Duration of Soil Activity of Foramsulfuron Plus Thiencarbazone-methyl Applied to Weed Species Typical of Sugar Beet Cultivation

Abstract

The duration of the soil activity of an acetolactate synthase-(ALS) inhibiting herbicide which is currently under approval for sugar beet cultivation was determined in a field trial series in Germany in 2013 and 2014. The herbicide containing foramsulfuron (FSN; 50 g L−1) and thiencarbazone-methyl (TCM; 30 g L−1) was applied in different dosages (25+15, 37.5+22.5 and 50+30 g FSN+TCM ha−1) to the bare soil. Five weed species (rapeseed, common lambsquarters, wild chamomile, blackgrass, barnyardgrass) were sown at 5, 10, 15 and 20d after application. The duration of the soil activity was assessed by determining percent weed control in the treated plots. The longest duration was observed after applying 50+30 g FSN+TCM ha−1, but the influence of environment was much stronger than the dosage effect. The mean duration of soil activity was 10 to 15 d in 2013 and longer than 20 d in 2014. Differences among weed species in their response to the herbicide treatments were small.

Selectivity of foramsulfuron + thiencarbazone‐methyl and classic herbicides in sensitive and non‐sensitive sugar beet genotypes

“…Moreover, the use of F + T could simplify weed control by applying a lower number of a.i.s than in the classic strategy. All benefits, including control of weedy crops (Wegener et al ., ) or increased flexibility in application timing due to high efficacy (Wendt et al ., , ), contrast with the risks of weed resistance and/or gene flow (Kudsk & Streibig, ). Thus, all agricultural measures have to be co‐ordinated throughout the whole crop rotation to minimise potential risks and to reach the full potential of systems with non‐sensitive crops and complementary herbicides.…”

“…A new herbicide for sugar beet cultivation containing the ALS‐inhibitors foramsulfuron and thiencarbazone‐methyl – referred to in the following text as ‘F + T’ – is currently being reviewed for EU‐wide approval (KWS SAAT SE, ). Compared with classic herbicides, applications of F + T can start later (beyond the cotyledon stage of the weeds) and the duration of soil activity is longer (Santel, ; Wendt et al ., , ).…”

Changes in Soil Microbial Parameters after Herbicide Application in Soils under Conventional Tillage and Non-Tillage

“…The herbicides S-metolachlor (SMOC), foramsulfuron (FORAM), and thiencarbazonemethyl (TCM) are widely applied in conservation agriculture but scarcely studied in the literature, especially FORAM and TCM [25]. They belong to different chemical groups (chloroacetanilide, sulfonylurea, and sulfonylamino-carbonyl triazolinone, respectively) with different structures and physicochemical properties, being used to control grasses and some broadleaf weeds in a large variety of crops sown in different seasons of the year [26].…”