Influence of predecessors on species diversity of weeds in winter wheat crops in the Eastern Forest-Steppe of Ukraine

Abstract

Goal. Determine the species composition of weeds, their dominant role and establish the type and level of weediness of winter wheat crops by cultivation on black fallow, after peas for grain and winter wheat as forecrops in the Eastern Forest-Steppe of Ukraine.
 Methods. The research was carried out by means of route surveys in field experiments located in a stationary nine-field steam-grain-row crop rotation and in a monoculture of winter wheat.
 Results. In total, according to the results of research in 2011—17, 63 species of weeds were found in crops. In the conditions of crop rotation in the fields of winter wheat after black fallow and peas for grain, 50 species and 45 species were found, respectively, and in monoculture — 41 species. The largest number of spring early and late weeds (41—49%), and the second and third places were occupied by wintering, winter and biennial (33—37%) and perennial (18—22%). The main weeds in the crops were: after black fallow — Setaria glauсa, Chenopodium album, Amaranthus retroflexus, Solanum nigrum, Fumaria officinalis, Polygonum lapathifolium, Cyclachaena xanthifolia, Delphinium consolida, Viola arvensis, Erigeron canadensis, Cirsium arvense; after peas for grain — S. glauсa, Echinochloa crus-galli, C. album, A. retroflexus, S. nigrum, F. officinalis, P. lapathifolium, Stachys annua, Malva neglecta, Polygonum aviculare, D. consolida, Thlaspi arvense, V. arvensis, C. arvense, Convolvulus arvensis; after winter wheat — S. glauсa, E. crus-galli, Ambrosia artemisiifolia, Fallopia convolvulus, Lactuca serriola, Capsella bursa-pastoris, D. consolida, Matricaria inodora, Crepis tectorum. In winter wheat crops, the largest share of dominance and subdominance, respectively, were Solanum nigrum L. (71%) and Setaria glauca (L.) Beauv. (71%) after peas for grain. The type of weediness of winter wheat crops depended on the predecessor. In monoculture, there was a higher level of weediness of winter wheat than in crop rotation.
 Conclusions. Rational selection of predecessors creates the basis for successful weed control in winter wheat crops.