Desempenho de cultivares de trigo coinoculadas com bactérias nodulíferas

Abstract

The microorganisms found in the rhizospheric region of the plants performance in their physiological and productive development through the fixation and supplement of nutrients and the production of plant development hormones. Between these nutrients stands out nitrogen, which is an essential element in the structure of plant tissues. The Wheat (Triticum aestivum L.) is first consumed cereals in the world and the need to reduce the application of nitrogen fertilization leads us to research the effectiveness of biofertilization. Thus, the objective of this work was to evaluate the efficiency of the nodulifer bacteria co-inoculation on the development of wheat cultivars. The experiment was conducted in a greenhouse in a randomized block design in a 13x3 factorial model with four replications. The treatments were: T1 (commercial wheat inoculant - Azospirillum brasilense), T2 - (commercial soybean inoculant - Bradyrhizobium japonicum), T3 (commercial cowpea inoculant - B. japonicum), T4 (MT08 - Rhizobium tropici), T5 ( MT16 - R. leguminosarum), T6 (MT15 - R. tropici), T7 (A. brasilense + inoculant for cowpea), T8 (A. brasilense + MT08), T9 (A. brasilense + MT16), T10 (A. brasilense + MT15 ), T11 (A. brasilense + B. japonicum), T12 (nitrogen control) and T13 (absolute control) and three wheat cultivars: BRS 394, BRS 264 and BRS 254. The variables analyzed were: number of leaves, plant height, Falker chlorophyll index, number of tillers and number of spikelets at 30, 40 and 50 days after sowing (DAS). After the cycle were avaluated air dry mass, root, total and grains, root volume, relationship between air dry mass and root, number of spikelet, mass of one hundred grains, one hundred grains, concentration and nitrogen accumulation in grains and gross protein. Data were subjected to analysis of variance and means compared by Scott-Knott test at 5% probability. There was isolated effect and interaction between treatments. The most efficient strains MT 15 (R. tropici) and inoculant for cowpea (B. japonicum) isolated or coinoculated with A. brasilense. The plant height at 40 and 50 DAS the highest averages were observed in the treatment with commercial inoculant for wheat. The Falker chlorophyll index was higher in treatments with comercial inoculant for wheat (A. brasilense) at 40 DAS (37,55) and MT 15 to 50 DAS (40,13). The inoculant for cowpea and MT 15 strain showed better efficiency in the dry mass of the area (80.40 g and 8.90 g) dry mass (4.11 g and 4.47 g) and volume (0.026 dm-3 and 0.029 dm-3) of roots, number of ears (14.91 the both), number of leaves at 30 DAS (66 and 77.33) and dry mass of the grains (5.8766 g and 5.2383 g). Based on the results, it is concluded that nodular bacteria have the potential for nitrogen supplementation to the tested wheat cultivars.