Control Of Broad-leaved Weeds Research Articles

Glucose-montmorillonite hydrochar composite activating peroxymonosulfate for sulfentrazone rapid degradation and phytotoxicity alleviation to rice

Sulfentrazone is an excellent herbicide for the control of broad-leaved weeds and some grasses. However, its herbicidal residues pose potential risks to the environment. The use of carbonaceous materials as catalysts for activating peroxymonosulfate (PMS) for managing pesticide contamination has attracted considerable attention. Herein, the rapid degradation of sulfentrazone in water and the alleviation of sulfentrazone-induced phytotoxicity alleviation to rice were investigated using glucose-montmorillonite hydrochar (GM-HC) activating PMS. The findings revealed that the GM-HC/PMS system can rapidly degrade sulfamethoxazole and achieved 93.90% of removal efficiency in 24 h. Specifically, GM-HC activating PMS generated the active species, including sulfate radicals (SO4•–), singlet oxygens (1O2) and superoxide radicals (O2•−), which speeds up the degradation of sulfentrazone. Five major degradation products of sulfentrazone and two possible degradation pathways were proposed. The C-Cl and C-CH3 of sulfentrazone molecules are the initiation sites attacked by active species for degradation according to density functional theory (DFT) calculation. Additionally, after the sulfentrazone was degraded by GM-HC/PMS system, sulfentrazone-induced phytotoxicity to rice seeds and seedlings was significantly alleviated. This work presents a novel approach for addressing herbicide wastewater pollution.Graphical

Pyroxasulfone based tank-mix herbicide combinations for diverse weed flora control in wheat

Field studies were conducted to assess the efficacy of pyroxasulfone alone and its combinations with other herbicides at different time of application against a diverse weed flora in wheat (Triticum aestivum L). Applications of pyroxasulfone at 125 g/ha as pre-emergence (PE) or early post-emergence (EPO) at 20 days after sowing effectively controlled the grass weeds (Phalaris minor Retz. and Avena ludoviciana Durieu). However, pyroxasulfone alone exhibited poor control of broad-leaved weeds, such as Medicago denticulata Willd and Rumex dentatus L. To address the limitations in controlling broad-leaved weeds, tank mix combinations of pyroxasulfone at 125 g/ha with either pendimethalin at 1000 g/ha or metsulfuron at 4 g/ha or metribuzin at 300 g/ha proved highly effective. Pre-emergence pyroxasulfone application in combination with either metsulfuron (125 + 4 g/ha) or with metribuzin (125 + 300 g/ha) in wheat gave effective control of diverse weed flora and improved wheat productivity by 52.1% and 51.2%, respectively, over untreated control. Ready mix combination of clodinafop + metribuzin 60 + 210 g/ha applied as post emergence (32 DAS) provided >99% control of P. minor, A. ludoviciana, M. denticulata and R. dentatus L., however the phytotoxicity with this treatment produced 6.7% lower yield as compared to season long weed free conditions. Among the herbicidal treatments, pre-emergence application of pyroxasulfone + metsulfuron at 125 + 4 g/ha had the highest net returns followed by alone application of pre-emergence metribuzin at 300 g/ha.

Early Spring Broadleaved Weed Control during Seedling Dormancy in Regenerated Pedunculate Oak Forests

In regenerated oak forests, weeds are present throughout the year, with the ones appearing in early spring representing a major problem. Hence, the aim of this study was to examine herbicides for early spring broadleaved weed control in regenerated oak forests while the seedlings are in a dormant stage. During 2019 and 2020, two experiments were set up in regenerated pedunculate oak forests with 2- and 3-year-old seedlings, and two herbicides were applied in two doses: fluroxypyr at doses of 360 g a.i. ha−1 and 540 g a.i. ha−1 and clopyralid at doses of 100 g a.i. ha−1 and 120 g a.i. ha−1. Fluroxypyr and clopyralid significantly reduced early spring broadleaved weeds in the regenerated pedunculate oak forests, but both doses of fluroxypyr provided greater control of the presented weeds than the applied doses of clopyralid. Manual weeding reduced broadleaved weeds in the experiments, but that method did not have a long-term effect on the reduction in weeds. The applied doses of the herbicides fluroxypyr and clopyralid did not cause phytotoxicity symptoms in the dormant oak seedlings. All investigated treatments significantly reduced fresh broadleaved weed biomass compared to the control. Fluroxypyr and clopyralid can be successfully used for the control of many early spring broadleaved weeds in regenerated pedunculate oak forests, but 2- and 3-year-old oak seedlings must be in the dormant stage.

Influence of residue management and simulated rainfall timings on pyroxasulfone efficacy and productivity of wheat in North West India

The adoption of new advanced technology for finest one pass sowing solution in residue in North West India has resulted in increased interest among weed scientists to improve weed management strategies due to herbicide resistant Phalaris minor and herbicide efficacy. A study was conducted over two consecutive crop seasons at Punjab Agricultural University, Ludhiana and Krishi Vigyan Kendra, Muktsar, Punjab, India. The objectives of the study were to find out pyroxasulfone rate required as pre emergence (PRE) in residue removal and incorporation scenarios for weed control and to compare efficacy of PRE application under simulating rainfall at 2, 5 and 10 days after sowing (DAS) and its effect on wheat grain yield. Incorporation of paddy residue (RI) gave 3.8 & 3.7% and 1.8 & 5.1% higher grain yield than residue removal (RR) at Ludhiana and Muktsar during 2020–21 and 2021–22, respectively. At Ludhiana, pyroxasulfone 191.25 g ha−1 recorded significantly less Phalaris minor than pyroxasulfone 127.5 ha-1 but provided similar control of broad leaved weeds (Rumex dentatus and Medicago denticulata). However, both doses of pyroxasulfone recorded similar control of grass and broad-leaved weeds at Muktsar. Simulated rainfall increased the efficacy of pyroxasulfone and recorded less P. minor when given at 2 DAS than 10 DAS at Ludhiana but at Muktsar all simulated rainfall events did not affect weed density and biomass. Phyto-toxicity of pyroxasulfone was not observed on wheat crop when simulated rainfall was applied 2, 5 and 10 DAS in wheat sown under different residue scenarios at both the locations.

Efficacy of Herbicides, Herbicide Tank Mixtures and Herbicide Combinations on Express Sun Oil-Bearing Sunflower (Helianthus Annuus L.)

During the period 2018-2020 a field experiment has been carried out with the oil-bearing sunflower hybrid P64LЕ121 (Helianthus annuus L.). It is a sulfo tolerant hybrid by ExpressSun technology. A total of 25 variants were investigated. They included untreated control, 2 herbicides applied alone in addition with adjuvant Trend 90, 10 herbicide tank mixtures and 10 herbicide combinations. Soil-applied combined herbicides were performed during after sowing before emergence period of the sunflower. Foliar-applied herbicides were performed during 3-4 leaf sunflower stage. Full control of annual broadleaved weeds in ExpressSun oil-bearing is provided by a single treatment with herbicide Fluence at a dose of 40 g/ha or with herbicide Evorelle express at a dose of 60 g/ha applied during 3-4 leaf sunflower stage. Full controls of perennial broadleaved weeds is provided by two treatments with herbicide Fluence in doses of 20+20 g/ha or with herbicide Evorelle express in doses of 30+30 g/ha, applied during 3-4 leaf and 7-8 leaf sunflower stages. In the presence of annual and perennial broadleaved and graminaceous weeds, it is necessary to apply Fluence and Evorelle express as herbicide tank mixtures together with foliar-applied antigraminaceous herbicides Fusilade forte, Stratos ultra or Targa max. In the absence of perennial graminaceous weeds, it is necessary to apply herbicides Fluence and Evorelle express as herbicide combinations with soil-applied antigraminaceous herbicides Dual gold or Indipen. The highest seed yield is obtained by herbicide tank mixture Fluence + Fusilade forte, followed by herbicide tank mixture Evorelle express + Stratos ultra. High seed yields are also obtained by use of herbicide combinations Indipen + Evorelle express and Dual gold + Fluence.

Evaluation of herbicides for control of broad-leaved weeds in barley (<em>Hordeum vulgare</em> L.)

Evaluation of herbicides for control of broad-leaved weeds in barley (<em>Hordeum vulgare</em> L.)

Physio-biochemical and nutrient constituents of peanut plants under bentazone herbicide for broad-leaved weed control and water regimes in dry land areas

The abundance of broad-leaved weeds in peanut fields represents the handicap in weed management programs, since limited specific herbicides can be recommended to control them. Moreover, the physio-biochemical constituents and nutritional status in peanut plants as affected by available herbicides, i.e., bentazone under water stress conditions are not well known. Therefore, field trials were conducted during the growing seasons in 2016 and 2017 to investigate the interactional impact of irrigation levels (I50, I75 and I100, representing irrigation by 50%, 75% and 100% of crop evapotranspiration, respectively) and weed control practices (bentazone, bentazone+hoeing once, hoeing twice and weedy check as control) on dominant broad-leaved weeds as well as peanut physiological and agronomic traits. Result indicated that the efficiency of weed control for each weeded treatment under I50 significantly equaled with its counterpart under I75 or I100. Bentazone+hoeing once diminished weed biomass by 89.3% and enhanced chlorophyll content of peanut plants by 51.2%. Bentazone relatively caused a reduction in carotenoides. Hoeing twice and bentazone+hoeing once under I100 in both growing seasons as well as hoeing twice under I75 in 2017 were the superior combinations for boosting pod yield of peanut plants. Treatment of bentazone+hoeing once and I75 recorded the lowest reduction in N utilization percentage and the highest increase in potassium utilization percentage of peanut plants. Eliminating weeds enhanced water use efficiency by 37.8%, 49.6% and 34.7% under I50, I75 and I100, respectively. In conclusion, peanut seems to be tolerant to bentazone at moderate water supply, thus it can be safely used in controlling the associated broad-leaved weeds.

Effect of different weed management practices on growth, yield attributes and yield of direct seeded rice (Oryza sativa L.)

A field experiment was conducted on Instructional cum Research Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.) during kharif season 2018 to evaluate the new formulation of oxyfluorfen (20 % DF) on weed control in direct seeded rice. Oxyfluorfen is a diphenyl-ether herbicide as a pre-emergence herbicide used for control of annual, perennial and broad leaved weeds in a various field crops. Pre-emergence (PE) application of oxyfluorfen 20 DF @ 720 g ha-1 gave significantly lower total weed density, weed dry weight and higher weed control efficiency at all the intervals. However, Oxyfluorfen 20 DF @ 240 g ha-1 as PE herbicide can keep the weed density and dry weight below the economic threshold level and increase the grain yield (49.51 q ha-1) and straw yield (64.52 q ha-1) in direct seeded rice. Unweeded control accounted for lower grain yield (5.83 q ha-1) which causes higher weed density and dry weight, respectively due to heavy competition of weeds for nutrients, space and light.

Isotope analysis method for the herbicide bromoxynil and its application to study photo-degradation processes

Bromoxynil is an increasingly applied nitrile herbicide used for post-emergent control of annual broadleaved weeds. Compound-specific isotope analysis (CSIA) of the compound is of interest for studying its environmental fate, yet is challenging following its polar nature. We present a CSIA method for bromoxynil that includes offline thin-layer chromatography purification followed by an elemental analyzer isotope ratio mass spectrometer (EA-IRMS). This method was shown to be accurate and precise for δ13C and δ15N analysis of the compound (standard deviation of replicate standards <0.5‰). The method was applied to photodegraded samples, either radiated under laboratory condition with a UV lamp, or exposed to sunlight under environmental conditions. Dominating degradation products were similar in both cases. Nevertheless, isotope effects differed, presenting a strong inverse carbon isotope effect (εC = 4.74 ± 0.82‰) and a weak inverse nitrogen isotope effect (εN = 0.76 ± 0.12‰) for the laboratory experiment, and an insignificant carbon isotope effect (εC = 0.34 ± 0.44‰) and a normal nitrogen isotope effect (εN = −3.70 ± 0.30‰) for the natural conditions experiment. The differences in δ13C vs. δ15N enrichment trends suggest different mechanism for the two processes. Finally, the obtained dual isotope trend for natural conditions provide the basis for studying the dominance of photodegradation as a degradation route in the environment.

Early post-emergence application of penoxsulam for weed control in transplanted rice

Results of field experiments conducted during kharif 2016 and 2017 to study the effect of penoxsulam on weeds in transplanted rice are reported. The study comprised 7 treatments consisting of 3 doses of penoxsulam 2.5 per cent OD (20, 22.5 and 25 g ha−1), bispyribac-Na 10 per cent SC (20 g ha−1), pretilachlor 50 per cent EC (750 g ha−1), hand weeding (20 and 40 d after transplanting, DAT) and un-weeded control. Echinochloa crusgalli, Leptochloa chinensis, Caesulia axillaris and Cyperus iria were the major weeds. Application of herbicides reduced weed density and increased grain yield as compared to un-weeded control during both the growing seasons. Penoxsulam at 25 g ha−1 provided effective control of grasses and broad-leaved weeds and sedges with 88.24 and 87.05 per cent weed control efficiency at 45 and 60 DAT. The treatment recorded significantly more panicle length, though the grain yield was at par with penoxsulam @ 22.5 g ha−1 (7.14 and 7.12 t ha−1 and 7.23 and 7.37 t ha−1, during 2016 and 2017 respectively). Penoxsulam at 25 g ha−1 recorded 21.5 and 23.9 per cent increase in grain yield over unweeded control during 2016 and 2017 respectively.

Weed Management in Azuki Bean with Postemergence Herbicides

A limited number of postemergence (POST) herbicides are available for weed management in azuki bean production in Ontario. A total of three field trials were conducted during 2017 to 2019 at the Huron Research Station, University of Guelph, Exeter, Ontario, Canada to evaluate the efficacy of various postemergence (POST) herbicides for weed control in azuki bean. Fomesafen, acifluorfen and acifluorfen + Assist® caused up to 6% crop injury and weed interference reduced azuki bean yield up to 42%. Bentazon, bentazon Forte, bentazon/acifluorfen, bentazon + fomesafen + Assist®, bentazon + fomesafen + Turbocharge® and bentazon Forte + fomesafen caused up to 16% injury and weed interference reduced azuki bean yield up to 53%. Fomesafen, acifluorfen, acifluorfen + Assist®, bentazon, bentazon Forte, bentazon/acifluorfen, bentazon + fomesafen + Assist®, bentazon + fomesafen + Turbocharge® and bentazon Forte + fomesafen provided 36% to 88% control of redroot pigweed (Amaranthus retroflexus L.), common ragweed (Ambrosia artemesiifolia L.), and common lambsquarters (Chenopodium album L.). Fomesafen, acifluorfen + Assist® and acifluorfen provided 59% to 83% control of flower-of-an-hour (Hibiscus trionum L.), but bentazon, bentazon Forte, bentazon/acifluorfen, bentazon + fomesafen + Assist®, bentazon + fomesafen + Turbocharge® and bentazon Forte + fomesafen provided 78% to 99% control of H. trionum. All POST herbicides evaluated provide 99% to 100% control of wild mustard (Sinapis arvensis L.) in azuki bean. Based on these results, none of the POST herbicide evaluated that included bentazon can be used safely for the control of annual broadleaved weeds in azuki bean under Ontario environmental conditions.

Evaluation of flucetosulfuron and ready-mix of penoxsulam + bentazone as post-emergent weed control options in direct seeded and transplanted rice

Post-emergent herbicides were evaluated in a series of field experiments for control of weeds in rice nursery as well as, direct seeded and transplanted rice during the kharif seasons of 2014 and 2015. Results of one of the studies showed that flucetosulfuron at 25-30 g ha-1 applied at 15-18 DAS (days after sowing) was effective for control of many broad-leaved weeds and some grass weeds [Echinochloa crus-galli (L.) Beauv.]. However, flucetosulfuron was not reasonably effective against major upland rice weeds namely Dactyloctenium aegyptium (L.) Willd and Digitaria sanguinalis (L.) Scop. infesting rice nursery and direct seeded rice (DSR). Under puddle transplanted rice (PTR) conditions, flucetosulfuron 25-30 g ha-1 applied at 15-19 days after transplanting had similar weed control levels and rice grain yields as obtained with bispyribac-Na at 20 g ha-1 and azimsulfuron at 35 g ha-1. However, in the DSR, weed control and rice grain yields with flucetosulfuron were poorer to that observed with application of azimsulfuron 35 g ha-1. In another field study, ready-mixture of penoxsulam + bentazone (1:36) at 840-1110 g ha-1 as post-emergent (18 DAS or 20 DAT) option was evaluated against weeds in DSR and PTR along with standard check herbicides, azimsulfuron 35 g ha-1, and cyhalofop-p-butyl 80 g ha-1. Penoxsulam + bentazone at 925-1110 g ha-1 was very effective for control of grass weed, E. crus-galli (98-100% control) and many broad-leaved weeds but was not effective against D. aegyptium and D. sanguinalis found in DSR. Consequently, the poor weed control (508-524 g m-2 total weed dry weight) with application of penoxsulam + bentazone combination at 925-1110 g ha-1 resulted in 1.45-1.48 t ha-1 lesser grain yield compared to azimsulfuron 35 g ha-1 (218.2 g m-2 total weed dry weight). Under puddle transplanted conditions, penoxsulam + bentazone combination and azimsulfuron 35 g ha-1 provided significantly better weed control than cyhalofop-p-butyl. The weed competition caused higher rice grain yield reductions in DSR (86-100%) than PTR conditions (25-52%). The results indicated azimsulfuron as better herbicide option for DSR than flucetosulfuron, penoxsulam, penoxsulam + bentazone and bispyribac-Na due to diverse weed flora control. Also, pot studies indicated that flucetosulfuron and azimsulfuron should be applied with cationic surfactant at 1000 ml ha-1 for better weed control efficacy. DOI: http://doi.org/10.25174/2249-4065/2019/96493

Bastard Cabbage (Rapistrum rugosum L.) Resistance to Tribenuron-Methyl and Iodosulfuron-Methyl-Sodium in Spain and Alternative Herbicides for Its Control

Complaints about the lack of control of Rapistrum rugosum with tribenuron-methyl and iodosulfuron-methyl-sodium in winter cereals in Northeastern Spain motivated this study. During 2015–2018, greenhouse trials were conducted to test the responses of two possibly resistant (R1 and R2) and two susceptible populations to both active ingredients to determine the response of these populations to alternative herbicides. In the first trial that was repeated twice, populations were treated with both active ingredients (three rates, six replicates), and the lack of control confirmed resistance both times. The second trial was conducted on the self-pollinated progeny of the initial populations (13 rates, 6 replicates) to confirm the heritable character of resistance and to determine the resistance factors related to survival and biomass. Resistance factors based on biomass were 188 and 253 for tribenuron-methyl and 42 and 26 for iodosulfuron-methyl-sodium for R1 and R2, respectively, confirming the strong resistance of the progeny. In the third trial, nine active ingredients (a.i.) registered for broadleaved weed control in winter cereals were tested on the four populations (two rates, four replicates). All the alternative herbicides, except florasulam, results in important phytotoxicity to all tested populations, with 100% efficacy for several a.i. This work is the first report of R. rugosum that is resistant to iodosulfuron-methyl-sodium and the first report in Europe of R. rugosum that is resistant to tribenuron-methyl.

Efficacy of Certain Tribenuron-Methyl Formulations for the Control of Broad-Leaved Weeds in Wheat under Field Conditions

Two field experiments were conducted during 2017-2018 and 2018-2019 seasons to evaluate the effect of eight tribenuron-methyl formulations (four as WG 75% and four as DF 75%) beside hand weeding (twice at 21 and 42 DAS) on broad-leaved weeds (BLWs) in wheat under field conditions. All the agricultural practices were carried out uniformly as recommended. All treatments were arranged in randomized complete block design and replicated four times each of 42 m2 (6×7 m). All formulations were applied at the rate of 8.0 gm fed.-1 in 200 L. water fed.-1 by Knapsack sprayer (CP3) at 30 days after sowing (DAS). After two months from sowing (2MAS) (one month after treatment, one MAT), weeds were collected from an area of 2m2 which was randomly selected from each plot (by using a square woody frame, 50 cm×50 cm). The removed annual BLWs were identified and counted for density as number m-2 and biomass [fresh weight gm m-2] in all treatments. In the untreated control, biomass, biomass%, density and density% for each BLW were recorded. The common prevailed annual BLWs in the experimental wheat field during both seasons were annual Sowthistle (Sonchus oleraceus L.), cheese weed, little mallow (Malva parviflora L.), chicory (Cichorium pumpilum Jacq.), dentated dock (Rumex dentatus L.), medic (Medicago intertexta (L.) Mill.), scarlet pimpernel (Anagallis arvensis L.), sea beet, wild beet (Beta vulgaris L.) and sweet clover, Indian melilot (Melilotus indica L.). The results clearly indicated that biomass and density were varied according to the dominant weed species and from season to another. The BLWs were the most dominant and also they were common in wheat fields and the biomass and density of BLWs were varied between years and weeds. The herbicidal treatments gave the minimum weed biomass and density and gave good weed control efficiency (WCE %) than hand weeding treatments. Granstar formulation completely controlled C. pumpilum weed (in the first season), A. arvensis, R. dentatus and S. oleraceus weeds (in the second season). Skylla formulation completely controlled M. parviflora and R. dentatus weeds in the first season. The tested tribenuron-methyl formulations did not cause complete control for B. vulgaris, M. intertexta and M. indica weeds in both seasons. In all cases, the herbicidal treatments increased significantly the biological yield, grain yield, straw yield, harvest index and thousand grain weight in comparison with untreated control. Also, Granstar, Skylla and Cash Cool herbicides were the most effective, while Ownostar was the least effective. We can concluded that, Granstar, Skylla and Cash Cool formulations are the most effective in controlling broad-leaved weeds in wheat field and consequently increased the grain yield.

Studies on integrated weed management practices in maize-A review

Worldwide yield losses in maize due to weeds are estimated to be around 37%. Weeds reduce crop yield by competing for light, water, nutrients and CO2, interfere with harvesting and increase the cost of cultivation. The predominant weed flora were Echinochloa crusgalli L. and Cynodon dactylon L. among monocots; Cyperus rotundus L. among sedges; and Amaranthus viridis L., Digera arvensis L., Portulaca oleracea L., Alternenthara sessili L. and Trianthema spp. among dicots in India. The infestation of these weeds is increasing day by day in the maize growing belt of the state especially where the farmers are using atrazine year after year. New herbicides with broad spectrum of weed control are highly essential for effective control of grasses, sedges and broad leaved weeds. So, in order to widen the weed control spectrum, it is desirable to use tank mix combinations of two herbicides having different mode of action and integrated weed management practices for better weed control.

Control of broad-leaved weeds in wheat under eastern sub-Himalayan plains

Control of broad-leaved weeds in wheat under eastern sub-Himalayan plains

The herbicide atrazine affects sperm quality and the expression of antioxidant and spermatogenesis genes in zebrafish testes

The herbicide atrazine (ATZ) is used worldwide in the control of annual grasses and broad-leaved weeds. The present study evaluated sperm quality parameters in zebrafish Danio rerio after 11-day exposure to nominal ATZ concentrations of 2, 10, and 100 μg L−1. All ATZ concentrations caused a decrease in motility, mitochondrial functionality, and membrane integrity, as measured using conventional microscopy or fluorescence microscopy with specific probes. The DNA integrity of sperm was not affected. The levels of expression of genes related to spermatogenesis, antioxidant defenses, and DNA repair were also investigated using RT-qPCR. The ATZ caused transcriptional repression of the spermatogenesis-related genes SRD5A2 and CFTR, the antioxidant defense genes SOD2 and GPX4B, and the DNA repair gene XPC. This is the first study to show that environmentally relevant concentrations of ATZ significantly affect the sperm quality in fish, possibly resulting in reduced fertility rates. In addition, we showed that the repression of genes related to spermatogenesis and cellular defense could be part of the mechanisms involved in the ATZ toxicity in the testes of male fish.

BELKAR™ - a new herbicide for the control of a wide range of broadleaf weeds in winter oilseed rape applied post-emergence in autumn

Autumn-applied pre-emergence herbicides are currently the primary options for weed control used in winter oilseed rape. A characteristic of the new product BELKARTM herbicide is that it will be applied post-emergence in autumn. BELKAR combines both active ingredients ArylexTM Active and Picloram and therefore contains two non-ALS mode of actions. While Picloram has been widely used in oilseed rape in recent years, Arylex is a new auxinic herbicide for the post-emergence weed control of important broad-leaved weeds. Arylex is the first member of the ‘Arylpicolinate’ structural class, a new class within the HRAC Group O. The ISO common name of Arylex is ‘halauxifen-methyl’ (DOW AGROSCIENCES, 2013). BELKAR is the first herbicide in Europe containing this active for the use in winter oilseed rape. With a maximum use rate of 0.5 L/ha, the product will deliver 4.8 g ae/ha of Arylex and 24 g ae/ha of Picloram. BELKAR can be applied as a sequential application from crop stage of BBCH 12-14 at rates of 0.25 L/ha or a single application with 0.5 L/ha from crop stage BBCH 16. BELKAR provides control of a wide range of key weeds, including most important ones such as Capsella bursa-pastoris, Centaurea cyanus, Galium aparine, Papaver rhoeas, Geranium spp., Thlaspi arvense, Matricaria spp. and Descurainia sophia. With BELKAR, a post-emergence herbicide application in autumn offers a viable option for effective weed control in oilseed rape. As a new concept, the tank mix combination BELKAR with the active ingredient Aminopyralid will even more expand the weed spectrum and will provide an alternative to preemergence herbicide applications in winter oilseed rape.

KORVETATM - a new herbicide for the control of a wide range of broadleaf weeds in winter oilseed rape applied in spring

KORVETA™ herbicide is a novel selective post-emergence herbicide for use on winter oilseed rape applied as a spring application. KORVETA provides superior control of a wide range of important annual broad-leaved weeds in winter oilseed rape, including Centaurea cyanus, Galium aparine, Matricaria spp. and Papaver rhoeas, combined with a robust crop safety. KORVETA combines both actives Arylex and clopyralid and therefore contains two non-ALS mode of actions. While clopyralid has been widely used in oilseed rape in recent years, Arylex is a new auxinic herbicide for the post-emergence weed control of key broad-leaved weeds. Arylex is the first member of the ‘Arylpicolinate’ structural class, a new class within the HRAC Group O. The ISO common name of Arylex is ‘halauxifen-methyl’ (Dow AgroSciences, 2013). With a maximum use rate of 1 L /ha, KORVETA will deliver 4.8 g ae/ha of Arylex and 120 g ae/ha of clopyralid. KORVETA is formulated as an emulsifiable concentrate (EC). KORVETA will be applied as a single application from crop stage BBCH 30 up to BBCH 50 and will give growers a new tool to control the key broad-leaved weeds occurring in oilseed crop in the spring.

Impact of mechanical mowing and chemical treatment on phytosociological, pedochemical and biological parameters in roadside soils and vegetation.

Many chemical and non-chemical strategies have been applied to control weeds in agricultural and industrial areas. Knowledge regarding the effects of these methods on roadside vegetation is still poor. A 2-year field experiment was performed along a road located near Livorno (Tuscany, central Italy). Eight plots/strips were identified, of which four were subjected to periodical mechanical mowing and the remaining four were treated with a chemical herbicide based on glyphosate (the producer's recommended rates were used for the selective control of broad-leaved weeds). Our results clearly showed that roadside soil and vegetation are a significant reservoir of anthropogenic activities which have a strong negative effect on several phytosociological, pedochemical and biological parameters. Compared with conventional mechanical mowing, chemical treatment induced (i) a significant increase in organic matter in the upper plot layers (+18%), and (ii) a marked reduction in weed height throughout the entire period of the experiment. Irrespectively of the kind of treatment, no significance differences were detected in terms of (i) biological quality of soil (the abundance and diversity of arthropod communities did not change), and (ii) plant elemental content (bulk concentrations of analysed trace elements had a good fit within ranges of occurrence in the "reference plant"). The glyphosate partially controlled broad-leaved weeds and this moderate efficacy is dependent upon the season/time of application. In conclusion, the rational and sustainable use of chemical herbicides may be a useful tool for the management of roadside vegetation.