Mixed Weed Flora Research Articles

Effect of herbicides on mixed weed flora in wheat (Triticum aestivum L.) and weed control efficiency

Effect of herbicides on mixed weed flora in wheat (Triticum aestivum L.) and weed control efficiency

Sequential herbicide application coupled with mulch enhances the productivity and quality of winter onion (Allium cepa L.) while effectively controlling the mixed weed flora

Weed control poses substantial difficulties for winter season onion (Allium cepa L.) cultivation in the north-western Indo-Gangetic Plains, primarily due to the constrained efficacy of the existing herbicides. To address this issue, a 2-year field study was conducted to assess the efficacy of pre- and post-emergence herbicides (pendimethalin, ethoxysulfuron, imazethapyr, and quizalofop-p-ethyl) individually and in combination with crop residue mulch for weed control in winter onion. The results revealed that using herbicides or mulches in isolation did not provide satisfactory weed control. However, the integration of natural mulch with pendimethalin followed by quizalofop-p-ethyl application proved to be the most effective weed control strategy, resulting in the least reduction in bulb yield (10.3%) compared to other treatments. On the contrary, combinations of pendimethalin with ethoxysulfuron or imazethapyr showed adverse effects on the onion crop and inflicted the highest yield losses among all treatments (78.6 and 83.4%, respectively). However, the combination of pendimethalin with quizalofop-p-ethyl coupled with crop mulch resulted in season-long weed control and over 80% bulb yield (36.58 t/ha) gains compared to the weed-free condition. These findings emphasize the efficacy of combining herbicides and mulches as an integrated weed management strategy for onions. By adopting such integrated approaches, farmers could improve weed control while maintaining bulb yield and quality, reducing the risks associated with herbicide resistance, and promoting sustainable onion production in the north-western Indo-Gangetic Plains.

Effect of Herbicide (Propaquizafop and Imazethapyr) on Weed Flora Associated with Blackgram in Central India

An experiment was conducted at Product Testing Unit, Department of Agronomy, JNKVV, Jabalpur to study the effect of application of propaquizafop and imazethapyr herbicide on weeds associated with blackgram. The experimental field was having mixed weed flora comprising of grassy as well as broad leaved weeds. Nine treatments comprised of four rates of application of propaquizafop+ imazethapyr at 47+70, 50+75, 53+80 and 56+85 g/ha and alone application of propaquizafop (100 g/ha), imazethapyr (100 g/ha), pendimethalin (1500 g/ha) and hand weeding twice at 20 and 40 DAS including weedy check, were laid out in Randomized Block Design with three replications. All herbicide treatments were applied in 500 liters of water per hectare, using flat fan nozzle as per the treatments. The dominant weed flora, species wise weed density, weed biomass, Weed control efficiency and weed index were recorded at different interval. The study revealed that the Echinochloa colona (29.39%) and Dinebra retroflexa (24.30%) were the found as dominant weeds in the field whereas, other monocot weeds like Cyperus iria (18.19%) and dicot weeds like Mullugo pentaphylla (12.23%), Eclipta alba (7.58%) and Alternanthera philoxeroides (8.31%) were also present in less numbers in blackgram under weedy check plots. Among the herbicidal treatments, activity of propaquizafop+imazethapyr mixture at the dose 53+80 and 56+85 g/ha emerged as effective control for the weeds associated with blackgram.

Effect of Herbicides Doses and Dates of Application on Weed, and Weed Indices in Wheat

Weeds pose a serious threat to wheat productivity. A study was undertaken during the winter season of 2019/20 in the experimental field, of the National Agronomy Research Centre, NARC, Khumaltar to assess various doses and application dates for controlling mixed weed flora in wheat. The experiment was laid out in a Randomized Complete Block Design with ten treatments replicated thrice with net a plot size of 6 sq. m. The treatments included metribuzin @ 250 g/ha at 25 DAS and 45 DAS, metribuzin @ 500 g/ha at 25 DAS and 45 DAS, carfentrazone @ 20 g/ha and @ 40 g/ha at 25 DAS, metribuzin+carfentrazone (@ 250 g/ha+ @ 20 g/ha) at 25 DAS, metribuzin+carfentrazone (@ 500 g/ha + @ 40 g/ha) at 45 DAS, pendimethalin @ 1000 g/ha at 2 DAS and weedy check. Data regarding the weed density and weed biomass were recorded following the standard procedures. The result revealed pendimethalin @ 1000 g/ha applied at 2 DAS, metribuzin @ 250 g/ha applied at 25 DAS, and metribuzin+carfentrazone (@ 250 g/ha + @ 20 g/ha) applied at 25 DAS, respectively, 24%, 33%, and 26% lower total weed density in comparison to the weedy check. The use of pendimethalin @ 1000 g/ha at 2 DAS showed the maximum herbicide efficiency index, 2.17%, closely followed by metribuzin @ 250 g/ha applied at 25 DAS (1.92%).

Herbicidal weed-management options for dry direct-seeded rice (Oryza sativa) in North-Eastern Plains of India

A field experiment was conducted during the rainy (kharif) seasons of 2017 and 2018 at Regional Station of the ICAR-Indian Agricultural Research Institute, Pusa, Samastipur, Bihar, to study the effect of herbicides in controlling mixed weed flora in direct-seeded rice (Oryza sativa L.). The experimental results revealed that, the alone and sequential application of herbicides significantly reduced the weed density and biomass of complex weed flora. The growth and yield attributes, viz. plant height at maturity, effective tillers/m2 , 1,000grain weight, grains/panicle and panicle length, were significantly influenced by application of herbicides. Weed-free condition resulted in significantly highest grain yield (4.49 t/ha). Among different herbicidal treatments, application of pendimethalin @ 1,000 ml/ha followed by (fb) tank-mix application of bispyribac sodium (25 g/ha) + pyrazosulfuron (15 g/ha) resulted in higher plant height (110.7 cm), higher number of effective tillers (320.0/m2 ), grains/panicle (132.2), ear length (29.8 cm), grain yield (4.49 t/ha), net returns (` 70,600/ha) and benefit : cost ratio (1.67), which was superior to rest of the treatments. Application of pendimethalin (1,000 ml/ha) fb tank-mix application of bispyribac sodium (25 g/ha) + pyrazosulfuron (15 g/ha) significantly reduced the weed density (56.8/m2 ) and weed biomass (26.6 g/m2 ).

Bio-efficacy of flumioxazin against mixed weed flora in the wastelands of Himachal Pradesh

Bio-efficacy of flumioxazin against mixed weed flora in the wastelands of Himachal Pradesh

Efficient weed management in groundnut (Arachis hypogaea) through appropriate herbicides

A field experiment was conducted during 2017–18 and 2018–19 in kharif season at Instructional Farm of Krishi Vigyan Kendra, Chhatarpur to study the suitable herbicides for effective management of weed flora of groundnut crop. Randomized block design was used with 4 replications consisting of 7 treatments as detailed in methodology. The results showed that combination of two compatible herbicide molecules like Imazethapyr 100 g a.i./ha + Quizalofop @37.5 g a.i/ha were quite effective against dominated mixed weed flora in groundnut, resulting in higher WCE, WCI, yield and economic net return (93.63%, 93.57%, 16.2 q/ha and `44655/ha) fb use of Imazethapyr @100 g a.i./ha + Fenoxaprop @37.5 g a.i/ha (90.44%, 90.5% 15.2 q/ha and `39380/ha respectively) as compared to control plot. Therefore, above herbicides will be better alternative for suppressing weed flora in the groundnut crop than the sole herbicide.

Effect of new generation herbicides on mixed weed flora and yield of direct seeded rice (Oryza sativa L.)

A field experiment was conducted during the “Navarai” season of 2019 and 2020 at Experimental Farm of the Department of Agronomy, Annamalai University, Annamalai Nagar, to find out the effect of new generation herbicides on direct seeded rice (Oryza sativa L.). The herbicide used were pre-emergence application of pyrazosulfuron-ethyl 10% WP at 200 g ha-1, pre-emergence application of metsulfuran-methyl 10% + chlorimuron-methyl 10% WP at 20g ha-1, pre-emergence application of pretilachlor 50% EC at 1250 ml ha-1, Early post-emergence application of pretilachlor 6% + pyrazosulfuran-ethyl 0.15% G at 615g ha-1, Early post-emergence application of bispyribac-sodium at 300 ml ha-1. The experimental result revealed that the new generation herbicide has a significant influence on weed flora and yield attributes and yield of direct seeding rice. The result indicated that application of Bispyribac-sodium 10% SC at 300 ml ha-1 at 15 DAS + one Hand weeding at 30 DAS recorded the lowest weed population, weed dry matter production and higher weed control index (WCI) and yield. Then twice hand weeding at 15, and 30 DAS was next in order. The lowest weed control index and yield were recorded with un-weeded control.

Study of the effect of different herbicides and herbicidal combinations on weed flora and chickpea yield

Chickpea (Cicer arietinum L.) is the third most important grain legume crop in the world and the first important legume in the South and West Asia. For Bulgaria the chickpea is an old traditional crop used mainly for human consumption and to a lesser extent for feed. One of the most important yield limiting factors in the chickpea seed production is the poor weed management. The establishment of the most appropriate herbicide or herbicide combination for the effective control especially of the weed flora is a priority task of the chickpea cultivation. The aim of this study was to investigate the effect of different herbicides and herbicidal combinations on weed flora and on the chickpea yield. The herbicides and herbicidal combinations were tested in nine treatments plus one weedy check control. All herbicides were used in pre-emergence applications at different doses. During the study the predominated weeds were Amaranthus retroflexus L. (redroot pigweed) and Convolvulus arvensis L. (field bindweed). Generally, all tested herbicidal combinations showed good control on the mixed weed flora and the grain yield was high. Three herbicidal combinations had the best effect on weed numbers and grain yield compared to the weed check: Clomazone -15 ml/da + S-metolachlor - 120 ml/da; Clomazone - 30 ml/da + S-metolachlor - 60 ml/da and Clomazone - 15 ml/da + Pendimethalin - 500 ml/da. Most of the studied herbicides and herbicidal combinations were tolerant, non-suppressive and showed a high positive effect on the chickpea yield.

Bio-efficacy of nicosulfuron against mixed weed flora in maize and its residual effect on succeeding crops

A field study was conducted during Spring and rainy (Kharif) season of 2017 at N.E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar U.S. Nagar, Uttarakhand, India to evaluate the effective dose of nicosulfuron for weed control in maize while assessing its effect on growth and yield of maize along with its residual effect on succeeding pea and cowpea fodder. Eight treatments were tested which include: post-emergence application (PoE) of nicosulfuron at different doses (30, 36, 42 and 50 g/ha), tembotrione 120 g/ha PoE, pre-emergence application (PE) of atrazine 1000 g/ha, hand weeding twice at 20 and 40 days after seeding (DAS) and weedy check. The weed community during both the seasons in the experimental area consisted of, grassy weeds: Phalaris minor, Eleusine indica, Digitaria sanguinalis, Echinochloa colona and Panicum maximum, broad-leaved weeds (BLW): Trianthema monogyna, Chenopodium album, Phyllanthus niruri, Parthenium hysterophorus and Mallugo stricta and a sedge Cyperus rotundus. Nicosulfuron at 50 g/ha resulted in 50-100% weed control, depending on the weed species. Nicosulfuron at 50 and 42 g/ha were equally effective in increasing grain yield of maize when compared with tembotrione and was found superior over atrazine during both the season. No phytotoxic symptoms on maize and no residual effect on succeeding pea and cowpea fodder crop were observed, at any doses of nicosulfuron. Hence, nicosulfuron at 42 g/ha PoE may be safely used for effective weed management and improved yield of maize.

Post-Emergence Herbicides for Effective Weed Management, Enhanced Wheat Productivity, Profitability and Quality in North-Western Himalayas: A ‘Participatory-Mode’ Technology Development and Dissemination

‘Participatory-mode’ adaptive research was conducted in wheat in north-western Himalayas (NWH) during 2008–2014 to develop an improved chemical weed management (ICWM) technology. First of all, two years ‘on-farm experimentation’ was performed in a randomized block design at 10 locations in NWH using seven treatments (Clodinafop @ 60 g a.i./ha (Clod); Clod followed by 2,4-D (Na-salt) @ 1.0 kg a.i./ha (Clod-fb-D); Isoproturon 75 WP @ 1.0 kg a.i./ha (Iso); Iso + D; Sulfosulfuron 75% WG @ 25 g a.i./ha + Metsulfuron 5% WG @ 2 g a.i./ha (Sulf + Met); weed-free-check; and un-weeded-check). In this study, the post-emergence application of Sulf + Met reported the lowest weed-index and NPK depletion by weeds with higher weed control efficiency (86.4%), weed control index (81.1%) and herbicide efficiency index (2.62) over other herbicides. Sulf + Met exhibited significantly higher wheat productivity (3.57 t/ha), protein yield, net-returns and water-productivity, which was followed by Iso + D and Clod-fb-D, all of which remained statistically at par with each other. An impact assessment of intensive technology-transfer programme (2008–2014) revealed a higher technology adoption rate (71–98%) of ICWM leading to higher wheat productivity (~22%) and net income gains (2.8–26.4%) in NWH. Overall, Sulf + Met proved highly effective against mixed weed flora in wheat to boost wheat productivity, profitability, quality and water productivity in addition to a higher technology adoption rate and NIGs to transform rural livelihoods in NWH.

Sequential application of diclosulam and cycloxydim for control of mixed weed flora in rabi-summer groundnut (Arachis hypogaea L.)

A field experiment was conducted during winter season (rabi-summer) of 2018-19 at S.V. Agricultural College Campus of Acharya N. G. Ranga Agricultural University, Andhra Pradesh, to evaluate the effect of pre-emergence (pendimethalin 38.7% CS, pendimethalin 30% EC and diclosulam 84% WDG @ 725, 1000 and 20 g/ha, respectively) and post-emergence (haloxyfop-p-ethyl 10.5% EC @ 135 g/ha and cycloxydim 20% EC @ 100 g/ha)herbicides on weed growth and yield of groundnut. The pre-dominant weed flora associated with groundnut was Cyperus rotundus L. (42%), Boerhavia erecta L. (15%), Dactyloctenium aegyptium (L.) Willd. (11%) and Commelina benghalensis L. (9%). Pre-emergence application of diclosulam 20 g/ha supplemented with hand weeding (HW) at 40 DAS or cycloxydim 100 g/ha at 20 DAS resulted in lower density and dry weight of all the categories of weeds including Cyperus rotundus. Pre-emergence application of diclosulam 20 g/ha resulted in phytotoxicity rating of "1" in 0-10 scale with yellowing of young leaves in groundnut and the crop recovered within 25 days after its application. Pre-emergence application of diclosulam 20 g/ha supplemented with HW at 40 DAS resulted in higher yield components and pod yield of groundnut, which was comparable with sequential application of diclosulam 20 g/ha as pre-emergence and cycloxydim 100 g/ha at 20 DAS. However, the former weed management practice obtained higher net returns and benefit-cost ratio than latter. These two weed management practices increased the pod yield of groundnut tby 48.8 and 44.2 %, respectively compared to un-weeded check.

Control of mixed weed flora with different herbicides in barley

Control of mixed weed flora with different herbicides in barley

Weed management in kharif rice in new alluvial zone of West Bengal

A field experiment was carried out during the Kharif season of two consecutive years 2015 and 2016 at Instructional Farm, Jaguli, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal with the focal objective to assess the effect of different weed control measures on yield of transplanted kharif rice, IET 4786. Experiment having 3 replications was conducted in Randomized Block Design with nine treatments, namely, T1- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 675 + 15 g a.i, T2- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 900 + 200 g a.i, T3- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 1125 + 25 g a.i, T4- Pendimethalin 30% EC @ 1500 g a.i, T5- Pyrazosulfuron ethyl 10 % WP @ 15 g a.i, T6- Pyrazosulfuron ethyl 10 % WP @ 20 g a.i, T7- Metsulfuron methyl 10 % + Chlorimuron ethyl 10 % WP @ 4 g a.i, T8- Hand weeding and T9- Weedy check. Significant variations were observed on the mixed weed flora as well as on performance of rice under the different herbicidal treatments.Pendimethalin 30% EC + Pyrazosulfuron ethyl 10% WP @ 1125+25 g a.i) was found to be the most effective recording the lowest weed population and weed dry weight with the highest weed control efficiency (83.5% in 2015 and 79.8 % in 2016) and the highest number of panicles m-2 (215.1 in 2015 and 231 in 2016), number of filled grains panicle-1 (85.39 in 2015 and 115.47 in 2016) and grain yield of rice (3.60 t/ha in 2015 and 5.30 t/ha in 2016). The lowest grain yield(2.20 t/ha in 2015 and 3.40 t/ha in 2016) and the highest weed density were observed in weedy check plots.

Effect of herbicides on mixed weed flora and economics of direct seeded rice (Oryza sativa L.)

Effect of herbicides on mixed weed flora and economics of direct seeded rice (Oryza sativa L.)

Efficacy of propanil for the mixed weed flora in direct-seeded rice

A field experiment was carried out at G.B. Pant University of Agriculture and Technology, Pantnagar, U.S. Nagar, Uttarakhand during rainy season of 2015 and 2016 to evaluate the efficacy of propanil 80% WG against mixed weed flora in direct-seeded rice. The most dominant weeds were: Echinochloa colona, Echinochloa crus-galli, Leptochloa chinensis, Eleusine indica and Digitaria sanguinalis among grassy weeds; Celosia argentea as broad-leaved weed and Cyperus spp. as sedge. Results revealed that propanil 4000 g/ha being on a par with 3000 g/ha was found most effective for controlling grassy as well as broadleaved weeds as compared to other herbicidal treatments. The lowest weed biomass (11.9 g/m2) and the highest weed control efficiency (73.6%) were also recorded with this treatment. Propanil 4000 g/ha being on a par with 3000 g/h recorded maximum grain yield (4.6 t/ha) which was superior to rest of the herbicidal treatments.

Tembotrione for post-emergence control of complex weed flora in maize

Bio-efficacy of tembotrione 42% SC w/v (34.4% SC w/w), a new herbicide for post-emergence control of mixed weed flora in maize was evaluated during rainy seasons 2009 to 2015 at CCS Haryana Agricultural University, Regional Research Station, Karnal and also through multi-location adaptive/farmer-participatory trials. Post-emergence application of tembotrione 120 g/ha along with surfactant (1000 ml/ha) at 2–4 leaf stage was found most effective against grassy and non-grassy weeds as compared to other herbicidal treatments either applied as pre-or post-emergence (including its lower doses, atrazine and 2,4-D) resulting into the highest productivity (3.77–4.44 t/ha) and profitability (B-C ratio 1.75–1.98) of maize in on-station experiment during 2009–2010. On an average, grain yield of maize under tembotrione 120 g/ha along with surfactant (4.04–5.00 t/ha) was also better than the atrazine 500–750 g/ha (3.59–4.43 t/ha) and untreated check (2.86–3.33 t/ha) at multi-location trials during 2013–2015. There was no residual toxicity of tembotrione on succeeding wheat. Residues of tembotrione at 120 g/ha + S 1000 ml/ha and 240 g/ha + S 1000 ml/ha in raw cobs, grains and straw of maize and soil were also below detectable level during 2015.

Crop establishment and weed management techniques to control in wet-rice weeds under lateritic soils of West Bengal

A field experiment was conducted in sandy loam soil at Visva-Bharati University, Sriniketan, West Bengal in three consecutive rainy season of 2008, 2009 and 2010 to study the effect of crop establishment techniques and weed management on weed dynamics and yield of rice. Conventional transplanting method was found to be the most effective in controlling all categories of weeds throughout the growth period because of stagnation of water in the plots. Among weed management practices, pyrazosulfuron-ethyl (25 g/ha at 3 DAS/DAT) + mechanical weeding (cono-weeder) was the most effective in controlling the mixed weed flora. Similar trend was also observed in dry matter of weeds. The highest grain yield (3.75 t/ha) was obtained under system of rice intensification (SRI) with pyrazosulfuron-ethyl (25 g/ha at 3 DAS/DAT) + mechanical weeding while drum seeded with no weed control practices recorded the lowest grain yield (2.00 t/ha). SRI system with pyrazosulfuronethyl + mechanical weeding also gave the highest net return (` 19890/ha).

Herbicide mixtures for weed control in dual purpose tall wheat and pendimethalin residue in wheat fodder and soil

Weeds are the biological constraints to increase wheat productivity in Asia. A field experiment was conducted during the Rabi seasons of 2015–16 and 2016–17 to evaluate the efficacy of pendimethalin, pinoxaden, metsulfuron, sulfosulfuron, clodinafop under sole, mixture and their sequential application against control of mixed weed flora in dual purpose wheat at area of farm CCS HAU Hisar (Haryana). The season-long growth of weeds reduced wheat yield up to 55.4 and 59.3% during 2015–16 and 2016–17, respectively. Before cutting of wheat for fodder, among herbicidal treatments, pre-emergence (PE) application of pendimethalin 1500 g/ha significantly reduced grassy (P minor) and broad-leaf weeds dry weight at 25 and 55 days after sowing (DAS) during both the years. After cutting, weed dry weight at 85, 115 DAS and at harvest was significantly reduced under sequential application of pendimethalin 1500 g/ha fb pinoxaden + metsulfuron (50 + 4) at 2 week after cutting (WAC) at 55 DAS, pendimethalin 1500 g/ha fb sulfosulfuron + metsulfuron (30 + 2) at 2 WAC and pendimethalin 1500 g/ha fb clodinafop + metsulfuron (60 + 4) at 2 WAC as compared to alone application of post-emergence (PoE). Among herbicidal treatments, significantly higher weed control efficiency, plant height, total tillers, grain yield and B:C ratio was observed under sequential application of herbicides than alone application of herbicides during both the years of study. Wheat fodder could be used safely for livestock as no residue was reported.

Control of mixed weed flora in wheat with sequential application of pre-and post-emergence herbicides

The field efficacy of pre-and post-emergence herbicides for control of mixed weed flora in wheat was evaluated in a field study conducted at Punjab Agricultural University, Ludhiana during Rabi seasons of 2014–15 and 2015–16. The season long growth of weeds reduced wheat yield upto 38.5%. Pendimethalin and metribuzin recorded 65–73 and 73–78% control of Phalaris minor, respectively and their tank-mix application enhanced P. minor control to 78–85%. Pendimethalin and metribuzin recorded 26–33 and 5863% control of Medicago denticulata, respectively and their tank-mix application enhanced control to 77–92% of this weed. Pendimethalin and metribuzin provided control of Rumex dentatus to the extent of 98–100% and 68–92%, respectively, while provided 98–100 and 63–72%, respectively control of C. album. Sequential application of pendimethalin as pre-emergence followed by sulfosulfuron as post-emergence recorded the highest weed control efficiency (96%) and wheat grain yield (4.8 t/ha), and it was at par to pre-emergence pendimethalin + metribuzin, post-emergence pinoxaden + metsulfuron, mesosulfuron + iodosulfuron, sulfosulfuron + metsulfuron and two hand weeding.