Weed development in sunflower and chickpea crops depending on micro-irrigation methods

The article presents the results of experimental studies on the effect of micro-irrigation methods (drip irrigation with the surface laying of irrigation pipelines (IP) and subsoil drip irrigation with laying of IP at a depth of 30 cm) on the species and quantitative composition of weeds. The variant with a natural moisture supply (without irrigation) served as a reference area. Field research was conducted in the period 2020-2021 on the lands of the Brylivs'ke experimental field of the Institute of Water Problems and Land Reclamation of NAAS (Dry Steppe subzone) in sunflower and chickpea crops. Monitoring of the number and species composition of weeds was carried out by applying the recording framework by the method of the Institute of Plant Protection of NAAS during the third decade of May and the third decade of August. Based on the results of experimental research, it was proved that the irrigation methods (and hence the conditions of moisture supply) reliably influenced the degree of weed development in sunflower and chickpea crops. It was specified that the implementation of subsoil drip irrigation on average over the years of research reduced the degree of weed development in sunflower and chickpea crops by 1,65 and 1,55 times, respectively, compared to the typical surface laying of drip irrigation pipelines. Ultimately, that reduced the pesticide load on the field agro-ecosystem by reducing the number of herbicide treatments of crops by an average of 33-50 %. The species composition of weeds was not significantly affected by the method of irrigation. In addition, the researchers have shown that, regardless of the irrigation method, weed development in crops significantly reduced the productivity of the investigated crops: sunflower by 18,0-21,2 % and chickpea by 27,9-29,7 %. At the same time, in non-irrigated conditions, the degree of weed development had a greater impact on crop yield; thus, yield reduction in the reference variant without irrigation was 24,6 % for sunflower and 30,0 % for chickpeas.