Strategier til ukrudtsbekæmpelse i sukkerroer
Konklusion
I tre forsøg undersøges strategier til bekæmpelse af ukrudt. Der har i år generelt været en meget god effekt af alle ukrudtsstrategier med Betanal, og de største forskelle blev observeret når man udelader Betanal i en strategi. Sæsonen 2023 var kendetegnet ved en meget tør og varm forsommer. Disse betingelser resulterede i nedsat effekt af de første ukrudtsbehandlinger, især jordmidlerne havde ikke den forventede virkning.
Der er udført forskellige strategier med og uden clomazon (Centium) – de fytotoksiske skader fra clomazonbehandlingerne har igen i år været tydelige – og det har resulteret i begrænsede udbyttetab i de parceller der har fået clomazon efter fremspiring. På effektdelen synes Centium efter fremspiring at kunne forøge effekten overfor hundepersille, sort natskygge og spildraps.
I årets forsøg har der været tre led med triflusulfuron-methyl (Safari) – der blev vist signifikant forskel på effekt af Safari overfor hundepersille, lugtløs kamille og spildraps. Der blev i november 2023 truffet beslutning i EU om at forbyde aktivstoffet triflusulfuron-methyl pr. 19/8 2024, og derfor er det fortsat vigtigt at lede efter alternativer til midlet.
I led 14 og 15 er to biostimulanter afprøvet mht. om de kan hjælpe planterne imod fytotoksiske skader fra herbicidbehandlingerne. Der er i årets forsøg fundet signifikant lavere niveau af skader i disse led i sammenligning med samme behandlingsstrategi uden biostimulanter. Der blev ikke målt udbyttestigning i leddene med biostimulanter, på trods af signifikant lavere niveau af fytotoksiske skader.
Conclusion
In three trials, strategies for weed control are investigated. This year has in general showed a very good effect of all weed control strategies with Betanal and the main differences in the trials were observed between entries with or without Betanal. The 2023 season was characterized by a very dry and hot early summer. These conditions resulted in decreased efficacy, especially of soil herbicides.
Different strategies have been carried out with and without clomazone (Centium) – the phytotoxic damage from clomazone treatments has been evident again this year – and this has resulted in limited yield losses in the plots that have received clomazone after emergence. On the efficacy part, Centium after emergence seems to be able to increase the effect against fool’s parsley, black nightshade and volunteer oilseed rape.
In this year’s trials, three entries were with triflusulfurone-methyl (Safari) – a significant difference was shown in the efficacy of Safari against fool’s parsley, scentless chamomile and volunteer oilseed rape. A decision was made in November 2023 in the EU to ban the active substance triflusulfurone-methyl, and therefore it remains important to look for alternatives to the herbicide, as season 2024 will be the last with this herbicide.
In treatment lines 14 and 15, two biostimulants have been tested to see if it can help plants against phytotoxic damage from herbicide treatments. In this year’s trials, significantly lower levels of phytotoxic damage have been found in the treatments entries that have received biostimulants compared to a treatment entry that has received the same treatment strategy, but without biostimulants. No yield increase of treatments with biostimulants was measured, despite significantly lower levels of phytotoxic damage.