Weed composition and control in apple orchards under intensive and extensive floor management

Abstract

Weed control in apple tree (Malus domestica [Suckow] Borkh.) orchards continues to be a major problem. Weeds compete with fruit trees, which is manifested in production quality and quantity. The aim of this study was to determine the weed flora of apple orchards with different floor management practices and to investigate the efficacy of the diquat, oxyfluorfen, glyphosate, and fluazifop-P-butyl herbicides. Experiments were conducted during 2015 and 2016 in orchards under intensive (Ruski Krstur) and extensive (Sombor) floor management. Annual, perennial broad-leaf, and grass weeds were identified. Dominant weed species in both apple orchards were Poa annua, Hordeum murinum, Conyza canadensis, Portulaca oleracea, Cynodon dactylon, Sorghum halepense, Carduus acanthoides, Amaranthus retroflexus, Cirsium arvense, Chenopodium album, and Solanum nigrum. After the first and second assessments, the best results occurred with glyphosate in both orchards and total efficacy ranged from 88.42% to 98.32% in the orchard under intensive floor management and 90.32% to 95.55% in the orchard under extensive floor management. Diquat and oxyfluorfen have shown good results, but their efficacy was lower than for glyphosate. Fluazifop-P-butyl, as a selective herbicide, showed low efficacy at both sites; it had high efficacy on grass weeds, but no effects on broad-leaf weeds.