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In Brazil, the peanut culture has been expanding mainly in the state of Sao Paulo, responsible for 80% of the national production. It is an edible culture produces oil of excellent quality, contains proteins rich in amino acids that make up to 36% of weight of the grain. Furthermore, it is associated with nitrogen-fixing bacteria. However, the practice of inoculation is not very common in peanuts, being this species considered susceptible to nodularity with a large number of rhizobia. However, known’s that inoculation with selected strains can increase the efficiency of symbiosis and peanut yield. Thus, the present study was proposed to evaluate the development of peanut inoculated with rhizobia and grown in Cerrado’s Oxisol. The experiment was conducted in a greenhouse, in a completely randomized design, five treatments, one cultivar (IAC 505) and four replicates. The treatments were composed of three strains of rhizobia and two controls, one absolute and the other with nitrogen fertilizer (50 mg⋅N⋅dm3). Each experimental plot has been consisted an 8 dm3 pot with three plants. The inoculation was done, applying 3 mL of bacterial broth (108 mL−1 cells) in the root system of each plant. The SPAD index, number and dry weight of nodules, dry mass of shoots and roots, number and weight of grains were analyzed. The response of Peanuts inoculated was significantly, as all inoculated plants showed similar development to nitrogen-fertilized, emphasizing the potential for supplying nitrogen in peanut development.

The aim of this study was to evaluate the effect of inoculation with rhizobium and co-inoculation with Azospirillum brasilense on phytometric characteristics of peanut plants grown in Latossolo Vermelho (Oxisol) with and without compaction. The experiment was conducted in a greenhouse, with a randomized block design in a 5x2 factorial scheme and 4 replicates, totaling 40 experimental units. Treatments were composed by commercial inoculant for peanuts (SEMIA 6144 strain); MT 15 strain; combination of MT 15 + A. brasilense; nitrogen control and absolute control. Plant height, number of leaves, number of branches per plant, stem diameter and Falker chlorophyll index were evaluated. The data were subjected to analysis of variance and, when significant, to Tukey test at 1% probability level. For the variables plant height, number of leaves, number of branches and stem diameter, the results were similar for all treatments, except for the absolute control and number of branches at 90 days after emergence (DAE) and stem diameter at 30 and 90 DAE. For stem diameter at 30 DAE, the results were similar to those found in the treatments with co-inoculation, commercial inoculant and nitrogen fertilization. There was interaction for Falker chlorophyll index at 60 DAE, with the best result found in the MT 15 strain. Inoculation with MT15 and co-inoculation with A. brasilense promoted good performance in peanut crop in terms of phytometric characteristics in soil with and without compaction. O objetivo do estudo foi avaliar o efeito da inoculação com rizóbio e da coinoculação com Azospirillum brasilense nas características fitométricas de plantas de amendoim cultivado em Latossolo Vermelho com e sem compactação. O experimento foi realizado em casa de vegetação, com delineamento de blocos ao acaso em esquema fatorial 5x2, e 4 repetições, totalizando 40 unidades experimentais. Os tratamentos foram compostos por inoculante comercial para amendoim (estirpe SEMIA 6144); estirpe MT 15; a combinação MT 15 + A. brasilense; testemunhas nitrogenada e absoluta. Foram avaliados altura de plantas, número de folhas, número de ramos por planta, diâmetro de caule e índice de clorofila Falker. Os dados foram submetidos à análise de variância e quando significativos, ao Teste de Tukey a 1% de probabilidade. Em relação às variáveis altura de plantas, número de folhas e de ramos e diâmetro de caule os resultados encontrados foram semelhantes para todos os tratamentos, com exceção da testemunha absoluta e do número de ramos aos 90 dias após a emergência (DAE) e do diâmetro de caule aos 30 e 90 DAE. Para o diâmetro de caule aos 30 DAE houve resultados similares ao tratamento coinoculado, ao inoculante comercial e à adubação nitrogenada. Houve interação para o índice de clorofila Falker aos 60 DAE em que a estirpe MT 15 obteve o melhor resultado. A inoculação com a estirpe MT15 e a coinoculação com A. brasilense proporcionaram à cultura do amendoim bom desempenho em relação às características fitométricas em solo com e sem compactação. &nbsp

Due to the search for viable and cost-effective ways to provide nitrogen for forage grasses, inoculation with diazotrophs presents high potential as an alternative to plant nutrition by reducing the use of nitrogen fertilizers. The objective of this work was to evaluate the nutrition of marandu grass (Brachiaria brizantha cv. marandu) subjected to inoculation with associative diazotrophic bacteria grown in Cerrado soil (Brazilian Savanna). The experiment was conducted in a greenhouse with a completely randomized design using five treatments (three strains of associative nitrogen fixing bacteria [MTH2, MTB1 and Y2], an inoculant formed by combination of strains AbV5 and AbV6 (Azospirillum brasilense) and a control (100 mg dm-3 of N-urea]) and five replications, totaling 25 experimental units. The inoculation was performed by inserting a 5 mL aliquot of bacterial broth containing 109 cells mL-1 in the soil near the root system of each plant. Three cuts were made at 30, 60 and 90 days after sowing. The variables: Falker chlorophyll index, nitrogen concentration in shoots and roots and crude protein in shoots of marandu grass were evaluated. The highest values for Falker chlorophyll index, nitrogen concentration, and crude protein were observed in the three cuts in plants that received N fertilization. The MTH2 strain positively influenced the nitrogen concentration in shoots and roots, and crude protein in shoots in the first and second cuts of marandu grass, whereas in the third cut, these parameters were influenced by nitrogen fertilization. In conclusion, the inoculation with associative diazotrophic bacteria may contribute positively to the nitrogen nutrition of marandu grass. Key words: Brachiaria brizantha, Cerrado, diazotrophic microorganisms.

Soil fertilization and the management of green manure are needed to maintain and increase the soil fertility of Cerrado. Thus, the objective of this study was to evaluate the concentration of nutrients in the shoots and roots of pigeon pea that was fertilized with phosphorus sources that are associated with liming in Cerrado Oxisol. This study was conducted in a greenhouse with a completely randomized design in a 3×2 factorial arrangement with twelve repetitions. The rock phosphate, triple superphosphate and control treatments were associated with the presence and absence of liming; the sources of phosphorus were evaluated. The chlorophyll index and the concentrations of nitrogen, phosphorus, potassium, calcium, magnesium and sulfur in the shoots and roots of pigeon pea that was grown for a period of 107 days were evaluated. In general, the chlorophyll index and nutrient concentration of pigeon pea did not differ when fertilized with phosphate rock and triple superphosphate. The fertilization with rock phosphate and triple superphosphate provides a greater nutrient absorption of pigeon pea in the presence of lime. Key words: Green manuring, Cajanus cajan, triple superphosphate, rock phosphate, chlorophyll index.

Biological nitrogen fixation (BNF) plays an important role in the cowpea cultivation. This study aimed to assess the foliar levels of chlorophyll and the yield components of cowpea subjected to combined inoculation of rhizobia in Cerrado soil. The experiment was carried out in field conditions, from December of 2014 to the march of 2015, in Rondonópolis, Mato Grosso, using randomized block design with ten treatments and three replicates. Were tested the single strains MT8 and MT15 (both of R. tropici), MT16 (R. leguminosarum), BR3267 (Bradyrhizobium japonicum), the strains combinations MT8+MT15, MT8+MT16, MT15+MT16, and MT8+MT15+MT16, nitrogen fertilization (70 kg ha-1 of N-urea), and absolute control (without inoculation of rhizobia and without nitrogen fertilization). Data were subjected to analysis of variance and the averages were compared by orthogonal contrast and F test (p≤0.05). Were assessed the Falker chlorophyll index (at the 40 and 60 days after sowing), number and dry matter of nodules (at the 40 days after sowing), number of pods per plant, grains yield, the concentration and accumulation of nitrogen in grains, and crude protein. The number of pods per plant was increased 33.6% in the combination MT8+MT15. The same effect was observed for the yield grain, which presented an increase of 8.7%, 13.8%, and 16.7% in the combinations MT8+MT16, MT15+MT16, and MT8+MT15, respectively. The nitrogen accumulation in the grains increased 42.7% with the inoculation of MT15 strain. The cowpea responds positively to the usage of combinations of rhizobia strains.

Cowpea culture is spreading in the Brazilian Cerrado Region and specifically in Mato Grosso State. To evaluate the productive characteristics of cowpea inoculated with rhizobia lineages and grown in the Cerrado of Mato Grosso State, we conducted an experiment in a randomized block design with seven treatments, which consisted of five rhizobia lineages. Four lineages were previously isolated from cowpea (MT08, MT15, MT16 and MT23); one was a recommended lineage for cowpea in Brazil (BR3267). Two controls were included: one was equivalent to 75 kg N ha-1 nitrogen and another was without nitrogen fertilization and without inoculation of rhizobia lineage. They were arranged in six blocks totaling 42 parts of 12.5 m² each. At 40 days after sowing (d.a.s.), six plants of ​​each part of floor area were collected to determine the variables plant height, dry mass of shoots and roots, total dry mass, number of nodules, dry mass of nodules, SPAD reading and relative efficiency of each lineage. Data were subjected to analysis of variance using the statistical analysis program SISVAR. To compare the means, it was evaluated with Tukey test at 5% probability and contrast analysis. Regarding the lineage used, the most satisfactory result for plant height was BR3267 lineage; however, there were statistical differences between treatments with nitrogen fertilization. There were significant differences between dry weight of shoots, total dry weight and dry weight of nodules. The BR3267 lineage presented better results in the dry mass of roots and for relative efficiency. The most satisfactory results for SPAD readings and number of nodules were observed in MT15 lineage. The BR3267 and MT15 lineages tested and analyzed had high symbiotic effectiveness for inoculation in cowpea. Key words: Vigna unguiculata, rhizobium, nitrogen fixation.

The programs of soybean breeding have sought to develop, over the years, more productive and more disease resistance cultivars. The objective of this study was to evaluate soybean cultivars and lines for agronomic characteristics and severity of foliar diseases. The experiment was conducted at the Federal University of Rondonia, in Moura-RO, the harvest 2007/2008 in dystrophic Typic. The experimental design was randomized blocks, evaluating 25 strains and five as control (Warranty, Chapadoes, Luziania, Msoy Msoy 8411 and 8914), with four replications. , Plant height at flowering and maturity, height of the first pod; lodging; leaf retention, productivity and number of days to flowering and maturity: the agronomic characteristics were evaluated. For diseases were evaluated septoria (Septoria glycines), the stain-eye frog (frogeye leaf spot) and target spot (Corynespora cassiicola), determining the severity. As for soybean rust (Phakopsora pachyrhizi), the behavior of genotypes to aggressiveness is noted. As they have good agronomic characteristics and low severity as to foliar diseases, UFUS 3, UFUS 6, 7 UFUS, UFUS 11, UFUS 14, 16 and UFUS UFUS 17 lines appear as the most promising materials for cultivation in the region of Rolim Moura-RO.

The cultivation of cowpea ( Vigna unguiculata ) has grown in Brazil, especially in the Cerrado of Mato Grosso, where it is produced in off-season. The association of cowpea plants with rhizobia has provided much of the nitrogen required by this culture. This study aimed at evaluating the development of cowpea inoculated with rhizobia recommended for pigeonpea ( Cajanus cajan ). The experiment was conducted at the Federal University of Mato Grosso, University Campus Rondonopolis-MT under greenhouse conditions. The experimental design was completely randomized with three treatments and four replications. The treatments were composed by commercial inoculant recommended for pigeonpea (composed by the combination of strains BR2003 and BR2801), nitrogen (without inoculation and application of 50 mg N dm -3 ) and a control (without inoculation and nitrogen fertilization). Plants height, SPAD index, number of pods, number of grain, number of nodules, length of pods, dry weight of nodules, dry grain, dry weight of shoot and relative efficiency of the strains were analyzed. Cowpea show significant response for inoculation in all variables, with increase in production equal or superior to the treatment with nitrogen fertilizer. These results indicate the inoculant recommended for pigeonpea has potential use for cowpea under the tested conditions.