Pre-emergence Application Of Pendimethalin Research Articles

Weed management with pre-and post-emergence herbicides in linseed

Field experiment was conducted at Research farm, College of Agriculture, JNKVV, Tikamgarh during Kharif 2013–14 to study the effect of herbicides for controlling weeds in linseed. There was prevalence of dicot weeds in experimental field as these weeds constituted the higher relative density (67.8%) at harvest as compared to monocot weeds which had only 18.04% relative density. On the basis of results, it can be concluded that hand weeding twice at 20 and 40 DAS recorded significantly the lowest weed density as well as weed dry weight followed by pre-emergence application of pendimethalin at 1.0 kg + imazethapyr at 1.0 kg/ha. The seed and straw yields of linseed was significantly higher under twice hand weeding at 20 and 40 DAS followed by pre-emergence application of pendimethalin at 1 kg/ha + imazethapyr at 1 kg/ha, pendimethalin at 0.75 kg/ha + imazethapyr at 1.0 kg/ha and post-emergence application of imazethapyr at 100 g/ha. The highest net monetary return obtained with twice hand weeding whereas the B: C ratio was the highest with the application of imazethapyr at 100 g/ha followed by imazethapyr at 75 g/ha.

Energy usage and economic analysis of cotton under various weed management practices

The objective of energy usage and benefit-cost analysis of Bt cotton was to determine the energy efficiency indices under different weed management practices in Bt cotton. The field experiment was carried out at college farm, Professor Jayashankar Telangana State Agricultural University, Rajendranagar, Hyderabad during Kharif, 2014 with ten weed management practices. The inputs in the calculation of energy usage in agro-ecosystems embraced labour, machinery, electricity, diesel oil, fertilizers, herbicides, pesticides, seeds, while seed cotton was included in the output. The results depicted that total input and output energy under different weed management practices were about 16051 to 18550 and 2360 to 16838 MJ/ha, respectively. Out of all the treatments tested the highest energy use efficiency (0.9), energy intensiveness (0.7 MJ/), specific energy (12.9 MJ/kg), energy productivity (0.9 kg/MJ), net energy (−1712 MJ/ha) of Bt cotton production system were reported in mechanical weeding thrice at 20, 40 and 60 DAS. However the lowest energy intensiveness of 0.5 MJ per rupee was reported in pre emergence application of pendimethalin at 1000 fb 2 HW at 20 and 50 DAS treatment.

Pre-and post-emergence herbicides for weed control in greengram and their residual effect on succeeding crops

Comparative efficacy of pre-and post-emergence herbicides in greengram and their residual effect on succeeding crops was studied during Kharif season of the year 2011–2013. Inter-culturing and hand weeding carried out at 20 and 40 DAS produced the lowest weed dry weight with higher weed control efficiency. Among herbicidal treatments, pre-emergence application of pendimethalin at 500 g/ha or imazethapyr 75 g/ha followed by interculturing and hand weeding at 30 DAS proved to be efficient in reducing weed dry weight with more than 70% of weed control efficiency and recorded higher seed and haulm yield of greengram. Further, it was observed that none of the herbicides applied at tested rates had adverse effect on succeeding wheat, chickpea and mustard crops.

Integrated weed management in aerobic rice

Field experiment was carried out to study the effect of integrated weed management in aerobic rice (Oryza sativa L.) for consecutive two Kharif seasons in 2011 and 2012 at Karaikal, Puducherry Union Territory with seven treatments in three replications. Grassy weeds dominated the weed flora, with Echinochloa colona as the major weed. Weed free condition maintained throughout the crop growth recorded significantly lower weed density, dry weight and higher weed control efficiency. Though the highest gross monetary returns ( 56, 000/ha) and net returns ( 25, 360/ha) was recorded in weed free condition, maximum B: C ratio (1.94) was recorded in pre-emergence application of pendimethalin 1.0 kg/ha along with a hand weeding at 30 days after sowing (DAS). Uncontrolled weeds accounted for 86.3% yield loss in aerobic rice under coastal ecosystem of Puducherry UT, India.

Effect of weed management options on weed flora and yield of kharif greengram (Vigna radiataL.)

A field experiment was conducted during kharif seasons of the years 2011–2013 at the farm of DWSR-Anand Centre, B. A. College of Agriculture, Anand Agricultural University, Anand (Gujarat) to study the integrated efficacy of various herbicides applied as pre-and post-emergence in greengram (Vigna radiata). Among the different weed management practices, inter-culturing and hand weeding carried out at 20 and 40 DAS were found most efficient having lowest weed dry weight with higher weed control efficiency. Further, pre-emergence application of pendimethalin @ 500 g/ha or imazethapyr 75 g/ha followed by interculturing and hand weeding at 30 DAS proved to be efficient in reducing weed dry weight, higher weed control efficiency and recording higher seed and haulm yield of greengram.

Effect of weed control on growth and productivity of soybean

A field experiment was carried out at research farm of Rajasthan College of Agriculture, Udaipur during Kharif 2014 in randomized block design (RBD) with 14 treatments pre-emergence application of pendimethalin 0.75 kg/ha + hand weeding 30 DAS resulted broad spectrum of weed control besides gives higher grain yield. This weed management method found to be promising to control weeds of soybean crop and would play an important role in areas where labour is too expensive and time is a constraint.

Effect of weed control practices on weed dynamics, yield and economics of soybean [Glycine max (L.) Merrill

The experiment was laid out in randomized block design with three replications and eight weed control treatments viz., weedy check, polythene mulching as pre emergence (PE), pendimethalin30EC (PE), chlorimuron ethyl 9g ha-1as post emergence (POE), quizalofop ethyl 50g ha-1 (POE), imazethapyr 100g ha-1 as early post emergence (EPOE), one hand weeding at 40 days after sowing (DAS) and two hand weeding at 20 and 40 DAS. The results showed that polythene mulching had the lowest weed dry matter due to effectively suppression of weed emergence. It was followed by twice hand weeding at 20 and 40 days after sowing. Weed index was found to be the highest with weedy check (42.10%) followed by the pre-emergence application of pendimethalin (19.09%). The effect of herbicide applied as pre-emergence was subdued at this belated stage, which may possibly be on account of longer period after application and restricted effective residual period. Plant height, number of pods per plant and grain yield of soybean was found to be highest in the treatments twice hand weeding at 20 and 40 DAS as well as polythene mulching. However, the net return and B:C ratio was lower in comparison to imazethapyr and quizalofop ethyl due to higher cost of labour and polythene material respectively. On an average, the application of imazethapyr as early post emergence (3.17) and quizalofop ethyl (3.02) gave significantly highest B:C ratio than the other treatments for soybean.

Management of Rottboellia cochinchinensis and other weeds through sequential application of herbicides in dry direct-seeded rice in the Philippines

Dry direct-seeded rice (DSR) systems are becoming popular due to resource conservation and economic returns but high weed pressure limits rice productivity. Rottboellia cochinchinensis (Lour.) W. D. Clayton is an emerging noxious weed of DSR and requires a suitable herbicide package for effective control. A field study was conducted to evaluate the efficacy of two pre-emergence (oxadiazon and pendimethalin) and two post-emergence (cyhalofop and bentazon) herbicides used in various combinations and sequences during two consecutive seasons (dry season, 2013–14 and wet season, 2014) at the International Rice Research Institute (IRRI), Los Baños, Philippines. Experiments were laid out in a randomised complete block design with three replications. Weedy plots were kept as control. All the herbicide treatments significantly reduced density and biomass of R. cochinchinensis and other dominating weeds at the flowering stage of rice during both seasons. The best treatment was pendimethalin followed by bentazon + cyhalofop, which caused 88–91% reductions in R. cochinchinensis density over the weedy control (9.4–13.0 plants m−2) during both seasons. It also reduced R. cochinchinensis biomass by 98–99% over the weedy control (331–344 g m−2). Different herbicide sequential treatments also controlled density and biomass of Cyperus rotundus L., Eclipta prostrata L., Echinochloa colona (L.) Link, and Murdannia nudiflora (L.) Brenan over the weedy control. Highest reductions in total weed density (82–84%) and total weed biomass (95–97%) over the weedy control were observed from pendimethalin followed by bentazon + cyhalofop applications during both seasons. All the herbicide treatments increased rice grain yield significantly over the control. The maximum grain yield was obtained from pendimethalin followed by bentazon + cyhalofop applications, which was 4.7 and 3.0 t ha−1 during the dry season, 2013–14 and the wet season, 2014, respectively. The results suggest that the pre-emergence application of pendimethalin followed by the combination of post-emergence herbicides (bentazon and cyhalofop) may control R. cochinchinensis and other noxious weeds in DSR effectively with subsequent increment in rice grain yield.

Rice Productivity and Profitability Under Different Crop Establishment Methods, Plant Densities and Weed Control in North-Western Indo-Gangetic Plains

The experiments were conducted at Students’ Research Farm, Department of Agronomy, Punjab Agricultural University, Ludhiana during summer seasons of 2009 and 2010 to study the yield and economics of rice under different establishment methods, plant densities and weed control methods. Rice was directly sown with different drills or broadcasting technique and manual transplanting. For weed control, alone pre-emergence application of pendimethalin 0.75 kg ha1 and sequential application of bispyribac sodium 0.025 kg ha−1/azimsulfuron 0.02 kg ha−1 was done along with one weed free treatment. Grain yield did not vary significantly among establishment methods and the highest benefit:cost ratio (B:C) was obtained when rice was direct seeded with the help of drills. The maximum grain yield (71.06 q ha−1) was recorded in weed free treatment which was statistically at par with sequential use of pendimethalin 0.75 kg ha−1 with bispyribac 0.025 kg or azimsulfuron 0.02 kg ha−1 applied 30 DAS. The B:C ratio increased as seed rate increases from 20 kg to 50 kg ha−1 and it was more for closer spaced direct seeded rice crop.

Effect of Weed Control on Performance of Guinea Grass-Legumes Intercropping System under Rainfed Conditions

A field experiment was conducted during 2006–2011 on sandy loam soil at Central Research Farm of Indian Grassland and Fodder Research Institute, Jhansi to study the effect of weed control on performance of Guinea grass-legumes intercropping system under rainfed conditions. Intercropping of Stylosanthes hamata with Guinea grass produced significantly higher total dry forage (5.18 t/ha) than Clitoria ternatea (3.89 t/ha), Macroptillium atropurpureum (4.19 t/ha) and S. seabrana (4.67 t/ha) during 1st year of experiment. While during 2nd, 3rd and 4th years, intercropping of Stylosanthes seabrana with Guinea grass produced significantly higher total dry forage yield (9.56, 6.56 and 6.04 t/ha) than Clitoria ternatea (7.92, 5.23 and 4.49 t/ha), Macroptillium atropurpureum (8.12, 5.34 and 4.76 t/ha) and S. hamata (8.76, 5.97 and 5.26 t/ha). In total dry forage yields, per cent contribution of S. seabrana were 34.90, 31.17, 41.62 and 40.73 during 1st, 2nd, 3rd and 4th years respectively. Crude protein yields (812.3, 587.0 and 538.7 kg/ha) were also increased significantly when guinea grass intercropped with S. seabrana than intercropping with C. ternatea, Macroptillium atropurpureum and S. hamata. In weed management practices, hand weeding 35 days after sowing in 1st year and 25 days after onset of monsoon rain from 2nd year onwards recorded significantly higher dry forage yields of both Guinea grass (3.52, 7.81, 4.53 and 4.21 t/ha) and legumes (1.81, 2.48, 2.15 and 1.72 t/ha) than weedy check, pre-emergence application of pendimethalin @ 0.75 kg a.i./ha and weeding with weeder cum mulcher during 1st, 2nd, 3rd and 4th years, respectively. The Maximum net return ( 4232, 20778, 14532 and 15390/ha) and net return per rupee invested ( 0.38, 2.26, 1.64 and 1.63) were obtained by intercropping of Guinea grass with S. seabrana during 1st, 2nd, 3rd and 4th years of study. Hand weeding 35 days after sowing in 1st year and 25 days after onset of monsoon rain from 2nd year onwards also recorded maximum net return ( 3771, 17053, 9796 and 10183/ha) during all the 4 years.

Evaluation of pre-emergence herbicides in gladiolus (Gladiolus)

An experiment was carried out to evaluate the effect of different herbicides on weed control and growth and development of gladiolus (Gladiolus (Tourn) L.) cv. White Prosperity grown at research farm of Directorate of Floricultural Research, New Delhi during 2011-12 and 2012-13 seasons. The major weeds infesting the experimental field were Ageratum conyzoides, Chenopodium album, Convolvulus arvensis, Cynodon dactylon, Cyprus rotundas, Digera arvensis, Digitaria adscendance, Euphobia hirta, Parthenium hysterophorus and Portulaca. The unweeded control plots recorded maximum weeds at 25 (153.2 m2) and 50 (180.7/m2) days after planting (DAP). Whereas significantly low weed count, fresh weight and dry weight were recorded in the pre-emergence application of Atrazine (@ 1.0 and 1.5 kg a.i./ha. The maximum weed control efficiency (WCE) was recorded in Atrazine (@ 1.5 kg a.i./ha (82.2)). However, pre-emergence application of Pendimethalin (1.0 and 0.75 kg a.i./ha) had superior effect on the plant height, spike length, rachis length and number of florets. The number of corms/plant, fresh weight of corms and diameter of corms were maximum with application of Atrazine (@ 1.0 and 1.5 kg a.i./ha) however, number of cormels were found maximum (28.6) in Pendimethalin @ 1.0 kg a.i./ha and lowest (2.4) in Atrazine @ 1.0 kg a.i./ha.

Weed management in irrigated castor (Ricinus communis L.) through herbicides

A field experiment was conducted to find out most suitable and cost effective weed management practice for irrigated castor grown on the light textured soils of Western Rajasthan. Ten treatment combinations comprising of four herbicides with or without inter culture along with weedy, weed free check and farmers practice were compared in Randomized Block Design with three replications. Three season's pooled results revealed that pre-emergence application of pendimethalin @ 1.0 kg/ha + inter culture 40 days aftersowing (DAS) produced maximum seed yield of 3652 kg/ha with weed control efficiency of 96.4% besides maximum net return of ` 74,464/ha and B:C ratio of 3.78. The weed competition index was also observed to be lowest in thistreatment (0.4%). However, pendimethalin @ 1.0 kg/ha (pre-emergence) + inter culture 40 DAS, fluchloralin @ 1.0 kg/ha (pre-plant incorporation) + inter culture 40 DAS and weed free plots remained at par with each other. Application of either quizalofop-ethyl or fenoxaprop-p-ethyl @ 50 g/ha at 25 DAS also brought down the weed stand and weed drymatter significantly compared to weedy check though the extent of control was not equivalent to weed free plots. This treatment (preemergence application of pendimethalin @ 1.0 kg/ha + inter culture 40 DAS) validated at five sitesin farmer'sfields recorded higher seed yield and net return compared to farmer's practice of weed control.

Chemical and mechanical weed management strategies for grain pearl millet and forage pearl millet

There are limited options for controlling weeds in grain and forage pearl millet production in eastern Canada. Field studies were conducted near Quebec City in 2005 and 2006 to evaluate the effectiveness of herbicidal treatments (s-metolachlor/benoxacor and pendimethalin) and harrowing to control weeds and maximize yield in grain and forage pearl millet cultivation. s-Metolachlor/benoxacor and pendimethalin were applied either preemergence or early postemergence at the full dose recommended for corn and at half of that dose. Harrowing was evaluated at the three- and the five-leaf stage of pearl millet. In both types of pearl millet, s-metolachlor/benoxacor applied preemergence reduced plant density and yield. All other herbicidal treatments caused no visual injury to pearl millet and adequately controlled annual weeds, leading to grain and forage yields similar or slightly lower than those of the hand-weeded control. Better barnyard grass control resulted from early postemergence application of s-metolachlor/benoxacor compared with that of pendimethalin. Preemergence application of pendimethalin was more effective at controlling barnyard grass than early postemergence application. Harrowing was not effective at controlling annual weeds, resulting in important millet yield losses.Key words: Pearl millet, Pennisetum glaucum, s-metolachlor/benoxacor, pendimethalin, mechanical weed control, weed harrowing

RESPONSE OF SOYBEAN AND ASSOCIATED WEEDS TO VARIOUS WEED CONTROL TREATMENTS

Two field experiments were conducted during two successive seasons of 2007 and 2008 in Meit Nagy Village, Meit Ghamr, Dakahlia Governorate, Egypt, to study the effect of some pre-or post-emergence herbicides either alone or accompanied with hoeing on soybean yield and its components and associated weeds. The results showed that the best treatments in controlling the annual bread leaves, annual grasses and total annual weeds throughout the vegetative period of soybean plants were : The pre-emergence application of Pendimethalin at 0.425 kg a.i./fed or Metribuzin at 0.140 kg a.i./fed followed by one hoeing (21 days after sowing) or post-emergence application of Bentazon at 0.180 kg a.i./fed preceded by one hoeing (21 days after sowing), or using hand hoeing twice (21 and 35 days after sowing) compared with single herbicidal treatments. Treatment of Pendimethalin at 0.425 kg a.i./fed followed by one hoeing improved the growth of soybean plants and resulting in the tallest plants, highest number of pods/plant, number of seeds/pod, seed index, seed yield/plant and per feddan and the highest oil % in the seeds as well as seed protein percentage compared to other weed control treatments.

Leaching behaviour of pendimethalin causes toxicity towards different cultivars of Brassica juncea and Brassica campestris in sandy loam soil.

An experiment was conducted at the farm of Zonal Adaptive Research Station, Uttar Banga Krishi Viswavidhyalaya, Pundibari, Cooch Behar, West Bengal to evaluate the effect of pendimethalin on the yield, weed density and phytotoxicity in different varieties of rai (Brassica juncea) and yellow sarson (B. campestris var. yellow sarson) under higher soil moisture regime in Terai region of West Bengal. Pre-emergence application of pendimethalin at higher dose i.e. 1.0 kg/ha recorded higher plant mortality (30.92%) due to the presence of higher concentration of pendimethalin residue (0.292 µg/g) till the tenth day of crop age and consequently had the reduced yield (12.59 q/ha) than the dose of 0.7 kg/ha (13.33 q/ha) where plant mortality was only 12.62% due to comparatively lower level of pendimethalin residue (0.192 µg/g). Although the application of pendimethalin at the rate of 1.0 kg/ha was able to control weed more efficiently (18.96/m2) than the dose of 0.7 kg/ha (30.41/m2) and subsequent lower doses. The herbicide leached down to the root zone resulting in phytotoxicity towards crop. Yellow sarson group (Brassica campestris) showed more susceptibility than rai (Brassica juncea) group against pendimethalin application at higher doses.

Weed control in rose-scented geranium (Pelargonium spp).

Abstract: Field investigations were carried out during 1999 and 2000 to identify effective chemical/ cultural methods of weed control in rose-scented geranium (Pelargonium spp). The treatments comprised pre-emergence applications of oxyfluorfen (0.15, 0.20 and 0.25 kg AI ha(-1)) and pendimethalin (0.50, 0.75 and 1.00kg AI ha(-1)), successive hand weeding, hoeing and mulching using spent of lemon grass (at 5 tonnes ha(-1)) 45 days after planting (DAP), three hand-weedings 30, 60 and 90 DAP, weed-free (frequent manual weeding) and weedy control. Broad-leaf weeds were more predominant than grass and sedge weeds, accounting for 85.8% weed density and 93.0% weed dry weight in 1999 and 77.2% weed density and 93.9% weed dry weight in 2000. Unrestricted weed growth significantly reduced geranium oil yield, by 61.6% and 70.6% in 1999 and 2000, respectively. Pre-emergence application of pendimethalin (0.75-1.00 kgAI ha(-1)) or oxyfluorfen (0.25 kg AI ha(-1)), successive hand-weeding, hoeing and mulching and three hand-weedings were highly effective in reducing weed density and dry weight and gave oil yield comparable to the weed-free check. Application of oxyfluorfen (0.15 or 0.20 kg AI ha(-1)) and pendimethalin (0.50 kg AI ha(-1)) were less effective in controlling the weed species in geranium. None of the herbicides impaired the quality of rose-scented geranium oil measured in terms of citronellol and geraniol content.

Integrated weed management in blackgram (Vigna mungo) under mid hills of Arunachal Pradesh

Field investigation was carried out during pre kharif seasons of 2009 and 2010 at ICAR, Research Complex NEH Region, Arunachal Pradesh Centre, Basar to develop integrated weed management for blackgram (Vigna mungo L.) var. PU-31 with pre plant incorporation of fluchloralin @ 1.5 lit/ha, pre-emergence application of pendimethalin @ 1.5 lit/ha and hand weeding. Pre-emergence application of pendimethalin @ 1.5 lit/ha + one hand weeding on 25 DAS was at par with 2 hand weeding at 15 and 25 DAS in respect of seed yield, net returns and B: C ratio. In weedy check, weeds removed 6 kg N, 2.8 kg P and 7.0 kg K/ha.

Weed management in fenugreek (TrigoneEla foenum-graecum)

An experiment was conducted during winter seasons of 1991-94 at Jobner, to study the effect of weed management on fenugreek (Trigonella foenum-graecum L.). The weed free treatment recorded the lowest weed dry weight and the highest weed control efficiency at all the stages of observation. Among rest of the treatments, the lowest weed dry weight and the highest weed control efficiency was obtained at 25 DAS with pre-plant incorporation of fluchloralin (1.25 kg/ha) at 50 DAS with pre-emergence application of pendimethalin (1.5 kg/ha) and at 75 DAS and at harvest with pre-emergence application of pendimethalin (1.0 kgtha) supplemented with hand weeding once (50 DAS). All the weed control measures - significantly increased mean number of branches and podstplant (except metolachlor @ 1.0 kg/ha) and seed yield (except metolachlor @ 0.5 and 1.0 kg/ha) was obtained under weed free condition, whereas maximum meanseed yield of 16.1 5 qtha and net return of Rs 14,304Iha with benefit : cost ratio of 3.79 were obtained with fluchloralin @ 0.75 kg/ha supplemented with hand weeding once, closely followed by hand weeding twice, weed free and oxyfluorfen @ 0.15 kg/ha supplemented with hand weeding once.

Weed management in Brassica species

4 A field study on weed management in Brassica species was carried out during 1995 96 and 1996 97. The Brassica species did not influence the weed intensity and their dry matter in any season of the experiment but weed management treatments decreased the weed population and dry weight and consequently increased the weed control efficiency, yield attributes, seed yield and mean net returns over weedy check. During both years .the maximum seed yield (1,705 and 1,945 kglha) was iecorded in weed free, followed by 2 manual weedings at 25 and 45 days after sowing (1,593 and 1,792 kglha) which was found most effective in controlling the weeds compared with other treatments. . Among the herbicides, pre emergence application of pendimethalin Q 1.0 kg a.i.1 ha recorded higher seed yield and found best substitute of repeated manual weeding where the labour costs are too high.

Weed control in chickpea (Cicer arietinum) under late sown condition

A field experiment was conducted during the winter season of 1993 94 to 1995 96 at Pulse Research Station, R.A.K. College of Agriculture, Sehore, Madhya Pradesh, to study the effect of weed management practices on chickpea (Cicer arietinum L.) under late sown condition. Two hand weedings at 30 and 45 days after sowing (DAS) (weed free) completely controlled the weeds. Significantly lowest weed dry matter and highest weed control effi ciency were observed when 1 hand weeding was done at 45 DAS. This treatment was followed by integration of 1 hand weeding at 45 DAS with pre emergence application of pendimethalin 0.75 kg/ha in reducing weed dry matter and in increasing the weed control efficiency. Significantly higher grain yield (1,723 kg/ha) was recorded in weed free plots. Among the.weed control treatments, pendimethalin 0.75 kg/ha coupled with 1 hand weeding at 45 DAS recorded higher.grain yield (1576 kg/ha).