No abstract

During the period 2020-2021 at the experimental field of the Institute for roses and aromatic plants - Kazanlak on meadow-cinnamon soil a field experiment was carried out in the oil-bearing rose plantation (Rosa damascena Mill.). The study was carried out on the herbicidal efficacy and selectivity of Centurion super (120g/l clethodim) and Cliofar 600 SL (600g/l clopyralid) applied in vegetation of the culture. High biological efficacy of 88-91% of clethodim has been reported against annual monocotyledon weeds and 90-92% against perennial weeds. Clopyralid has a high herbicidal effect on the annual and perennial dycotyledon weeds - 90-96%. During the study period, a higher yield of fresh blossom was obtained with the herbicides used compared to the control by 230 and 700kg/ha. With regard to the amount of essential oil obtained, it was found that the herbicides under study exceeded the control by an average of 285 and 425kg/ha. The results of the study show that in all herbicide-treated variants, visual symptoms of phytotoxicity were not observed.

During the period 2014 – 2015 the herbicidal effect and the selectivity of isoxaflutole (Merlin 750 WG), oxadiargyl (Raft 400 SC), imazamox (Pulsar 40) and flumioxazine (Pledge 50 VP) were studied on lavender fields, Hemus and Jubilejna varieties. The present work focuses on the influence of low doses of the applied preparations on the yield and composition of the essential oil compared with untreated control. The results of two-year studies show that the treated variants have a higher yield on average of 0.7-1.6 kg / dka. The odoriferous ingredients range in the limits: linalyl acetate (20.0 - 38.6 %); linalool (20.6 - 46.2 %); lavandulyl acetate (1.9 - 5.9 %); 1,8 cineole (0,4 - 4,9 %) and camphor (0,2 - 0,6 %). Applying oxidiarigil results in greater changes in the composition of the Jubilejna variety, whereas the Hemus variety has the most influence by isoxaflutole.