Influ?ncia de Azospirillum Brasilense e horm?nios reguladores de crescimento no desempenho agron?mico e econ?mico de Triticum Aestivum

The wheat crop is demanding in Nitrogen, whereas its productivity and higher grain quality depends on this macronutrient. However, the application of N in mineral form can result in losses by leaching and volatilization, resulting in only about 50% of applied N being taken up by plants. The use of N-fixing bacteria in grasses has attracted the attention of researchers in recent years, and among the bacteria under study is Azospirillum brasilense, mainly inoculated into Zea mays L. and Triticum aestivum L. The association between the bacteria and the root system of the plants allows both N fixation and induction of hormones production, notably auxin. This causes the improvement of the root system allowing better exploitation of the soil, favoring the absorption of water and minerals resulting in improved yield and grain quality. This study aimed to evaluate the effect of the inoculation with A. brasilense and the application of growth regulators based on gibberellic acid, cytokinin and 4-indol-3-indolebutyric acid in the development and yield of wheat, also determining the economic viability usage of these technologies. Therefore, were made assessments of the variables Number of spikes.m-2, Number of grains per spike-1, 1000 grains weight, yield per area (Kg ha-1), hectoliter weight, the production costs related to the use of the technology and the price paid for the wheat. The implementation of the field experiment was conducted in the first fortnight of June 2014 in guava site located in the municipality of Cand?i-PR, using the cultivar IPR Catuara TM, early cycle, medium height, belonging to enhancing wheat class. The experimental design was randomized blocks, with two levels for Azospirillum brasilense factor (with and without inoculation) and three levels for growth regulator factor (without application, with application via seed and foliar application). The agronomical data were recorded in spreadsheets and submitted to Factorial Analysis of Variance (ANOVA) and the Scott-Knott test (p<0.10). By interpretation of the ANOVA it was observed interaction between the factors. The usage of A. brasilense can increase the yield of the wheat cultivar used, even when associated with application of foliar growth regulator. Differences between treatments were observed in variable yield, plant height and lodging index. For yield, the application of the bacteria and the growth regulator in seeds resulted in lower yields, while the use of the bacteria associated with the growth regulator applied to the leaves resulted in the higher yields. Plants treated only with the bacteria resulted in lower plant height, differing of other treatments. For the lodging index there was difference only between the control and the treatment with the use of growth regulator via seed without inoculation with bacteria. With regard to the economic context, it was found that the treatment constituted only by the inoculation with A. brasilense has shown the greater economic viability on the circumstances tested.A cultura do trigo ? exigente em Nitrog?nio, sendo que sua produtividade e posterior qualidade dos gr?os dependem deste macronutriente. Entretanto, a aplica??o de N na forma mineral pode apresentar grandes perdas por lixivia??o e volatiliza??o, sendo que apenas cerca de 50% do N aplicado ? aproveitado pelas plantas. A utiliza??o de bact?rias fixadoras de N em po?ceas tem despertado a aten??o dos pesquisadores nos ?ltimos anos, sendo que dentre as bact?rias em estudo temos Azospirillum brasilense aplicada principalmente em Zea mays L e Triticum aestivum L. A associa??o da bact?ria ao sistema radicular das plantas permite tanto a fixa??o de N como a promo??o de horm?nios, principalmente a auxina. Isso estimula o aumento das ra?zes e propicia uma melhor explora??o do solo, favorecendo a absor??o de ?gua e sais minerais e permitindo melhora na produtividade e qualidade de gr?os. O presente trabalho teve como objetivo verificar a influ?ncia da inocula??o com A. brasilense e da aplica??o de horm?nios reguladores de crescimento a base de ?cido giber?lico, citocinina e ?cido 4-indol-3-ilbut?rico no desenvolvimento e rendimento de trigo, bem como a viabilidade econ?mica do uso dessas tecnologias. Para tanto foram avaliadas as vari?veis N? de espigas m-2, N? de gr?os espiga-1, Massa de 1000 gr?os, produtividade por ?rea (Kg ha-1), peso hectol?trico e tamb?m os custos de produ??o relacionados ao uso das tecnologias e o pre?o pago pelo trigo. A implanta??o do experimento a campo ocorreu na primeira quinzena do m?s de Junho de 2014 no s?tio goiabeira localizado no munic?pio de Cand?i-PR, utilizando a cultivar IPR Catuara TM, de ciclo precoce, altura m?dia, pertencente a classe de trigo melhorador. O delineamento experimental empregado foi o de blocos ao acaso, com dois n?veis para o fator Azospirillum brasilense (com e sem inocula??o) e tr?s n?veis para o fator regulador de crescimento (sem aplica??o, com aplica??o via semente e com aplica??o via foliar). Os dados agron?micos foram registrados em planilhas e submetidos a An?lise de Vari?ncia Fatorial (ANOVA) e ao teste de Scott-Knott (p