RESUMO

Seed treatment with plant growth-promoting bacteria represents the primary strategy to incorporate them into agricultural ecosystems, particularly for crops under extensive management, such as maize. In this study, we evaluated the seed bacterization levels, root colonization patterns, and root competitiveness of a collection of autochthonous Pseudomonas isolates that have demonstrated several plant-probiotic abilities in vitro. Our findings indicate that the seed bacterization level, both with and without the addition of various protectants, is specific to each Pseudomonas strain, including their response to seed pre-hydration. Bacterization kinetics revealed that while certain isolates persisted on seed surfaces for up to 4 days post-inoculation (dpi), others experienced a rapid decline in viability after 1 or 2 dpi. The observed differences in seed bacterization levels were consistent with the root colonization densities observed through confocal microscopy analysis, and with root competitiveness quantified via selective plate counts. Notably, isolates P. protegens RBAN4 and P. chlororaphis subsp. aurantiaca SMMP3 demonstrated effective competition with the natural microflora for colonizing the maize rhizosphere and both promoted shoot and root biomass production in maize assessed at the V3 grown stage. Conversely, P. donghuensis SVBP6 was detected at very low levels in the maize rhizosphere, but still exhibited a positive effect on plant parameters, suggesting a growth-stimulatory effect during the early stages of plant development. In conclusion, there is a considerable strain-specific variability in the maize seed bacterization and survival capacities of Pseudomonas isolates with plant-probiotic traits, with a correlation in their root competitiveness under natural conditions. This variability must be understood to optimize their adoption as inputs for the agricultural system. Our experimental approach emphasizes the critical importance of tailoring seed bacterization treatments for each inoculant candidate, including the selection and incorporation of protective substances. It should not be assumed that all bacterial cells exhibit a similar performance.

RESUMO

Amid concerns on the myriad of existing chemical stressors in agroecosystems, pesticides and particularly neonicotinoid insecticides are in the forefront. Despite that, these neurotoxic compounds remain the dominant group of insecticides in worldwide use with the added versatility of use in seed coatings. Such use sparks environmental concerns counterbalanced by their reported insecticidal efficacy and potential plant bioactivation. Nonetheless, this alleged double benefit and interconnection expected with neonicotinoids has been little explored particularly when the whole plant phenology is considered. Regardless of the expected efficacy against targeted insect pest species, like whiteflies, neonicotinoids may spark dual effect on plants - negative at higher concentrations, positive at low concentrations, which is consistent with the hormesis phenomenon that may be expressed as a plant bioactivation. This effect may also cascade to the targeted insect species, what deserves attention. Therefore, soybean seeds treated with increasing concentrations of the neonicotinoid thiamethoxam were followed throughout their development in greenhouse, recording the plant response and yield, besides their effect in whiteflies (Bemisia tabaci MEAM1). Thiamethoxam application was correlated to leaf contents of thiamethoxam and its metabolite clothianidin. Plant hormesis was found for leaf area and root growth, but not for other plant morphological or physiological parameters, nor plant yield. The insecticide concentration-dependency compromised whitefly population growth without evidence of cascading any plant-mediated hormesis to the insects. Thus, although plant hormesis was recognized with thiamethoxam in treated soybean seeds in relevant parameters, no evidence of plant bioactivation was observed to justify its use with such a secondary objective, nor did this hormesis impair whitefly control.

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Zinc (Zn) is a micronutrient considered essential to plants which can be supplied through seed treatment. The treatment of soybean [Glycine max (L.) Merr.] seeds with Zn, however, is still not well known as regards the uptake and mobilization dynamics of the nutrient during the germination process. This study aimed to evaluate the uptake and distribution dynamics of Zn applied to soybean seeds at two levels of vigor during germination using X-ray micro-fluorescence spectroscopy (µ-XRF). Zinc treatments corresponded to 0, 2, 4 and 8 g of Zn per kg of seeds. High and low vigor seeds that had been treated were located appropriately so as to promote germination. Zn intensity measurements with µ-XRF were taken in different parts ("regions") of the seeds (seed coat, cotyledon, and embryonic axis) after 8, 16 and 24 h of imbibition and seedlings (primary root, hypocotyl, plumule, cotyledon, and seed coat) after 48, 72 and 96 h of germination. High vigor seeds showed higher Zn intensity in the embryonic axis in the first 16 h, while low vigor seeds showed higher intensity after 24 h. After 48, 72 and 96 h of germination low vigor seedlings showed higher Zn intensity than high vigor seedlings in the primary root. It was concluded that µ-XRF is an efficient technique for identifying variances in the dynamics of Zn uptake and mobilization during the germination of soybean seeds with different vigor levels.

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RESUMO

The present study aimed to evaluate the effect of seed coating with Si in response to infection in a cultivar susceptible and resistant to Colletotrichum lindemuthianum, on the physiological and health potential of seeds and seedlings, during the initial development of bean culture. The experiment was carried out in a completely randomizeddesign, in a 2 × 2 × 2 factorial scheme, with four replications, where the factors were: cultivar (BRS Esplendor and IPR Tuiuiú), silicate application (with and without Agrosilício® coating) and inoculation (seeds inoculated or not with C. lindemuthianum). In the evaluation of the initial development of the culture, the following variables were measured: germination, first count of the germination test, emergence, emergence speed index (IVE), total seedling length, shoot and root length, total dry mass, aerial part dry matter, root dry matter and aerial part dry matter at 15 days after sowing (DAS). The incidence of C. lindemuthianumin beans was determined by the paper roll method. Covering the seeds with Si reduces the incidence and severity of C. lindemuthianumand provides greater growth of bean seedlings. The effect of responses potentiated by Si is more expressive in the cultivar of greater susceptibility.

O presente trabalho teve por objetivo, avaliar o efeito do recobrimento de sementes com Si em resposta à infecção em uma cultivar suscetível e resistente ao Colletotrichumlindemuthianum, sobre o potencial fisiológico e sanitário de sementes e plântulas, durante o desenvolvimento inicial da cultura do feijão. O experimento foi realizado em delineamento inteiramente casualizado, em esquema fatorial 2 × 2 × 2, com quatro repetições, onde os fatores foram: cultivar (BRS Esplendor e a IPR Tuiuiú), aplicação de silicato (com e sem recobrimento com Agrosilício®) e inoculação (sementes inoculadas ou não com C. lindemuthianum). Na avaliação do desenvolvimento inicial da cultura foram mensuradas as seguintes variáveis: germinação, primeira contagem do teste de germinação, emergência, índice da velocidade de emergência (IVE), comprimento total da plântula, comprimento de parte aérea e de raiz, massa seca total, massa seca de parte aérea, massa seca de raiz e massa seca de parte aérea aos 15 dias após semeadura (DAS). A incidência de C. lindemuthianumem feijão foi determinada pelo método do rolo de papel. O recobrimento das sementes com Si diminui a incidência e a severidade de C. lindemuthianume proporciona maior crescimento das plântulas de feijão. O efeito de respostas potencializadas pelo Si tem maior expressividade na cultivar de maior suscetibilidade.

Assuntos

RESUMO

The present study aimed to evaluate the effect of seed coating with Si in response to infection in a cultivar susceptible and resistant to Colletotrichum lindemuthianum, on the physiological and health potential of seeds and seedlings, during the initial development of bean culture. The experiment was carried out in a completely randomizeddesign, in a 2 × 2 × 2 factorial scheme, with four replications, where the factors were: cultivar (BRS Esplendor and IPR Tuiuiú), silicate application (with and without Agrosilício® coating) and inoculation (seeds inoculated or not with C. lindemuthianum). In the evaluation of the initial development of the culture, the following variables were measured: germination, first count of the germination test, emergence, emergence speed index (IVE), total seedling length, shoot and root length, total dry mass, aerial part dry matter, root dry matter and aerial part dry matter at 15 days after sowing (DAS). The incidence of C. lindemuthianumin beans was determined by the paper roll method. Covering the seeds with Si reduces the incidence and severity of C. lindemuthianumand provides greater growth of bean seedlings. The effect of responses potentiated by Si is more expressive in the cultivar of greater susceptibility.(AU)

O presente trabalho teve por objetivo, avaliar o efeito do recobrimento de sementes com Si em resposta à infecção em uma cultivar suscetível e resistente ao Colletotrichumlindemuthianum, sobre o potencial fisiológico e sanitário de sementes e plântulas, durante o desenvolvimento inicial da cultura do feijão. O experimento foi realizado em delineamento inteiramente casualizado, em esquema fatorial 2 × 2 × 2, com quatro repetições, onde os fatores foram: cultivar (BRS Esplendor e a IPR Tuiuiú), aplicação de silicato (com e sem recobrimento com Agrosilício®) e inoculação (sementes inoculadas ou não com C. lindemuthianum). Na avaliação do desenvolvimento inicial da cultura foram mensuradas as seguintes variáveis: germinação, primeira contagem do teste de germinação, emergência, índice da velocidade de emergência (IVE), comprimento total da plântula, comprimento de parte aérea e de raiz, massa seca total, massa seca de parte aérea, massa seca de raiz e massa seca de parte aérea aos 15 dias após semeadura (DAS). A incidência de C. lindemuthianumem feijão foi determinada pelo método do rolo de papel. O recobrimento das sementes com Si diminui a incidência e a severidade de C. lindemuthianume proporciona maior crescimento das plântulas de feijão. O efeito de respostas potencializadas pelo Si tem maior expressividade na cultivar de maior suscetibilidade.(AU)

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RESUMO

Visto que a cada ano são lançados novos produtos para o tratamento de sementes, pesquisas que visem determinar o desempenho de sementes de soja tratadas com diferentes combinações de produtos ao longo do armazenamento apresentam relevância para o mercado de sementes. Diante disso, objetivou-se avaliar o efeito do tratamento de sementes com diferentes agroquímicos durante o armazenamento de duas cultivares de soja. Foram conduzidos estudos independentes para cada cultivar, utilizando o delineamento experimental inteiramente casualizado com esquema de parcelas subdivididas, sendo a parcela constituída pela combinação dos produtos no tratamento das sementes (T1-Maxim Advanced; T2-Maxim Advanced + Cruiser; T3-Cruiser+ Amulet + Maxim Advanced; T4-Avicta + Cruiser + Maxim Advanced; T5-Maxim Advanced + Cruiser + A17960; T6-Cropstar + Derosal Plus; T7-Standak Top; T8-Dermacor + Derosal Plus; T9-Dermacor + Derosal Plus + Cruiser; T10-Cruiser Opti + Maxim Advanced) e a subparcela composta pelos períodos de armazenamento (0, 45, 90, 135 e 180 dias). O potencial fisiológico das sementes tratadas foi avaliado por meio do teste de germinação, teste de envelhecimento acelerado e emergência em canteiro. Com base nos resultados obtidos, conclui-se que as combinações de produtos com thiametoxam em sua formulação apresenta, no geral, menor redução da qualidade fisiológica ao longo do armazenamento. As sementes tratadas com os produtos combinados de Imidacloprido+Tiodicarbe e Carbendazim+Thiram reduzem o potencial fisiológico das sementes ao longo do período de armazenamento.(AU)

Since new seed treatment products are launched each year, research aimed at determining the soybean seeds treated performance with different combinations of these products throughout the storage are important for the seed market. The objective of this study was to evaluate the effect of seed treatment with different products during the storage of two soybean cultivars. Independent studies were conducted for each cultivar, using a completely randomized experimental design in a split plots. The plot consisted of the combination of the products in the seed treatment((T1-Maxim Advanced; T2-Maxim Advanced + Cruiser; T3-Cruiser + Amulet + Maxim Advanced; T4-Avicta + Cruiser + Maxim Advanced; T5-Maxim Advanced + Cruiser + A17960; T6-Cropstar + Derosal Plus; T7-Standak Top; T8-Dermacor + Derosal Plus; T9-Dermacor + Derosal Plus + Cruiser; and T10-Cruiser Opti + Maxim Advanced) and the subplot constituting of storage periods (0, 45, 90, 135 and 180 days). The physiological quality evaluation of treated seeds was carried out through germination, accelerated aging, and emergence tests. Based on the results obtained, it is concluded that the combinations of products with thiamethoxam in its formulation show, in general, lower reduction of the physiological quality throughout the storage. Seeds treated with the combined products of Imidacloprid + Thiodicarb and Carbendazim + Thiram reduce the physiological potential of the seeds over the storage period.(AU)

Assuntos

RESUMO

Visto que a cada ano são lançados novos produtos para o tratamento de sementes, pesquisas que visem determinar o desempenho de sementes de soja tratadas com diferentes combinações de produtos ao longo do armazenamento apresentam relevância para o mercado de sementes. Diante disso, objetivou-se avaliar o efeito do tratamento de sementes com diferentes agroquímicos durante o armazenamento de duas cultivares de soja. Foram conduzidos estudos independentes para cada cultivar, utilizando o delineamento experimental inteiramente casualizado com esquema de parcelas subdivididas, sendo a parcela constituída pela combinação dos produtos no tratamento das sementes (T1-Maxim Advanced; T2-Maxim Advanced + Cruiser; T3-Cruiser+ Amulet + Maxim Advanced; T4-Avicta + Cruiser + Maxim Advanced; T5-Maxim Advanced + Cruiser + A17960; T6-Cropstar + Derosal Plus; T7-Standak Top; T8-Dermacor + Derosal Plus; T9-Dermacor + Derosal Plus + Cruiser; T10-Cruiser Opti + Maxim Advanced) e a subparcela composta pelos períodos de armazenamento (0, 45, 90, 135 e 180 dias). O potencial fisiológico das sementes tratadas foi avaliado por meio do teste de germinação, teste de envelhecimento acelerado e emergência em canteiro. Com base nos resultados obtidos, conclui-se que as combinações de produtos com thiametoxam em sua formulação apresenta, no geral, menor redução da qualidade fisiológica ao longo do armazenamento. As sementes tratadas com os produtos combinados de Imidacloprido+Tiodicarbe e Carbendazim+Thiram reduzem o potencial fisiológico das sementes ao longo do período de armazenamento.

Since new seed treatment products are launched each year, research aimed at determining the soybean seeds treated performance with different combinations of these products throughout the storage are important for the seed market. The objective of this study was to evaluate the effect of seed treatment with different products during the storage of two soybean cultivars. Independent studies were conducted for each cultivar, using a completely randomized experimental design in a split plots. The plot consisted of the combination of the products in the seed treatment((T1-Maxim Advanced; T2-Maxim Advanced + Cruiser; T3-Cruiser + Amulet + Maxim Advanced; T4-Avicta + Cruiser + Maxim Advanced; T5-Maxim Advanced + Cruiser + A17960; T6-Cropstar + Derosal Plus; T7-Standak Top; T8-Dermacor + Derosal Plus; T9-Dermacor + Derosal Plus + Cruiser; and T10-Cruiser Opti + Maxim Advanced) and the subplot constituting of storage periods (0, 45, 90, 135 and 180 days). The physiological quality evaluation of treated seeds was carried out through germination, accelerated aging, and emergence tests. Based on the results obtained, it is concluded that the combinations of products with thiamethoxam in its formulation show, in general, lower reduction of the physiological quality throughout the storage. Seeds treated with the combined products of Imidacloprid + Thiodicarb and Carbendazim + Thiram reduce the physiological potential of the seeds over the storage period.

Assuntos

RESUMO

The objective of this study was to develop biodegradable coatings for agriculture crop seeds based on starch, gelatin, and polyvinyl alcohol (PVA). Developed materials were characterized according to their microstructures, barrier properties, influence on germination of maize seeds, and ability to sustain Azospirillum brasilense Ab-V5 viability in coated maize seeds. The coatings were obtained employing different proportions of starch, gelatin, and PVA, ranging from 0 to 3.0 g/100 g of each material, respectively. Samples formulated with the pure polymers showed the highest values of water absorption capacity, solubility, and water vapor permeability, and the ternary mixtures showed the lowest values. Single polymer formulations and the binary starch-gelatin mixture (CS50GL50) favored maize seeds germination compared to the uncoated maize seeds. In addition, seed coating obtained from CS50GL50 formulation resulted in A. brasilense Ab-V5 viability in coated seeds up to 15 days after bacterial immobilization, being considered a promising low-cost, biodegradable, and renewable source material to be used in agriculture.

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RESUMO

Objetivou-se avaliar o teor de proteínas em sementes de soja produzidas em solos de várzea a partir da aplicação de biorregulador via tratamento de sementes e aplicação foliar. O trabalho foi dividido em dois experimentos, tratamento de sementes (Experimento I) e aplicação foliar (Experimento II) com diferentes doses de Stimulate®, sendo utilizado duas cultivares de soja (BMX Potência RR e Fundacep 64 RR,) e delineamento experimental inteiramente casualizado para ambos os experimentos. Para o tratamento de sementes foi utilizado as doses de 0;250;500;750 e 1000 mL 100 kg sementes-1, já para a aplicação foliar utilizou-se as doses de 0; 187,5; 375,0; 652,5 e 750,0 mL ha-1, sendo os experimentos conduzidos no campo e em vasos na safra agrícola de 2013/2014. Os experimentos foram conduzidos até a fase de maturação de campo, sendo realizada a colheita das sementes e, posteriormente, determinado o teor de proteína total e solúvel. As doses de biorregulador aplicadas no tratamento das sementes, até a maior dose aplicada, proporcionam aumentos no teor de proteína bruta das sementes produzidas em vasos da cultivar BMX Potência RR. Quando produzidas em campo, as doses de biorregulador, via tratamento de sementes e aplicação foliar, não promovem diferença significativa no teor de proteína das sementes. Ainda se constatou acréscimos no teor de proteína total na cultivar Fundacep 64 RR, e redução no teor de proteína solúvel na cultivar BMX Potência RR com uso de biorregulador, independentemente do modo de aplicação.(AU)

This study aimed to evaluate the protein content in soybean seeds produced in lowland soil from plant growth regulator applied via seed coating and leaf spraying. The study was divided into two experiments: Seeds coating (Experiment I) and leaf spraying (Experiment II) with different Stimulate® doses. Two soybean cultivars were used (BMX Potência RR and Fundacep 64 RR) and the experimental model used was a completely randomized design. For the seed coating, the doses used was 0; 250; 500; 750 e 1000 mL 100 kg seeds-1, and for the leaf spraying was 0; 187.5; 375.0; 652.5 e 750.0 mL ha-1. The experiments were carried out during the 2013/2014 season at experimental field and pots. In the maturity period was performed the seed harvest, afterward determined the total and soluble protein content. The bioregulator doses applied in seed treatment, up to the highest dose, increase the crude protein content of seeds produced in pots of BMX Potência RRcv. When produced in the experimental field, doses of bioregulator in seed treatment and leaf spraying do not promote difference in the protein content of the seeds. Increases were observed in the total protein content in Fundacep 64 RR cultivar, and reduction in soluble protein content in BMX Potência RR with the use of bioregulator, regardless of the mode of application.(AU)

RESUMO

Objetivou-se avaliar o teor de proteínas em sementes de soja produzidas em solos de várzea a partir da aplicação de biorregulador via tratamento de sementes e aplicação foliar. O trabalho foi dividido em dois experimentos, tratamento de sementes (Experimento I) e aplicação foliar (Experimento II) com diferentes doses de Stimulate®, sendo utilizado duas cultivares de soja (BMX Potência RR e Fundacep 64 RR,) e delineamento experimental inteiramente casualizado para ambos os experimentos. Para o tratamento de sementes foi utilizado as doses de 0;250;500;750 e 1000 mL 100 kg sementes-1, já para a aplicação foliar utilizou-se as doses de 0; 187,5; 375,0; 652,5 e 750,0 mL ha-1, sendo os experimentos conduzidos no campo e em vasos na safra agrícola de 2013/2014. Os experimentos foram conduzidos até a fase de maturação de campo, sendo realizada a colheita das sementes e, posteriormente, determinado o teor de proteína total e solúvel. As doses de biorregulador aplicadas no tratamento das sementes, até a maior dose aplicada, proporcionam aumentos no teor de proteína bruta das sementes produzidas em vasos da cultivar BMX Potência RR. Quando produzidas em campo, as doses de biorregulador, via tratamento de sementes e aplicação foliar, não promovem diferença significativa no teor de proteína das sementes. Ainda se constatou acréscimos no teor de proteína total na cultivar Fundacep 64 RR, e redução no teor de proteína solúvel na cultivar BMX Potência RR com uso de biorregulador, independentemente do modo de aplicação.

This study aimed to evaluate the protein content in soybean seeds produced in lowland soil from plant growth regulator applied via seed coating and leaf spraying. The study was divided into two experiments: Seeds coating (Experiment I) and leaf spraying (Experiment II) with different Stimulate® doses. Two soybean cultivars were used (BMX Potência RR and Fundacep 64 RR) and the experimental model used was a completely randomized design. For the seed coating, the doses used was 0; 250; 500; 750 e 1000 mL 100 kg seeds-1, and for the leaf spraying was 0; 187.5; 375.0; 652.5 e 750.0 mL ha-1. The experiments were carried out during the 2013/2014 season at experimental field and pots. In the maturity period was performed the seed harvest, afterward determined the total and soluble protein content. The bioregulator doses applied in seed treatment, up to the highest dose, increase the crude protein content of seeds produced in pots of BMX Potência RRcv. When produced in the experimental field, doses of bioregulator in seed treatment and leaf spraying do not promote difference in the protein content of the seeds. Increases were observed in the total protein content in Fundacep 64 RR cultivar, and reduction in soluble protein content in BMX Potência RR with the use of bioregulator, regardless of the mode of application.

RESUMO

We aimed to unravel the events which favor the seed-rhizobacterium Bacillus amyloliquefaciens strain ALB629 (hereafter ALB629) interaction and which may interfere with the rhizobacterium colonization and growth on the spermosphere of common bean. Seed exudates from common bean were tested in vitro for ALB629 biofilm formation and bacterial growth. Furthermore, the performance of ALB629 on plant-related variables under drought stress was checked. Seed exudates (1 and 5% v/v) increased ALB629 biofilm formation. Additionally, the colony forming units for ALB629 increased both in culture and on the bean seed surface. The bean seed exudates up-regulated biofilm operons in ALB629 TasA and EpsD by ca. two and sixfold, respectively. The high-performance liquid chromatography (HPLC)-coupled with MS showed that malic acid is present as a major organic acid component in the seed exudates. Seeds treated with ALB629 and amended with malic acid resulted in seedlings with a higher bacterial concentration, induced plant drought tolerance, and promoted plant growth. We showed that seed exudates promote growth of ALB629 and malic acid was identified as a major organic acid component in the bean seed exudates. Our results also show that supplementation of ALB629 induced drought tolerance and growth in plants. The research pertaining to the biological significance of seed exudates in plant-microbe interaction is unexplored field and our work shows the importance of seed exudates in priming both growth and tolerance against abiotic stress.

RESUMO

O objetivo desse estudo foi avaliar a resposta de sementes revestidas e não revestidas em duas condições hídricas, quanto à germinação e o desempenho inicial de plântulas. O experimento foi realizado no Laboratório de Análise de Sementes da Universidade do Oeste Paulista (UNOESTE), utilizando sementes comerciais revestidas e não revestidas de Panicum maximum Jacp. cv. Tanzânia. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 2 x 2, com quatro repetições, sendo 2 tipos de sementes (revestidas e não revestidas) e dois potenciais hídricos (0 e -0,6 MPa). Avaliou-se: germinação de sementes, comprimento da parte aérea e raiz e suas massas de matéria seca. A diferença de potencial hídrico reduz a germinação independente do tipo de sementes. A germinação das sementes revestidas foi superior às sementes não revestidas. Em condição de restrição hídrica as sementes revestidas proporcionam plântulas com maior crescimento de parte aérea. Em condição de disponibilidade de água proporcionaram menor crescimento de raiz.(AU)

The aim of this study was to evaluate the coated seeds response and uncoated two water conditions for germination and early seedling performance. The experiment was conducted at the Seed Analysis Laboratory of the Universidade do Oeste Paulista (UNOESTE) using coated and uncoated commercial seed of Panicum maximum Jacp. cv. Tanzania. We used a completely randomized design in a factorial 2 x 2, with four replications, with 2 types of seeds (coated and uncoated) and two water potential (0 and -0.6 MPa). Were evaluated: seed germination, shoot length and root and its mass of dry matter. The difference in water potential reduces germination independent of the type of seed. Germination of the pelleted seed was superior to uncoated seeds. In water stress condition the coated seeds provide seedlings with greater shoot growth. In conditions of water availability provided lower root growth.(AU)

Assuntos

RESUMO

O objetivo desse estudo foi avaliar a resposta de sementes revestidas e não revestidas em duas condições hídricas, quanto à germinação e o desempenho inicial de plântulas. O experimento foi realizado no Laboratório de Análise de Sementes da Universidade do Oeste Paulista (UNOESTE), utilizando sementes comerciais revestidas e não revestidas de Panicum maximum Jacp. cv. Tanzânia. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 2 x 2, com quatro repetições, sendo 2 tipos de sementes (revestidas e não revestidas) e dois potenciais hídricos (0 e -0,6 MPa). Avaliou-se: germinação de sementes, comprimento da parte aérea e raiz e suas massas de matéria seca. A diferença de potencial hídrico reduz a germinação independente do tipo de sementes. A germinação das sementes revestidas foi superior às sementes não revestidas. Em condição de restrição hídrica as sementes revestidas proporcionam plântulas com maior crescimento de parte aérea. Em condição de disponibilidade de água proporcionaram menor crescimento de raiz.

The aim of this study was to evaluate the coated seeds response and uncoated two water conditions for germination and early seedling performance. The experiment was conducted at the Seed Analysis Laboratory of the Universidade do Oeste Paulista (UNOESTE) using coated and uncoated commercial seed of Panicum maximum Jacp. cv. Tanzania. We used a completely randomized design in a factorial 2 x 2, with four replications, with 2 types of seeds (coated and uncoated) and two water potential (0 and -0.6 MPa). Were evaluated: seed germination, shoot length and root and its mass of dry matter. The difference in water potential reduces germination independent of the type of seed. Germination of the pelleted seed was superior to uncoated seeds. In water stress condition the coated seeds provide seedlings with greater shoot growth. In conditions of water availability provided lower root growth.

Assuntos

RESUMO

Brassica oleracea var italica occupies a special place in the internal and external market of vegetables seeds. Vegetables producers demand seeds with high degree of purity, germination and vigor, since seeds' quality is the basis for the success of the production. In this work, broccoli seeds were coated in a spouted bed, by an aqueous suspension of hidroxy-ethyl-cellulose. Effects of the operating variables: spouting air temperature, atomizing air pressure and coating suspension flow rate over the dependent variables: seeds germination, seeds accelerated aging and the speed of seeds germination in soil, were investigated in a factorial scheme trial. The maximum processing time was 120 min. A totally randomized experiment evaluated and compared seeds germination and vigor of the coated and non-coated seeds. There was no identifiable, pronounced difference on germination of coated and non-coated seeds, accelerated aging of seeds, and speed of seeds germination in the soil. Coating with hidroxy-ethyl-cellulose in the spouted bed did not alter broccoli seeds physiologic quality. The surface of coated seeds presented satisfactory distribution and spreading of the polymer film, uniform and individual coating and homogeneous aspect.

Dentre as sementes de hortaliças comercializadas no mercado interno e externo, a Brassica oleracea var. itálica ocupa lugar de destaque. Os produtores de hortaliças têm exigido sementes com alto grau de pureza, germinação e vigor, uma vez que a qualidade das sementes é considerada a base para o sucesso do sistema de produção. Neste trabalho foi avaliado o recobrimento de sementes de brócolos em leito de jorro, utilizando uma suspensão aquosa de hidroxi-etil-celulose. Através de um planejamento fatorial completo de três fatores e dois níveis, determinou-se quantitativamente o efeito das variáveis operacionais: temperatura do ar de jorro, pressão de atomização e vazão de suspensão, sobre as variáveis dependentes: poder de germinação, envelhecimento acelerado e velocidade de germinação em solo. O tempo máximo de processo foi de 120 min. Um delineamento inteiramente casualizado foi aplicado para as mesmas variáveis dependentes, neste caso, avaliando diferenças entre sementes recobertas e não recobertas. Não houve diferença pronunciada na germinação, envelhecimento acelerado das sementes e velocidade de germinação em solo entre sementes recobertas e não recobertas. É possível recobrir sementes de brócolos com hidroxi-etil-celulose, em leito de jorro sem prejuízo à qualidade fisiológica das sementes. A superfície das sementes recobertas apresentou distribuição e dispersão satisfatória do polímero, recobrimento uniforme e individual e aspecto homogêneo.

RESUMO

Brassica oleracea var italica occupies a special place in the internal and external market of vegetables seeds. Vegetables producers demand seeds with high degree of purity, germination and vigor, since seeds' quality is the basis for the success of the production. In this work, broccoli seeds were coated in a spouted bed, by an aqueous suspension of hidroxy-ethyl-cellulose. Effects of the operating variables: spouting air temperature, atomizing air pressure and coating suspension flow rate over the dependent variables: seeds germination, seeds accelerated aging and the speed of seeds germination in soil, were investigated in a factorial scheme trial. The maximum processing time was 120 min. A totally randomized experiment evaluated and compared seeds germination and vigor of the coated and non-coated seeds. There was no identifiable, pronounced difference on germination of coated and non-coated seeds, accelerated aging of seeds, and speed of seeds germination in the soil. Coating with hidroxy-ethyl-cellulose in the spouted bed did not alter broccoli seeds physiologic quality. The surface of coated seeds presented satisfactory distribution and spreading of the polymer film, uniform and individual coating and homogeneous aspect.

Dentre as sementes de hortaliças comercializadas no mercado interno e externo, a Brassica oleracea var. itálica ocupa lugar de destaque. Os produtores de hortaliças têm exigido sementes com alto grau de pureza, germinação e vigor, uma vez que a qualidade das sementes é considerada a base para o sucesso do sistema de produção. Neste trabalho foi avaliado o recobrimento de sementes de brócolos em leito de jorro, utilizando uma suspensão aquosa de hidroxi-etil-celulose. Através de um planejamento fatorial completo de três fatores e dois níveis, determinou-se quantitativamente o efeito das variáveis operacionais: temperatura do ar de jorro, pressão de atomização e vazão de suspensão, sobre as variáveis dependentes: poder de germinação, envelhecimento acelerado e velocidade de germinação em solo. O tempo máximo de processo foi de 120 min. Um delineamento inteiramente casualizado foi aplicado para as mesmas variáveis dependentes, neste caso, avaliando diferenças entre sementes recobertas e não recobertas. Não houve diferença pronunciada na germinação, envelhecimento acelerado das sementes e velocidade de germinação em solo entre sementes recobertas e não recobertas. É possível recobrir sementes de brócolos com hidroxi-etil-celulose, em leito de jorro sem prejuízo à qualidade fisiológica das sementes. A superfície das sementes recobertas apresentou distribuição e dispersão satisfatória do polímero, recobrimento uniforme e individual e aspecto homogêneo.

RESUMO

Significant advances have been made in our knowledge of forage seed physiology, technology, and stand establishment practices; however, stand establishment continues to be one of the most common production problems affecting forage crops in the USA. There is a need for research on stand establishment of forage crops under abiotic and biotic stress. Although the forage seed industry produces and markets seed of high quality, new methods of assessing seed vigor are needed and their use should be expanded in the industry to enable matching seed lot performance to specific environmental conditions where performance can be maximized. Seed treatment and seed coating are used in the forage seed industry, and studies have shown they are of benefit in some environments. There is an increase in no-tillage seeding of forage crops, but improvements in the no-tillage planting equipment are needed to make them better suited to small seeds. Other recent developments in seeding techniques include broadcasting seed with dry granular and fluid fertilizers, which improves the efficiency of the seeding operation.

Progressos recentes têm sido obtidos nos conhecimentos referentes a fisiologia, tecnologia e práticas para o estabelecimento do estande, em espécies forrageiras. No entanto, o estabelecimento de estandes adequados ainda se constitui em um dos problemas mais freqüentes para a produção de forrageiras nos Estados Unidos. Há necessidade de pesquisas sobre esse assunto, principalmente quando as sementes são expostas a estresses abióticos e bióticos. Embora a indústria de sementes forrageiras produza e comercialize materiais de alta qualidade é necessário o desenvolvimento de novos métodos para a avaliação do vigor. A utilização desses testes necessita ser incentivada, para permitir a associação entre o desempenho de lotes de sementes e condições ambientais específicas, onde o desempenho pode ser maximizado. O tratamento e a cobertura de sementes com películas são usados pela indústria de sementes forrageiras; pesquisas têm demonstrado benefícios desses procedimentos. Têm sido constatados acréscimos das áreas de culturas forrageiras semeadas sob o sistema de plantio direto; no entanto, há necessidade do aprimoramento dos equipamentos destinados à semeadura direta, visando adequá-los ao trabalho com sementes pequenas. Outros desenvolvimentos recentes nas técnicas de semeadura incluem a distribuição de sementes com fertilizantes granulados e/ou fluidos visando beneficiar a eficiência da semeadura.

RESUMO

Significant advances have been made in our knowledge of forage seed physiology, technology, and stand establishment practices; however, stand establishment continues to be one of the most common production problems affecting forage crops in the USA. There is a need for research on stand establishment of forage crops under abiotic and biotic stress. Although the forage seed industry produces and markets seed of high quality, new methods of assessing seed vigor are needed and their use should be expanded in the industry to enable matching seed lot performance to specific environmental conditions where performance can be maximized. Seed treatment and seed coating are used in the forage seed industry, and studies have shown they are of benefit in some environments. There is an increase in no-tillage seeding of forage crops, but improvements in the no-tillage planting equipment are needed to make them better suited to small seeds. Other recent developments in seeding techniques include broadcasting seed with dry granular and fluid fertilizers, which improves the efficiency of the seeding operation.

Progressos recentes têm sido obtidos nos conhecimentos referentes a fisiologia, tecnologia e práticas para o estabelecimento do estande, em espécies forrageiras. No entanto, o estabelecimento de estandes adequados ainda se constitui em um dos problemas mais freqüentes para a produção de forrageiras nos Estados Unidos. Há necessidade de pesquisas sobre esse assunto, principalmente quando as sementes são expostas a estresses abióticos e bióticos. Embora a indústria de sementes forrageiras produza e comercialize materiais de alta qualidade é necessário o desenvolvimento de novos métodos para a avaliação do vigor. A utilização desses testes necessita ser incentivada, para permitir a associação entre o desempenho de lotes de sementes e condições ambientais específicas, onde o desempenho pode ser maximizado. O tratamento e a cobertura de sementes com películas são usados pela indústria de sementes forrageiras; pesquisas têm demonstrado benefícios desses procedimentos. Têm sido constatados acréscimos das áreas de culturas forrageiras semeadas sob o sistema de plantio direto; no entanto, há necessidade do aprimoramento dos equipamentos destinados à semeadura direta, visando adequá-los ao trabalho com sementes pequenas. Outros desenvolvimentos recentes nas técnicas de semeadura incluem a distribuição de sementes com fertilizantes granulados e/ou fluidos visando beneficiar a eficiência da semeadura.