Pendimethalin Fb Research Articles

Weed growth and productivity of green gram (Vigna radiata L.) under integrated weed management practices

Green gram is a short-duration crop that requires initial control of weeds for better crop establishment. The growth and productivity of green gram under integrated weed management was studied at the Agricultural farm of Faculty of Agricultural Sciences, Siksha ‘O’ Anusandhan, deemed to be University, Bhubaneswar, in the summer 2022. Ten treatments comprised of recommended herbicides, the stale seedbed technique, an aqueous extract of Calotropis gigantea and their combination were designed in the RBD with 3 replications. Results showed that the minimum density and biomass of weeds and maximum growth of green gram were found in twice hand weeding, which was statistically significant with the pre-emergence application of pendimethalin fb imazethapyr as post-emergence and the stale seedbed technique fb imazethapyr as post-emergence. The maximum yield (10.70 q/ha) was documented under two-hand weeding at 15 and 30 DAS, which was statistically comparable with the yield levels of sequential application of pendimethalin fb imazethapyr (10.17 q/ha) and stale seedbed technique fb imazethapyr as post-emergence (9.92 q/ha). Thus, pendimethalin at 750 g/ha at 1 DAS or stale seedbed at 15 days before sowing (DBS), followed by imazethapyr at 75 g/ha at 20 DAS, appeared to be effective in reducing the diverse weed flora significantly and achieving higher growth and yield in summer green gram.

Effect of Pre- and Post-emergence Herbicide on Weed Growth and Productivity of Summer Mungbean (Vigna radiata)

The current study aimed to investigate at the Agronomy farm (Faridpur) K.N.I.P.S.S Sultanpur, Uttar Pradesh during kharif 2022-2023. The research was conducted in randomized complete block design (RCBD) with 8 treatments, viz. weedy check, one hand weeding at 15 DAS, hand weeding at 15 and 30 DAS, pendimethalin @ 0.75 kg a.i./ha as pre-emergence (W3), quizalofop-ethyl @ 60 g /ha (20 DAS), Imazethapyr @ 60 g /ha (20 DAS), pendimethalin (PE) fb imazathapyr (20 DAS), pendimethalin (PE) fb quizalofop ethyl (20 DAS). Among all the treatments, growth and yield attributes such as pods count/plant (38.17), seeds count pod-1 (8.66) and yield (12.89 q/ha) were obtained highest with hand weeding at 15 and 30 DAS. Furthermore, the concurrent use of pre- and post-emergence herbicides, demonstrated by combinations like pendimethalin (PE) followed by imazathapyr at 20 DAS and pendimethalin (PE) followed by quizalofop ethyl at 20 DAS, yielded outcomes similar to those achieved through manual weeding.

Response of Green Gram [Vigna radiata (L.) Wilczek] to Different Weed Management Practices

Background: Green gram is an important pulse crop known for its nutritive values as a rich source of protein and high culinary application in Indian dietary system. However, like any other crop, it faces the challenge of weed competition, which can significantly reduce its yield and quality. The objective of this study was to determine the best suitable weed management practices for green gram. Methods: Field experiment was conducted during summer season of 2021 at School of Agricultural Sciences, Nagaland University, Medziphema Campus. There were seven weed management treatments and one treatment kept as control. All treatments were replicated thrice. Result: Hand weeding at 20 and 40DAS showed greater weed control and recorded higher values in growth and yield and showed at par values with other weed management practices pre-emergence application of pendimethalin fb hand weeding at 20 DAS, Pendimethalin @ 0.75 kg ha-1 (PE) fb Rice straw mulching @ 5 t ha-1, Imazethapyr @ 0.5 kg ha-1 (PoE) at 15 DAS fb Quizalofop p-ethyl @ 0.15 kg ha-1 (PoE) at 30 DAS and Pendimethalin @ 0.75 kg ha-1 (PE) fb Quizalofop p-ethyl @ 0.15 kg ha-1 (PoE) at 30 DAS. However, the use of only rice straw could not perform better. This indicates the advantages of integration of weed management practices. With hand weeding a laborious task concerning in large field condition, other integration of weed management will serve a viable option for profitable weed management in green gram.

Weed seedbank as influenced by tillage and herbicide in direct seeded rice‐mustard cropping sequence in lateritic soil of eastern India

AbstractThe above‐ground community dynamics of weeds represent the soil weed seedbank in an agro‐ecosystem. Hence, understanding the seedbank will offer an idea for future weed management tactics. We aimed to determine the density of weed seedbank and emergence of major weeds in direct seeded rice (DSR) (Oryza sativa L.)—mustard (Brassica campestris L. var. yellow sarson) cropping sequence under varied tillage and herbicide combinations. The present study on weed seedbank was conducted using seedling emergence method after collecting the soils at the harvest of mustard at the completion of 2 years field experimentation. The experiment was conducted in split‐plot design with two tillage practices [zero tillage (ZT) and conventional tillage (CT)] in main plot and eight weed management practices in DSR [oxadiargyl followed by (fb) bispyribac‐sodium, penoxsulam + cyhalofop‐butyl, oxadiargyl fb penoxsulam + cyhalofop‐butyl, fenoxaprop‐p‐ethyl + ethoxysulfuron, oxadiargyl fb fenoxaprop‐p‐ethyl + ethoxysulfuron, pendimethalin fb bispyribac‐sodium, unweeded control, and weed free check] as subplot. The carry‐over effect of tillage and weed management practices were recorded in mustard crop. Seed emergence study revealed that ZT reduced the emergence of grassy weeds (by 13.7%) and total weed emergence (19.5%) in comparison to the CT (p < 0.05). However, emergence of broadleaf weeds was 24.5% higher in ZT than in CT. The higher infestation was recorded for Ludwigia parviflora (Jacq.) Raven under penoxsulam + cyhalofop‐butyl, fenoxaprop‐p‐ethyl + ethoxysulfuron, Cyperus iria (L.) under fenoxaprop‐p‐ethyl + ethoxysulfuron, and Eleusine indica (L.) Gaertn. under pendimethalin fb bispyribac‐sodium, oxadiargyl fb bispyribac‐sodium. Sole application of post‐emergence (POE) herbicide decreased the total weed emergence by 22.2%–28.1% than unweeded control (p < 0.05). Whereas, sequential application of PRE + POE herbicides decreased the total weed emergence by 32.8%–36.9% than unweeded control (p < 0.05). Notably, sedge weeds such as Cyperus iria (L.) and Fimbristylis miliacea (L.) Vahl were lower in ZT than in CT under herbicide treated plots (by 66.6%–84.3%) than unweeded control. Thus, ZT with oxadiargyl 90 g a.i. ha−1 fb fenoxaprop‐p‐ethyl + ethoxysulfuron (90 + 15 g a.i. ha−1) as tank‐mix can be effectively used to lower the weed seedbank density vis‐à‐vis managing complex weed flora in DSR and rice‐mustard cropping sequence.

Impact of Pre and Post-emergence Herbicide Mixtures in Direct Seeded Rice (Oryza sativa L.)

Rice (Oryza sativa L.) is a major source of food for more than half of the world population especially in South and Southeast Asia and Latin America. A field experiment was conducted at Krishi Vigyan Kendra, Yamunanagar district, Haryana during Kharif season of 2022 to study the effect of pre and post-emergence herbicides combinations herbicides in direct-seeded rice under irrigated condition. The experiment was laid out in a Randomized block design with three replications. The weed management treatments were T1: Pendimethalin + pyrazosulfuron T2:Pendimethalin + pyroxasulfone, T3:Pretilachlor + pyrazosulfuron, T4: Fenoxaprop-p-ethyl with safener + ethoxysulfuron,T5: Cyhalofop-butyl + penoxsulam and metsulfuron-methyl + chlorimuron-ethyl, T6.:Triafamone + ethoxysulfuron, T7: Pendimethalin + pyrazosulfuron fb bispyribac-sodium, T8: Pendimethalin + pyroxasulfone fb bispyribac-sodium, T9:Pretilachlor + pyrazosulfuron fb bispyribac-sodium, T10:Pendimethalin fb fenoxaprop-p-ethyl + ethoxysulfuron T11: Weed free, T12:Weedy check. Among herbicides, application T10 (pendimethalin fb fenoxaprop-p-ethyl + ethoxysulfuron) and T5 (cyhalofop-butyl+ penoxsulam and metsulfuron methyl + chlorimuron ethy (pre-mix) was superior over other treatment. Application of pendimethalin fenoxaprop-p-ethyl + ethoxysulfuron reduced 58.89% grassy weed and 50 % BLWs compared to weedy check plot at 60 DAS. Assessment at 60 DAS and at harvest showed that bispyribac-sodium was effective in controlling E. colona and E. crus-galli. However, bispyribac-sodium did not control D. aegyptium and L. chinensis. Fenoxaprop significantly reduced the densities of Dactyloctenium aegyptium, L. chinensis, and Digitaria sanguinalis. Fenoxaprop tank-mix with ethoxysulfuron appeared to be synergistic for the control of E. crusgalli and E. colona, and Cyperus sp. as this tank mixture. Integration of pendimethalin fb fenoxaprop-p-ethyl+ ethoxysulfuron provided control of all type of weeds with highest grain yield (6.1 t ha-1) among different treatments which was statistically at par with weed free (6.3 t ha-1). In economics points of views, the highest B-C ratio (3.03) was obtained in cyhalofop-butyl + penoxsulam + metsulfuron methyl + chlorimuron ethy followed by pendimethalin fb fenoxaprop-p-ethyl + ethoxysulfuron (2.98).

Herbicide Program to Control Parthenium hysterophorus in Grain Sorghum in an Arid Environment

Parthenium weed (Parthenium hysterophorus L.) is an emerging production constraint in many summer crops including sorghum (Sorghum bicolor L. Moench), but limited control options are available. In this field study, the efficacy of sole and sequential applications of a pre-emergence (pendimethalin) and a post-emergence (bromoxynil) herbicide was evaluated for parthenium weed control in grain sorghum over two years. Pendimethalin or bromoxynil alone could only provide 54% and 63% control, whereas their sequential application provided 86% control of parthenium weed over the weedy treatment. The sorghum plants in pendimethalin followed by bromoxynil treatment had the highest leaf fresh weight per plant, plant dry biomass, plant height, and the number of heads among the herbicide treatments. Sorghum fresh forage yield, dry fodder yield, 1000-grain weight, and grain yield were highest in the weed-free treatment followed by the pendimethalin followed by (fb) bromoxynil treatment. Overall, the herbicide treatment performance was in an order of pendimethalin fb bromoxynil > bromoxynil > pendimethalin for weed control and sorghum yield improvement. These results suggest that pendimethalin followed by bromoxynil may provide acceptable control (>85%) of parthenium weed and may improve sorghum grain yield (up to 23%).

Influence of Crop Establishment Methods and Weed Management Practices on Growth and Yield Attributes of Wheat

An experiment was conducted in Rabi season of 2019-20 and 2020-21; consist of six crop establishment methods viz., Conventional till wheat - residue removed, Conventional till wheat - residue incorporation at 20 days before sowing (30 cm height), Conventional till wheat - mulching (6 t ha-1), Zero till wheat without residue and Zero till wheat – residue as mulch (6 t ha-1), zero till wheat- residue retention (30 cm) was assigned to main plots and weed management practices viz., weed free (weeds were removed with the help of hand weeding during entire crop period), Weedy check, Pendimethalin (1 kg ha-1, PE) fb sulfosulfuron + metsulfuron (30 + 2 g ha-1, PoE) and Pendimethalin (1 kg ha-1, PE) fb iodosulfuron + carfentrazone (2.5 + 20 g ha-1, PoE) were allocated to sub plots. Among crop establishment methods, zero tillage with residue mulching @ 6 t ha-1 and among the weed management practices, Pendimethalin (1 kg ha-1, PE) fb iodosulfuron + carfentrazone (2.5 + 20 g ha-1, PoE) recorded maximum plant height and yield attributes of wheat over rest of the treatments.

Residual effects of herbicides on weed interference and productivity in wheat (Triticum aestivum) under a conservation agriculture-based onion (Allium cepa)–wheat cropping system

A field experiment was conducted during the rainy (kharif) and winter (rabi) seasons of 2015–16 and 2016–17 at the ICAR-Indian Agricultural Research Institute, New Delhi, to evaluate the effects of conservation agriculture (CA) and carryover weed management on weed interference and crop productivity of wheat [Triticum aestivum (L.) emend Fiori & Poal] in an onion (Allium cepa L.)–wheat system. Three conventional and conservation tillage and 7 weed-management treatments were laid out in a split-plot design, with 3 replications. The CA-based zero-till raised-bed system with residue retention (ZTRB + R) resulted in significant reduction in total weed density and biomass compared to conventional till flat bed (CTFB), which led to higher weed control efficiency (11%), grain (4.02 t/ha) and straw yield (4.24 t/ha), and net returns 46000 `/ha in the year 2016–17. The zero-till flat bed with residue (ZTFB + R) and ZTRB + R led to an increase in wheat grain yield by 5.1 and 3.6%, and net returns by 28 and 18% than CTFB respectively. Among the herbicidal treatments, the pendimethalin followed by (fb) ethoxysulfuron resulted in the highest reduction in weed density (29 and 34%) and weed dry weight (55 and 56%) in both years, and the pendimethalin fb quizalofop was comparable with it in these regards. The pendimethalin fb quizalofop- or ethoxysulfuron- treated plots provided higher wheat grain yield (4.24 t/ha), net returns 49000 `/ha and net benefit: cost (B: C) in the year 2016–17. The pendimethalin fb ethoxysulfuron had higher residual effect on weeds in wheat but inflicted severe phytotoxicity to onion in previous season that reduced onion yield significantly. Therefore, the pendimethalin fb quizalofop application to onion is most preferred considering onion and wheat crops safety and may be adopted under zero-till raised-bed for higher productivity and profitability in onion–wheat cropping system.

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 ).

Effect of tillage and herbicides on growth, weed control and energetics of chickpea (Cicer arietinum) grown in sequence with sorghum (Sorghum bicolor)

An experiment was conducted during 2019–20 on sandy clay-loam soil at the Rani Lakshmi Bai Central Agricultural University, Jhansi, Uttar Pradesh, to evaluate the effect of tillage and herbicides on growth, weed control, economics and energetics of chickpea (Cicer arietinum L.). Treatments included 3 tillage, viz. zero-tillage (ZT), ZT along with sorghum [Sorghum bicolor (L.) Moench] residue (ZT + R) and conventional tillage (CT), in main plot; and 4 weed-management practices, viz. pendimethalin alone, pendimethalin followed by (fb) clodinafop-propargyl + Na-acifluorfen, pendimethalin fb hand-weeding and unweeded check, in subplots. Chickpea growth and development was higher under ZT + R, which led to higher grain yield, economics, and energetics. Net returns under ZT + R were 13.5% more than ZT but 36.7% more than CT. Chickpea grown under ZT and ZT + R with pendimethalin fb clodinafop + Na-acifluorfen was 32.7–43.5% more energy-efficient than the same treatment under CT. This study indicated that chickpea grown after sorghum under ZT + R with pendimethalin fb clodinafop + Na-acifluorfen was economical and energy-efficient apart from providing higher grain yield in Bundelkhand region.

Productivity and profitability of direct-seeded rice under varying establishment methods and weed management practices

A field experiment was conducted at Banaras Hindu University, Varanasi (2016-17) to evaluate the effect of crop establishment and weed management practices on productivity, economics and resource-use efficiency of direct-seeded rice (DSR). The treatments included three crop establishment methods, viz. Zero-tillage-DSR+Sesbania co-culture (ZT-DSR+SCC), ZT-DSR+residue+Sesbania co-culture (ZT-DSR+R+SCC) and Conventional till-DSR+Sesbania coculture (CT-DSR+SCC) assigned to main-plots and five weed management practices, viz. WMP1- pendimethalin (1000 g/ha) fb bispyribac-sodium (25 g/ha) 20 days after sowing (DAS), WMP2-pendimethalin (1000 g/ha) fb pyrazosulfuron (30 g/ha) 20 DAS+1 hand weeding (HW) 45 DAS, WMP3- pendimethalin (1000 g/ha) fb chlorimuron+metsulfuron (4+4 g/ha) 20 DAS+1 HW 45 DAS, WMP4- Weed-free and WMP5- Weedy check assigned to sub-plots. The experiment was laid-out in a three-time replicated split-plot design. Results showed that, ZT-DSR+R+SCC recorded higher growth parameters, such as dry matter accumulation (DMA), leaf area index (LAI), yield attributes and enhanced grain yield, net return and water productivity by 16.9, 61.9 and 20% and 11.0, 69.7 and 10.3% during 2016 and 2017, respectively over CT-DSR+SCC. Among weed management practices, pendimethalin (1000 g/ha) fb chlorimuron+metsulfuron (4+4 g/ha) 20 DAS+1 HW 45 DAS recorded higher DMA, LAI, yield attributes and finally enhanced grain yield, net returns and water productivity by 31.9, 39.2 and 33.3% and 35.7, 36.6 and 37.5% during 2016 and 2017, respectively over weedy check. Hence, ZT-DSR+R+SCC along with pendimethalin (1000 g/ha) fb chlorimuron+metsulfuron (4+4 g/ha) 20 DAS+1 HW 45 DAS could be adopted for higher yield, net returns and resource-use efficiency of DSR.

Bio-efficacy of pre and post-emergence herbicides on lentil yield, weed control efficiency, weed index, nutrient uptake and economics

Lentil (Lens culinaris Medikus) is an important grain legume crop. Among all the biotic factors, weed infestation is being an adverse impact on growth, yield, nutrient uptake and economics due to lentil short stature, low branching, lack of protective canopy and it’s unable to smother the weeds. Although, applying pre emergence herbicides, in many situation early weed control herbicides are not that much efficient for attaining higher yields due to lentil is long duration crop and critical weed competition upto 40-60 DAS. Sequence use of pre and post-emergence herbicides and application of early post-emergence herbicides may help in controlling the weeds at later stages of crop growth period. To understand resources distribution in lentil a field experiment was laid out at BAU research farm, Sabour during Rabi of 2019-20 in RCBD replicated thrice with 13 treatments to assess the effect of various pre and post-emergence herbicides in lentil. Out of 13 treatments, weed free treatment produced significantly higher grain yield and haum yield and new generation herbicides application of pendimethalin fb quizalofop-ethyl + imazethapyr and oxyflurofen fb quizalofop-ethyl + imazethapyr were statistically at par with weed free treatment. Weed control efficiency, Weed index, Nutrients uptake and Economics by different weeds treatments were recorded significantly higher in pendimethalin fb quizalofop-ethyl + imazethapyr, oxyflurofen fb quizalofop-ethyl + imazethapyr and imazethapyr + imazomox at 60 DAS and at harvest. Ultimately, it can be concluded that, application of pendimethalin fb quizalofop-ethyl + imazethapyr and oxyflurofen fb quizalofop-ethyl + imazethapyr in lentil brings in enhancing grain yield and achieving more net returns, B:C ratio apart from suppressing the weeds through higher weed control efficiency and lower weed index.

Weed Control Efficiencies, Grain Yield and Economics as Affected by Seedbed Preparation and Weed Management Practices in Central Terai, Nepal

Grain yield under dry direct seeded rice (DDSR) is primarily limited due to weeds. Therefore, a field experiment was conducted at Rampur, Chitwan during the monsoon season, of 2014. The treatments consisted of two methods of seedbed preparation in the main plot and six weed management methods in the sub-plot arranged in split plot design with four replications. Results revealed that the grain yield of dry-direct seeded rice did not vary due to seedbed preparation methods. However, weedy check treatments reduced more than 92.78 % of grain yield of dry-direct seeded rice compared to weed-free check. The herbicidal treatments were found to be superior for the benefit-cost ratio. Pendimethalin fb Bispyribac sodium recorded the highest net returns of NRs 68.73 thousand ha-1 and the benefit-cost ratio of 2.55. Sequential application of Pendimethalin followed by Bispyribac sodium was proved to be the most efficient weed management method for dry-direct seeded rice.

Bio-efficacy of Herbicides with Different Water Volumes and Spray Timing under Zero Tillage Rice Residue Retention Scenario against Phalaris minor in Wheat

Background: Continuous use of the similar modes of action-based herbicides leads to the development of herbicide resistance in wheat-associated weeds in north-west India. Accelerated development of multiple resistance against most of the available post-emergence herbicides emphasize the use of pre-emergence herbicides. But, the efficacy of pre-emergence herbicide is a matter of concern as surface retained stubbles and/or straw alter herbicide efficacy associated with a direct interception of herbicide.
 Methods: A field study was conducted for two rabi seasons (2018-19 and 2019-20) to optimize spray volume and time of application for improving the bio-efficacy of pre-emergence herbicides under zero tillage full rice residue scenario. The herbicidal treatments (g/ha) included pendimethalin + pyroxasulfone (1000.0+127.5) as pre-emergence (PE), pyroxasulfone (127.5) as PE, pyroxasulfone (127.5) as early post emergence (EPoE), aclonifen+diflufenican (1002+200) EPoE, halauxifen methyl+ fluroxypyr (7.3+233.4) as EPoE, flumioxazin (100) as PE with two different water volumes 500 and 1000 liter/ha along with pendimethalin fb pinoxaden (1500+50) in 500 l/ha water volume, pendimethalin (1500) as PE in 375 l/ha water volume, weed free and weedy check.
 Results: The present study showed that pendimethalin + pyroxasulfone as PE with a higher spray volume of 1000 l/ha and alone application of pyroxasulfone as EPoE produced similar Phalaris minor control as with pendimethalin fb pinoxaden (PE fb Post) under full rice residue scenario in zero-till wheat.

System productivity, energetics and economics of soybean (Glycine max)-wheat (Triticum aestivum) cropping system as influenced by weed management practices

A field experiment was conducted during 2015–16 and 2016–17 to assess the system productivity, energetics and economics of weed management practices in soybean (Glycine max L.)-wheat (Triticum aestivum L.) cropping system at ICAR-Directorate of Weed Research, Jabalpur, Madhya Pradesh. The experiment comprised 10 treatments having combinations of sole and sequential application of pre-emergence and post-emergence herbicides in both the crops, and their integration with hand weeding undertaken in randomized block design replicated thrice. The highest system productivity (8.04 t/ha) was obtained by employing two hand weedings, sequential application of pendimethalin followed by (fb) imazethapyr in soybean and pendimethalin fb mesosulfuron + iodosulfuron in wheat as well as by integrating either pre or post-emergence herbicides with one hand weeding. Among weed management practices, energy requirement was lowest in sole post-emergence herbicide treatment, however, integration of manual weeding required maximum energy. The energy input for hand weeding was a major share of integrated weed management practices, and it varied from 54–83% of the total treatment energy. Due to requirement of less energy for sole post-emergence herbicides, energy output, net energy return and energy ratio were the maximum. Total output energy was higher (258×103 MJ/ ha) in post-emergence herbicide fb hand weeding treatment because of higher system productivity (7.29 t/ha), and this treatment was more energy efficient and gave the highest economic returns among the weed management practices. The highest benefit: cost ratio (3.10) was obtained by the application of post-emergence herbicides in both the crops.

Effect Of Seedbed Preparation Methods And Herbicide Application On Yield And Economics Of Dry Direct-Seeded Rice At Parwanipur, Nepal

Field experiments were conducted during the 2016 and 2017 normal season (June-November) dry direct[1]seeded rice (DDSR) at RARS Parwanipur to assess the effect of various combinations of herbicides mixture under seedbed preparation to evaluate different attributes of weed control efficiencies (WCE) coupled with grain yield and economics of DDSR. The experiment was laid out in two factors factorial strip plot design with four replications. Treatments consisted of nine levels of weed management practices that include weed free, weedy check, Pendimethalin, Bispyribac sodium, Ethoxysulfuron, Pendimethalin followed by (fb) Bispyribac sodium, Pendimethalin fb Ethoxysulfuron, Bispyribac sodium tank mix with Ethoxysulfuron and Pendimethalin fb tank mixture of Bispyribac sodium and Ethoxysulfuron as horizontal factor whereas two levels of seedbed preparation methods (stale seedbed and normal seedbed) as the vertical factor. The result of the experiments revealed lower weed intensity (WI) and higher weed control efficiency (WCE), net return and benefit-cost (B:C) ratio with Pendimethalin fb tank mixture of Bispyribac sodium and Ethoxysulfuron in both the years 2016 and 2017. Grain yield was significantly higher with weed free treatment followed by Pendimethalin fb tank mixture of Bispyribac sodium and Ethoxysulfuron in both the years due to higher WCE and lower WI which resulted in better growth and development of DDSR. Therefore, the Pendimethalin fb tank mixture of Bispyribac sodium and Ethoxysulfuron is a better option for DDSR under Parwanipur condition during main season rice DDSR rice production.

Effect of cultivars and weed management practices on productivity, profitability and energetics of dry direct-seeded rice

A field experiment was conducted from September 2019 to January 2020 (thaladi season) at Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal, Puducherry to study the effect of cultivars and weed management practices on productivity, profitability and energetics of dry direct-seeded rice (DDSR). The experiment was laid out in a split-plot design (SPD) with 15 treatment combinations and replicated thrice. Cultivars (ADT 46, CO 52 and improved white ponni) were assigned to main plots and 5 weed management practices viz. application of pendimethalin @ 1 kg a.i ha-1 as pre-emergence (PE); bispyribac-sodium @ 0.02 kg a.i ha-1 as post-emergence (POE) at 20 DAS; pendimethalin @ 1 kg a.i ha-1 followed by (fb) bispyribac-sodium @ 0.02 kg a.i ha-1; hand weeding (HW) twice at 20 and 40 DAS and weedy check were assigned to sub-plots. Results have shown that cultivars 'ADT 46' was the most promising cultivar for DDSR situation since it recorded the highest grain yield (3.76 t ha-1), energy use efficiency (4.43), energy productivity (0.3 kg MJ-1), net returns (Rs. 43.74 × 103 ha-1) and benefit: cost ratio (1.52). Among the weed management practices, sequential application of pendimethalin fb bispyribac-sodium found superior over other treatments in terms of grain yield (3.73 t ha-1), energy use efficiency (4.35), energy productivity (0.3 kg MJ-1), net returns (Rs. 42.27× 103 ha-1) and benefit: cost ratio (1.43). Thus, cultivation of 'ADT 46' integrated with sequential application of pendimethalin fb bispyribac-sodium could be recommended for DDSR under coastal deltaic ecosystem of south India.

Effect of sowing and weed control methods on nutrient uptake and soil fertility in direct-seeded rice (Oryza sativa)

A 2-year field experiment consisting of 3-planting methods and 5-weed control options was conducted in a three-time replicated split-plot design at Varanasi during kharif 2016-17 to assess the nutrient uptake by direct-seeded rice (Oryza sativa L.) and available nutrient status of soil under different methods of establishing crop and managing weeds. Zero-till direct-seeded rice (ZT-DSR) + residue + Sesbania brown manuring (SBM) recorded lower density and dry-weight of weeds, higher organic carbon (OC), available N, P and K in soil and enhanced N, P and K uptake by 8.9, 6.7, 7.8% and 23.7, 24.5 and 10.2% in grain and straw, respectively, over conventionally-tilled direct-seeded rice (CT-DSR) + SBM. Among weed control options, the use of pendimethalin (1000 g/ha) fb chlorimuron + metsulfuron (4 + 4 g/ha, 25 DAS) + 1 HW (45 DAS) resulted in lower density and weeds, higher OC, available N, P and K in soil and improved N, P and K uptake in grain and straw by 23.6, 20.9 and 33.0 and 26.7, 25.5 and 26.6%, respectively over weedy check. However, higher EC and pH and lower nutrient (N, P and K) and protein content in grain and straw were found under weed-free condition. Overall, ZT-DSR + residue + SBM and application of pendimethalin (1000 g/ha) fb chlorimuron + metsulfuron (4 + 4 g/ha, 25 DAS) + 1 HW (45 DAS) proved better with respect to reduction in weed biomass, OC, available soil nutrients (N, P and K) and their uptake in DSR.

Influence of nutrient and weed management on weed dynamics and productivity of upland rice (Oryza sativa)

The field experiment was conducted during kharif 2019 at ICAR-CURRS-NRRI at Hazaribagh, Jharkhand. The experiment was conducted to evaluate precision nutrient management and weed management practices for achieving minimum weed menace and maximum crop productivity. Under precision nutrient management, Nutrient Expert ® guided NPK recorded lesser weed density (7.76, 8.07 and 8.62) at all three stages. Pendimethalin fb hand weeding resulted in comparatively lesser weed density (7.72, 7.29 and 7.34 at 25, 60 DAS and at harvest). Nutrient Expert ® guided NPK resulted in maximum grain yield (3.63 t/ha), followed by Leaf Colour Chart (LCC) guided N + Full P & K (3.41 t/ha), which was significantly higher over RDF. Among the weed management aspects, pendimethalin fb hand weeding and bispyribac-Na were observed with significantly higher grain yield (4.09 and 3.79 t/ha). Hence Nutrient Expert ® guided NPK and pendimethalin fb hand weeding can be recommended for better weed management and enhanced productivity.

​Effect of Integrated Weed Management on Weed and Yield of Direct Seeded Rice

Background: Weeds are the major threat to direct seeded rice and a single strategy of weed control may not be effective for season-long weed control. Intending to accomplish the long-term and sustainable weed management of direct seeded rice, the integration approach of weed management strategies seems a better alternative. The current field study was aimed to evaluate the impact of integration of different weed control methods on direct seeded rice under irrigated ecosystem on weed growth and rice yield. Methods: The experiment was laid out in randomized block design with three replications and twelve treatments during 2017 at G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India. The twelve treatments included the combination of cultural, mechanical, physical and chemical weed management methods. Result: Combination of stale seedbed technique integrated with pre-emergence application of pendimethalin with mechanical weeding at 25 DAS followed by 1 hand weeding at 45 DAS, Sesbania (line sowing) fb application of pendimethalin (PE) fb 1 mechanical weeding at 25 DAS fb 1 hand weeding at 45 DAS, stale seedbed with application of pendimethalin (PE) with Sesbania brown manuring supplemented with mechanical weeding (25 DAS) fb hand weeding at 45 DAS, mulching with wheat straw mulch along with post-emergence application of penoxsulam (20 DAS) fb 1 hand weeding at 45 DAS and application of pendimethalin (PE) fb penoxsulum (PoE) at 20 DAS fb 1 hand weeding at 45 DAS with a row spacing of 25 cm found to be similar in the suppression of weed population and weed density at 40 and 60 DAS and crop yields (4.3, 4.1, 4.2, 4.0 and 4.2 t/ha, respectively) were on par with weed free plot i.e. 4.4t/ha. Application of pendimethalin (PE) fb penoxsulum (PoE) at 20 DAS fb 1 hand weeding at 45 DAS with row spacing of 25cm recorded 93.7%, 90.6% and 4.5% weed control efficiency, weed control index and weed index respectively, which was similar with above integrated weed management treatments. A negative correlation of the weed density and dry matter with the yield of rice was recorded.