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Background: Weeds are the major biotic constraint to reduce the rice productivity in direct wet seeded rice. Weed infestation and competition are severe in direct wet seeded rice as compared to transplanted rice, because of the simultaneous growth of both crops and weeds. The yield loss due to weeds varies from 40 to 100 per cent in direct seeded rice. Use of herbicides either singly or in combination with manual or mechanical weeding in puddled direct seeded rice has been highlighted by several workers. Use of alternative herbicides with wide spectrum control of the weeds in direct seeded puddled rice is the need of the present time. The present study aimed to evaluate different weed management practices in direct wet seeded rice under sodic soil. Methods: A field experiment was conducted during Samba season (Rabi) 2016-17. To evaluate the weed management practices in direct wet seeded rice under sodic soil. The treatments comprised of different combination of weed management practices viz., pre emergence, early post emergence herbicides, mechanical weeding and hand weeding twice were tested. Total weed density and weed dry weight, weed control efficiency, yield parameters and yield of rice were recorded. Result: Among the different weed management practices, the lowest total weed density, total weed dry weight and higher WCE, yield attributes, grain and straw yields were registered under application of PE pyrazosulfuron ethyl 25 g/ha fb EPOE bispyribac sodium 25 g/ha. This was followed by application of PE pretilachlor 0.75 kg/ha fb EPOE bispyribac sodium 25 g/ha. [ABSTRACT FROM AUTHOR]

Background: Groundnut encounters severe infestation of weed especially during the early stages of growth due to less crop canopy which allows higher weeds growth and thus crop becomes more susceptible to weed competition. During rainy season, effective and economical weed control is not possible through manual and mechanical weeding due to unfavorable soil conditions and also the unavailability of costly labours. Herbicides have been accepted as cost effective tool to manage weed menace in groundnut. The current study aims to study the efficancy of different post-emergence and pre-mix combination of post-emergence herbicides on weeds, growth and yield of groundnut. Methods: The field experiment was conducted at AICRP Weed Management Field, Department of Agronomy, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (M.S.) during three consecutive Kharif seasons of 2015-2017. The experiment was laid out in randomized block design with ten treatments replicated thrice. The treatments comprised of one pre emergence and five different post emergence herbicides and compared with weed free and weedy check. Result: The results revealed that weed free was found most effective to control weeds in groundnut with lowest weed count, weed dry matter of weeds and maximum gross monetary returns (Rs. 117641/ha), net monetary returns (Rs. 80894/ha). Among the herbicides, application of Imazethapyr + Imazomox 0.10 kg/ha POE 20 DAS produced less weed count and weed dry matter and highest weed control efficiency (80.68%) and lower weed index (6.71%) as well as maximum growth, yield attributes and pod yield in groundnut over all the other herbicidal treatments viz. plant height (30.25), dry matter accumulation (18.11 g), number of pods/plant (32.35) and pod yield (2448 kg/ha) and highest pooled B:C ratio (3.74). [ABSTRACT FROM AUTHOR]

Background: Generally, farmers cultivate clusterbean [Cyamopsis tetragonoloba (L.) Taub] on rainfed area but seldom adopt weed control practices in it. It becomes very difficult and uneconomical to maintain weed free environment throughout crop period in the field under rainfed conditions. Therefore, the current study was aimed to find an effective weed control practice in clusterbean under rainfed conditions. Methods: Effect of weed management practices of clusterbean with T1: Pendimethalin @ 1 litre/ha (PE), T2: Imazethapyr @ 0.1 kg/ha at 20 days (POE), T3: Stale bed technology, T4: One hand weeding at 20 DAS (days after sowing), T5: Two hand weedings at 20 and 40 DAS, T6: Imazethapyr @ 0.1 kg/ha at 20 days + hand weeding at 40 DAS, T7: Pendimethalin @ 1 litre/ha (PE) + hand weeding 35 DAS, T8: Pendimethalin @ 1 litre/ha (PE) + imazethapyr 0.1 kg/ha at 30 DAS and T9: Weedy check were investigated under rainfed conditions. Result: Weed control efficiencies of imazethapyr @ 0.1 kg/ha at 20 days + hand weeding at 40 DAS (T6), pendimethalin @ 1 litre/ha + hand weeding at 40 DAS (T7) and pendimethalin @ 1 litre/ha (PE) + imazethapyr @ 0.1 kg/ha at 20 days (PoE) (T8) were statistically similar. Imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS recorded higher growth characters viz., plant height, dry matter and yield attributing characters viz., number of branches, number of pods/plant and seed index than other treatments. The highest seed yield was recorded in imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS (422 kg/ha), being statistically at par with pendimethalin @ 1 litre/ha (PE) + one hand weedings at 40 DAS (390 kg/ha) and pendimethalin @ 1 litre/ha (PE) + imazethapyr @ 0.1 kg/ha at 20 days (PoE) (392 kg/ha) which was significantly higher than other treatments. Imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS recorded 27.9 and 33.9 per cent higher seed yield than imazethapyr @ 0.1 kg/ha at 20 days (PoE) and one hand weedings at 40 DAS, respectively. The net returns and benefitcost ratio were maximum for imazethapyr @ 0.1 kg/ha at 20 days (PoE) + hand weeding at 40 DAS (T6). It is inferred that imazethapyr @ 0.1 kg/ha at 20 days (PoE) + one hand weedings at 40 DAS was found the most effective and economic approach for weed control in clusterbean under rainfed conditions. [ABSTRACT FROM AUTHOR]

Background: Chickpea yield losses due to weed competition have been estimated to range between 40 and 87% depending on weed species and density. As farmers continue to realize the usefulness of herbicides, larger quantities are applied to the soil. These herbicides could be leached down, then accumulate to toxic levels in the soil and become harmful to microorganisms, plant, wild life and human being. Hence, there is a need to determine the effect of different herbicides on the growth and multiplication of agriculturally important microorganisms, which in turn could affect the crop growth and yield. Thus there is a need to test pre and post-emergent herbicides for their effect on beneficial soil microflora, as they could be both beneficial and harmful depending on the herbicide used. In this context, a field experiment was conducted to study the effect of herbicides on soil microflora, root nodulation, growth and yield of chickpea under rainfed condition during the rabi season of 2017-18 and 2018-19 at Zonal Research Station, Chianki, Palamau, (Birsa Agricultural University, Ranchi), Jharkhand (India). Methods: In this experiment conducted during rabi season 2017-18 and 2018-19 at Zonal Research Station, Chianki, Birsa Agricultural University, Ranchi, Jharkhand, India. The eight treatments were taken under RBD in three replications. Observations and analysis were carried out by following the standard procedures. Result: The present investigation clearly brought out that two hand weeding followed by pendimethalin was the best sought out option on controlling weed population, for higher growth and yield of chickpea. Based on the results obtained, it could be inferred that two hand weeding are costly as compared to pendimethalin and it had least adverse effect on microbial population and nodulation. Therefore, pendimethalin can be used to get the higher plant growth and yield of chickpea. [ABSTRACT FROM AUTHOR]

In India the highest loss (33%) is caused by weeds, followed by pathogens (26%), insects (20%), storage pests (7%), rodents (6%) and others (8%). Weeds compete with the crop for both above and below ground resources. Critical period of weed competition starts from 17 to 29 days after planting of corn, at an acceptable yield loss of 5 to 10 per cent. Herbicides are efficient tools for checking weed infestation and its usage is increasing throughout the globe due to increasing labour cost and quick weed control in various situations. The common weed management practice for Maize is pre-emergence application of selective herbicides like atrazine or pendimethalin followed by one hand weeding. Managing weeds through pre-emergence, post-emergence and sequential use of herbicides will be an ideal means for controlling the weeds in the view of economics and effectiveness in maize. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during kharif season of 2016 at Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalaya, Chitrakoot, Satna (M.P.) to study the efficacy of different herbicides against weeds in mungbean. The weed density recorded at 30 and 60 DAS was significantly lower under pendimethalin 30 EC + imazethapyr 2 EC (Ready mix) 0.75 kg/ha as pre-emergence (PE) followed by pendimethalin PE. However, significantly lower weed dry weight and statistically superior weed control efficiency were noted in twice hand weeding at 20 DAS and 40 DAS and pendimethalin + imazethapyr (R.mix.) 0.75 kg/ha at same stages of crop (30 and 60 DAS). While, yield attributes viz. pods/plant (21.8) was significantly higher in plot treated with imazethapyr 10 SL @ 40g/ha applied at 20 DAS and statistically at par with imazamox 35 WG+ imazethapyr 35 WG 60g/ha applied at 20 DAS and clodinafop - propargyl 8% + aciflourfen - sodium 16.5% (WP) 187.5 kg/ha applied at 20 DAS. Application of clodinafop - propargyl 8% + aciflourfen - sodium 16.5% (WP) 187.5 kg/ha at 20 DAS produced significantly maximum seed yield (531 kg/ha) of mungbean closely followed by imazethapyr 10 SL @ 40g/ha at (528 kg/ha) and pendimethalin 30 EC + imazethapyr 2 EC (R.mix) 0.75 kg/ha (521 kg/ha). However, stover yield (2699 kg/ha), gross returns ('58464/ha) and net returns ('43163/ha) were obtained significantly superior under clodinafop - propargyl 8% + aciflourfen-sodium 16.5% (WP) 187.5 g/ha. [ABSTRACT FROM AUTHOR]

Currently, the cultivation of citronella grass (Cymbopogon nardus L.) is widely developed in highland areas dominated by Andosol soil. Andosol possesses low phosphorous availability, strongly bound to Al and Fe. This research was aimed to examine the effect of P fertilizer on C. nardus L. at Andosol. The research was conducted from June 2014 to August 2015. Phosphate fertilization stimulated plant growth, yield and oil quality of citronella grass on Andosol. The most suitable Phosphorus dosage at 1.08 g plant-1 (10.8 kg ha-1) produced high total fresh herb yield and oil quality of citronella grass. Total fresh herb yield increased 21.2% (3.4 kg plant-1 year-1) compared to control. Whereas citronella content, oil content and oil yield were 35.2%, 1.64% and 1.27% respectively. The phosphate residue in Andosol can be potentially utilized for the next planting season. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during kharif season 2012 and 2013 at Rajmata Vijayaraje Scindia Krishi Vishwa Vidhyalaya RVSKVV, College Farm Gwalior (M.P.) to asses the suitable method for weed control in soybean. On the basis of two years pooled data results weeding twice at 20 and 40 DAS significantly highest growth, yield attributes and seed yield as compared to the unweeded control and was at par with pendimethalin (750 g a.i./ha) + one hand weeding, trifluralin (1000 g a.i./ha) + one hand weeding at 20 DAS and imezathapyr(100 g a.i./ha) + one hand weeding at 40 DAS. These treatments also recorded lower weed dry biomassand higher weed control efficiency. Pendimethalin (750 g a.i./ha) + one hand weeding at 20 DAS resulted higher net return ('63500) and B:C (2.58) ratio followed by trifluralin + one hand weeding and hand weeding twice at 20 and 40 DAS. In addition to hand weeding twice, pre emergence herbicide Pendimethalin (750g a.i/ha) + one hand weeding at 20 DAS can be effectively used as an alternative for controlling weeds for obtaining optimum seed yield in soybean. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Research Farm of Agriculture Research Station, S.K. Rajasthan Agricultural University, Bikaner during 3 consecutive kharif season of 2014, 2015 and 2016with fourteen weeds control treatments of pendimethalin 1.0 kg/ha (PPI), pendimethalin 1.0 kg/ha (PE), imazethapyr + pendimethalin 800g/ha, imazethapyr + pendamethalin 900g, imazethapyr + pendamethalin 1000g, imazethapyr 50g, imazethapyr 70g/ha, imazethapyr + imazemox 60g/ha, imazethapyr + imazemox 70g/ha, oxyfluorfen 40g/ha, fenoxaprop p-ethyl 50g/ha, propaquizafop 62g/ha, weed free and weedy check in randomized block design with three replications. Weed free was found most effective to control weeds in groundnut and recorded lowest weed count and weed dry matter of both broad leaved and grassy weeds. Among the different herbicides, application of imazethapyr + pendamethalin 800g recorded efficiently controlled weed count and weed dry matter of both broad leaved and grassy weeds as well as significantly highest yield attribute and yield in groundnut over all the other herbicidal treatments viz. dry matter accumulation (75.2g), number of pods/plant (31.2), pod (2979 kg/ha), haulm (7711 kg/ha) and biological yield (10690 kg/ha). Among the different herbicides, application of imazethapyr + pendamethalin 800g recorded higher net returns of '84132/ha and B:C ratio of 2.22. [ABSTRACT FROM AUTHOR]

The field experiment carried out during kharif seasons of 2015 and 2016 at Research Farm, College of Agriculture, RVSKVV, Gwalior, Madhya Pradesh indicated that HG 2-20 (V2) was significantly superior under weed control efficiency, crop growth and yield attributes, seed yield and economics over HG 563 (V1). 30 cm x 10 cm (S1) crop geometry observed significantly effective over 45 cm x 6.5 cm (S2). Weed free situation (W5) was significantly superior in similar parameters; while lower values were observed under weedy plot (W6). Among herbicidal treatments; Imazethapyr 35% WG + Imazamox 35% WG (Pre-mix) @ 40 g a.i./ha (W4) followed by Imazethapyr 10% EC @ 75 g a.i./ha (W3) were achieved statistically at par and significantly effective results over rest of the treatments. In case of interaction; the significantly superior values were registered under interaction of HG 2-20 (V2) with 30 cm x 10 cm (S1) to weed free situation (W5) over rest of the interactions. Among interaction of herbicidal treatments with varieties and crop geometries; Imazethapyr 35% WG + Imazamox 35% WG (Pre-mix) @ 40 g a.i./ha (W4) combined with HG 2-20 (V2) and 30 cm x 10 cm (S1) earned significantly effective over other interactions. [ABSTRACT FROM AUTHOR]

The effects of herbicides, alone application or in combination with insecticides, on performance of soybean [Glycine max (L.) Merrill] were examined at ICAR-Indian Agricultural Research Institute, New Delhi during rainy seasons of 2013 and 2014. Alone application of imazethapyr 10 SL @ 1.01/ha or in combination with indoxacarb 14.5 SC @ 300 ml/ha and rynaxypyr 20 SC @ 100 ml/ha lowered monocot and dicot weed count, reduced weed dry matter and increased weed control efficiency in comparison with other herbicide and insecticide applications, individual or in combinations. These results suggested that the imazethapyr can effectively control different categories of weeds, especially of monocots in soybean field. However, seed yield, net returns and B: C ratios were higher in the quizalofop ethyl 5 EC (1.01/ha) applied plots followed by combined application of rynaxypyr 20 SC (100 ml/ha) + quizalofop ethyl 5 EC (1.01/ha). [ABSTRACT FROM AUTHOR]

A field experiment was conducted during rabi season of 2010-2011 and 2011-12 at Pantnagar in tarai soil of Uttarakhand to study the effect of different herbicides on plant growth, weed dynamics, nutrient uptake and yield of dwarf fieldpea. Results revealed that uncontrolled weeds caused 27.3 and 39.4 per cent reduction in grain yield of dwarf fieldpea during first and second year, respectively as compared to two hand weedings done at 20 and 40 days after sowing (DAS). Among the chemical treatments, minimum nutrient removal of 3.0 kg N,0.5 kg P and 3.3 kg K ha-1 by weeds was recorded under pendimethalin 1.0kg ha-1 (PE)+ imazethapyr 0.05 kg ha-1 (POE,30 DAS) as against 11.4 kg N, 1.96 kg P and 12.6 kg K ha-1, respectively in weedy check Two hand weedings done at 20 and 40 DAS, which remained at par with pendimethalin1.0 kg ha-1 (PE) + imazethapyr 0.05 kg ha-1 (POE, 30 DAS) and pendimethalin 1.0kg ha-1 (PE) + quizalofop ethyl 0.05kg ha-1 (POE, 30 DAS) caused significant reduction in weed dry weight and increased the value of plant height, number of leaves per plant and dry matter accumulation per plant as compared to weedy check. These treatments produced 27.1, 23.1 and 16.0 per cent more number of pods/plant and yielded 50, 40 and 35.7 per cent higher grain yield, respectively over weedy check. The maximum weed control efficiency was computed under two hand weedings followed by pendimethalin 1.0 kg ha-1 (PE)+ imazethapyr 0.05kg ha-1 (POE, 30 DAS) and pendimethalin 1.0kg ha-1 (PE)+ quizalofop ethyl 0.05 kg ha-1 (POE, 30 DAS). [ABSTRACT FROM AUTHOR]

A field experiment was conducted during rabi season of 2011-2012 at College of Agriculture, Vellayani, Kerala, India to evaluate three promising new generation herbicides for managing water cabbage. The experiment was laid out in randomized block design with eight treatments replicated thrice. The treatments comprised of Azimsulfuron @ 20 and 30 g/ha, bispyribacsodium @ 20 and 30 g/ha, (metsulfuron-methyl + chlorimuron-ethyl) @ 4 and 6 g/ha, 2-4 -D @ 1 kg/ha and a weedy check. The results of the field study on weed control efficiency of the different herbicides indicated that 2, 4-D @1 kg a.i. ha-1 was most effective for controlling water cabbage. Among the new generation herbicides (metsulfuron methyl + chlorimuron ethyl) @ 6 g a.i. ha-1 and bispyribac sodium @ 30 g a.i. ha-1 were equally effective for controlling water cabbage. Azimsulfuron at both doses were found to be least effective in controlling water cabbage. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effect of herbicides and phosphorus sources on productivity of wheat (Triticum aestivum L.). The weed flora at site were Chenopodium murale, C. album, Anagallis arvensis, Convolvulus arvensis, Melilotus indica, Spergulla arvensis, Malva parviflora, Fumaria parviflora, Rumex obtusifolius and Coronopus didymus among broadleaf weeds and Phalaris minor in grassy weed. The experiment consisted of eight herbicide (weedy check, 2,4-D at 500 g ha-1, triasulfuron at 15 g ha-1, carfentrazone at 20 g ha-1, isoproturon at 750 g ha-1, 2,4-D + isoproturon at 500 + 750 g ha-1, triasulfuron + isoproturon at 15 + 750 g ha-1, carfentrazone + isoproturon at 20 + 750 g ha-1) and three phosphorus sources (DAP, SSP and PROM) making twenty four treatment combinations. These treatments were evaluated in randomized block design with four replications. Amongst the weed control treatments tank mixture of carfentrazone + isoproturon (20 + 750 g ha-1) resulted in complete elimination of all the broadleaf weeds except Convolvulus arvensis. Isoproturon and its tank mixture with other reduced weed density and dry matter of Phalaris minor significantly than weedy check and rest of the treatments. Tank mix application of herbicides tended to reduce weed dry matter significantly in comparison to singly applied herbicides, however, carfentrazone + isoproturon resulted in minimum weed dry matter (11.29 kg ha-1) and highest weed control efficiency (97.33%). Consequently, it produced significantly higher grain (5816 kg ha-1) and straw (8904 kg ha-1) yields and net returns ( ₹65267 ha-1) compared to other treatments. This mixture recorded significantly lower N, P and K uptake by weeds with concomitant 84.9, 119.5 and 73.3 % higher uptake of these nutrient elements by wheat crop over weedy check. [ABSTRACT FROM AUTHOR]

An experiment was carried out for three consecutive years from 2011 to 2013 at Floricultural Research Station, Hyderabad to find out efficient and economically feasible chemicals for weed control in Gladiolus. Among four pre- emergence herbicides i.e Atrazine, Metribuzin, Butachlor and Pendimethalin each at two different concentrations, the highest weed control efficiency at 75 DAP(63.7%) was achieved with Pendimethalin applied at 1 kg a.i/ha followed by Metribuzin 0.5 kg a.i /ha (63.2%). Though Pendimethalin @ 0.75 kg a.i/ha was effective in controlling the weeds as well as promoting growth and flower quality of the crop, the highest gross monetary returns per hectare and maximum B:C ratio was achieved with Butachlor@1.5kga.i/ha with highest corm yield of 1,66,250 corms per ha. [ABSTRACT FROM AUTHOR]

Field investigation was carried out during kharif season of 2012 the results showed that unchecked weeds caused a reduction of 66.67% in black gram yield. Two hand weeding at 25 and 50 DAS recorded maximum number of pods /plant, number of seeds /pod, 1000 seeds weight,seed yield and higher weed control efficiency followed by Imazathapyr+Imazamox (premix) @ 50 g/ha PoE at 20 DAS. Imazathapyr+Imazamox (premix) @ 50 g/ha at PoE 20 DAS registered highest net return and B:C ratio followed by Imazathapyr +Pendimethalin (premix) @ 1000 g/ha PE. [ABSTRACT FROM AUTHOR]