EFFECT OF INORGANIC AND CHELATE FORMS OF ZINC- AND COPPER-CONTAINING FERTILIZERS ON WHEAT GRAIN PRODUCTIVITY AND QUALITY CHARACTERISTICS

The paper presents the results of experiments on evaluating the effectiveness of the use of zinc and copper chelates with oxyethylenediphosphonic acid against the background of their comparison with tradi-tional (sulfate) forms of microelements in the cultivation of soft winter (Moskovskaya 56 variety) and spring wheat (Zlata variety). In field experiments conducted in 2018–2020 on the territory of the Nizhny Novgorod Region, zinc and copper chelates were used at an active ingredient dose of 100 g/ha. It was found that the chelate form of zinc contributed to an increase in the yield of winter wheat grain by 0.37 t/ha (3.13 t/ha in the control variant). On spring wheat, the highest grain yield was noted when using the sulfate form of zinc (2.13 t/ha of grain), which exceeded the control value by 1.01 t/ha. The best in terms of weight of 1000 grains (58.65 g) on winter wheat was the variant with zinc sulfate, where the maximum value of this indicator (54.56 g) was recorded. Both trace elements had a positive effect on the mass of 1000 seeds of spring wheat: the variation ranged from 41.80–42.70 g against the background of copper-containing fertilizers to 42.40–44.97 g against the background of zinc forms of fertilizers, while it was proved that chelates showed themselves in the best way compared to the control (39.13 g). The maxi-mum content of crude gluten was characterized by the grain of winter (21.0 %) and spring (24.7 %) wheat on the variant with foliar feeding with zinc sulfate, where the increase to the control was 3.2 and 3.5 %, respectively. The gluten deformation index ranged from 52 units on spring wheat up to 80 units on winter wheat, which characterrized it as good and satisfactorily weak, respectively. When using the sulfate form of zinc, there was a tendency to increase the concentration of crude (11.87 %) and digestible (9.50 %) protein in winter wheat grain. The chelate form of zinc showed close values, but still yielded to the variant with metal sulfate. On spring wheat, the best in terms of the content of crude (10.61 %) and digestible (8.49 %) protein was the variant with the use of zinc sulfate, which provided an increase to the control of 0.23 and 0.18 %, respectively.