The effect of nitrogen fertilizing and fungicide application on the yield and selected parameters of grain quality of winter wheat

In 2001–2004 an influence of gradually increased portions of nitrogen (100–130–160 kg/N.ha–1) applied on the wheat variety Ebi in combination with the modified fungicidal protection in the yield and the selected quality grain parameters were observed within the small-plot field trials. Nitrogenous fertilizers according to the amount of nitrogen contained were applied in 2–4 terms during vegetation in regeneration (55kg/N.ha–1), 1st production (45kg/N.ha–1), 2nd production (30kg/N.ha–1) and qualitative portion (30kg/N.ha–1). The fungicidal protection was based on the equal treatment in the phase of BBCH 37 and with regard to the varieties different treatment in the phase of BBCH 55. The dependence on the year was proved at all observed parameters. Higher intensity of nitrogenous fertilization had no decisive impact on the yields. From the point of view of increased yields, the second production nitrogenous fertilization had the strongest impact; it increased the grain yields by 0.084–0.461 t./ha–1. Higher intensity of nitrogenous fertilization positively influenced the baker’s grain quality. The increased portions of nitrogen decisively increased the volume of N-substances in all trial years. The second production nitrogenous fertilization increased the N-substances volume from 0.1 to 0.8%. Qualitative additional fertilization increased their volume from 0.26 to 1.38%. Higher N portions increased sedimentation in most cases. The falling number was not considerably influenced. The mechanical grain qualities (volume weight, number full grains, and GTW) were relatively less influenced than the baker’s quality by the nitrogenous fertilization. The application of fungicides positively influenced not only the yields but also mechanical qualities of the grain, i.e. volume weight, thousand grains weight and portion of Full grains. On the contrary the baker’s quality was not decisively influenced. It was proved that the decisive fungicidal treatment is the one applied in the period of coming to ear (BBCH 55). Single fungicidal treatment in the early period of the flag leaves (BBCH 37) increased the yields only by 6% and the grain quality was not decisively influenced. Double treatment then increased the yields by 18.15% in average. The highest increases were reached at fungicidal varieties fertilized with the nitrogen portion (19.55%), the lowest after application of the N portion on the level of 100kg/ha–1. Here the grain yields were also in average 16.77% higher than the yields of the untreated varieties. The highest grain yields after the application of fungicide was reached in 2003 (26.16%) and the lowest in 2001 (14.16%). The differences in the yields at the varieties with the full fungicidal protection and different spectrum of fungicides used were not statistically evident in the trial duration. The increase in the yields contrary to untreated variety and the variety with the limited fungicidal protection (application of fungicides only in BBCH 37) was statistically evident in most cases. The least effective was the impact of the fungicide Caramba in the portion of 1 l/ha–1. On the contrary, the varieties containing the fungicides with the agent from the group of strobilurins including Charisma containing the agent of famoxate proved very good results. GTW was most influenced by the fungicidal protection. The relative increase of GTW was between 7.53–11.48%. This value was positively influenced by the application of Juwel followed by Amistar in full as well as reduced portion combined with azol contained in Caramba. With regard to the fact that these trends were reached in all years of the trial, we can say that strobilurins have the positive impact on the value of this parameter. In average of the trial duration as well as in particular years the positive impact of the double fungicidal treatment on the number of full grains (2.76–3.37% increase) was proved. On the contrary, the fungicidal protection decreased the value of the falling number by 1.52–10.23%.