Herbicides Pendimethalin Research Articles

Residual effect of pre and post emergence herbicides and fertility levels on succeeding crops after soybean

Herbicides proved important tool in modern farming systems. With the intense farming practice and multiple cropping, the paucity of agricultural labour is seen. Their peak demand for a short period, inaccessible field conditions during crop seasons also encourages using herbicides in modern farming. But continuous application of herbicides in intense cropping systems may leads to it’s residue accumulation in the soil. This persistence of a herbicide may limit the choice of succeeding crops. Therefore, residual studies are essential to determine the feasibility of any herbicide. Rabi sorghum, bajra, barley and ragi are the important succeeding crops grown after soybean in South Saurashtra region. Therefore, the present study about residual effect of pre and post emergence herbicides and fertility levels in succeeding crops after soybean was undertaken at Instructional Farm of Junagadh Agricultural University, Junagadh during Kharif season of 2006. Eighteen treatment combinations comprising six levels of weed management practices as main plot treatments viz., W 1 Pre-emergence pendimethalin @ 0.5 kg ha + HW and IC at 30 DAS, W 2 – Postemergence quizalofop-ethyl @ 40 g ha at 25 DAS + HW and IC at 45 DAS, W 3 Post-emergence imazethapyr @ 75 g ha at 25 DAS + HW and IC at 45 DAS , W 4 2 HW + 2 IC at 20 and 40 DAS, W 5 Weed free upto 60 DAS through hand weeding and W 6 Unweeded control and three levels of fertilizers as sub plot treatments viz., F 1 20:40:20 kg N:P 2 O 5 :K 2 O ha F 2 30:60:30 kg N:P 2 O 5 :K 2 O ha F 3 40:80:40 kg N:P 2 O 5 :K 2 O ha were tried in Split Plot Design with three replications. The soil of the experimental plot was low in available nitrogen, medium in available phosphorus and high in available potash. Pre-emergence application of pendimethalin herbicide was done after 24 hours of sowing of soybean and post pre-emergence application of herbicide quizalofop-ethyl and imazethapyr was done after 25 days after sowing. The succeeding crops Rabi sorghum, bajra, barley and ragi were sown after harvesting of soybean within a week. The biometric observation about germination percentage of succeeding crops was done after 10 days of sowing. Plant height

Effect of nonwoven fabric cover on the efficacy and selectivity of pendimethalin in lettuce

The objective of this study was to com pare the effect of nonwoven fabrics used for growth acceleration in lettuce on the efficacy and selectivity of pendimethalin herbicide at varying application rates. Small plot experiments were conducted with head lettuce in Prague, Czech Republic during 2011–2013. Herbicide efficacy was higher in plots covered by nonwoven fabric, but selectivity was influenced negatively. Nonwoven fabric cover increased the efficacy of pendimethalin applied at rates of 600 and 1200gha−1. The highest efficacy was recorded against Chenopodium album (96–100%) and Amaranthus retroflexus (>90%). Efficacy against Echinochloa crus-galli ranged between 85% and 100%, against Solanum physalifolium between 77% and 100%, and against Mercurialis annua between 72% and 99%. Selectivity of pendimethalin to lettuce was lower in 2014, when intensive precipitation was recorded during the growing season. Lettuce injury (15–27%) was recorded on plots covered by nonwoven fabric treated by pendimethalin at a rate of 1200gha−1. The effect of pendimethalin on lettuce yield was not significant. Changes in photosynthesis rates can be assigned more to the effect of fabric coverage than to that of pendimethalin. The values obtained were affected both by the density of stomata as well as their distribution on leaves, and these vary in response to environmental conditions.

Weed dynamics and productivity of blackgram (Vigna mungoL.) as influenced by pre-and post-emergence herbicides

A field experiment was conducted during kharif seasons of 2012 and 2013 at the Research Farm of Mahatma Gandhi Chitrakoot Gramodaya Vishwa Vidhyalaya, Chitrakoot, Satna (M. P.) to study the weed dynamics and productivity of blackgram [Vigna mungo (L.) Hepper.] as influenced by pre-and post-emergence herbicides. Among weed control treatments, six treatments including pre-emergence herbicides (pendimethalin @ 1 kg/ha and oxyflourfen @ 0.2 kg/ha), post-emergence herbicide (imazethapyr @ 0.1 kg/ha) and their combinations were tested. All the growth and productivity parameters were influenced significantly due to single and double herbicidal applications to control the existing weed flora. The dual herbicides comprising pendimethalin+imazethapyr (W5) brought about significantly higher seed yield (858 kg/ha), straw yield (1155 kg/ha) and harvest index (42.64%) of blackgram over remaining treatments. While both the dual herbicides (pendimethalin or oxyflourfen as pre-emergence followed by post-emergence application of imazethapyr) proved equally superior to other single herbicides in respect to weed control efficiency (89.57 to 91.62%)

Productivity Enhancement and Gap Analysis of Moth Bean (Vigna acontifolia (Jacq.)) through Improved Production Technologies on Farmers’ Participatory Mode

A total 81 of frontline demonstrations were conducted on farmers’ fields in villages viz., Kalali, Rampura, Jhitra, Dalpatgarh and Mukanpura of Pali district in Rajasthan state during 2010, 2011, 2012, 2013 and 2014 to demonstrate production potential and economic benefit of improved technologies comprising sowing method, nutrient management and chemical weed control and adoption of whole package of practices for the crop. Pre-emergence application of herbicide Pendimethalin at 1.0 kg a.i/ha in 550 liters of water used for effective control of the weeds during kharif season in rainfed condition. The findings of the study revealed that improved technology recorded a mean yield of 629 kg/ha which was 53.5% higher than obtained by farmers’ practice (414 kg/ha). The higher mean net income of 24730/-ha with a Benefit: Cost ratio of 3.6 was obtained with improved technologies in comparison to farmers’ practices (12950/ha). Yield gap analysis revealed that though there was mean additional return of 11780/ha with a mean additional gain of 7820/ha, still there was an extension gap of 215 kg/ha seed yield, indicating that along with many move front line demonstrations there is a need to disseminate the improved technologies among the farmers with effective extension methods like training and demonstrations. However, the mean technology gap of 639 kg/ha seed yield clearly indicates that research efforts are needed in realizing the potentiality of the moth bean crop in Rajasthan state.

Behaviour of pendimethalin and oxyfluorfen in peanut field soil: effects on soil biological and biochemical activities

A field experiment was conducted to study the dissipation kinetics of herbicides pendimethalin and oxyfluorfen in black soil of peanut field at half recommended rate (HRE), recommended rate and double recommended rate as well as to assess their effects on soil microbial parameters and enzymatic activities. In addition, their role in the transformations and availability of some plant nutrients like nitrogen transformation (through ammonification and nitrification processes) and availability of phosphorous were also studied. Incorporation of these herbicides was found to stimulate the activity of soil microbial biomass carbon, fluorescein diacetate hydrolysing activity, alkaline phosphatase and ammonification rates, while dehydrogenase activity, acid phosphatase, nitrification rate and available phosphorous was adversely affected. However, urease remains almost unchanged except for little stimulation at later stages. Dissipation of pendimethalin and oxyfluorfen followed first-order reaction kinetics with half-life (T1/2) of 13.7–20.1 and 21.5–27.4 days, respectively. Residues of both herbicides persisted up to 60 days in the soil at all the doses except 45 days for pendimethalin at HRE.

In situ bismuth-film electrode for square-wave cathodic voltammetric detection of pendimethalin at nanomolar level

An in situ plated bismuth-film electrode (BiFE) was used for the study of the herbicide pendimethalin. A single peak was observed by cyclic voltammetry at −0.520V associated with the reduction of pendimethalin in HCl solution at pH3.0. Square-wave cathodic voltammetry (SWCV) was used for the analytical procedures after the preparation of the BiFE using 10.0μmolL−1 Bi(III) for 80s at −0.250V. A peak current at −0.585V related to the reduction of the herbicide was obtained, which increased linearly with the pendimethalin concentration in the range of 0.3 to 1.0μmolL−1. The limit of detection attained was 37.0nmolL−1. The sensor prepared in situ was applied for the determination of pendimethalin in simulated samples of tap water and sea water with satisfactory results being obtained compared with the UV–vis spectroscopy technique. In addition, pendimethalin was spiked and determined at nanomolar level in samples of water collected from a local river. The recovery values for such experiments were between 93% and 96%.

Resistance profile of herbicide-resistant Alopecurus myosuroides (black-grass) populations in Denmark

Alopecurus myosuroides Huds is one of the most important grass-weeds in North-western Europe and is also the most important herbicide-resistant weed species in European agricultural systems. Fifty-three Danish A. myosuroides populations, previously confirmed to be fenoxaprop-P resistant, were evaluated for five and two known mutation points within the ACCase and ALS genes, respectively. The resistance pattern of 28 out of the 53 populations was investigated to four herbicides using a seed bioassay technique. A whole plant dose response experiment was conducted on seven populations in 2012 and 2013 to evaluate the accuracy of the seed bioassay results. Two resistant populations from the UK and a susceptible population from Denmark were included as reference populations in all experiments. Of the 53 populations, nine (17%) populations were ACCase target site resistant (TSR), all with a mutation at the Ile-1781 position. No mutations conferring TSR to ALS inhibitors were detected in the 53 populations. The seed bioassay results showed that all populations had varying degrees of resistance to fenoxaprop-P. In contrast, all populations were susceptible to cycloxydim suggesting that non-target site resistance (NTSR) was present in all populations including the ones where TSR were found. The seed bioassay was not a suitable method for detecting resistance to the residual herbicides pendimethalin and prosulfocarb. The whole plant dose response experiment results confirmed the results of the seed bioassay for fenoxaprop-P and cycloxydim. Three and two out of seven populations were also resistant to flupyrsulfuron and pendimethalin, respectively, while all resistant populations were susceptible to mesosulfuron + iodosulfuron. The widespread occurrence of particularly NTSR is a severe challenge to the effective management of A. myosuroides. In Denmark this challenge is even more prominent due to few modes of action being available for A. myosuroides control mainly due to national regulation on groundwater protection.

Carbon Dioxide Evolution and Oxidoreductase Enzyme Activities in Relation to Herbicides Application in an Alluvial Soil of Varanasi

Laboratory incubation study was carried out in Gangetic alluvial soil of Varanasi at recommended and double the recommended dose of glyphosate, paraquat and pendimethalin to assess their impact on carbon dioxide (CO2) evolution, dehydrogenase & catalase activities and the soil bacterial population. Both stimulating and inhibiting effects were noticed from the application of herbicides glyphosate, paraquat and pendimethalin on the decomposition of organic matter. The rate of periodical changes of CO2 evolution (mg CO2-C g−1 soil) from the herbicides applied soil, followed the order pendiemthalin > paraquat >glyphosate. The dehydrogenase activity (mg TPF g−1 day−1) was more stimulant at double the recommended dose of the herbicides after 42 days of incubation. Both stimulating and/or inhibiting effects were observed on catalase activity (i mole H2O2 consumed min−1 g−1 soil) and bacterial population in soil as influenced by the herbicides.

Controle de Urochloa plantaginea com herbicidas residuais e performance agronômica de dois cultivares de feijoeiro

O objetivo deste trabalho foi avaliar os efeitos da utilização de herbicidas residuais, aplicados em pré-emergência do feijoeiro, sobre a redução da infestação de plantas daninhas e o desempenho agronômico da cultura. Foram realizados dois experimentos a campo, sendo que um tinha o cultivar UFT -06 (Grupo Carioca, ciclo curto e porte ereto) e o outro o cultivar IPR Graúna (Grupo Preto, ciclo longo, hábito prostrado). Os tratamentos foram constituídos da aplicação dos herbicidas pendimethalin (1,2 e 1,4 kg ha-1) e trifluralin (1,2 e 1,4 kg ha-1); e, dimethenamid (1,4 e 1,6 kg ha-1) e S-metolachlor (1,4 e 1,6 kg ha-1), e mais testemunha com e sem (TSC) controle. Nas áreas experimentais predominavam infestação de Urochloa plantaginea (papuã). Avaliou-se a densidade e a massa desta espécie daninha, e o número de legumes e a produtividade do feijoeiro. Trifluralin foi o herbicida que mais reduziu a infestação da planta daninha e aumentou o rendimento do feijoeiro, quando comparado aos demais produtos. O cv. de feijão UTF-06 foi mais competitivo com U. plantaginea do que IPR Graúna. Os tratamentos com herbicida reduziram a infestação da infestante, mas isso não resultou em maior produtividade do feijoeiro, quando comparado com o tratamento capinado.

Effect of Pendimethalin, Trifluralin and Terbutryn on Lolium multiflorum growing with barley during pre-emergence stage

Three herbicides, namely Pendimethalin, Trifluralin and Terbutryn were used to control the Italian ryegrass (Lolium multiflorum) associated with barley (Hordeum vulgare). The first herbicide Pendimethalin gave an effective control of L. multiflorum at doses as low as .125kg a.i/ha and few plants survived with rates 0.5kg a.i/ha. Effects on barley were severe; at dose of 0.25kg a.i/ha barley plants decreased by more than 50%. Trifluralin controlled ryegrass numbers up to 90% at 1kg/ha and caused little damage to barley plants. The last herbicide Terbutryn decreased the numbers of ryegrass plants quite effectively; it also damaged barley plants even at very low doses.

Spectrum of patients intentionally poisoned with an emulsified concentrate pendimethalin herbicide

ObjectiveStudies on the acute toxicity of pendimethalin herbicide in humans are limited. Therefore, this study investigated the clinical characteristics of acute intentional pendimethalin herbicide poisoning.Material and methodA retrospective observational case...

Simultaneous analysis of herbicides pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl by LC-MS/MS and safety evaluation of their harvest time residues in peanut (Arachis hypogaea L.).

This paper reports a simple and rapid method for simultaneous determination of the residues of selected herbicides viz. pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl in peanut by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A modified approach of the QuEChERS methodology was used to extract the herbicides from the peanut kernel without any clean-up. The method showed excellent linearity (r(2) > 0.99) with no significant matrix effect. Accuracy of the method in terms of average recoveries of all the four herbicides ranged between 69.4 -94.4% at spiking levels of 0.05, 0.10 and 0.25mgkg(-1) with intra-day and inter-day precision RSD (%) between 2.6-16.6 and 8.0-11.3, respectively. Limit of quantification (LOQs) was 5.0μgkg(-1) for pendimethalin, imazethapyr and quizalofop-p-ethyl and 10.0μgkg(-1) for oxyfluorfen. The expanded uncertainties were <11% for determination of these herbicides in peanut. The proposed method was successfully applied for analysis of these herbicide residues in peanut samples harvested from the experimental field and the residues were below the detection level.

New pesticides regulation: potential economic impacts of the withdrawal of Pendimethalin in horticultural crops

The Thematic Strategy on the Sustainable Use of Pesticides moves forward towards the sustainability of agriculture fostering the use of Integrated Pest Management (IPM) practices in the European Union (EU). EC Regulation 1107/2009 was adopted in this framework leading to the eventual drop in the Vademecum of authorized substances of some important pesticides which are presently used in EU agriculture. Herbicide Pendimethalin will have to renew its registration in 2016 under the new regulation and there is a high probability that it will be removed. In this study we analyze the potential impact of the prohibition of Pendimethalin in two export driven horticultural crops grown in Southeastern Spain - lettuce and celery - to provide an illustration of possible consequences of the loss of certain active substances due to the new regulation. To do so, gross margin stochastic models are developed and used to generate Monte-Carlo simulations to look at farms’ economic results and their production risks. Econometric models are used to examine consumers’ and producers’ surplus in export markets of lettuce and celery. The results show that the Pendimethalin ban might modify the economic risk profile that the farm faces, affecting the crops’ profitability in the short-term. These changes would pass on to markets through shifts in supply and price and finally to European consumers, who would be the major losers.

Evaluation of different weed management practices in cabbage (Brassica oleraceavar.CapitataL.)

A field experiment was conducted during rabi 2010 at Model Orchard, College of Horticulture, Rajendranagar, Hyderabad to study the effectiveness of integrated weed management in cabbage. The experiment was laid out in randomized block design with three replications and 13 treatments with pre-emergence herbicides (PE) pendimethalin, oxyfluorfen, alachlor and a post-emergence herbicide propaquizafop and cultural practices hand weeding, black polythene mulch and their combinations. The results indicated that the pre-emergence application of oxyfluorfen followed by soil covering with black polythene mulch recorded least weed count, dry weight of weeds, higher weed control efficiency (72.63 per cent) and favoured the head initiation, early yield, fresh weight and dry weight of heads and highest economic yield (32 t ha−1), which was at par with treatment Pendimethalin C.S (PE) fallowed by black polythene mulch.

Effects of post emergence herbicides on weed control and yields of field pea and their residual effect on succeeding sorghum and mungbean crop.

A field experiment was conducted during 2008-09 and 2009-10 to evaluate different post emergence herbicides applied against weeds in field pea and their residual effect on succeeding sorghum and mungbean crop. Pendimethalin herbicide applied 1.5 kg ha-1 as pre-emergence gave effective control against all the weeds whereas, among post emergence herbicides imazethapyr was found effective against broadleaf weeds and quizalofop-ethyl was effective only against grassy weeds. During both the years, application of imazethapyr 50 g ha-1 at 30 days after sowing gave effective control of weeds and resulted minimum density and dry biomass of weeds compared to all the post emergence herbicide treatments. During second year, residual effect of imazethapyr was observed only on sorghum crop.

Response of vetch, lentil, chickpea and red pea to pre- or post-emergence applied herbicides

Broad-leaved weeds constitute a serious problem in the production of winter legumes, but few selective herbicides controlling these weeds have been registered in Europe. Four field experiments were conducted in 2009/10 and repeated in 2010/11 in Greece to study the response of common vetch (Vicia sativa L.), lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.) and red pea (Lathyrus cicera L.) to several rates of the herbicides pendimethalin, S-metolachlor, S-metolachlor plus terbuthylazine and flumioxazin applied pre-emergence, as well as imazamox applied post-emergence. Phytotoxicity, crop height, total weight and seed yield were evaluated during the experiments. The results of this study suggest that common vetch, lentil, chickpea and red pea differed in their responses to the herbicides tested. Pendimethalin at 1.30 kg ha-1, S-metolachlor at 0.96 kg ha-1 and flumioxazine at 0.11 kg ha-1 used as pre-emergence applied herbicides provided the least phytotoxicity to legumes. Pendimethalin at 1.98 kg ha-1 and both rates of S-metolachlor plus terbuthylazine provided the greatest common lambsquarters (Chenopodium album L.) control. Imazamox at 0.03 to 0.04 kg ha-1 could also be used as early post-emergence applied herbicide in common vetch and red pea without any significant detrimental effect.

Impacto de herbicidas em isolados de Trichoderma spp.

O uso de microrganismos é uma alternativa para o controle de doenças em plantas. Todavia, é prudente verificar a interação desse com os demais métodos de controle empregados em determinada cultura. Dessa forma, objetivou-se avaliar a fungitoxicidade dos herbicidas sobre o crescimento e desenvolvimento dos isolados de Trichoderma spp. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 6 x 6 x 4, com quatro repetições. O fator A correspondeu aos herbicidas pendimethalin, clomazone, carfentrazone-ethyl, oxadiazon, thiobencarb + propanil e byspiribac-sodium; o fator B, às doses dos herbicidas - 0, 25, 50, 75, 100 e 200% da dose recomendada; e o fator C, aos isolados de Trichoderma spp. AJAM 18, CE 66, TRI 01 e TRI 02. O ensaio foi realizado em condições in vitro; avaliaram-se o crescimento micelial radial (CMR) e a esporulação dos isolados após aplicação dos herbicidas. Observaram-se diferenças de sensibilidade dos isolados para o mesmo produto testado. O oxadiazon reduziu o CMR dos isolados AJAM 18 e TRI 01 em 66 e 35%, respectivamente. No entanto, reduziu apenas 16% do CMR do isolado TRI 02 e não alterou o CMR do isolado CE 66 mesmo em 200% da dose recomendada. Verificaram-se diferentes efeitos dos produtos em cada isolado. A mistura comercial de thiobencarb+propanil foi altamente tóxica aos isolados de Trichoderma spp., com reduções em torno de 85% no CMR e no número de esporos. Por outro lado, o byspiribac-sodium pouco afetou os isolados, apresentando reduções inferiores a 10% no CMR e na esporulação. O carfentrazone-ethyl e byspiribac-sodium demonstraram ser compatíveis com os isolados de Trichoderma spp. estudados.

Exacerbation of symptoms in agricultural pesticide applicators with asthma

Exacerbation is a critical event in asthma management. We investigated whether exacerbation of symptoms is associated with farming exposures among agricultural pesticide applicators with asthma. Participants were pesticide applicators with active asthma (wheezing and breathing problems in past 12 months) who completed enrollment questionnaires for the Agricultural Health Study (AHS). Exacerbation of asthma was defined as having visited a hospital emergency room or doctor for an episode of wheezing or whistling in the past 12 months. Exposures of interest were using 36 specific pesticides in the past 12 months and conducting various agricultural activities. Adjusted odds ratios (ORs) were estimated by logistic regression while controlling for potential confounders. The 926 AHS adult pesticide applicators with active asthma included 202 (22%) with exacerbation. Inverse associations with exacerbation were observed for two herbicides [glyphosate, odds ratio (OR) = 0.5, 95% confidence interval (CI) 0.3, 0.8, and paraquat, OR = 0.3, 95% CI 0.1, 0.9] and several agricultural activities (repairing engines, grinding metal, driving diesel tractors, and performing veterinary procedures). Only asthma cases with allergies (i.e., doctor-diagnosed hay fever or eczema, 46%) had positive exacerbation-pesticide associations, with OR = 2.1 (95% CI 1.1, 4.1) for the herbicide pendimethalin and OR = 10.2 (95% CI 1.9, 55) for the insecticide aldicarb. The inverse associations with two pesticides and specific farm activities are consistent with the possibility that asthma cases prone to exacerbation may avoid exposures that trigger symptoms. Although limited by small sample size and a cross-sectional design, our study suggests that use of specific pesticides may contribute to exacerbation of asthma among individuals with allergies.

Acute severe suicidal poisoning by herbicide pendimethalin; a rare case report from rural India

No abstract available DOI: http://dx.doi.org/10.4038/sljfmsl.v3i2.5434 Sri Lanka Journal of Forensic Medicine, Science & Law-December 2012-Vol.3 No.2 p. 1-5

Green house studies on the biology of winter annual grasses and the use of cover crops and herbicides for their control

Greenhouse studies were initiated in two small (Polypogon fugox) and large (Phalaris minor) seeded annual grasses in 2007 at Cornell University, Ithaca, NY USA. These two annual grasses were very common in wheat fields of midhills and terai regions of Nepal. P fugox was taken for biological study. Days to emergence took 8-11 days in green house. Early emerged panicles were longer than those emerged late. Panicle took 10-12 days to emerge completely from the flag leaf. Panicles per plant were 120. Seeds were very small having about 1091 seeds per panicle. So one fully matured plant could produce seeds about 130920. Study on eco-biology needs to continue in the future. P fugox and P minor responded differently to buckwheat residues. Among different treatments emergence and growth of both weeds were suppressed more by buckwheat residues when left on the surface than incorporated. P minor was less affected by buckwheat residues. It might be due to larger seed compared to P fugox. Post emergence herbicides clodinofop and pinoxaden were effective on both grasses. Isoproturon and tralkoxydim were effective on P fugox. Sulfosulfuron was good in reducing plant growth to some extent. Preemergence herbicides pendimethalin and s-metolochlor were effective in reducing emergence and growth of both weeds. Isoproturon and and sulfosulfuron suppressed plant growth reducing dry plant biomass. DOI: http://dx.doi.org/10.3126/ajn.v2i0.7529 Agronomy Journal of Nepal (Agron JN) Vol. 2: 2011 pp.139-148