Effectiveness of protecting amaranth crops from fungal diseases

Abstract

Given the current small acreage, the development of diseases on amaranth plants is insignificant. However, with the expansion of cultivated areas and under weather conditions favourable for the development of pathogens and unfavourable for plant growth, crops may develop mycoses caused by fungi of the genera Fusarium, Cercospora, Colletotrichum, Alternaria, Rhizoctonia, Pythium and Cladosporium, as well as viral diseases. Research on the ef-fectiveness of fungicides on amaranth crops was conducted in 2022–2023 on dark grey podzolic soil at the experi-mental field of the Department of Plant Production Technologies of the Lviv National University of Natural Re-sources. The experimental design included a control and five variants of fungicide application during the panicle formation phase of amaranth plants. The effectiveness of the following preparations was studied: Abacus, 12.5 % s.e. (suspension emulsion), Acanto Plus, 28 % s.c. (suspension concentrate), Amistar Extra, 28 % s.c., Quadris Top, 32.5 % s.c., Madison, 26.3 % s.c., which contain two active ingredients – from the triazole group and the stro-bilurin group. At the time of spraying amaranth with the studied preparations in the budding phase, the degree of plant damage by the main diseases was weak and amounted to: anthracnose – 2.5 %, phomopsidosis – 3.0 %, alter-nariosis – 2.0 %. On the third day after spraying, the difference in plant damage was observed between the experi-mental variants and the control, but was not noticeable between the variants themselves. On the seventh day after spraying, the development of diseases in the variants with fungicides differed slightly depending on the product applied and increased in the control. The use of fungicides effectively limited the further development of anthrac-nose, phomopsis and alternariosis on plants. Plant damage in the fungicide-treated variants was minimal compared to the control. The effectiveness of fungicides containing two active ingredients – from the triazole and strobilurin groups – at the beginning of the budding phase has been established. The choice of specific preparations for spraying plants should be made taking into account the dominant types of phytopathogens.