Chemical Control of Curled Dock (Rumex crispus L.) and Other Weeds in Noncropped Areas

Abstract

Rumex crispus L. is an invasive species widespread in our country and in particular in the region of North Bulgaria. It is characterized by high biological and ecological plasticity. Owing to its great reproductive potential, the weed has been assigned to the list of economically most important weeds in the country. With the purpose of studying the possibility of chemical weed control in noncropped areas with heavy natural background infestation with R. crispus L. and other dicotyledonous weeds, two field trials were carried out. A ready-to-use herbicide mixture 2,4-D 140.2 g/l-1 + Triclopyr 144 g/l-1, trade product Genoxon 3X (X0050), was tested at two doses of active ingredient, 3552 and 2842 ml/ha-1. It was found that: (1) population density of Rumex crispus L. can be successfully reduced by treatment at the stage of early stem formation; herbicide efficacy with 3552 and 2882 ml/ha-1 doses on the 21st day after treatment was 100% and 90.5%, respectively, at the end of vegetation 94.4 and 85.7%, respectively; (2) herbicidal efficacy was lower when R. crispus L. was treated at the 5 - 6 leaf stage, being 100 – 94.1% and 80 – 76.5% respectively for the indicated doses and time of recording; (3) at the studied doses the herbicide controlled both annual dicotyledonous weeds (Amaranthus spp., Chenopodium album L., Portulaca oleracea L.) and perennial dicotyledonous ones (Cirsium arvense L., Sonchus arvensis L., Convolvulus arvensis L., Carduus acanthoides L.), but it was not toxic to monocotyledonous weeds.

Rumex crispus L. je invazivna vrsta koja se nalazi širom naše zemlje, a naročito u području severne Bugarske. Karakteriše ga visoka biološka i ekološka plastičnost. Zbog svog velikog reproduktivnog potencijala, ovaj korov je stavljen na listu ekonomski najznačajnijih korova u zemlji. U cilju proučavanja mogućnosti hemijskog suzbijanja korova u oblastima bez useva, sa velikom pozadinskom prirodnom infestacijom R. crispus L. i drugim dikotiledonim korovima, izvedena su dva poljska ogleda. U ispitivanju je korišćena gotova mešavina herbicida 2,4-D 140,2 g/l-1 + triklopir 144 g/l-1 u obliku preparata Genoxon 3X (X0050), i to u dve doze aktivne materije: 3552 i 2842 ml/ha-1. Doneti su sledeći zaključci: (1) gustina populacije Rumex crispus L. može se uspešno smanjiti tretmanom u stadijumu početnog razvoja stabljike; efikasnost herbicida u dozama od 3552 i 2882 ml/ha-1 21. dana nakon tretmana bila je 100% i 90,5%, respektivno, a na kraju vegetacije 94,4 i 85,7%; (2) efikasnot herbicida bila je niža kada je vrsta R. crispus L. tretirana u stadijumu 5-6 listova i iznosila je 100-94,1% i 80-76,5% za ispitivane doze u navedeno vreme ocenjivanja; (3) primenjene doze herbicida suzbile su jednogodišnje dikotiledone (Amaranthus spp., Chenopodium album L., Portulaca oleracea L.) i višegodišnje dikotiledone korove (Cirsium arvense L., Sonchus arvensis L., Convolvulus arvensis L., Carduus acanthoides L.), ali herbicid nije pokazao toksičnost za monokotiledone korove.