Optimizing herbicide doses for weed control in winter wheat (Triticum aestivum L.) in the Moscow region of Russia

Abstract

One of the main reasons for the reduction of winter wheat yields in Russia, as in most major wheat-producing countries, is the massive infestation and rapid spread of annual weed species. Thus, this study was conducted during 2022 at D.N. Pryanishnikov Russian Research Institute of Agro chemistry, Russia with main objective to optimize the concentration of broad-spectrum herbicides: Lintur, VDG (659 g/kg dicamba-sodium + 41 g/kg triasulfuron), Bucephalus, KE (480g/L carfentrazone-ethyl), Camaro SE (6. 25 g/L florasulam + 300 g/L 2,4-D), Prima Forte 195 SE (180g/L 2,4-D + 10g/L aminopyralid +5g/L florasulam), and their plant growth regulator mixtures Moddus, KE (250 g/L trinexapac-ethyl) to protect winter wheat crops from weeds at Barbino (Russia). An inventory conducted on the study plot showed that the total number reached 434 pants/m2 weeds, with a total of 9 weed species namely Cirsium arvense, Cardaria draba, Galium aparine, Matricaria discoidea, Chenopodium album, Polygonum aviculare, Galeopsis tetrahit, Capsella bursa-pastoris, and Sinapis arvensis of which 73.9% are annual species with a vegetative cycle parallel to that of winter wheat. Herbicide application at 50% showed little difference in weed control efficacy (%) compared to standards and ranged from 56.0 to 100.0% depending on treatment and weed species. Both individually applied herbicides and their mixtures with Moddus and free weed control contributed to a significant increase in yield and the increase was from 12.3 to 23.7%. Yield when using the options mixture with the growth regulator Moddus was higher than the individual application of herbicides regardless of the dose. Yield at a dose of 50% was slightly higher or lower compared with the manufacturer's standard. In general, the growth regulator did not affect herbicide efficacy, but its combination with herbicides improved yield structure elements and increased yield quality of winter wheat.