RESUMOCo-inoculation of Rhizobium tropici and Azospirillum brasilense in common beans grown under two irrigation depths 1 The alternative technique of co-inoculation or mixed inoculation with symbiotic and non-symbiotic bacteria has been studied in leguminous plants. However, there are few field studies with common beans and under the influence of the amount of irrigated water. Thus, the objective of this study was to evaluate the efficiency of inoculation and coinoculation of common beans with Rhizobium tropici and Azospirillum brasilense under two irrigation depths. The experiment was carried out in the winter of 2012 and 2013, in Selvíria, state of Mato Grosso do Sul. The experimental design was composed of randomized blocks in split-plot scheme with two irrigation depths in the plots (recommended for common beans and 75% of the recommended) and five forms of nitrogen (N) supply in the split-plots (control noninoculated with 40 kg ha . The use of 75% of the recommended irrigation depth provides similar grain yield to the recommended irrigation depth in common beans cropped in winter.

-The effect of mixture of seeds of Brachiaria brizantha, cv. Marandu, with different sources, granulometry, and phosphatic fertilizer doses during various periods of exposure on the physiological potential of the seeds has been assessed. The treatments consisted in seed exposure during periods of 0, 3, 6, 12, 24, 36, 48, 72, 96, and 120 h to the following fertilizers: ground granulated single superphosphate (SS), and powdered (SSp); and ground granulated ammonium monophosphate (AMP), at doses of 40 and 80 kg P 2 O 5 ha -1 . Tests of germination, tetrazolium, moisture content, and vigor (first count, electrical conductivity, emergence, emergence speed, and fresh mass of seedlings) were performed. It has been concluded that seed physiological potential of B. brizantha cv. Marandu is reduced with increase on the exposure period to phosphatic fertilizer. Such effect, however, is dependent on the product source, granulometry, and dose. SSp was the most harmful to seeds, followed by SSp and AMP, respectively. Moreover, considering a 60% germination rate as acceptable, it may be inferred that seeds can be kept in contact with AMP and SSp, in dose of 80 kg of P 2 O 5 ha -1 , respectively, for periods of 71.2 and 16.2 hours.Index terms: phosphorus, seed-fertilizer mixture, exposure period, vigor. Termos para indexação: fósforo, mistura adubo-semente, período de exposição, vigor. Potencial fisiológico de sementes de1

No abstract

No abstract

No abstract

The study was carried out in Selvíria-MS, in the 2011/12 and 2012/13 agricultural years, aiming to evaluate the efficiency of Azospirillum brasilense in nitrogen fixation in upland rice, as a function of doses and application methods of the inoculant containing this diazotrophic bacterium. The experimental design was randomized blocks, arranged in a 4 x 4 factorial scheme, with 4 doses of inoculant (control without inoculation, 100, 200 and 300 mL of the commercial product ha-1) and 4 application methods (seed inoculation, application in the sowing furrow, soil spraying after sowing, and foliar spraying at the beginning of plant tillering), with 4 replicates. During the experiment, the agronomic characteristics, production components and yield of the rice crop were evaluated. It was concluded that the inoculant containing Azospirillum brasilense promotes increase (19%) in the yield of upland rice under sprinkler irrigation when used at the dose of 200 mL ha-1, regardless of the application methods.

Dentre os vários reguladores vegetais já conhecidos, sabe-se que alguns podem proporcionar redução na altura das plantas de arroz e, consequentemente, reduzir ou até mesmo eliminar o acamamento. Mas também se sabe que o thidiazuron (TDZ), um regulador de efeito citocinínico, se mostrou potencialmente benéfico para a cultura do arroz, melhorando suas características agronômicas e elevando a produtividade. Assim, o objetivo do trabalho foi verificar uma possível combinação entre o etil-trinexapac e o thidiazuron, visando, concomitantemente, a redução no grau de acamamento e a elevação de produtividade na cultura do arroz de terras altas irrigado por aspersão em região de Cerrado brasileiro. Usou-se a cultivar ANa 5015, no delineamento experimental de blocos ao acaso em esquema fatorial 4x2, com quatro repetições, sendo os tratamentos a combinação de quatro doses de thidiazuron (0,0; 0,5; 1,0 e 1,5g ha-1) aplicadas por ocasião do perfilhamento e da aplicação de etil-trinexapac (presença ou ausência) em dose fixa (50 g ha-1) por ocasião da diferenciação floral. Verificou-se que as doses de thidiazuron aplicadas não diferiram significativamente do tratamento testemunha nas características agronômicas analisadas, nem houve interação do thidiazuron com o etil-trinexapac. Conclui-se que a cultivar ANa 5015 não se mostrou responsiva à aplicação de thidiazuron e a aplicação de 50 g ha-1 de etil-trinexapac por ocasião da diferenciação floral reduz a altura de plantas, em 0,09 m, bem como a produtividade em 974 kg ha-1 em relação ao tratamento testemunha.

The corn crop is one of the most cultivated in the world and one of the most need studies that seek alternatives on the use of Azospirillum brasilense. This bacterium produces growth hormones that may benefit the corn crop. The work objective was to verify the agronomical performance of corn crop, in function of foliar Azospirillum brasilense inoculation, associated with nitrogen doses. The research was performed in Selvíria, Mato Grosso do Sul State, Brazil, which is in the Brazilian Cerrado. The corn crop was cultivated during season (Spring/Summer) and late season (Summer/Autumn), under conventional tillage system. Experimental design of randomized blocks was used, with factorial scheme 4 × 2. The treatments were made in four nitrogen doses (0, 30, 60 and 90 Kg ha-1) with and without the foliar applying (in stage V6) of the inoculant containing A. brasilense. The inoculant used had the strains AbV 5 and AbV 6 of A. brasilense (2×10 8 viable cells mL-1) and, the dose 200 mL ha-1 was used. The nitrogen fertilization was made with ammonium sulfate, also on phenological stage V6. The following evaluations were made: Final plant population, foliar nitrogen content, foliar chlorophyll index, ear insertion height, plants height, stalk diameter, ears length, ears diameter, thousand grain weight and grain productivity. The foliar inoculation with the A. brasilense bacterium proved to be advantageous for the corn crop, and therefore, an option for the farmer. Because of the large volume of products used in seed (fungicide, insecticide, plant growth regulators) and the lack of information on the degree of interference of these products on the bacteria, it becomes pertinent the study of other inoculation forms on crops. Other studies that verify the influence of A. brasilense bacteria in foliar application on the physiology of the shoot and root of crops should be encouraged.