Herbicidal weed control in plum orchards

Effective weed control in orchards, including plum (Prunus domestica L.) is essential for obtaining high and stable yields. In 2018 a field trial with well-established, new and promising soil- and foliar herbicide products was conducted. Some of the herbicides object of evaluation were applied before, and others during the vegetation of the crop. The efficacy of the studied soil herbicide products was reported on the 30^th, 60^th, 90^th and 120^th day after application, and the efficacy of the foliar herbicides on the 7^th, 14^th, 28^th and 56^th day after application was evaluated. The existing weeds on the field with the highest density were Stellaria media L., Poa annua L., Veronica hederifolia L., Lamium amplexicaule L., and the perennial species Taraxacum officinale L. Before the application of the foliar herbicides the weeds with the highest density were Veronica hederifolia L., Stellaria media L., Poa annua L., Capsella bursa-pastoris Medik., Alopecurus myosuroides Huds., Conyza canadensis L., Portulaca oleracea L., Solanum nigrum L., Polygonum aviculare L., Amaranthus retroflexus L., Setaria viridis L. Taraxacum officinale L. and Convolvulus arvensis L. It was found that at the present weed infestation the application of Stomp Aqua CS (455 g L^‑1 pendimethalin) had an excellent herbicide efficacy. The efficacy of the herbicide product Pledge 50 WG (flumioxazin 500 g kg^‑1) (400 g ha^‑1) is appropriate if the infestation is presented by more difficult-to-control weed species. It was also observed that the application of the total contact bio-herbicide with active substance eucalyptus oil had short efficacy after which a secondary weed infestation developed on the field. The application of the total systemic herbicide Roundup Energy (450 g L^‑1 glyphosate) was found to be a highly effective mean for weed control in plum orchards.