Dynamics of chlorophylls and dry matter accumulation in the leaves of Miscanthus × gigantheus under the influence of agricultural technology
Authors: Honcharuk O. M. , Prysiazhniuk O. I. 
Published: December 2022

Purpose. To reveal the peculiarities of the accumulation of chlorophyll and dry matter in the leaves of Miscanthus × gigantheus under the influence of elements of agricultural technology.

Methods. The research was conducted in the conditions of the Bila Tserkva Experimental Breeding Station of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agricultural Sciences in the years 2019–2021 in accordance with generally accepted methods. Miscanthus × gigantheus variety ‘Osinnii Zoretsvit’ was grown according to the scheme of a three-factor field experiment, which included inoculation with Azophosphorin, (1 l/ha), adsorbent MaxiMarin granulated (30 kg/ha), potassium humate (Humifield) (50 g/ha) and antistress product AminoStar (1.0 l/ha) for foliar fertilization during the growing season.

Results. The content of dry matter in the stage of the beginning of tillering, this indicator varied over the treatments in the range from 41.8 to 45.5%, as of 12.08 – from 45.6 to 47.3%, and in the stage of emergence into the leaf tube – from 51.1 up to 54.5%. At the same time, all deviations between the treatments were within the experimental error. Some tendency to increase this indicator was noted only in the treatments of complex application of Potassium humate (Humifield), 50 g/ha + AminoStar, 1.0 l/ha. The content of chlorophylls a and b in the leaves of miscanthus plants at the time of tillering was 1.53 and 0.80 mg/kg, on average, in the treatments without applying Azophosphorin, respectively, and in the case of using this product – 1.73 and 0.96 mg/kg, and the amount of chlorophyll in these treatments of the experiment increased by 0.36 mg/kg. As of 12.08, in the treatment with Azophosphorin, an increase in the concentration of chlorophylls to 4.17–4.35 mg/kg was noted with the additional use of potassium humate (Humifield), 50 g/ha and AminoStar, 1.0 l/ha separately and in the complex. In the stage of emergence into the leaf tube, the effect of Azophosphorin on the content of chlorophylls in the leaves decreased, because during the formation of a significant amount of biomass, the needs of plants and the root system formed by them are quite significant in order to find alternative sources of mineral nutrition in the soil. At the same time, when applying foliar fertilizer Potassium humate (Humifield), 50 g/ha + AminoStar, 1.0 l/ha, the trend of chlorophyll accumulation in plant leaves and their amount remained within the range of 6.82–7.09 mg/kg.

Conclusions. The application of the studied agrotechnical measures did not significantly affect the accumulation of dry matter in the leaves of miscanthus during the growing season in the third year of cultivation. As for the content of chlorophylls, inoculation with Azobacterin had a significant impact on the formation of this indicator at the initial stages of the crop development. However, the effect of this factor decreased already during the tests in the stage of emergence into the leaf tube, and the tendency towards an increase in the content of chlorophyll was observed only in the treatments of the use of the drugs Potassium humate (Humifield) and antistress product AminoStar.