Розвиток ринхоспоріозу та його шкідливість на посівах ячменю озимого в умовах західного лісостепу

Abstract

The article presents the results of research on the development of rhynchosporiosis on winter barley varieties: Zbruch, Valkiria, Snihova koroleva, Dostoinyi, Status, Darii on a natural background in the conditions of the Western Forest-Steppe. It has been established that the development of this disease depends on weather conditions, vegetation phases of the culture and variety. During 2021–2023, in the phase of emergence into the tube, the lesion was 0.5–5.0%, in the ear phase – 1.0–7.0%, in the milk ripeness phase – 13.5–35.0%. The lowest development of the disease was noted in the following varieties: Snihova koroleva (14.7%), Valkiria (14.7%), Status (14.2%). The species composition of rhynchosporiosis is presented by the causative agent Rhynchosporium graminicola Heinsen. Taking into account climate changes, the development of this disease on the studied varieties increased in 2023 compared to previous years. The appearance and development of rhynchosporiosis on winter barley is facilitated by the increased amount of precipitation in the third decade of May and the first decade of June (Hydrothermal moisture coefficient was 1.4 and higher). It should be noted that damage to winter barley by this disease affects the length of the ear, the number of grains in it, the weight of the grain in the ear and the weight of 1000 grains. The coefficient of harmfulness, depending on the level of development of the rhynchosporiosis, was in Zbruch 0.24–0.38%. The higher the development of the disease, the higher the coefficient of harmfulness was. Thus, with 50% development of rhynchosporiosis, the harmfulness coefficient was 0.3; and with 75%, respectively, 0.36; at 90% – 0.38. With 90% disease development, there was a decrease in the number of grains by 5.1 pcs. compared to healthy plants. The mass of grain in an ear decreased by 0.16 g, the mass of 1000 grains decreased by 3.4 g.