Evaluation of two chemical weed control systems in sugar beet in Germany and the Russian Federation

Abstract

Roundup Ready® sugar beets are widely grown in the USA since their market introduction in 2005. The system has proven to be cost-efficient and reliable. However, the negative social image among consumers and politicians has prohibited the adoption of this technology in Europe. Seven field experiments were conducted over three years in Germany and the Russian Federation to compare weed control efficacy and sugar beet yields of post-emergent glyphosate applications with conventional selective herbicides. Although weed infestations at the Russian sites were higher than in Germany, weed control efficacies were similar at both locations ranging between 78% and 100%. Glyphosate applications resulted in significantly higher weed control efficacies than the conventional herbicides in four out of 7 experiments. In five experiments, a single glyphosate application gave equal weed control efficacy as two and three glyphosate applications. White sugar yield was always higher in the weed control treatments than in the untreated plots. There was no yield difference between treatments based on glyphosate and conventional herbicide applications in 6 out of 7 experiments. The results demonstrate a slight benefit of the glyphosate-based weed control program compared to the conventional herbicide system in terms of weed control efficacy.Keywords: weed management; competition; Beta vulgaris; pesticide; yield loss 489Plant Soil Environ. Vol. 61, 2015, No. 11: 489-495 doi: 10.17221/482/2015-PSE dosage of the herbicide usually has to be increased to achieve suitable biological efficacy of the weeds. However, the increase of the herbicide application rate may cause stress to the crop and potentially express symptoms of phytotoxicity. The application is typically conducted as a tank mixture of several herbicidal substances adjusted to the weed species present (Petersen 2008). Weed shift caused by conventional weed control with selective herbicides has favoured several difficult-to-control-weeds, such as Fallopia convolvulus L., Mercurialis annua L., Solanum nigrum L. and Aethusa cynapium L. (Vasel et al. 2012). These weeds became less susceptible to herbicides or escaped weed control by late emergence.Roundup Ready® system based on glyphosatetolerant sugar beet cultivars and use of glyphosate containing herbicide is an alternative technology for weed management in sugar beet (Nichterlein et al. 2013). In the USA, this technology was very rapidly adopted by farmers and in 2009, 85% of the sugar beets produced in the USA were Roundup Ready® cultivars (Nichterlein et al. 2013). This technology combines high weed control efficacy with high selectivity and is supposed not to require herbicide application at early growth stages of the weeds. Usually, two to three glyphosate application is performed starting at 4-leaf stage of sugar beets (Dewar et al. 2003, Brookes and Barfoot 2013, Muoni et al. 2013, May et al. 2014). This claim is contradicting the view of weed freeness necessary for yield protection reported by other authors (K...

Effect of different single herbicide doses on sugar beet yield, quality and associated weeds

“…The results emphasized that all the herbicidal treatments except Tigro at the lower dose did not affect sugar beet pigmentation of leaves. Chitband et al (2014) reported that PSII inhibitor herbicide such as chloridazon controlled weeds at higher doses more than other herbicides (except of Portulaca oleracea) by 90 percent reduction in aboveground dry matter yield.…”

“…Up to 100% of the crop yield may be lost because of weed competition if weed control is poor or not performed at all (Schweizer and Dexter 1987). Special attention on weed control has to be paid during the critical period at an early stage of sugar beet development (Bezhin et al 2015), a period of the first 60 days after emergence when sugar beet does not tolerate competitive interactions with weeds without losing yield (Kobusch 2003;Petersen 2008;Jalali and Salehi 2013).…”

Enhancing Sugar Beet (Beta vulgaris L.) Yield and Quality: Evaluating the Efficiency of Chemical and Mechanical Weed Control Strategies

“…A study by Bezhin et al [19] evaluated two chemical weed management systems within a sugar beet field, consistently revealing higher yields of white sugar in plots treated with chemicals as compared to untreated ones. This underscores the urgency of effective weed management, especially when dealing with competitive weed species like Chenopodium album, Amaranthus retroflexus, and Polygonum convolvulus, which can outcompete sugar beet plants and rapidly reduce yields [20].…”