Comparative evaluation of increased rates of the herbicide fluroxypyr in green onions
Weeds are the main competitors of onions in vegetation.
There is a lack of herbicidal options for weed control in this crop.
Therefore, a field experiment in two consecutive vegetation seasons (2020 and 2021) was performed.
The study was stated in the base for training and implementation at the Agricultural University of Plovdiv, Bulgaria.
The grown onion cultivar was Lyaskovski 90. The trial included increased rates of Hurler EC (200 g L‑1 fluroxypyr) applied at rates from 0.3 to 1.8 L ha‑1 (treatments 2-7) in the 2nd-3rd leaf of the crop (BBCH 12-13). The obtained results were compared with untreated weedy control (treatment 1). The efficacy of the applied herbicidal product and its rates against the weed species Amaranthus retroflexus L. and Portulaca oleracea L. was recorded.
The selectivity of the herbicidal product to the crop by using the 9-score visual phytotoxicity scale of EWRS (European Weed Research Society) was estimated.
The following crop plant parameters were under evaluation: total chlorophyll content, fresh weight, leaf number, and total soluble solids content.
The efficacy against P. oleracea varied from 43.50 to 95.75% from the rates from 0.3 to 1.8 L ha‑1. The control against A. retroflexus was lower NDASH from 46.75 to 91.25% between the rates from 0.3 to 1.8 L ha‑1, respectively.
No phytotoxic symptoms were found for the rates from 0.3 to 0.6 L ha‑1. Phytotoxicity score 3 at the rates of 0.9 and 1.2 L ha‑1 (yellowing of the young leaves) was observed.
Increasing the rates to 1.5 and 1.8 L ha‑1 phytotoxicity score 4 (chlorosis and stunting) was found.
The studied parameters as total chlorophyll content and total soluble solids content decreased from the rates of 0.9-1.8 L ha‑1. A slight decrease was found for the leaf number and fresh weight after the application of the rates from 0.3 to 0.9 L ha‑1 while the decrease was more severe for the higher evaluated rates of Herler EC.
Neshev, N., Yanev, M., Mitkov, A. and Shopova, N. (2024). Comparative evaluation of increased rates of the herbicide fluroxypyr in green onions. Acta Hortic. 1398, 125-132
DOI: 10.17660/ActaHortic.2024.1398.17
https://doi.org/10.17660/ActaHortic.2024.1398.17
DOI: 10.17660/ActaHortic.2024.1398.17
https://doi.org/10.17660/ActaHortic.2024.1398.17
onions, weeds, fluroxypyr, selectivity, fresh weight
English