Emergence Herbicides Research Articles

Effect of Unmanned Aerial Vehicle Sprayed Herbicides on the Soil Properties and Nutrient Availability in Rabi Groundnut

Herbicides are normally applied by manually operated knapsack sprayers, which are laborious, uneven and prone to human mistakes. Unmanned aerial vehicles (UAVs) are a promising agricultural spraying alternative to manual operation. Drone herbicide spraying was compared to knapsack sprayers in this study. A two year field experiment was conducted at Regional Agriculture Research Station, Research Farm, Palem, Nagarkurnool, Telangana during rabi 2022-23 and 2023-24. A ready-mix post emergence herbicide with combination of Imazethapyr 3.75% + propaquizafop 2.5% ME was applied to groundnut at 20-25 DAS. The experiment consisted of 12 treatments viz., 75% recommended dose (RD), 100% RD and 125% RD which were applied with drone using 20 and 40 L ha-1 spray fluid and sprayed from 2.0 and 2.5 m height from canopy, Checks (5) were also maintained (manual spray of 75% RD,100%RD and 125% RD, weedy check and weed free) in the experiment for comparative evaluation of drone applied and manually applied herbicides. Experiment was laid out in 3X2X2 FRBD and replicated thrice. Results of the experiment showed that application of different doses of ready mix herbicide did not significantly influence the soil physical and chemical properties observed after harvest of the crop. Similarly, the available macro-nutrient status was also not significantly influenced by drone sprayed herbicide application compared to manual spraying using knapsack sprayer.

Effect of different post emergence herbicides on growth and yield of pigeonpea (Cajanus cajan L. Mill)

Effect of different post emergence herbicides on growth and yield of pigeonpea (Cajanus cajan L. Mill)

Efficacy of Pre and Post Emergence Herbicides against Complex Weed Flora, Yield and Economics of Blackgram under High Hills Wet Temperate Zone of Himachal Pradesh

Background: Implementing integrated strategies for weed management is essential in maximizing blackgram yield. Unchecked weed proliferation leads to substantial decrease in crop productivity. Methods: The current field experiment was conducted at Salooni, Himachal Pradesh, to evaluate the efficacy of different integrated weed management practices during Kharif 2022 and 2023. Eleven treatments targeting weed control were evaluated both at pre and post - emergence stages. Result: The predominant weeds were Echinochloa colona, Galinsoga parviflora, Cyperus species and other broad leaf weeds were Plantago lanceolata, Trifolium repens, Trianthema species, Ageratum conyzoides. Data on weed dynamics revealed that; after weed-free treatment, the application of Imazethapyr 75 g/ha as PE fb HW at 30 DAS; Pendimethalin 1.0 kg/ha as PE fb HW at 30 DAS and Pendimethalin 1.0 kg/ha + imazethapyr 75 g/ha (PE) recorded a significantly lower total weed count as compared to other treatments. Parameters related to blackgram growth and yield, including plant height, number of branches per plant, pods per plant, grain yield and haulm yield were significantly higher with weed-free treatment followed by application of imazethapyr 75 g/ha as PE fb HW at 30 DAS, remaining at par with application of pendimethalin 1.0 kg/ha + imazethapyr 75 g/ha (PE) and pendimethalin 1.0 kg/ha as PE fb HW at 30 DAS. The most economically efficient weed control method was the combination of pendimethalin 1.0 kg/ha + imazethapyr 75 g/ha (PE), as it resulted in the highest net returns and marginal benefit-cost ratio.

Bio-efficacy of herbicides on weeds in direct-seeded rice in Konkan region of India

Rice cultivation by direct seeding is viewed as both cost and labor-saving practice and becoming popular alter- native to transplanting. Weeds are a more serious problem in DSR than in transplanted rice. The field experimen- tal is conducted to evaluate the bio -efficacy of pre and post – emergence herbicides, hand-weeding on weed con- trol, yield components, yield and their economic feasibility for cost effective weed control in direct seeded rice. The experiment was laid out in randomized block design with three replications and seven treatments, viz. Pre-emer- gence oxadiargyl 80% WP @ 100 g/ha, Pre-emergence oxadiargyl 80% WP @ 100 g/ha fb HW at 30 DAS, oxadiargyl 80% WP (PE) @ 100 g/ha fb Post-emergence bispyribac- Na @ 25 g/ha at 25 DAS, Pre-emergence oxadiargyl 80% WP @ 100 g/ha fb Post-emergence metasulfuron- methyl + chlorimuron – ethyl @ 4 g/ha at 25 DAS, Pre-emergence oxadiargyl 80% WP @ 100 g/ha fb Post-emergence carfentrazone ethyl 40% @ 25 g/ha at 25 DAS. Weed density under weedy check (WC) situation showed that monocot weeds (grasses and sedges) were more pre-dominant wherein grasses and sedges constituted 74.80% and 11.48%, respectively, BLWs 14.20% of total weed density at 60 DAS of crop. Amongst the herbicide treatments, application of Oxadiargyl (PE) @ 100 g/ha fb HW at 30 DAS recorded significantly lowest number of weeds/m2, dry weight/m2. The highest grain yield (4.02 t/ha) and benefit cost (1.48) were recorded with the pre-emergence application of Oxadiargyl (PE) @ 100 g/ha fb HW at 30 DAS.

Weed management options in drum seeded wetland rice

High labour requirement and cost for raising nursery and transplanting of the seedlings has necessitated the shift from transplanted rice to direct-seeded rice. To reduce the requirement of large quantity of seeds, incidence of pests and diseases in broadcasting and to ensure uniform seed distribution for consistent crop growth and easier maintenance, mechanization is needed in direct-seeded rice. The major constraint experienced in wet DSR is the occurrence of high weed infestation as emerging seedlings in direct-sown fields are less competitive with concurrently emerging weeds. An experiment was conducted at M. S. Swaminathan Rice Research Station, Moncompu, Kerala Agricultural University during kharif and rabi 2021-22, with eight treatments and three replications in randomised complete block design to identify suitable cost-effective agronomic management practices to enhance the productivity of drum seeded rice and to maximise its resource-use-efficiency. The results revealed wet DSR using drumseeder as a viable crop establishment method for reducing the seed requirement, cultivation time, energy, cost of cultivation, pest and disease infestation, minimise plant stress due to transplanting and sustaining yield. There was significant variation in the yield and yield attributes in drum seeding depending on the weed management strategies adopted viz., two conoweedings, post emergent herbicide application, pre followed by post emergent herbicide application, post emergent herbicide application followed by conoweeding. Post-emergence application of Chlorimuron ethyl + Metsulfuron methyl @ 0.004 kg/ha and Penoxsulam + Cyhalofop butyl @ 0.135 kg/ha as tank mix at 18 DAS followed by conoweeding at 30 DAS was found economical in drum seeding which was on par yield with broadcasted crop yield under post emergent herbicide application.

Evaluation of post emergence herbicides spraying in maize (Zea mays L.) by using drone

Evaluation of post emergence herbicides spraying in maize (Zea mays L.) by using drone

Efficacy of pre and post emergence herbicides on yield and economics of linseed (Linum usitatissimum L.)

Efficacy of pre and post emergence herbicides on yield and economics of linseed (Linum usitatissimum L.)

Five years of conservation tillage and weed management in a rice-chickpea rotation of northern Gangetic Plains of India: Weed growth, yield benefits and economic profitability

Cropping system diversification of cereal-cereal systems with alternative systems preferably with pulses/legumes is demand of time across the globe for sustenance of natural resources and climate resilience. Rice-chickpea has been advocated as a futuristic cropping system in rice ecologies of South Asia for diversification of dominating rice-wheat system. However, the long-term sustainability of this system with respect to weed severity/growth, crop/system productivity, profitability, and yield stability under variable tillage, crop residues, and weed management practices has not been studied elaborately. Hence, present study was undertaken for five consecutive years in split-plot design with four tillage and residue management practices in main plot (conventional and zero tillage with and without residues), and three weed control practices (pre + post emergence herbicides and manual weeding) in sub-plot. Conservation tillage system comprising zero-tilled (ZT) direct seeded rice (ZTDSR) - ZT chickpea with rice residue retention (ZTDSR-ZTC+RR) led to the lower weed density in chickpea (by 10 %) and system (by 7 %) than conventional-tilled (CT) puddled transplanted rice - CT chickpea without residues (PTR-CTC-R; farmer practice). Among weed management practices, pendimethalin 1 kg a.i. ha−1 – metsulfuron-methyl + chlorimuron ethyl (ready-mix) 4 g a.i. ha−1 in rice and oxyfluorfen 150 g a.i. ha−1 – propaquizafop 100 g a.i. ha−1 in chickpea decreased the weed density in system by 14–22 % (p < 0.05) than pendimethalin + one hand weeding. The best weed management practice (pendimethalin – metsulfuron-methyl + chlorimuron ethyl) had significantly total weed density rice (by 7 %) and system (by 10 %) than current recommendation of the Indo-Gangetic Plains region (pendimethalin - bispyribac-sodium). It suggested that rotation of bispyribac-sodium with metsulfuron-methyl+chlorimuron ethyl (mixture herbicide) could reduce weed density and increase yield over time. Mean of five years indicated a non-significant yield difference among conservation and conventional tillage systems in rice. However, conservation tillage practice (ZTDSR-ZTC+RR) had 10 % higher chickpea yield and 4 % higher system yield (five years mean) over the PTR-CTC-R (p < 0.05). Further, conservation tillage comprising ZT in both crops in system with added residues (ZTDSR-ZTC+RR) resulted in an economic benefit of INR 22,000 than the conventional tillage in both crops without residues (PTR-CTC-R). Moreover, five years sustainable yield index was 16 % higher in ZTDSR-ZTC+RR system than conventional-tilled rice-chickpea system. Thus, conservation tillage with suitable pre- + post- emergence herbicides such as pendimethalin – metsulfuron-methyl + chlorimuron ethyl in rice and oxyfluorfen – propaquizafop in chickpea can reduce the weed density and enhance the crop and system productivity over time than conventional tillage. This system can also sustain the yields of component crops and system in long-run with higher yield stability over conventional tillage without residues. This system can be adopted in the cereal-cereal based cropping system of rice ecologies to diversify the system and to reverse the weed infestation and yield decline.

Phytotoxic Response and Variation in Yield Traits for Post Emergence Herbicides in Chickpea (Cicer arietinum L.)

Phytotoxic Response and Variation in Yield Traits for Post Emergence Herbicides in Chickpea (Cicer arietinum L.)

Investigation on the Carry-over Effects of Various Pre- and Post-emergence Herbicides Applied Alone and in Combination to Cotton on Succeeding Chickpea Crop

A field experiment was conducted in kharif and rabi season during 2018-19 and 2019-20 at cotton research scheme farm, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani (M.S) under irrigated condition (drip) and studied the effect of various pre- and post- emergence herbicide treatments used alone or in combination for weed control on cotton and subsequent chickpea (Cicer arietinum L.) crop. Without using any weed control techniques, chickpea was grown on the same field after the cotton crop had been harvested. Three replications of the randomized block design were used to evaluate seven different treatments. The crop was significantly affected by all herbicide applications, with the exception of hand weeding at 30, 60, and 90 DAS. From the current study, it can be concluded that crops like chickpeas cannot be grown in a safe order after cotton because using pyrithiobac sodium 62.5 g/ha as PE + quizalopfop ethyl 50 g/ha at 60 DAS as the weed management practice in cotton had a significant impact on growth, yield, and economics.

Chemical Weed Control in Field Pea [Pisum sativum(L.) var arvense

Field pea [Pisum sativum (L.) var arvense] is an important pulse crop mainly grown as a winter vegetable in the plains of north India. The effect of ready-mix application along with various pre- and post- emergence herbicides were evaluated for effective and season long weed control in pea. Pre-emergence application of pendimethalin +imazethapyr (ready-mix) at 1250 g ha-1 provided excellent control of Coronopus didymus, Anagallis arvensis and Chenopodium album similar to weed free conditions and resulted in highest yield (1795 kg ha-1) among the herbicidal treatments. Post-emergence (2-4 leaf stage) application of imazethapyr alone and its different ready-mix combinations with imazamox at 60-80 g ha-1 provided 86.0-94.0% control of weeds at 60 DAS and resulted the grain yield ranging 1503-1620 kg ha-1.The maximum weed control index at 30 DAS (91.5%) was recorded with pre-emergence application of pendimethalin + imazethapyr at 1250 g ha-1 followed by pendimethalin + imazethapyr (PRE) at 1000 g ha-1 (87.80%). Pre-emergence application of pendimethalin + imazethapyr (RM) at 1250 g/ha gave the highest net return along with the highest Benefit Cost Ratio (2.36) followed by the same combination at 1000 and 800 g ha-1.

Efficacy of Different Pre and Post Emergence Herbicide Application on Late Sown Maize Crop Under Variable Planting Density

Efficacy of Different Pre and Post Emergence Herbicide Application on Late Sown Maize Crop Under Variable Planting Density

Simultaneous determination of bromoxynil and MCPA in commercial samples and raw materials using reversed phase high performance liquid chromatography

This study encompasses a quick, efficient, repeatable and reproducible analytical method for simultaneous determination of Bromoxynil (3, 5-Dibromo-4-hydroxybenzonitrile) and MCPA (2-methyl-4-chlorophenoxyacetic acid) using RP-HPLC with UV-Detector. Bromoxynil + MCPA is one of the most selective post emergent herbicide formulations for the control of important broad leaf weeds infesting small grains (wheat, barley, oats, rye), conservation reserve program areas and grass grown for seed. Optimum weed control is achieved when Bromoxynil + MCPA is applied to actively growing weed seedlings. So, a simple, repeatable, reproducible and efficient simultaneous analytical method was developed for Bromoxynil + MCPA. The developed method was applied for the detection and quantitation of these pesticides in formulations and raw materials with excellent recoveries. It was validated according to ICH Guidelines with excellent linearity R2 = 0.992 for Bromoxynil and 0.998 for MCPA. For Bromoxynil, LOD = 1.57 mg/L and LOQ = 5.22 mg/L while for MCPA the LOD = 1.08 mg/L and LOQ = 3.62 mg/L was found. The proposed method has shown high precision (RSD %) 0.06% and 0.11% for Bromoxynil and MCPA respectively while the trueness has been calculated in terms of recovery percentage obtained as “mean value of Bromoxynil 99.53% and MCPA 100.10%” which is excellent under optimized conditions. For repeatability and reproducibility, five replicate readings of standard and sample were taken and had found within acceptable limits of relative standard deviation (RSD ≤ ± 2%). Finally, the robustness of the developed method was determined by changing flow rate and mobile phase ratios that has found within the permissible limits (% RSD NMT 1.5). So, the proposed analytical method has found to be more precise, valid and accurate at commercial scale.Graphical

Residual phytotoxicity effects of different integrated herbicides management in soils from field-treated plots and post-harvest field

Soil residual phytotoxicity of commonly used herbicides in cotton crop in India were investigated through bioassay. Pendimethalin at 900 g a.i. ha-1, oxyfluorfen at 180 g a.i. ha-1, oxadiargyl at 90 g a.i. ha-1, quizalofop-ethyl at 40 g a.i. ha-1, imazethapyr at 75 g a.i. ha-1, propaquizafop at 50 g a.i. ha-1 and glyphosate at 960 g a.i. ha-1 were applied to field plots of 6.0 x 6.0 m2. Sorghum and cucumber were used in the bioassay and succeeding crops groundnut, green gram &amp; pearl millet to test the residual effect of herbicides in the soil of the treated plots and post-harvest field. Soil, sampled at 30 day after treatment (DAT) for pre emergence herbicide and until 2 weeks (WAT) for post emergence herbicide later, show significant affect the seed germination and seedling development stage of sorghum and cucumber. There was no residual toxicity of pre and post-emergence herbicides as observed through field bioassay after harvesting cotton crop and it was found safe to grow groundnut, green gram and pearl millet as succeeding crop.

Productivity of Dry Direct Seeded Rice as Influenced by Herbicide Combinations

A field experiment was conducted during Kharif, 2022, in Institute of Rice Research, Rajendranagar, Hyderabad in Telangana state, India. Fourteen weed management practices were evaluated in a randomized complete block design, replicated thrice. Weed management in Dry DSR can be done by adopting mechanical/ Hand weeding at 20, 40, 60 DAS under labour available conditions. Under labour scarcity conditions PE application of Pendimethalin 38.4% + Pyrazosulfuron ethyl 0.85% ZC 900 + 20 g/ha (Ready mix) followed by Metsulfuron Methyl 10% + Chlorimuron ethyl 10% WP 4 g/ha + Cyhalofop Butyl 10% EC 75g/ha (Tank mix) PoE weed followed by mechanical weeding at 40-45 DAS is the best option. Other suitable Pre emergence herbicides that can be used are Pyrazosulfuron ethyl 10% WP 20 g/ha, Pendimethalin 38.4% + Pyrazosulfuron ethyl 0.85% ZC 900 + 20 g/ha (Ready mix) and Pendimethalin 38.7 % CS 677.25 g/ha. Post emergence application of Triafamone 20% + Ethoxysulfuron l0% WG 44+22.5 g/ha (Ready mix) and Penoxsulam 1.02 % + Cyhalofop-butyl 5.1% OD 135 g/ha (Ready mix) at 2-4 weed leaf stage.

Weed management in soybean using early post emergence herbicide in lateritic soil and residual effects of herbicide in succeeding crops

Weed management in soybean using early post emergence herbicide in lateritic soil and residual effects of herbicide in succeeding crops

Studies on weed density and weed control efficiency of post emergence herbicides in wheat (Triticum aestivum L.)

Studies on weed density and weed control efficiency of post emergence herbicides in wheat (Triticum aestivum L.)

Johnson Grass (Sorghum halepense) Interference, its Effect on Crops Yield and Soil attributes under Different Cropping Systems and Management Practices

Johnson grass (Sorghum halepense) is one of the most detrimental and toxic weeds among the weed species. Its environment is expanding unceasingly due to deeply expanding of its rhizomes in the soil, self-pollinating reproduction strategy, accelerated growth and poor management which results in production losses of major agronomic crops. Mungbean and sorghum are important crops grown on significant acreage around the world, and a major constraint for their production losses is weeds interference. Thus, field studies were conducted to examine Johnson grass interference, control, and recovery under different management practices and cropping system and its effects on crops production and soil health. Our results indicated that the Johnson grass density was minimized by the application of plastic sheet mulch treatment under wheat-mungbean cropping system. Johnson grass competition had a significant impact on growth and grain yield of both mungbean and sorghum. The crop yield parameters; 100 grain weight and grain yield were lowest in the non-treated treatment (control), while the greatest values of these parameters were recorded in the plastic sheet mulch and post emergence herbicide treatments with wheat-mungbean cropping system. Similarly, soil building attributes; available nitrogen, available phosphorus, available potassium and organic matter content were positively affected by the interaction of plastic sheet mulch + wheat-mungbean cropping system. Besides this, benefit-cost ratio of the research shows that wheat-mungbean cropping system with application of plastic sheet mulch and post emergence herbicide also proved to be economically feasible. Overall, we have concluded that wheat-mungbean and wheat-sorghum are most resilient cropping system with the implementation of plastic sheet mulch and Post Emergence Herbicide to suppress the spread of Johnson grass under changing climatic scenarios.

Weed Management in Soybean through Post Emergent Herbicides

Weed infestation is a complex and regular threat to soybean production all over the world. Successful weed control is most important factor for fruitful soybean production, because losses due to weeds have been one of the major limiting factors in soybean production. Hence a study was carried out using post emergent herbicides at College of Agriculture,Raichur.during kharif 2020 and 2021.The experiment was laid in randomized complete block design with three replications, and it consists of twelve treatments ( viz., Clorimuron ethyl @ 37.5 g a.i, Imazethapyr + Imazamox @ 100 g a.i, Propaquizafop + Imazethapyr @ 100 g a.i, Profoxydim (at three doses viz., 35, 55 and 75 g a.i and another three set of these doses were added with adjuvant @ 2ml/liter of water), Propaquizafop @ 75 g a.i., and weed free check and weedy checks were also maintained. Results were indicated that among the herbicide treatments, combi products viz.,Imazethapyr + Imazamox @ 100 g a.i, Propaquizafop + Imazethapyr @ 100 g a.i. suppressed the weed density effectively and increased the weed control efficiency (88.41 % and 84.14%) next to weed free check. Yield parameters like number of pods per plant, test weight and grain yield also recorded higher in Imazethapyr + Imazamox @ 100 g a.i. (31.93,82.19g and 1622 kg ha-1) among the herbicides tested. BC ratio was recorded significantly higher in Imazethapyr + Imazamox @ 100 g a.i.(3.29) and it was on par with weed free check(3.22). From this trial, it can be concluded that broad spectrum or combi products like Imazethapyr + Imazamox can be used as a effective post emergent herbicide in soybean to suppress both monocot and dicot weeds

Effect of Pre and Post Emergent Herbicides on Weed Management, Yield and Economics in Irrigated Chickpea (Cicer arietinum L.)

A field experiment was conducted to study the effect of pre and post emergence herbicides on growth and yield of chickpea at College of Agriculture, Vijayapura, during rabi, 2021-22. The experiment was laid out in RCBD with three replications. The experiment consisted of 11 treatments involving two pre-emergence herbicides (Pendimethalin, Pendimethalin + Imazethapyr) and five post-emergence herbicides (Imazethapyr + Imazamox, Propaquizafop + Imazethapyr, Imazethapyr, Quizalofop ethyl and Aciflor + Clodinafop), intercultivation at 20 and 40 DAS, weed free check and weedy check. Among the herbicidal treatments, significantly lower weed population per m2 (2.40), lower total dry weight of weeds (3.18 g), higher weed control efficiency (84.98%), lower weed index (11.06 %), higher grain yield (2197 kg/ha), haulm yield (2766 kg/ha), net returns (₹ 80621/ha) and B:C ratio (3.01) was recorded with sequential application of Pendimethalin 38.7% CS @ 800 g a.i./ha as PE fb Propaquizafop 2.5% + Imazethapyr 3.75% W/W ME (RM) @ (125 g a.i./ha) as PoE at 25 DAS compared to all other treatments. Among herbicidal treatments lowest grain yield (923 kg/ha) and haulm yield (2098 kg/ha) were recorded with Imazethapyr 35% + Imazamox 35% WG (RM) @ 70 g a.i./ha as PoE at 25 DAS due to phytotoxicity and the results were almost near to weedy check which recorded 38.18 pods/plant, 100 seed weight of 22.36 g, 16.96 g of seed yield / plant, grain yield (896 kg/ha) and haulm yield (2056 kg/ha).