil with presence of Al, but did not influence soybean yield in either soil, with and without Al.

Inter-simple sequence repeat (ISSR) markers were used to evaluate genetic divergence among eight Coffea species and to identify the parentage of six interspecific hybrids. A total of 14 primers which contained different simple sequence repeats (SSR) were used as single primers or combined in pairs and tested for PCR amplifications. Two hundred and thirty highly reproducible fragments were amplified, which were then used to estimate the genetic similarity and to cluster the Coffea species and hybrids. High levels of interspecific genetic variation were revealed. The dinucleotide motif (GA)9T combined with other di- tri- and tetra-nucleotides produced a greater number of DNA fragments, mostly polymorphics, suggesting a high frequency of the poly GA microsatellite motifs in the Coffea genomes. The genetic similarity ranged from 0.25 between C. racemosa and C. liberica var. dewevrei to 0.86 between C. arabica var. arabica and Hybrid N. 2. The C. arabica species shared most of its markers with five of the six hybrids suggesting that it is the most likely candidate as one of the progenitors of those hybrids. These results revealed that ISSR markers could be efficiently used for genetic differentiation of the Coffea species and to identify the parentage of Coffea interspecific hybrids.

Knowledge of the genetic variability among genotypes is important for the transfer of useful genes and to maximize the use of available germplasm resources. This study was carried out to assess the genetic variability of 14 elite Coffea arabica cultivars using random amplified polymorphic DNA (RAPD) associated with a prior digestion of genomic DNA with restriction endonucleases. The accessions were obtained from the Coffea collection maintained at the Instituto Agronômico do Paraná (IAPAR), located in Londrina, Paraná, Brazil. Twenty-four informative RAPD primers, used in association with restriction enzymes, yielded 330 reproducible and scorable DNA bands, of which 224 (68%) were polymorphic. The amplified products were used to estimate the genetic variability using Dice's similarity coefficient. The data matrix was converted to a dendrogram and a three-dimensional plot using principal coordinate analysis. The accessions studied were separated into clusters in a manner that was consistent with the known pedigree. The associations obtained in the dendrogram and in the principal coordinate analysis plot suggest the probable origin of the Kattimor cultivar. The RAPD technique associated with restriction digestion was proved to be a useful tool for genetic characterization of C. arabica genotypes making an important contribution to the application of molecular markers to coffee breeding.