Methods of Zinc and Manganese Application in Two Soybean Cultivars.

Studies have been developed aiming to identify the best management manganese (Mn) and zinc (Zn) application of seeking to soybean (Glycine max L.) productivity. However, there is still no agreement in the results because the dynamics of these nutrients is also influenced by the time and method of application. The aim of this study was to determine the effect of methods of Mn and Zn application in soybean cultivars. Experiment was conducted at experimental field of the Federal Institute of Science and Technology of Mato Grosso (IFMT), Campo Novo dos Parecis, Mato Grosso, Brazil (13¼ 40' 31" S and 57¼ 53' 31" E and altitude of 572 m) from October 2013 to February 2014. Experimental design was a randomized block in a factorial scheme  2 x 10, with 4 replications. Treatments were: two cultivars of soybean (TMG 1179 RR and TMG 4182) with ten treatments of methods of Zn and Mg application (T1: without Mn and Zn application; T2: Mn application in soil; T3: Zn application in soil; T4: Mn in foliar application; T5: Zn in foliar application; T6: Mn in soil application + Mn in foliar application; T7: Zn in soil application + Zn in foliar application; T8: T2 + T3; T9: T4 + T5 and T10: T6 + T7), in 80 plots of 20 m² each. Sulfate manganese was used as source of Mn and sulfate of zinc as source of Zn, with recommendation, 5 kg ha^-1 when applied to soil and (0.5%) when applied on the leaves. It were evaluated the productivity and concentrations of Mn and Zn in soybean grains. The highest productivity (4,000 kg ha^-1) was obtained by cultivar TMG 4182. Zinc in soil application increased 500 kg ha^-1 of grain when compared to the control treatment. There were no differences between cultivars in grains Zn concentrations. Highest Mn concentrations in the grains were observed in TMG 1179 cultivar (20 mg kg^-1 of Mn). Manganese and Zn application did not provide increase productivity for the transgenic cultivar, while the Zn application increased productivity in TMG 4182 cultivar.