Pendimethalin Fb Research Articles

Effect of Weed Management Practices on Weed Dynamics, Nutrient Depletion, Productivity and Profitability of Summer Mungbean (Vigna radiata) under Zero Tillage Condition

Background: Weeds are prime factor that adversely effects on growth, quality and yield of mungbean during summer and rainy season. Being a short duration crop, it faces heavy weed competition right from the early growth stages to harvesting. The critical period of crop weed competition in mungbean was initial 25-30 days, yield may be reduce up to 50-90% if weeds not manage at this stage. Hence, there is a need to find out the successful weed management strategies to realize higher growth and yield. The progressive transformation of agriculture concerning intensive use of herbicides is gaining status in recent years due to easy, lower cost, timeliness and successful controlling weeds. Therefore, keeping above information in view, the present study was undertaken to assess the effect of different weed management practices in summer mungbean under zero tillage condition to find out the better weed management, higher productivity and profitability.Methods: In this field-laboratory investigation during summer season, 2019, different herbicides were applied to manage weeds in mungbean. Eight treatments were applied based on various application windows. In the field and laboratory, the collected samples were determined for crop weed competition, yield attributes, yields and net returns. Result: The results revealed that weed free treatment was recorded lowest weed population at 30 DAS and harvest (1.8 and 2.9), weed dry weight (1.1 and 1.9g) and highest weed control efficiency (96.3 and 94.9%) followed by Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The similar results also observed in nutrients removed by weeds. Among yield attributes, weed free treatment recorded the longest pod length, no. of pods/plant, no. of seeds/pod and test weight (7.9, 21.0, 9.7 and 43.0g, respectively) which was at par with Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The magnitude of seed yield was increased under weed free (10.1 q/ha) and Shaked (Propaquizafop + Imezathyper) (9.5 q/ha) treatments by 127.9 and 113.8%, respectively over weedy check. Application of Shaked (Propaquizafop + Imezathyper) recorded highest net returns (Rs 55,079/ha) and B: C (2.8) over rest of the treatments. It can concluded that application of Shaked (Propaquizafop + Imezathyper) @ 2 L/ha at 20 DAS recommended for better weed control, higher yield and net returns of summer mungbean under zero tillage condition.

Effects of Conservation Agricultural Practices on Soil Microbial Population and Yield of Cotton

Field investigations were conducted to assess the effect of conservation agricultural practices on soil biological properties and yield of cotton during the kharif season of 2018 and 2019. The experiments were laid out in a split plot design with four main factors viz., conventional tillage with irrigation schedule of 0.8 IW/CPE ratio (M1), conventional tillage with irrigation schedule of 0.6 IW/CPE ratio (M2), minimum tillage with irrigation schedule of 0.8 IW/CPE ratio (M3) and minimum tillage with irrigation schedule of 0.6 IW/CPE ratio (M4). Sub plot had six treatments of weed and nutrient management viz., crop residue mulch with 100% RDF (S1), crop residue mulch with 75% RDF (S2), pre-emergence application of pendimethalin fb one hand weeding with 100% RDF (S3), pre-emergence application of pendimethalin fb one hand weeding with 75% RDF (S4), mechanical weeding twice with 100% RDF (S5) and mechanical weeding twice with 75% RDF (S6). Total microbial populations viz., bacteria, fungal, and actinobacteria were higher in cotton rhizosphere soil with the minimum tillage of irrigation at 0.8 IW/CPE ratio (M3) in the main plot treatments. Cotton rhizosphere soil with crop residue mulch with 100% RDF (S1) recorded a higher microbial population and it was statistically similar with pre-emergence application of pendimethalin fb one hand weeding with 100% RDF (S3) in the sub plot treatments. Among the treatment combination, minimum tillage with irrigation at 0.8 IW/CPE ratio (M3) and crop residue mulch with 100% RDF (S1) recorded a higher microbial population. Similarly, a higher seed yield of cotton was also recorded with minimum tillage and irrigating the crop at 0.8 IW/CPE ratio and pre-emergence application of pendimethalin fb one hand weeding along with application of 100% RDF (M3S3)

Performance of rice cultivars with weed management practices in dry direct-seeded rice

Weeds are the most important biotic constraint in direct-seeded rice (DSR) production. A field experiment was carried out in split plot design replicated thrice during September 2019 to evaluate the performance of different cultivars integrated with weed management practices under DSR at Pandit Jawaharlal Nehru College of Agriculture & Research Institute, Karaikal, Puducherry UT, India. The treatment combination consisted of three cultivars in main plot (ADT 46, CO 52 and White Ponni) and five levels of weed management practices in the sub-plots (application of pendimethalin 1.0 kg/ha as pre-emergence herbicide at 3 DAS, bispyribac-sodium 0.02 kg/ha as post-emergence herbicide at 20 DAS, sequential application of pendimethalin 1.0 kg/ha followed by bispyribac-sodium 0.02 kg/ha, hand weeding twice at 20 and 40 days after sowing (DAS) and unweeded control. Results revealed that rice cultivar ADT 46 integrated with sequential application of pendimethalin fb bispyribac-sodium (1.0 kg/ha fb 0.02 kg/ha) reduced the weed density and weed dry weight, and increased the growth, yield attributes and rice grain yield. Uncontrolled weeds caused 51.9 % yield loss in dry-DSR under coastal deltaic ecosystem.

Efficacy of pre and post-emergence herbicides on growth and yield of Wheat (Triticum aestivum L.) under Doon Valley of Uttarakhand

A field experiment was directed during Rabi season 2018-2019 at experimental farm of Doon (P.G.) College of Agriculture Science and Technology, Selaqui, Dehradun (Uttarakhand) using pre-and post-emergence herbicides combined with Hand Weeding for successfully controlling of weeds, their result on yield and production economics on Wheat (Triticum asetivum L.) variety used ‘Unnat PBW-343’. The dominant weed species present in field were Phalaris minor, Cynodon dactylon (L.) amongst dicot weeds like as Chenopodium album, Coronopus didymus, Fumaria parviflor, Medicago denticulate, Malva praviflora Vicia, Sativa Rumex debtatus, Sisymbrium irio among monocot, were observed during growing period. Lowest weed dry weight was observed in hand weeding at 30 and 60 Days after sowing. Higher Weed control efficiency up to (86.31 %) was recorded by Hand weeding at 30 and 60 Days after sowing. The treatment pendimethalin fb Sulfosulfuron @ 1 + 0.018 kg a.i.ha-1 P.E at 2 DAS and PoE at 30 DAS (T6) recorded greater yield attributes and seed and Stover yield (2540 kg/ha and 2668 kg/ha) and maximum net monetary return (Rs 36250) and Benefit: Cost ratio and 1.86.

Evaluation of different weed management practices in dry direct seeded spring rice at Baniyani, Jhapa, Nepal

A field experiment was conducted during the spring season of 2020 to evaluate the different weed management practices in dry directed seeded spring rice under Prime Minister Agriculture Modernization Project (PMAMP) super zone at Baniyani, Jhapa. The experiment was laid out in randomized complete block design (RCBD) with seven weed management related treatments and three replications. The treatments consisted of pre-emergence application of Pretilachlor, pre-emergence application of Pendimethalin, pre-emergence application of Pretilachlor fb post-emergence butachlor pre-emergence application of Pendimethalin fb post-emergence Bispyribac Na, Sesbania co-culture along with pre-emergence application of Pendimethalin along with two control treatments (weedy free and weedy check). The rice variety Hardinath-1 was used in the experiment. Data regarding the weed flora, weed density, weed dry weight, growth, yield attributes and yield were recorded and analyzed. The highest number of effective tillers per m2 (371.51) and number of grains per panicle (145.43) were obtained in Pendimethalin treated plot and were statistically as par with Sesbania co-culture + Pendimethalin (363.44 m-2 and 140.54 respectively). Higher and statistically similar grain yield was observed in Sesbania co- culture + Pendimethalin (4870kg ha-1) and Pendimethalin treated plots (4780 kg ha-1). The experiment concluded that there was reduction in yield by 66.78 percent due to presence of weed as compared to weed free. Pre-emergence application of Pendimethalin was most beneficial in terms of gross returns, net returns and B:C ratio compared to other weed management practices and hence was most economical.

Evaluation of weed competitiveness of direct-seeded rice (Oryza sativa) genotypes under different weed management practices

Performance of eight rice (Oryza sativa L.) genotypes (‘Swarna Shreya’, ‘IR84899-B-179-13-1-1-1’,‘IR83929-BB- 291-2-1-1-2’,‘DRR-42’,‘IR84899-B-183-20-1-1-1’,‘IR84894-143-CRA-17-1’,‘DRR-44’,‘Rajendra Bhagwati’) was evaluated in three weed management practices, i.e. application of pendimethalin @1.0 kg/ha as pre-emergence (PE) at 2 days after sowing (DAS) followed by (fb) bispyribac-Na @30 g/ha as post-emergence (POE) at 20 DAS and two hand weedings (40 and 60 DAS)-low weed pressure; application of pendimethalin @ 1.0 kg/ha as PE fb bispyribac- Na @ 30 g/ha as POE at 20 DAS-medium weed pressure and pendimethalin @ 1.0 kg/ha alone-high weed pressure during rainy seasons of 2016 and 2017 at Patna, Bihar. Application of pendimethalin (PE) followed by bispyribac-Na (POE) and two hand weedings (low weed pressure) significantly reduced weed infestation compared to pendimethalin alone (medium weed pressure). Markedly lower weed density was recorded with ‘IR84899-B-179-13-1-1-1’. Low weed pressure produced 90 and 26% more grain yield (2.53 t/ha) compared to medium (2.01 t/ha) and high weed pressure (1.33 t/ha).Significantly higher grain yield was recorded with ‘IR84899-B-179-13-1-1-1’ (2.32 t/ha) followed by ‘Swarna Shreya’ (2.18 t/ha). Low weed pressure had significantly higher gross returns (45.9×103 `/ha) and net returns (14.1×103 `/ha). Amongst genotypes, ‘IR84899-B-179-13-1-1-1’ had the highest gross returns (44×103 `/ha) and net income (17.6×103 `/ha). Hence, it may be concluded that application of pendimethalin (PE) fb bispyribac-Na (POE) along with hand weeding had significant impact on reduction of weed infestation and helps in achieving the higher grain yield of direct-seeded rice genotypes in eastern India.

Effect of pre and post emergence herbicidal application on weed dynamics and yield in lentil (Lens culinaris)

Lentil is one of the early domesticated species belongs to genus Lens of the Fabaceae family. Among all the biotic factors, weed infestation is being an adverse impact on growth and yield due to lentil short stature, low branching, lack of protective canopy and it’s unable to smother the weeds. Although, applying pre emergence herbicides, in many circumstances early weed control herbicides are not that much efficient for attaining higher yields due to lentil is long duration crop and critical weed competition upto 40-60 DAS. Sequence use of pre and post-emergence herbicides and application of post-emergence herbicides may help in controlling the weeds at later stages of crop growth period. Therefore, the experiment was initiated to find out best weed control practices among 13 treatments considered in this research to get higher yields in lentil. Out of 13 treatments, weed free treatment produced significantly higher grain yield and straw yield and pendimethalin fb quizalofop-ethyl + imazethapyr and oxyflurofen fb quizalofop-ethyl + imazethapyr were statistically at par with weed free treatment. Weed densities and biomass of different weeds were recorded significantly lower in pendimethalin fb quizalofop-ethyl + imazethapyr, oxyflurofen fb quizalofop-ethyl + imazethapyr and imazethapyr + imazomox at 60 DAS and at harvest. Ultimately, it can be concluded that, application of pendimethalin fb quizalofop-ethyl + imazethapyr and oxyflurofen fb quizalofop-ethyl + imazethapyr in lentil brings in enhancing grain yield and achieving more net returns apart from suppressing the weeds through higher weed control efficiency and lower weed index.

Nitrogen level with herbicidal combination on growth and yield attributes in wheat crop

An experiment was conducted at agronomy research farm on silty loam soil, having pH 8.6, EC 0.36 dSm-1, organic carbon 0.31%, available N, P and K 178.0, 14.5 and 231.5 kg ha-1, respectively. Experiment consisted of 9 treatment combinations together three levels of nitrogen viz. 80, 120 and 160 kg N ha-1 and three herbicide treatments viz. pendimethalin fb 2, 4-D (1 + 0.5 kg a.i. ha-1),clodinafop + metsulfuron (0.06 + 0.004 kg a.i. ha-1) and sulfosulfuron (0.025 kg a.i. ha-1) result reveal that All the herbicides applied as post-emergence, except pendimethalin. All the growth and yield contributing characters viz. plant height,, Leaf Area Index, number of effective shoots, spike length, number of grain spike-1 as well as test weight of grain were significantly higher in 160 kg N ha-1 and clodinafop + metsulfuron (0.06 + 0.004 kg ha-1). With respect to economics 160 kg N ha-1 combined with clodinafop + metsulfuron (0.06 + 0.004 kg ha-1).

Effect of different integrated weed management practices on yield and economics of dry direct seeded rice

A field experiment was conducted during 2017-2018 at N. E. Borlaug Crop Research Centre of Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, to study effect of different integrated weed management practices on yield and economics of dry direct seeded rice in tarai region. Higher grain yield, biological yield, harvest index characters were recorded under pre emergence application of pendimethalin fb penoxsulam (PoE) fb 1HW 45 DAS at 25 cm spacing which was statistically at par with stale seed bed with shallow tillage fb application of pre-emergence application of pendimethalin fb 1 mechanical weeding (MW) with conoweeder at 25 DAS along with 1HW at 45 DAS, mulch fb penoxsulam (PoE) fb 1HW at 45 DAS, Sesbania line sowing with pre-emergence application of Pendimethalin fb 1 mechanical weeding fb 1HW at 45 DAS and stale seed bed with shallow tillage fb Sesbania line sowing fb pre-emergence pendimethalin fb brown manuring with 2,4-D at 500 g/ha fb1 HW at 45 DAS. Whereas, benefit cost ratio was found higher (2.1) under pre emergence application of pendimethalin fb penoxsulam(PoE) fb 1HW 45 DAS at 25 cm spacing which was statistically at par with stale seed bed with shallow tillage fb application of pre-emergence application of pendimethalin fb 1 mechanical weeding (MW) with conoweeder at 25 DAS along with 1HW at 45 DAS, mulch fb penoxsulam (PoE) fb 1HW at 45 DAS and Sesbania line sowing with pre-emergence application of pendimethalin fb 1 mechanical weeding fb 1HW at 45 DAS. From the study it can be concluded that above three integrated practices were same effective as recommended practice for controlling weed with higher return.

Effect of weed management practices and nitrogen levels on weed intensity and bulb yield of onion in loamy sand soils

Field experiment was conducted on onion to develop efficient integrated weed management practicesunder various levels of nitrogen. Two hand weeding at 20 and 40 DAT or application of pendimethalin (PP) +oxadiargyl at 40 DAT or application of pendimethalin (PP) fb 1 HW at 40 DAT combined with 100 kg N ha−1 were recorded significantly higher bulb weight, bulb yield and net returns. Thus, either of above integrated weedmanagement practice can be used for rabi (winter) season onion in loamy sand soils.

Weed management practices in rice (Oryza sativa) + brahmi (Bacopa monnieri) intercropping system

A field study was carried out during two consecutive kharif seasons 2015–2016 at Norman E Borlaug Crop Research Centre, G B Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, to evaluate the effect of different weed management practices and different row ratios on yield, yield attributes and economics of the rice (Oryza sativa L.) + brahmi (Bacopa monnieri) intercropping system. The dominant weed floras were Echinochloa crus-galli, Echinochloa colona, Alternanthera sessilis, Caesulia axillaris and Cyperus rotundus. Among different herbicides, pendimethalin followed by (fb) cyhalofop-butyl fb, one hand weeding at 45 days after sowing in 2:1 row ratios had minimum weed density (16.83 and 9.82/m2), dry weight (7.35 and 3.97 g/m2) and highest weed control efficiency (73.36 and 83.45%). Intercropping of rice with brahmi, exhibited greater potentiality and realized significantly higher plant height, dry matter accumulation, number of nodes, number of branches, number of panicles/m2 and 1000 grain weight. Dry herbage yield of brahmi and grain yield were highest in sole crop of rice (5.3 and 6.56 t/ha) and brahmi (2.07 and 2.35 t/ha). Furthermore, pendimethalin fb cyhalofop-butyl fb one hand weeding at 45 DAS in 1:1 ratio of rice and brahmi gave highest net returns (255426.1 and 317163.1/ha) and benefit cost ratio (10.1 and 11.07) and also high value of land equivalent ratio (1.76 and 1.85) and area time equivalent ratio (0.88 and 0.92) during both years.

Performance of different herbicides on wheat grain yield and correlation between growth and yield attributes of wheat and weeds

A field experiment was conducted at Siswal, Hisar, Haryana during 2016–17 and 2017–18 to study the effect of different herbicides applied alone or mixtures on weeds and yield of wheat (Triticum aestivum). Significantly higher grain yield was obtained in weed free treatment, which was statistically similar with pinoxaden + metsulfuron and pendimethalin fb pinoxaden treatments, but significantly higher than all other treatments during both the years. Weed free, pinoxaden + metsufuron and pendimethalin fb pinoxaden treatments produced 70.9, 67.7 and 64.9; 69.4, 67.0 and 64.3% higher grain yield as compared to weedy check treatment, respectively during 2016–17 and 2017–18. Statistically similar grain yield was recorded in pyroxasulfone and pyroxasulfone + pendimethalin treatments, it was 54.1 and 51.1; 55.3 and 52.4% higher to weedy check treatment, respectively during 2016–17 and 2017–18. Application of flumioxazin and flumioxazin + pendimethalin provided effective weed control, but grain yield was lower due to crop phytotoxicity after first irrigation in light texture soils. Significant positive correlation between grain yield, growth and yield attributes, per cent control of weeds and weed control efficiency, but negative correlation was observed between grain yield and weed dry weight, panicle length, seeds/panicle, test weight of wild oat and weed index.

Weed and nitrogen management in direct-seeded rice

A field experiment was conducted during Kharif seasons of 2014, 2015 and 2016 with an objective to assess the feasibility of weed and nutrient management in direct-seeded rice. The experiment was laid out in a factorial RBD with eighteen treatment combinations including six weed management treatments, viz. pretilachlor, pendimethalin, pretilachlor followed by (fb) bispyribac-sodium, pendimethalin fb bispyribac-sodium, weed free and weedy check and three nitrogen (N) levels, viz. 80, 100 and 120 kg N/ha with three replications. Significantly lower weed biomass was recorded with weed free which [2 hand weedings (HW) at 20 and 40 days after seeding (DAS)] was at par with pendimethalin 1.0 kg/ha pre-emergence treatment (PE) fb bispyribac-sodium 0.04 kg/ha, post-emergence treatment (PoE). Similarly, the highest weed control efficiency (WCE, 73.0%) and the lowest weed index (WI) were also recorded with weed free treatment, followed by pendimethalin 1.0 kg/ha fb bispyribac sodium 0.04 kg/ha (WCE, 71.2%). Rice growth and yield attributes, viz. plant height, effective tillers, panicles length, grains/panicle were improved significantly under combine application of PE and PoE herbicides either pendimethalin 1.0 kg/ha or pretilachlor 0.75 kg/ha (PE) fb bispyribac 0.04 kg/ha (PoE) and weed free [2 HW at 20 and 40 DAS]. Further, weed free treatment as well as pendimethalin 1.0 kg/ha fb bispyribac 0.04 kg/ha were found equally effective and recorded significantly higher rice grain and straw yield and nutrient use efficiency (NUE) with higher net returns compared to rest of treatments. Application of 120 kg N/ha significantly increased the plant height, effective tillers/plant, panicle length, grain/panicle, grain and straw yield, N content and NUE % over rest of the treatments in all aspects of yield and yield attributes. It was concluded that 2 HW at 20 and 40 DAS or application of pendimethalin 1.0 kg/ha fb bispyribac-Na 0.04 kg/ha for weed control appeared to be a viable strategy along with 120 kg N/ha for achieving higher and profitable yield of direct-seeded rice.

Integration of chemical and manual control methods for sustainable weed management in inbred and hybrid rice

Herbicidal weed control is gaining popularity in the developing countries but its efficacy still remains unclear. Therefore, an experiment was conducted to find out appropriate weed management practices for inbred and hybrid rice. The experiment comprised of inbred and hybrid varieties (two of each), and eight weed control treatments arranged in randomized complete block design with three replicates. Hybrid varieties performed better in terms of yield attributes and yield than inbred varieties. The highest grain yield (5.3 t ha−1) was obtained from the hybrid Agrodhan-12 and the lowest one (4.3 t ha−1) was from inbred Binadhan-7. Weed free treatment resulted in the highest grain yield (6.1 t ha−1) and the lowest one was with weedy treatment (1.96 t ha−1). The highest grain yield was obtained from Agrodhan-12 in weed free condition (6.9 t ha-1), while the lowest value was in inbred BRRI dhan49 under weedy condition (1.73 t ha−1). Weed-free treatment and the treatments of Pretilachlor fb Penoxsolum, Pretilachlor fb hand weeding, and Pendimethalin fb hand weeding showed similar performances in reducing weed density and eventually resulted in similar and the highest grain yield. Based on these results it may conclude that Pretilachlor applied at 2 days after transplanting (DAT) fb Penoxsolum at 21 DAT is the best weed management option. But from sustainability viewpoint, Pretilachlor or Pendimethalin applied at 2 DAT along with one hand weeding at 35 DAT may be recommended for effective weed management in inbred and hybrid rice during monsoon season.J. Bangladesh Agril. Univ. 15(2): 158-166, December 2017

E Efficacy and Economics of Herbicidal Weed Management in Monsoon Rice of Bangladesh

Weed management is a challenging task in sustainable rice production. Physical and cultural methods of weed control are laborious and expensive, whereas chemical control is cheaper and less time consuming despite of some detrimental effect on environment with its inappropriate application. Considering these points, an experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh, Bangladesh during July–December 2015 to find out appropriate weed management practices for inbred and hybrid rice. The experiment comprised of four rice varieties (two inbred; BRRI dhan49 and Binadhan-7, and two hybrids; Dhani gold and Agrodhan-12); and eight herbicidal weed control treatments (season-long weedy or weed free, Pretilachlor fb Penoxsolum or 2,4-D dimethyl amine, Pendimethalin fb Penoxsolum or 2,4-D dimethyl amine, Pretilachlor or Pendimethalin fb one-time hand weeding). Eleven weed species belonging to five families were observed in the experimental plots. The highest weed density and dry weight were found in season-long weedy treatment and the lowest one was found in Pretilachlor fb one-time hand weeding. The highest above ground crop biomass (9.7 t ha-1) and harvest index (46.3%) were obtained from the hybrid variety Agrodhan-12 and the lowest biomass (8.3 t ha-1) was obtained from the inbred variety Binadhan-7. Season long weed free condition resulted the highest above ground crop biomass (10.9 t ha-1), harvest index (48.7%), highest yield increase over control (213.8), weed control efficiency (100%) and gross return (BDT 141480 ha-1) and the lowest values for all those parameters were obtained from season-long weedy treatment. Season-long weed free treatment combined with Pretilachlor or Pendimethalin fb one-time hand weeding showed the best performance in reducing weed density and increasing above ground crop biomass, but gross return was higher because of high labour wages in these treatments. The highest BCR (2.5) was observed in Pretilachlor fb Penoxsolum. Therefore from economic view point Pretilachlor fb Penoxsolum is the best combination. But from sustainability view point Pretilachlor or Pendimethalin along with one-time hand weeding may be recommended for effective weed management in inbred and hybrid rice during monsoon season.

Effect of weed management and fertility levels on productivity of clusterbean [Cyamopsis tetragonoloba (L.)Taub

A field experiment was conducted during Kharif seasons of 2014 and 2015 at Udaipur (Rajasthan) to find out the effect of weed management on productivity of clusterbean under varying fertility levels. The results revealed that among various weed management practices, two hand weeding 20 and 40 DAS recorded significantly lower weed dry matter, higher weed control efficiency, higher values of yield attributes, seed, haulm and biological yield during both the years over rest of the treatments except sequential application of pendimethalin fb imazethapyr which was statistically at par. Further, application of Imazethapyr fb hand weeding and pendimethalin fb hand weeding also gave comaparable results with pendimethalin fb imazethapyr in terms of weed control efficiency and yields. Among the fertility levels application 20 Kg N + 40 Kg P2O5 ha-1 significantly increased pods plant-1 (24.04), seeds pod-1, (7.12), test weight ( 25.33 g), seed ( 1035 kg ha-1), haulm (2161 kg ha-1) and biological (3196 kg ha-1 ) yield and harvest index ( 31.98 %) of clusterbean over 10 Kg N + 20 Kg P2O5 ha-1 however, it was found statistically at par with fertility level 30 Kg N + 60 Kg P2O5 ha-1. Therefore, clusterbean should be fertilized with 20 Kg N + 40 Kg P2O5 ha-1 and weeds must be controlled with pendimethalin (PE) fb imazethapyr 0.1 kg ha-1 20 DAS .

Evaluation of herbicide combinations for controlling complex weed flora in wheat

A field experiment was conducted during the Rabi seasons of 2014–15 and 2015–16 on a silty clay loam soil at Palampur. Avena ludoviciana (36.3%), Phalaris minor (27.5%), Lolium temulentum (13.9%), Anagallis arvensis (10%) and Coronopus didymus (6.9) were the major weeds. Herbicide combinations (pendimethalin 1.0 kg/ha + metribuzin 175 g/ha, pendimethalin 1.0 kg/ha fb sulfosulfuron 18 g/ha, sulfosulfuron 20 g/ha + metsulfuron 4 g/ha, pinoxaden 60 g/ha + metsulfuron 4 g/ha, clodinafop 60 g/ha + metsulfuron 4 g/ha, isoproturon 1.0 kg/ha + 2, 4-D 0.5 kg/ha) were superior to sole application of herbicides (pendimethalin 1.25 kg/ha, sulfosulfuron 25 g/ha, metribuzin 210 g/ha and clodinafop 60 g/ha) in reducing weed count and dry weight and increasing plant height, number of tillers, crop dry matter, yield attributes and yield of wheat. Clodinafop + metsulfuron, pinoxaden + metsulfuron and pendimethalin fb metsulfuron being better than other combinations gave 28.6, 22.5 and 23.1% higher grain yield of wheat over hand weeding twice. Weeds reduced the grain yield by 51.9%. With unit increase in weed count per m2, the wheat grain yield was decreased by 13.3 kg/ha. The cost of weed control under herbicidal treatments was 9.0–28.9% of that under hand weeding lowest being under metribuzin and highest under pendimethalin fb sulfosulfuron. Clodinafop + metsulfuron gave the highest net returns due to weed control and marginal benefit: cost ratio (MBCR). Clodinafop + metsulfuron resulted in highest weed control efficiency (WCE), weed control index (WCI), crop resistance index (CRI), treatment efficiency index, crop intensity index and weed index. Weed management index, agronomic management index and integrated weed management index were highest under sulfosulfuron followed by clodinafop + metsulfuron. Based on overall impact index clodinafop + metsulfuron, pinoxaden + metsulfuron, sulfosulfuron + metsulfuron, pendimethalin fb sulfosulfuron and pendimethalin + metribuzin were recommended for effective weed management in wheat under mid hill conditions of Himachal Pradesh.

Nutrient uptake by clusterbean as influenced by weed management and sulphur nutrition

A field experiment was carried out during two consecutive seasons of Kharif 2013 and 2014 to evaluate effect of weed management and sulphur nutrition on the nutrient uptake by weeds and crop in clusterbean [Cyamopsis tetragonoloba (L.) Taub.]. Minimum weed dry matter of narrow-leaved (239 kg/ha), broad-leaved (285 kg/ha) and total dry weight (524 kg/ha) was observed under hand weeding at 20 and 40 days after sowing (DAS), which was closely followed by the sequential application of preemergence application of pendimethalin 0.75 kg/ha followed by (fb) imazethapyr 0.075 kg/ha as postemergence. The highest seed (1.22 t/ha), haulm (2.44 t/ha) and biological yields (3.66 t/ha) was registered in hand weeded twice, which was statistically at par to pendimethalin fb imazethapyr. Hand weeding twice and pendimethalin fb imazethapyr, with non-significant difference between these two, saved N and P uptake by 56, 47 and 55, 46%, respectively, compared to weedy check in combined uptake of nutrient both by weeds and crop.

Herbicides combinations for control of complex weed flora in transplanted rice in Lateritic belt of West Bengal

The field trial was laid out in RBD with 12 treatments and replicated thrice in agricultural farm of Visva-Bharati during Kharif, 2014. The herbicidal treatments were bispyribac and penxsulam alone; tank of bispyribac with ethoxysulfuron and (chlorimuron + metsulfuron); pretilachlor fb ethoxysulfuron and (chlorimuron + metsulfuron) pyrazosulfuron fb (chlorimuron + metsulfuron) ready mix of penoxsulam + cyhalofop, ready mix of triafamone + ethoxysulfuron and pendimethalin fb bispyribac. Two hand weeding and weedy check also included with an idea to find out the best herbicides/herbicide mixtures for weed control in transplanted rice. Early post-emergence application of penoxsulam + cyhalofop as ready-mix was found most effective in controlling total weed population recorded the highest number of effective tillers/m2, number of grains/panicle and grain yield of transplanted rice.

Weed management in turmeric

Pre-emergence metribuzin 0.7 kg/ha, pendimethalin 1.0 kg/ha and atrazine 0.75 kg/ha each followed by i) hand weeding (HW) (45 and 75 DAP, days after planting), ii) fenoxaprop 67 g/ha + metsulfuron-methyl 4 g/ha (45 DAP) and iii) mulch + HW (75 DAP); pre-emergence oxyflourfen 0.3 kg/ha and oxadiargyl 0.25 kg/ha and post-emergence glyphosate 1.23 and 1.85 kg/ha (25 DAP) each followed by HW (45 and 75 DAP); HW (25, 45 and 75 DAP) and untreated control were evaluated at Palampur during 2014, 2015 and 2016 to develop an effective weed management strategy in turmeric for mid hill conditions of Himachal Pradesh. Treatments constituting fenoxaprop + metsulfuron-methyl were phyto-toxic resulting in poor turmeric crop canopy formation thereby more growth of Ageratum sp. and lower plant height, plant stand, daughter corms/mother corm, rhizome yield and economics. Other weed control treatments were effective in controlling Echinochloa colona and other grassy weeds. With every g/m2 increase in weed dry weight, the fresh turmeric rhizome yield was reduced by 64.2 kg/ha. Pre-emergence atrazine/metribuzin/pendimethalin fb mulch fb hand weeding had effectively controlled weeds and increased the fresh rhizome yield by 54.1 to 54.9%, cured rhizome yield by 57.6 to 59.4% and net return by 66.4 to 68.3% being comparable to hand weeding thrice. However, hand weeding thrice was the costliest treatment. Atrazine/metribuzin/pendimethalin fb mulch fb hand weeding had lower weed persistence index and weed index and higher weed management index, agronomic management index, integrated weed management index and overall impact index than other treatments. Residues of metribuzin, atrazine, pendimethalin, oxyfluorfen and metsulfuron--methyl in soil and rhizomes of turmeric were found below detectable level. Based on overall impact index metribuzin fb mulch fb hand weeding, atrazine fb mulch fb hand weeding and pendimethalin fb mulch fb hand weeding in that order are recommended as an alternative to hand weeding thrice in turmeric.