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The objective of this work was to investigate the impact of pesticides on the survival of the plant growth- promoting bacteria Azospirillum in the surface of coated seeds as well as in the maize rhizosphere. Our results showed that the greater the time that the bacteria are in contact with the seed surface, the higher the cell mortality. In uncoated maize seeds, inoculation increased bacterial concentration in root tissues and ensured superior plant growth up to 12 hours of Azospirillum contact with the seed surface, while for the coated seeds, a similar performance was observed only up to six hours of exposure.

O presente estudo objetivou avaliar o rendimento da cultura e o potencial fisiológico de sementes de milho em resposta a pré-inoculação com Azospirillum brasilense. Quatro doses de inoculante foram aplicadas via tratamento industrial de sementes, 30 dias antes da semeadura. Outros três tratamentos compuseram o ensaio: um contendo metade da recomendação de nitrogênio mineral, o segundo com metade da dose + inoculação momentos antes da semeadura, e um terceiro com a dose total de nitrogênio mineral. Na avaliação da qualidade fisiológica empregaram-se os testes de primeira contagem, germinação, frio modificado, emergência em areia, índice de velocidade de emergência e condutividade elétrica, ao passo que em campo foram avaliados o diâmetro do colmo, massa seca da parte aérea, número de grãos por fileira, número de fileiras por espiga, massa de mil grãos e produtividade. Os delineamentos empregados foram de inteiramente casualizado para qualidade fisiológica e em blocos completos com tratamentos casualizados para ensaio de campo. Independentemente da dose, o inoculante não prejudicou a germinação e vigor das sementes de milho ao longo do armazenamento. Já em relação à produtividade, a inoculação efetuada momentos antes da semeadura assegurou desempenho superior àqueles obtidos quando o inoculante foi aplicado às sementes juntamente com os defensivos.

Although accelerated aging is one of the tests most used for evaluation of the physiological quality of soybean seeds, there are few studies that relate it to other physiological tests used for the crop. In this context, the objective of this study was to investigate the relationship of accelerated aging to the results of physiological performance obtained in the vigor tests most frequently used in the soybean quality control system (germination, first count, seedling vigor classification, accelerated aging, electrical conductivity, emergence speed index, final emergence in sand substrate, and field emergence). The experiment was conducted with seeds that had different vigor levels, adopting a completely randomized experimental design with four replications. Pearson simple correlation analysis (r) and simple linear regression analysis at both 1% and 5% probability were conducted on the data. The results showed that the seedling vigor classification test (r = 0.9160) and the field emergence test (r = 0.9198) were those that best correlated with accelerated aging, followed by the germination (r = 0.8690), first count of germination (r = 0.8460), and electrical conductivity (r = 0.8912) tests.

The objective of this study was to compare the effect of anticipated and traditional inoculation of Bradyrhizobium spp. in industrially treated soybean seeds. The experiment was conducted in a randomized complete block design, with 10 treatments and 4 replications. Different combinations of insecticides and fungicides of industrial treatment of seeds, traditional inoculation and long-term (LT) inoculation, as well as different pre-inoculation periods performed at 0, 5 and 10 days before soybean sowing were evaluated. A treatment containing only nitrogen mineral fertilization and also a control treatment were included. The characteristics number of nodules per plant, seeds Nitrogen content, number of pods per plant, mass of thousand seeds and grain yield were evaluated. Results indicated that LT pre-inoculation combined with fludioxonil and thiamedoxan allowed seed storage up to 10 days without affecting soybean yield components.

As new cultivation techniques arise, crops require the development of new technologies and management practices that aim higher yields with lower production cost. Thus, the objective of this study was to evaluate the efficiency of co-inoculation and different ways of application of Bradyrhizobium japonicum and Azospirillum brasilense and nitrogen fertilization on nodulation and yield of soybean. The experiment was established in November 2013 in an area located in the Iguatemi Experimental Farm, of State University of Maringa (UEM). The design was a randomized block with four replications. The treatments consisted of a control, fertilization with nitrogen (200 kg N ha -1 ), standard inoculation in seeds (liquid and peat inoculant), co-inoculation on seed and co-inoculation at sowing, using different doses of inoculant B. japonicum and A. brasilense. The following determinations were carried out in the field and in the laboratory: number of nodes at flowering, mass of nodules at flowering, the shoot dry mass, nitrogen content in the shoot, grain nitrogen content, number of pods/plant, thousand grain mass and yield. The results showed that inoculation through seed treatment with liquid inoculant presents an adequate option to farmers, in the conditions of this experiment. Nitrogen fertilization did not increase yield and yield components, being unnecessary.

The number of sweet corn cultivars adapted to the climatic conditions and with agronomic traits recommended to the Brazilian market is still limited. Thus, the aim was to investigate the general and specific combining ability (GCA and SCA, respectively) in relation to the grain yield (GY) and total soluble solid (TSS) contents of seven lines of sweet corn (su1) and eight lines of supersweet corn (sh2) by diallel crosses. For TSS, the inbred lines SC6 and SC7 of sweet corn, and SSC7 and SSC8 of supersweet corn showed higher GCA effect. For GY, the inbred lines SC1 and SC2 of sweet corn and SSC4 and SSC6 of supersweet corn showed higher GCA effect. For TSS in sweet corn, the hybrids '4 × 6' and '1 × 7' showed the superior Ŝij estimates across all evaluated environments. For GY, the hybrid '5 × 7' was the most relevant because it showed higher Ŝij estimates in most of the evaluated environments. Additionally, the hybrids '1 × 4', '3 × 4', and '1 × 7' showed positive Ŝij values across all environments. In supersweet corn, the hybrids '2 × 8', '3 × 6', and '5 × 6' should be selected as the most promising for both traits (TSS and GY), because they presented positive and high Ŝij estimates across the six environments. RESUMO O número de cultivares de milho doce adaptada às condições climáticas e com características agronômicas recomendadas para o mercado brasileiro ainda é restrito. Assim, objetivou-se investigar as capacidades de combinações gerais e específicas em relação ao rendimento de grãos (GY) e teor de sólidos solúveis totais (TSS) de sete linhagens de milho doce (su1) e oito linhagens de milho super-doce (sh2) pela análise de cruzamentos dialélicos. Para TSS, as linhagens SC6 e SC7 de milho doce, e SSC7 e SSC8 de milho super-doce apresentaram valores superiores para capacidade geral de combinação. Para rendimento de grãos, as linhagens SC1 e SC2 de milho doce, e SSC4 e SSC6 apresentaram valores superiores para capacidade geral de combinação. TSS em milho doce, os híbridos 4x6 e 1x7 apresentaram as estimativas Ŝijsuperiores em todos os ambientes avaliados. Para GY, o híbrido 5x7 foi o mais relevante pois apresentou amais alta estimativa Ŝij na grande maioria dos ambientes. Além disso, os híbridos 1x4, 3x4 e 1x7 destacaram-se com valores positivos em todos os ambientes. Em milho super-doce, os híbridos 2x8, 3x6 e 5x6 devem ser selecionados como os mais promissores para ambos os caracteres (TSS e GY), pois apresentaram estimativas Ŝij positivas e altas nos seis ambientes.

This study aimed to compare the results of germination, vigor, and yield of high- and low-vigor soybean seeds submitted to on-farm application of biostimulant with its application via industrial treatment 60 days before sowing. The experimental design was a factorial arrangement of 6 × 2 × 2 (technology × vigor level × strategy of biostimulant application) for the laboratory experiment and of 6 × 2 (technology × strategy of biostimulant application) for the field experiment. Germination, accelerated aging, emergence in sand, seedling dry biomass, and electrical conductivity were assessed in the laboratory, while stand, one thousand-grain weight, and yield were assessed in the field. Biostimulant application in soybean seeds not coated with pesticides did not affect the physiological quality regardless of the application moment (at the day of sowing or at 60 days before sowing). However, when applied in seeds coated with fungicides and insecticides, better results of germination, vigor, and yield were obtained with the on-farm use of biostimulant.

The aim of this study was to evaluate the effect of industrial seed treatments on the physiological potential of soybean seeds over storage. Four mixtures of agrochemical products in association with two fertilizers were tested. The agrochemical product mixtures were carbendazim/thiram + imidacloprid/thiodicarb; pyraclostrobin, thiophanate-methyl, and fipronil; thiophanate-methyl/fluazinam + bifenthrin/imidacloprid; and metalaxyl-m/fludioxonil + thiamethoxam. The two fertilizers were 7% N, 16% P2O5, 0.6% Co, and 2.5% Mo; and 1% Co, 10% Mo, and 7% P2 O5. The experiment was carried out in a completely randomized design in a split-plot arrangement in time, with four replications. The treatments were allocated in the plots, while the storage periods (0, 30, 60, 90, and 120 days) constituted the split-plots. The following tests were carried out in each period: first count of germination, germination, accelerated aging, emergence speed index in sand substrate, and final seedling emergence in sand substrate. Seed germination and vigor declined over the storage period, especially after industrial treatment. Pesticide mixtures of a carbendazim/thiram fungicide base and an imidacloprid/thiodicarb insecticide base most impaired seed physiological potential throughout storage, regardless of fertilizer use in the industrial treatment. Resumo: O objetivo no trabalho foi avaliar o efeito do tratamento industrial sobre o potencial fisiológico de sementes de soja durante o armazenamento. Quatro misturas de defensivos agrícolas (carbendazim/thiram + imidacloprido/tiodicarbe; piraclostrobina, tiofanato metílico e fipronil; detiofanato-metílico/fluazinam + bifentrina /imidacloprido e metalaxil-m/fludioxonil + thiamethoxam) associadas a dois fertilizantes (7% N, 16% P2O5, 0,6% Co, 2,5% Mo e 1% Co, 10% Mo e 7% P2O5) foram testadas. Adotou-se o delineamento experimental inteiramente casualizado em parcelas subdivididas no tempo, com quatro repetições. Nas parcelas foram alocados os tratamentos e nas subparcelas os períodos de armazenamento (0, 30, 60, 90 e 120 dias). Em cada período foram realizados os testes de primeira contagem, germinação, envelhecimento acelerado, índice de velocidade de emergência e emergência de plântulas em substrato de areia. A germinação e o vigor das sementes de soja são reduzidos ao longo do armazenamento, sobretudo após o tratamento industrial. Caldas à base de carbendazim/thiram + imidacloprido/tiodicarbe prejudicam o potencial fisiológico das sementes ao longo do armazenamento, independentemente do emprego de fertilizantes no tratamento industrial.

EnglishThe aim of this study was to evaluate popcorn genotypes for resistance to the fall armyworm, Spodoptera frugiperda. The experiment used a completely randomized design with 30 replicates. The popcorn genotypes Aelton, Arzm 05 083, Beija-Flor, Colombiana, Composto Chico, Composto Gaucha, Marcia, Mateus, Ufvm Barao Vicosa, Vanin, and Viviane were evaluated,along with the common maize variety Zapalote Chico. Newly hatched fall armyworm larvae were individually assessed with regard to biological development and consumption of food. The data were subjected to multivariate analyses of variance and genetic divergence among genotypes was evaluated through the clustering methods of Tocher based on generalized Mahalanobis distances and canonical variable analyses. Seven popcorn genotypes, namely, Aelton, Arzm 05 083, Composto Chico, Composto Gaucha, Marcia, Mateus, and Viviane,were shown to form a cluster (cluster I) that had antibiosis as the mechanism of resistance to the pest. Cluster I genotypes and the Zapalote Chico genotype could be used for stacking genes for antibiosis and non-preference resistance. Key words: antibiosis; nutrition index; plant breeding; Spodoptera frugiperda portuguesO objetivo do estudo foi avaliar genotipos de milho pipoca para resistencia a lagarta-do-cartucho, Spodoptera frugiperda. O experimento foi conduzido em delineamento inteiramente casualizado com 30 repeticoes. Foram avaliados os genotipos de milho pipoca Aelton, Arzm 05 083, Beija-Flor, Colombiana, Composto Chico, Composto Gaucha, Marcia, Mateus, Ufvm Barao Vicosa, Vanin, Viviane e Zapalote Chico. Larvas recem-eclodidas foram individualizadas para avaliacao do desenvolvimento biologico e consumo alimentar. Os dados foram submetidos a analise multivariada de variância e a divergencia genetica entre genotipos foi avaliada atraves dos metodos de agrupamento de Tocher, com base na distância generalizada de Mahalanobis e analise de variaveis canonicas. Sete genotipos,Aelton, Arzm 05 083, Composto Chico, CompostoGaucha, Marcia, Mateus e Viviane formaram um cluster (cluster I) que apresentaram antibiose com o mecanismo de resistencia a praga. Os genotipos do cluster I e Zapalote Chico podem ser usados para empilhar genes para resistencia por antibiose e nao-preferencia. Palavras-chave: antibiose; melhoramento de plantas; Spodoptera frugiperda

Industrial seed treatment assures uniform coverage of seeds with insecticides, fungicides, micronutrients and bioestimulant at precise dose, however often resulting in higher slurry volume. Furthermore, seeds are coated long periods of time prior sowing and may influence germination and vigor. Thus, the aim of this work was to evaluate the influence of seven industrial seed treatments and their respective slurry volumes on the physiological potential of soybean seeds at 0, 15, 30, 45, 60 and 90 days of storage. In each storage period, the variables germination, accelerated aging test and emergency speed index were evaluated and studied in the repeated measures in time model. The products used were: fungicide (thiabendazole, fludioxonil and mefenoxam), insecticide (thiametoxam), insecticide/nematicide (abamectin), micronutrients (cobalt and molybdenum), bioregulator, drying powder and polymer. High volumes of seed-coating mixtures reduce the physiological quality of soybean seeds over storage. However, the slurry composition also influenced on the maintenance of the seed germination and vigor throughout the storage.

RESUMO - A inoculacao das sementes com Azospirillum spp. e uma pratica que tem sido rotineiramente realizada no milho, sobretudo via formulacao liquida. Todavia, as respostas relativas a outros modos de inoculacao com diferentes formulacoes sao, ainda, pouco conhecidas. Desta forma, objetivou-se com este trabalho avaliar a eficiencia agronomica de doses de A. brasilense em formulacao polimerica em po, aplicada diretamente na caixa semeadora, sobre os componentes da produtividade do milho. Para tanto, foi conduzido um ensaio em blocos casualisados, com quatro repeticoes. Os tratamentos consistiram de uma testemunha, dose total de N, ½ dose de N; ½ dose de N + inoculacao comercial padrao e ½ dose de N + quatro doses de inoculante em po (1, 2, 4 e 8 g kg-1), aplicado na caixa semeadora. Foram avaliados os caracteres produtividade, numeros de fileira por espiga e de graos por fileira, massa de mil graos, materia seca da parte aerea e teores de N nos graos e na parte aerea. Nas condicoes testadas, a dose de 2 g kg-1 de sementes do inoculante, quando associada a adubacao nitrogenada de 90 kg ha-1, apresentou superioridade no rendimento da cultura, ultrapassando, inclusive, a inoculacao comercial com produto liquido. Palavras-chave: Zea mays, fixacao biologica, inoculante, rendimento. MAIZE YIELD IN RESPONSE TO THE APLICATION OF Azospirillum spp. INTO THE SEED TANK ABSTRACT - Seed inoculation with Azospirillum spp . is a practice that has been routinely carried out in maize crop, especially via liquid formulation. However, responses concerning other methods of inoculation of different formulations are still poorly understood. The objective of this work was to evaluate the agronomic efficiency of the application of powder formulation of Azospirillum brasilense directly into the sowing box. For this purpose, a randomized block trial with 4 replications was carried out. The treatments tested consisted of absence of N fertilizer, the full N recommendation and a combination of the half of recommended N associated with the inoculation of four doses of A. brasilense (1, 2, 4 and 8 g kg-1) in powder formulation. The following variables were evaluated: number of kernel per row, number of row per ear, shoot dry biomass, thousand seed weight, grain N content, shoot N content and grain yield. All treatments submitted to inoculation with the powder formulation showed higher yields than the treatment in which the total dose of N was applied. However, superior results were obtained for the treatment in which ½ dose of N was associated with the powder inoculant in the proportion of 2 g kg-1 of seed. Keywords: Zea mays , biological fixation, inoculant, productivity.

Current study evaluates the effects of bio-regulator associated with foliar fertilizers on the yield components, productivity and chemical composition of soybean. The experimental design was entirely randomized blocks, with four replications. The treatments consisted of: T1-absolute control, T2-application of 0.25 L h(-1) Stimulate in R1 stage of development, T3-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1, T4-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1; T5-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 2 L h(-1) Mover in R5.1, T6-application of 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1 and T7-application of 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R1. Application of Sett and Mover is a potentially efficient handling as it favors the soybean agronomic performance in R1 stage. Chemical composition of processed grains has influence with applying bio-regulator and foliar fertilizers.

The aim of the study was to evaluate seed germination and vigor of maize subjected to different products and storage periods. The experimental design was completely randomized in a split plot on time. In the plots were distributed nine treatments: an untreated control, one treatment called “standard treatment”, with addition of fungicide (fludioxonil + metalaxyl-M) and insecticide (thiamethoxam). From the standard treatment, six treatments with combinations of inoculant (Azospirillum brasilense), micronutrients (nitrogen + potassium + zinc + boron + copper + iron + manganese + molibdenium) and bioregulator. Lastly, a treatment called “complete treatment” including all products. In subplots the storage periods of zero, 15, 30, 45, 60 and 90 days were evaluated. Seed vigour of maize was reduced by seed treatments and storage. Micronutrients addition resulted in higher fitotoxicity in comparison to the addition of other products, regardless of storage period. The treatment with the combination of fungicide, insecticide and inoculant proved to be feasible, and was the most promising seed treatments. None of the studied treatments affected the germination in up to 45 days of storage, however the complete treatment with 3200 mL .100 kg-1 reduced seed vigour. Resumo: O objetivo do trabalho foi avaliar a germinação e vigor das sementes de milho submetidas a diferentes produtos e períodos de armazenamento. O delineamento experimental foi inteiramente casualizado em esquema de parcelas subdivididas no tempo. Na parcela foram distribuídos nove tratamentos: uma testemunha não tratada, um tratamento denominado de “tratamento padrão”, com adição de fungicida (fludioxonil + metalaxyl-M) e inseticida (thiamethoxam). A partir do tratamento padrão, seis tratamentos com combinações de inoculante (Azospirillum brasilense), micronutrientes (nitrogen + potassium + zinc + boron + copper + iron + manganese + molibdenium) e biorregulador. Por fim, um tratamento denominado de “tratamento completo”, incluindo todos os produtos. Na subparcela, os períodos de armazenamento 0, 15, 30, 45, 60 e 90 dias foram avaliados. O vigor das sementes de milho foi reduzido pelos tratamentos de sementes e pelo armazenamento. A adição de micronutrientes resultou em maior fitotoxicidade em comparação à adição de outros produtos, independente do período de armazenamento. O uso de fungicida, inseticida e inoculante se mostram viáveis, como os mais promissores tratamentos de sementes. Nenhum dos tratamentos estudados afetaram a germinação até 45 dias de armazenamento, porém o tratamento completo, com 3200 mL. 100 kg-1 reduziu o vigor de sementes.