A matéria orgânica é a principal responsável pela boa produtividade das culturas por possibilitar melhorias nas propriedades químicas, físicas e biológicas do solo. Os ácidos húmicos presentes na matéria orgânica têm sido estudados uma vez que as plantas apresentam respostas às suas aplicações no solo ou nas folhas. Muitos produtos comerciais compostos por substâncias húmicas têm sua origem a partir da mistura de adubos minerais com o produto resultante da decomposição de materiais orgânicos. Os bioestimulantes têm sido amplamente comercializados por apresentarem respostas no incremento da produtividade das culturas, principalmente em regiões onde as plantas estão sendo cultivadas em ambientes estressantes. Estes produtos possibilitam aumento na absorção de nutrientes e de água pelas plantas, bem como influenciam a atividade hormonal das plantas. Alguns estudos mostram resultados controversos sobre o uso de bioestimulantes nas plantas, sendo necessárias, portanto, novas pesquisas para melhor avaliação dos efeitos destes produtos na agricultura. Alguns deles mostram que a aplicação de bioestimulantes aumenta a atividade antioxidante na planta e, consequentemente, melhora seu sistema de defesa contra os estresses abióticos. Com base nestes fatos, o objetivo deste trabalho foi estudar o efeito de diferentes bioestimulantes aplicados em diferentes doses em plantas de milho e de soja no conteúdo de nutrientes, na produção de matéria seca e nos níveis de enzimas antioxidantes nas plantas. / Organic matter is the main source for high crop productivity since it improves chemical, physical and biological properties of the soil. Humic acids of the organic matter have been studied for many scientists. Plants have shown some improvements in their growth when they are subjected to applications of humic acids in the soil as well as via foliar. Many commercial products have humic acids in their compositions. They have been commercialized because they have increased crop production, especially when plants are subjected to severe environment. These products improve nutrient and water uptake, as well as they influence hormonal activities in plants. Some researches have shown application of biostimulants increases antioxidant activity in plants. So, they enhance defense system against abiotic stresses. But there are some studies showing that biostimulants have not caused any significant differences in plant growth. The aim of this research was evaluate biostimulants sources applied in different doses in maize and soybean in nutrient content as well as in the antioxidant enzymes levels in the plants.

Made available in DSpace on 2017-07-10T15:14:21Z (GMT). No. of bitstreams: 1 DissertacaoMatheusACosta1.pdf: 1680984 bytes, checksum: 07e7751a0b98112526470e65e8aace0a (MD5) Previous issue date: 2015-03-09 / Among the macroalgae grown on a commercial scale today, the red alga Kappaphychus alvarezii noteworthy due to its ease of cultivation and importance as a source of carrageenan extraction, one ficocolóide used in various industrial sectors because of its emulsifying and stabilizing properties. In the process of obtaining this compound, obtained as a byproduct a liquid extract, which has been employed in agriculture. However considering the potential biological activity of oligosaccharides and derivatives, which can be obtained from the solid fraction of seaweed source of carrageenan, the use together of these biomasses, solid and liquid extract biomass, can maximize the efficiency benefits associated with the use of the extract this alga in agriculture. In addition, the high total organic carbon content of that biomass mixture can collaborate in the legal recognition of this potential product as liquid organic fertilizer. The process for obtaining the oligassacarídeos from solid biomass and seaweed, then diluting the liquid extract was acidic hydrolysis. The hydrolytic arranged 2³ factorial arrangement of treatments ranged sulfuric acid solution in 0.2 and 0.4 molar, the temperature at 100 to 127 ° C and reaction time 15 and 30 minutes. The two samples of biomass hydrolyzate that had the highest percentage of organic carbon, and 11.6% and 12.6%, were selected for field trials in soybean, where each sample was diluted in liquid extract at 25% concentrations and 75%. Different doses of these two sample bases and pure liquid extract were tested in seed treatment and foliar spray in soybean. For this first application technology the lowest dose evaluated (2.5 ml kg-1 seed) presented with greater efficiency to increase of growth parameters. And for foliar technology the highest dose evaluated (500 mL ha-1) showed up, apparently more interesting for grain yield increase. / Dentre as macroalgas cultivadas em escala comercial hoje, a alga vermelha Kappaphychus alvarezii merece destaque devido a sua facilidade de cultivo e importância como fonte de extração de carragenana, um ficocolóide utilizado em diversos setores industriais devido às suas propriedades emulsificante e estabilizante. No processo de obtenção deste composto, obtém-se um extrato líquido como subproduto, o qual vem sendo empregado na agricultura. Todavia considerando a potencial atividade biológica de oligossacarídeos e derivados, que podem ser obtidos a partir da fração sólida da alga fonte de carragenana, o uso em conjunto dessas biomassas, extrato líquido e biomassa sólida, pode maximizar a eficiência dos benefícios associados ao uso do extrato desta alga na agricultura. Além disso, o alto conteúdo de carbono orgânico total dessa mistura de biomassas pode colaborar no reconhecimento legal deste potencial produto como fertilizante orgânico liquido. O processo para obtenção dos oligassacarídeos a partir da biomassa sólida da alga e, então diluição no extrato líquido, foi a hidrolise ácida. Os tratamentos hidrolíticos dispostos em arranjo fatorial 2³, variaram a solução de ácido sulfúrico em 0,2 e 0,4 molar, a temperatura em 100 e 127°C e tempo de reação em 15 e 30 minutos. As duas amostras de biomassa hidrolisada que tiveram o maior percentual de carbono orgânico, sendo 11,6 % e 12,6%, foram selecionadas para experimentação agrícola na cultura de soja, onde cada amostra foi diluída no extrato líquido em concentrações de 25% e 75%. Diferentes doses destas duas bases amostrais e do extrato líquido puro foram testadas no tratamento de semente e pulverização foliar na cultura de soja. Para esta primeira tecnologia de aplicação a menor dose avaliada (2,5 mL kg de semente-1) apresentou-se com maior eficiência para incremento de parâmetros de crescimento. E, para a tecnologia via foliar a maior dose avaliada (500 mL hectare -1) demonstrou-se, aparentemente, mais interessante para incremento de produtividade de grãos.

A matéria orgânica é a principal responsável pela boa produtividade das culturas por possibilitar melhorias nas propriedades químicas, físicas e biológicas do solo. Os ácidos húmicos presentes na matéria orgânica têm sido estudados uma vez que as plantas apresentam respostas às suas aplicações no solo ou nas folhas. Muitos produtos comerciais compostos por substâncias húmicas têm sua origem a partir da mistura de adubos minerais com o produto resultante da decomposição de materiais orgânicos. Os bioestimulantes têm sido amplamente comercializados por apresentarem respostas no incremento da produtividade das culturas, principalmente em regiões onde as plantas estão sendo cultivadas em ambientes estressantes. Estes produtos possibilitam aumento na absorção de nutrientes e de água pelas plantas, bem como influenciam a atividade hormonal das plantas. Alguns estudos mostram resultados controversos sobre o uso de bioestimulantes nas plantas, sendo necessárias, portanto, novas pesquisas para melhor avaliação dos efeitos destes produtos na agricultura. Alguns deles mostram que a aplicação de bioestimulantes aumenta a atividade antioxidante na planta e, consequentemente, melhora seu sistema de defesa contra os estresses abióticos. Com base nestes fatos, o objetivo deste trabalho foi estudar o efeito de diferentes bioestimulantes aplicados em diferentes doses em plantas de milho e de soja no conteúdo de nutrientes, na produção de matéria seca e nos níveis de enzimas antioxidantes nas plantas. / Organic matter is the main source for high crop productivity since it improves chemical, physical and biological properties of the soil. Humic acids of the organic matter have been studied for many scientists. Plants have shown some improvements in their growth when they are subjected to applications of humic acids in the soil as well as via foliar. Many commercial products have humic acids in their compositions. They have been commercialized because they have increased crop production, especially when plants are subjected to severe environment. These products improve nutrient and water uptake, as well as they influence hormonal activities in plants. Some researches have shown application of biostimulants increases antioxidant activity in plants. So, they enhance defense system against abiotic stresses. But there are some studies showing that biostimulants have not caused any significant differences in plant growth. The aim of this research was evaluate biostimulants sources applied in different doses in maize and soybean in nutrient content as well as in the antioxidant enzymes levels in the plants.

The increasing concerns launched by debates about climate changes added to the uncontrolled growth of world population have opened a market to natural inputs for a more sustainable agriculture. Taking those concerns together, it is very important to think in advance in terms of finding solutions to increase the food production, with improved quality and in a supposed changing environment. Natural substances such as seaweed biostimulants are coming up as inputs for crops yield and abiotic stress tolerance enhancement with increasing use in agriculture. In this scene, it is important to understand effects and mode of action of these substances on plant physiology to permit the development of consistent products and guarantee the delivery of solutions to growers that assist them in solving their needs. Therefore, this research was carried out aiming to understand the role of agrochemicals (classical plant growth regulators and seaweed biostimulants) on root development and hormonal relations of tomato \'Micro-Tom\' and Arabidopsis under water deficit conditions. Ascophyllum nodosum extracts (ANE) ability to stimulate endogenous hormonal responses in conditions of drought and osmotic stress was tested. We carried out experiments with two plant models: one is classically used in plant science studies and the other, a crop-like plant model whose scientific findings can be applied for several crops. We used tomato hormonal mutants and reporter lines grown in conditions of drought stress to study the effects of plant growth regulators and seaweed extracts on root growth and hormonal responses, respectively. Additionally, we tested in vitro the effects of these substances on root growth of Arabidopsis seedlings under osmotic stress conditions. The root development of tomato and Arabidopsis was negatively affected by the presence of water deficit caused by drought and osmotic stress, respectively. Gibberellins biosynthesis inhibitors only affected the root growth of gibberellin-deficient mutant (gib-3). Extracts of the same seaweed presented different effects on root growth of Arabidopsis seedlings and hormonal responsiveness in roots of tomato, possibly due to variability in their compositions. ANE A and B show opposite effects on root growth. ANE A promotes root growth, whereas ANE B shows inhibitory effects. These substances seem to have little influence on auxin responses in roots, however, they alter the balance between abscisic acid and ethylene under drought conditions. The standardization of the composition of seaweed extracts complemented with studies on their physiological and molecular effects in crops is crucial for the establishment of these agricultural inputs as one of the solutions for current and future requirements of food production. / As crescentes preocupações oriundas a partir dos atuais debates sobre mudanças climáticas somadas ao descontrolado crescimento da população mundial têm dado espaço para o uso de insumos agrícolas naturais, objetivando sustentabilidade na agricultura. Diante de tais preocupações, é importante pensar antecipadamente e encontrar maneiras de aumentar a produção e a qualidade de alimentos, em um ambiente de supostas mudanças climáticas. Substâncias naturais, como bioestimulantes à base de alga, estão ganhando relevância como melhoradores da produtividade e tolerância a estresses abióticos com crescentes usos na agricultura. Diante desse cenário, é importante compreender os efeitos e modos de ação dessas substâncias na fisiologia das plantas para permitir o desenvolvimento de produtos consistentes e garantir aos produtores soluções que atendam às suas necessidades. Portanto, este estudo foi realizado com o objetivo de entender o papel de agroquímicos (reguladores vegetais clássicos e biostimulantes à base da alga) sobre o desenvolvimento radicular e relações hormonais do tomateiro \'Micro-Tom\' e Arabidopsis sob condições de estresse hídrico. Foi testada a habilidade de extratos Ascophyllum nodosum (ANE) em estimular respostas hormonais em condições de seca e estresse osmótico. Foram realizados experimentos com duas plantas-modelo: Arabidopsis que é largamente utilizada em estudos científicos de plantas e o tomateiro \'Micro-Tom\', uma planta-modelo mais adequada para estudos aplicados à agricultura sob condições tropicais. Foram utilizados mutantes hormonais e linhas-repórter de tomate cultivadas em condições de seca para o estudo dos efeitos dos reguladores vegetias e extratos de alga no crescimento radicular e respostas hormonais, respectivamente. Além disso, foram testados in vitro os efeitos dessas substâncias no crescimento radicular de plântulas de Arabidopsis em condições de estresse osmótico. O desenvolvimento radicular do tomateiro e Arabidopsis foi negativamente afetado pela ocorrência do déficit hídrico causado por seca e estresse osmótico, respectivamente. Inibidores de giberelinas afetaram apenas o crescimento radicular do mutante com baixo nível endógeno giberelinas (gib-3). Extratos da mesma espécie de alga apresentaram diferentes efeitos no crescimento radicular de plântulas de Arabidopsis e resposta hormonal em raízes de tomateiro. ANE A e B aprensenta efeitos opostos no desenvolvimento de raízes. ANE A promove o crescimento radicular enquanto ANE A inibe. ANEs pouco influenciam as respostas auxínicas, contudo, essas substâncias alteram o balanço entre entre ácido abscísico e etileno sob condições de estresse hídrico por seca. A padronização da composição de extratos de alga somada aos estudos sobre os seus efeitos fisiológicos e moleculares em culturas é crucial para o estabelecimento desses insumos agrícolas como uma das soluções para as necessidades atuais e futuras da produção de alimentos.

Biostimulants offer an innovative approach to potentially improve crop yield and quality under abiotic stresses. Particularly, plant-derived protein hydrolysates (PH), a mixture of amino acids and soluble peptides from enzymatic or chemical hydrolysis of agricultural waste, are gaining global interest due to their sustainability and positive effects on crops. However, a functional role of the PH in crop yield and quality remains uncertain and is proposed to be associated with its phytohormone-like activities or serve as an additional nitrogen (N) source. Besides, the effects of PH on crop yield and quality are limited in intensive production systems such as greenhouse facilities. The purposes of this research are to examine the effects and mechanisms of PH on crops and to assess the potential of PH application to reduce fertilizer use in crop production. The specific objectives were to; 1) elucidate the hormone-like activities of PH in the adventitious rooting formation of cuttings, 2) evaluate the effects of different PH application methods on greenhouse crop yield and quality under different N levels when plants are grown with a commercial growing medium, and 3) examine the effects of PH application methods on yield and quality of hydroponically grown lettuce under different N levels and forms. Three conclusions were that 1) <a>the hormonal effects of PH are attributed to brassinosteroid-mediated processes, and PH has overlapping functions with auxin during adventitious rooting of cuttings in a plant species-specific manner</a>, 2) root application of PH (PH-R) effectively improves nutrient uptake compared to foliar spray of PH (PH-F), subsequently, increases the lettuce and tomato yield and quality regardless of N levels while PH-R did not change the chemical properties of growing media, and 3) PH-R effectively increases root growth, and subsequently, improving shoot yield and quality with significant PH × N levels and PH × NO₃:NH₄ratios interactions. Also, PH-R counteracted the negative effects of low NO₃:NH₄ratios on lettuce yield. The outcomes provide the optimization of PH and N fertilization in modern sustainable greenhouse production and the development of a new strategy for producing high-quality greenhouse crops with improved nutrient use efficiency.

No description available.

<p>U ovom istraživanju je utvrđen uticaj primjene biostimulatora na morfolo&scaron;ke i fiziolo&scaron;ke parametre rasta i razvoja, te na mineralni sastav kod sezonskog cvijeća, kadifice i stalnocvjetajuće begonije.&nbsp; Uticaj biostimulatora je ispitan kroz tri godine istraživanja u za&scaron;tićenom prostoru i na otvorenom polju. Istraživanje je provedeno na mladim biljkama-rasadu prije presađivanja i na odraslim biljkama. U fazi rasada primjenjen je biostimulator Radifarm, a u fazi odraslih biljaka primjenjeni su biostimulatori Megafol, Kendal i Viva.&nbsp; Tretman sa primjenjenim biostimulatorima, u sve tri godine istraživanja i oba načina uzgoja, je značajno uticao na povećanje svježe i suhe mase korijena i nadzemnog dijela ispitivanih cvjetnih vrsta. Takođe, svi praćeni morfolo&scaron;ki parametri rasta i razvoja bili su pod pozitivnim uticajem tretmana biostimulatorima. Kod rasada kadifice i stalnocvjetajuće begonije, tretman Radifarmom je snizio sadržaj prolina u listovima te se i na taj način potvrdio pozitivan uticaj biostimulatora na smanjenje abiotskog stresa. Svi primjenjeni biostimulatori su značajno ubrzali cvjetanje i produžili vrijeme cvatnje u poređenju sa kontrolnim biljkama. Tretmani biostimulatorima su uticali na povećanje ukupnog sadržaja svih elemenata ishrane u cijelim biljkama kadifice i stalnocvjetajuće begonije. Rezultati pokazuju korist primjene biostimulatora u uzgoju sezonskog cvijeća u fazi rasada, ali i u fazi uzgoja na otvorenom polju, jer pozitivno utiču na procese rasta i razvoja kroz ublažavanje abiotskog stresa uzrokovanog presađivanjem. Na kraju, javlja se potreba za daljim istraživanjem mogućnosti primjene biostimulatora i na druge poljoprivredne kulture, kao preporučljive tehnolo&scaron;ke mjere za&scaron;tite životne sredine, jer primjenom biostimulatora ne dolazi do ispiranja azotnih materija u dublje slojeve zemlji&scaron;ta.</p> / <p>This research showed the effect of biostimulant application on morphophysiological growth and development indicators and plant mineral content of seasonal flowers, marigold and begonia.&nbsp; Biostimulant effect was investigated in three years, where plants were grown in greenhouse and in open field. Young seasonal plants before transplanting and adult plants after transplanting in open field were analysed to determine the influence of biostimulant application. Biostimulant Radifarm was applied before transplanting, and Megafol, Kendal and Viva after transplanting.&nbsp; Treatment with applied biostimulants, in three years of investigation and both growing conditions, significantly increased root and stem fresh and dry weight of seasonal flowers. Also, all morphological properties were under positive influence of biostimulants treatment. Furthermore, treatment with biostimulant Radifarm resulted by lower proline content in leaves, which confirmed positive effect biostimulant on abiotical stress conditions. All applied biostimulants, significantly increased earlier flowering and ensured longest flowering in marigold and begonia. The most significant influence of biostimulants application in role of plant nutrition was increased mineral nutrients total content in the whole plant in both sampling.&nbsp; Results showed advantage of biostimulants application in seasonal flowers seedlings production, but also after transplanting in open filed, because their application intensified growth process through damage reduction caused by abiotic stress during transplanting. At the end, there is a need for further investigation of biostimulant function, their application possibilities on others agricultural plants and their combinations in modern agriculture towards environmental friendly production strategy.</p>

Thesis (MScAgric (Horticulture))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Creasing, also known as albedo breakdown, is a preharvest disorder that affects the albedo of citrus fruit causing creases on the surface of the fruit. It is a recurrent problem in Navel and Valencia oranges and can cause individual orchard losses which often exceed 50%. Although the contributing factors are known, the physiological basis of creasing development is unresolved and the current control measures do not prevent creasing satisfactory. Hence, better control measures and further understanding of the physiology of creasing development is required. The objective of this two-year study was to determine if the position of fruit in a tree, light and carbohydrate manipulation techniques, and albedo mineral nutrients influence creasing development. Furthermore, the most effective application timing of gibberellic acid (GA3) with the least negative effect on fruit rind colour development and the effectiveness of cytokinins, other products and different root biostimulants to reduce creasing incidence were evaluated. The position of fruit in the tree and light influenced the development of creasing and the distribution of mineral nutrients in the albedo. Creasing incidence was higher on the south side than on the north side of the tree and fruit from the inside sub-sectors had a greater creasing incidence compared to fruit from the outside sub-sectors. The shady part of outside fruit was more creased compared to the sunny part of the fruit and covering fruit with brown paper bags increased creasing severity. The light manipulation techniques used on the leaves and fruit increased the nitrogen (N), phosphorus (P), potassium (K) and manganese (Mn) concentrations in the albedo and differences in the albedo mineral nutrients amongst the sub-sectors evaluated were observed, but creasing severity or creasing incidence was not significantly correlated with the albedo mineral concentrations at harvest. Albedo mineral concentrations earlier in the season may play a role in creasing development, as creasing severity was significantly correlated with copper (Cu), K, and Mn concentrations in the albedo during stage II of fruit development. Creasing incidence and albedo mineral concentrations were not affected by any of the carbohydrate manipulation techniques used in this study. The incidence and severity of creasing was significantly reduced, with a minor negative effect on fruit rind colour development, by the application of GA3, from mid November to mid January. Localised fruit application of CPPU [N-(2-chloro-4-pyridyl)-N-phenylurea], MaxCel (6- Benzyladenine) and CPPU in combination with calcium after physiological fruit drop reduced the incidence and severity of creasing, although creasing incidence was not significantly different from the control. The application of Messenger®, AVG (aminoethoxyvinylglycine) and different root biostimulants did not reduce creasing incidence. The results showed that cytokinins could reduce creasing incidence and justify further studies on application and uptake efficiency. The use of different root biostimulants are not recommended, but it is suggested that treatment effects may be more pronounced over a longer period. / AFRIKAANSE OPSOMMING: Kraakskil is ‘n vooroes abnormalitiet wat die albedo van sitrusvrugte affekteer, deur krake op die oppervlak van vrugte te veroorsaak. Dit is ‘n algemene probleem in Navel en Valencia lemoene en kan boordverliese van tot 50% of soms hoër veroorsaak. Alhoewel die bydraende faktore bekend is, is die fisiologiese basis van kraakskil ontwikkeling onopgelos en die beskikbare beheermaatreëls is nie bevredigend nie. Dus, beter beheermaatreëls en ‘n beter begrip van die fisiologie van kraakskil ontwikkeling is nodig. Die doel van die twee-jaar studie was om te bepaal of die posisie van vrugte in ‘n boom, lig en koolhidraat manipulasie tegnieke en minerale elemente in die albedo, kraakskil ontwikkeling beïnvloed. Die mees effektiewe toedieningstyd van gibberelliensuur (GA3) sonder ‘n negatiewe effek op vrugkleur is bepaal en die effektiwiteit van sitokiniene, ander produkte en verskillende wortel biostimulante om kraakskil voorkoms te verminder, is geëvalueer. Die posisie van vrugte in ‘n boom en lig het kraakskil ontwikkeling en die verspreiding van minerale element in die albedo beïnvloed. Kraakskil voorkoms was hoër aan die suidekant van die boom as aan die noordekant en vrugte in die binnekant van die boom het ‘n groter kraakskil voorkoms as vrugte in die buitekant van die boom gehad. Die skadukant van buitevrugte het meer kraakskil gehad as die sonkant en die toemaak van vrugte met ‘n bruin papiersak het die graad van kraaksil verhoog. Die lig manipulasie tegnieke wat op die blare en vrugte gebruik is, het die stikstof (N), fosfaat (P), kalium (K) en mangaan (Mn) konsentasies in die albedo verhoog en verskille in die albedo minerale elemente tussen sub-sektore is waargeneem, maar betekenisvolle korrelasies is nie tussen die graad en voorkoms van kraakskil en die albedo minerale element konsentrasies by oestyd waargeneem nie. Albedo minerale element konsentrasies vroeër in die seisoen mag ‘n rol speel by kraakskil ontwikkeling, omdat die graad van kraakskil betekenisvol gekorreleer was met albedo koper (Cu), K, en Mn konsentrasies tydens fase II van vrugontwikkeling. Kraakskil voorkoms en albedo minerale element konsentrasies is nie deur enige van die koolhidraat manipulasie tegnieke geaffekteer nie. Die voorkoms en graad van kraakskil is betekenisvol verlaag, met ‘n geringe negatiewe effek op vrugkleur, deur die toediening van GA3 vanaf mid November tot mid Januarie. Gelokaliseerde vrugtoedienings van CPPU [N-(2-chloro-4-piridiel)-N-phenielureum], MaxCel (6- Bensieladenien) en CPPU saam met kalsium na fisiologiese vrugval het die voorkoms en graad van kraakskil verlaag, alhoewel kraakskil voorkoms nie betekenisvol van die kontrole verskil het nie. Die toediening van Messenger®, AVG (amino etoksievinielglisien) en veskillende wortel biostimulante het nie kraakskil voorkoms verlaag nie. Die resultate het getoon dat sitokiniene kraakskil voorkoms kan verlaag en verdere studies op die toediening en opname effektiwiteit word aanbeveel. Die gebruik van verskillende wortel biostimulante word nie aanbeveel nie, maar die effek behoort meer sigbaar te wees na ‘n langer periode van behandeling.

Made available in DSpace on 2014-08-20T13:44:50Z (GMT). No. of bitstreams: 1 dissertacao_fernanda_weber.pdf: 115778 bytes, checksum: a5ce0bf91102716c69848aabf0c38db3 (MD5) Previous issue date: 2010-12-16 / The use of quality seeds and the use of products that enable improvement of their performance in the field, are important elements for a high agricultural production. Biostimulants are plant growth substances that can act alone or in comination to promote plant development. Through these substances it is possible to influence many physiological and/or morphological processes such as germination, vegetative growth, flowering, fruiting, senescence and abscission. This interference can occur by the application of these substances on seeds, soil or leaves. In such a way that needs to be absorbed to performance its role. The aim of this study was to evaluate the effect of "biostimulant" use in early treatment of soybean seeds. Seed samples treated 15 and 5 days before the day of sowing and in the day of sowing with the product "FERTIACTYL LEG® were used. These samples were sent to laboratory and were submitted to germination, vigor and root length tests. The experiment was conducted at the Laboratory of the Research Support Foundation of the West of Bahia and the samples were subjected to germination and vigor tests in the Seed Analysis Laboratory Sol (LASSOL), located in Barreiras/BA. / A utilização de sementes com qualidade e o emprego de produtos que possibilitem melhoria de seu desempenho no campo, são elementos importantes para uma alta produção agrícola. Os bioestimulantes, são substâncias de crescimento vegetal que podem atuar isoladamente ou em combinação na promoção do desenvolvimento das plantas. Através destas substâncias pode-se interferir em diversos processos fisiológicos e/ou morfológicos, tais como a germinação, crescimento vegetativo, florescimento, frutificação, senescência e abscisão. Esta interferência pode ocorrer pela aplicação dessas substâncias via sementes, via solo ou via foliar, de modo que, elas precisam ser absorvidas para que possam exercer sua atividade. O objetivo desse trabalho foi avaliar o efeito do uso de bioestimulante em tratamento de sementes de soja. Foram avaliadas amostras de sementes tratadas cinco e 15 dias antes da semeadura e no dia da semeadura com o produto FERTIACTYL LEG®. Essas amostras foram enviadas a laboratório para realização dos testes de germinação, vigor e comprimento de raiz. O ensaio foi conduzido no Laboratório da Fundação de Apoio à Pesquisa e Desenvolvimento do Oeste Baiano e as amostras foram submetidas aos testes de germinação e vigor no Laboratório de Análises de Sementes Sol (LASSOL), situado em Barreiras/BA. O uso do bioestimulante Fertiactyl leg® não causou efeito na germinação de sementes em nenhum dos tratamentos. As aplicações antecipadas (aos cinco e aos quinze dias antes da semeadura) do bioestimulante Fertiactyl leg® nas sementes proporcionaram desempenho superior no envelhecimento acelerado, enquanto que a aplicação do produto no dia da semeadura proporcionou um maior comprimento de raízes comparada a não aplicação do produto. A aplicação do bioestimulante Fertiactyl leg® não prejudicou o desempenho de sementes de soja.

Sustainable agriculture practices include a better exploitation of soil natural resources. Arbuscular mycorrhizal fungi (AMF) plays an important role in this context, with native communities in soils that establishes a mutualistic association with most plant species and maximizes their access to mineral nutrients, especially phosphorus. Seed treatment may consist in a good alternative to stimulate AMF root colonization, since early stages of crop growth, by using biostimulant formulations applied to seeds. This research had the objective to evaluate the early mycorrhization of soybean plants in response to seaweed extracts applied to seeds. The treatments consisted of a control (CTR, distilled water), two seaweed extracts, from Ascophyllum nodosum (ANE) and Ecklonia maxima (EME) species and a synthetic formulation containing formononetin (FOR), commercially used as mycorrhization stimulant. The first experiment was conducted in greenhouse, with the aim to evaluate different parameters of soybean early growth and development and AMF root colonization in response to the seed treatments, under different rates of phosphorus added to the soil (0, 50, 100 and 200 mg.dm-3). The second experiment was conducted in growth chamber, with the objective to evaluate qualitative and quantitative aspects of mycorrhization in response to the seed treatments with biostimulants, at early plant growth stages. In this experiment, the influence of treatments on the structure of AMF, bacterial and fungal communities in the soybean rhizosphere were analyzed, through PCR/T- RFLP fingerprinting. Phosphorus rates applied to soil significantly influenced (P&#60;0.10) biometric and physiological parameters of soybean plants, while the seed treatments only influenced leaf chlorophyll content and nitrogen balance at a significant level, despite some trends to increase leaf area, shoot dry mass and nodulation. Formononetin applied to soybean seeds increases AMF root colonization compared to control, independently of P rate applied to soil, while ANE and EME presented intermediate values for this parameter, not differing from both control and formononetin. When considered some qualitative parameters of mycorrhiza establishment, such as frequency and intensity of mycorrhization, both synthetic and natural biostimulants presented significant improvements, with EME and FOR providing higher values in general. The phenological stage of soybean significantly influenced AMF, bacterial and fungal community structures in rizosphere, while the biostimulant seed treatments only significantly influenced the bacterial community. However, a relatively large variation in the microbial community structures could be attributed to the interaction between phenological stage of plants and the seed treatment with biostimulants. / Práticas agrícolas sustentáveis incluem uma melhor exploração dos recursos naturais do solo. Os fungos micorrízicos arbusculares (FMA) desempenham um papel importante neste contexto, com comunidades nativas nos solos que estabelecem uma associação mutualística com a maioria das espécies cultivadas e maximizam o acesso a nutrientes minerais, especialmente o fósforo. O tratamento de sementes pode consistir em uma alternativa interessante para estimular a colonização por FMA, desde estádios iniciais de crescimento da cultura, utilizando formulações de bioestimulantes aplicadas às sementes. Esta pesquisa teve como objetivo avaliar a micorrização precoce de plantas de soja em resposta a extratos de algas aplicados nas sementes. Os tratamentos consistiram de uma testemunha (CTR, água destilada), dois extratos de algas marinhas, das espécies Ascophyllum nodosum (ANE) e Ecklonia máxima (EME) e uma formulação sintética contendo formononetina (FOR), comercialmente utilizada como estimulante de micorrização. O primeiro experimento foi conduzido em casa de vegetação, com o objetivo de avaliar diferentes parâmetros de crescimento e desenvolvimento inicial das plantas de soja e a colonização de raízes por FMA, em resposta aos tratamentos de sementes; estas avaliações foram realizadas sob diferentes doses de fósforo adicionadas ao solo (0, 50, 100 e 200 mg.dm-3). O segundo experimento foi conduzido em câmara de crescimento, com o objetivo de avaliar aspectos qualitativos e quantitativos da micorrização em resposta ao tratamento de sementes com bioestimulantes, nas fases iniciais de crescimento das plantas. Neste experimento, analisou-se a influência dos tratamentos na estrutura de comunidades de FMA, bactérias e fungos na rizosfera das plantas de soja, através de PCR/T-RFLP. As doses de fósforo aplicadas no solo influenciaram significativamente (P&#60;0,10) nos parâmetros biométricos e fisiológicos das plantas de soja, enquanto os tratamentos de sementes influenciaram significativamente apenas o teor de clorofila e o balanço de nitrogênio. A formononetina aplicada nas sementes de soja aumentou a colonização da raiz por FMA em relação ao controle, independentemente da dose de P aplicada ao solo, enquanto ANE e EME apresentaram valores intermediários para este parâmetro, não diferindo tanto da testemunha como da formononetina. Quando considerados alguns parâmetros qualitativos do estabelecimento de micorrizas, tanto os bioestimulantes sintéticos como os naturais apresentaram melhorias significativas. O estádio fenológico da soja influenciou significativamente as estruturas de comunidades de FMA, bactérias e fungos na rizosfera das plantas de soja, enquanto os tratamentos de sementes com bioestimulantes somente influenciaram significativamente a comunidade bacteriana. No entanto, uma variação relativamente grande nas estruturas da comunidade microbiana pôde ser atribuída à interação entre estádio fenológico das plantas e o tratamento de sementes com bioestimulantes.