Weed Science

Post-emergence application of two insecticide molecules chloropyriphos 200 g/ha, fipronil 50 g/ha and three herbicide molecules chlorimuron-ethyl + metsulfuron-methyl at 4 g/ha, bispyribac-sodium at 25 g/ha, cyhalofop-butyl + penoxsulam at 135 g/ha were tested alone as well as in combination with an untreated control against grass, sedge, broad-leaf weed and stem borer for their compatibility during winter seasons 2015-16 and 2016-17. Tank mix application of cyhalofop-butyl + penoxsulam  + fipronil (135 + 50 g/ha) recorded lowest incidence of dead heart (0.59%), white ear (3.53%), total weed density (8 no./m2) and weed biomass ( 3.5 g/m2) and enhanced weed control efficiency (84.6%), grain yield (5.23 t/ha), net returns (` 40.44 x103/ha) and benefit : cost ratio (2.02). Dead heart percentage was less (0.59 to 1.55%) in sole fipronil and its combination with different herbicide than that of chloropyriphos (0.92 to 1.92%). There was no difference in grain yield of rice in treatments, which received application of cyhalofop-butyl + penoxsulam alone and with fipronil indicating the compatibility of herbicide with insecticide.

Field study was carried out to determine the long term effect of herbicide application on soil microbial community in rice- rice cropping sequence in acid soil of North-East India. Treatment comprised of absolute control with one hand weeding, butachlor + 2,4-D with 100% NPK through chemical fertilizer, butachlor + 2,4-D with 75% NPK through chemical fertilizer and 25% through organic source, butachlor + 2,4-D rotated with pretilachlor with 100% NPK through chemical fertilizer and butachlor + 2,4-D rotated with pretilachlor with 75% NPK through chemical fertilizer 25% through organic source. Result revealed that, after 14 years of continuous use of herbicide and organic input along with recommended dose of fertilizer application demonstrated significant increase in the activity of acid phosphatase. The effect of herbicide application was more prominent with sole chemical fertilizer than with organic manure for 25% N fertilizer replacement. Dehydrogenase activity in soil was increased following herbicide application up to 14 days after that it again decreased more prominent with addition of organic manure than with chemical fertilizer. No characteristic trend of urease activity was observed after application of herbicide. Significant inhibition of respiration was observed after application of herbicide up to 14 days followed by gradual recovery afterwards. Microbial biomass carbon in soil was significantly enhanced by application of organic manure for 25% N fertilizer substitution. Under rice-rice cropping system, application of herbicide showed temporary decline in microbial population and enzyme activities up to 14 days. Application of organic manure for 25% N fertilizer substitution significantly enhanced the microbial population and enzyme activities as compared to sole application of chemical fertilizers. Further application of butachlor rotated with pretilachlor resulted in higher microbial population as well as enzyme activities.

Field experiments were conducted during Kharif season of 2009 and 2010 to study the effect of methods of seeding and rice cultivars on dynamics of weeds in direct-seeded rice under rainfed upland conditions of Nagaland. Two seeding methods viz., line seeding and broadcasting and four local direct-seeded rice cultivars, viz. ‘Kezie’, ‘Chongloiman’, ‘Leikhumo’ and ‘Kotsala’ were evaluated under the trial in split-plot design. A total of 29 weed species were recorded, out of which Digitaria setigera Roth ex Roem. & Schult, Cynodon dactylon (L.) Pers., Cyperus rotundus Linn., Borreria articularis (L. f.) F. N. Will., Ipomoea triloba L. and Mimosa pudica L. were the dominant weed species. The line sowing was found superior over broadcasting in recording lower density, biomass and relative weed growth rate of grass, sedge and broad-leaf weeds. It also recorded significantly higher grain yield of rice. Among the cultivars ,‘Chongloiman’ and ‘Kezie’ were at par with each other and recorded significantly lower density and biomass of associated grass, sedge and broad-leaved weeds. The highest grain yield during both the years was recorded by the cultivar ‘Chongloiman’ which was at par with ‘Kezie’.

The terminal residues of flufenacet were quantified in soil and wheat grains. Flufenacet was applied at 250 and 300 g/ha on 21 and 35 days after the sowing of wheat at the Research Farm of Punjab Agricultural University, Ludhiana. Matrix solid phase dispersion (MSPD) method was used for the extraction of flufenacet from soil and grain samples. The herbicide residues were quantified using High Performance Liquid Chromatography (HPLC) equipped with UV-Vis detector and were confirmed with gas chromatographic tandem mass spectrometry (GC-MS/MS). The average recoveries of flufenacet extracted from the matrix ranged from 80.9 to 93.0% and 88.0 to 96.2% when quantified using HPLC and GC-MS/MS, respectively with relative standard deviation less than 10%. Both HPLC and GC-MS/MS offer high reproducibility, however GC-MS/MS was more sensitive having limit of detection (LOD) and limit of quantification (LOQ) as 0.001 and 0.003 μg/g, respectively. Terminal residues of flufenacet in the soil and wheat grain samples were below the detectable limit. Thus, the use of flufenacet in wheat under sub-tropical humid conditions could be considered safe.

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.

A systemic field study on bioefficacy of different herbicides in greengram (Vigna radiata L.) under irrigated condition of Gujarat and its residual effect on succeeding mustard crop was conducted during Kharif 2014 and 2015 at AAU, Anand. Among the tested options, hand hoeing at 20 and 40 days after sowing (DAS) and pre-emergence (PE) application of imazethapyr + pendimethalin ready mix (RM) at 1000 g/ha proved their supremacy in achieving highest seed yield (1.45 and 1.43 t/ha) with highest B:C of 2.91 & 2.88, respectively. These treatments provided season long control of weeds with the weed control efficiency (WCE) of 93% and 89%, respectively. Moreover, post-emergence (PoE) application of imazethapyr 70 and 80 g/ha or imazethapyr + imazamox ready mix (RM) 80 g/ha provided excellent WCE of more than 85%, but posed their negative impact on symbiotic parameters such as nodule number, plant dry weight and secured lower net return. Treatment receiving pre-emergence application of imazethapyr 80 g/ha was only found superior to achieve all profits with low input cost but did not control weeds effectively. Additionally, imazethapyr and its ready mix combination irrespective of dose did not show any residual effect to succeeding mustard crop.

The investigation was undertaken at Birsa Agricultural University, Ranchi during Kharif, 2014 and 2015. The experiment was laid out in randomized block design with sixteen treatments replicated thrice. The treatments comprised of pre- and post-emergence of imazathepyr 50, 70 and 80 g/ha; pre- and post-emergence of ready mix imazethapyr 35% + imazamox 35% (Odyssey) 50, 70 and 80 g/ha; pre-emergence (PE) of pendimethalin 1000 g/ha, ready mix imazethapyr 2% + pendimethalin 30% (Vallor) 1000 g/ha, hoeing twice and weedy check. Post-emergence (PoE) of imazethapyr 35% + imazamox 35% 70 g/ha similar to PE of imazethapyre 80 g/ha, imazethapyr 35% + imazamox 35% 70 g/ha, imazethapyr 35% + imazamox 35% 80 g/ha, pendimethalin 1000 g/ha and PoE of imazethapyr 80 g/ha, imazethapyr 35% + imazamox 35% 50 g/ha recorded 69.86 and 126.72% significantly higher seed (1.12 t/ha) and straw yield (2.33 t/ha) respectively, 168.63% higher net return (` 24,126/-) and 192.41% higher B:C ratio (2.31) compared to weedy check owing to 87.29 and 86.08% weed control efficiency.

In context of the emerging challenge of weed management in lentil under rainfed drought prone ecologies in India, a field experiment was conducted in the winter seasons of 2012-13 and 2013-14 to evaluate the performance of different herbicides in lentil under rainfed conditions. Among the herbicidal treatments, the maximum plant height (40.5 cm), plant population (143.7 plants/m2), branches per plant (5.67), pods per plant (59.03), nodules per plant (21.27), dry weight of nodules per plant (29.44 mg) and dry matter accumulation (486.30 g/m2) of lentil at maturity were recorded in plots treated with pendimethalin (pre-emergence) followed by quizalofop-ethyl (post-emergence) at 750 g and 50 g/ha. Pendimethalin followed by quizalofop-ethyl recorded significantly lower weed index (12.97%) with higher grain yield (1741.0 kg/ha) as compared with control and it was closely followed by pendimethalin alone (14.64%). Imazamox plus imazethapyr caused severe crop phytotoxicity and the crop had a slow growth and reduced crop biomass. The maximum benefit cost ratio of 3.83 was recorded in the plot treated with pendimethalin at 750 g/ha (pre-emergence) as compared to other herbicides. Thus, pendimethalin alone and with quizalofop-ethyl were equally effective in controlling the broad-spectrum of weeds in lentil with high yield advantage.

A field experiment was conducted during the winter seasons of 2012–13 and 2013–14 at Varanasi (U.P.) to evaluate the effect of fertility levels and weed management on lentil and associated weeds. Cyperus rotundus, Chenopodium album, Solanum nigrum and Cynodon dactylon were the major weeds found in association with lentil. Application of 75% RDF + Plantgro 9 kg/ha (foliar spray at 35, 50 and 65 DAS) recorded minimum density and dry matter accumulation of weeds and recorded higher yield attributes, yield (1.28 t/ha) and nutrient uptake by the crop followed by 100% RDF + 2% urea spray at pre-flowering and pod initiation. Among herbicides, application of imazethapyr 37.5 g/ha minimized the density and dry matter accumulation by weeds, and significantly increased yield attributes, yield and nutrient uptake by crop.

A field experiment was conducted at Research Farm of Agriculture Research Station, SK Rajasthan Agricultural University, Bikaner during Kharif seasons of 2015 and 2016 to test the efficiency of herbicides in groundnut. The experiment comprised of 14 weed control treatments arranged in randomized block design (RBD) with three replications. Among the different herbicides tested,  imazethapyr + pendamethalin 1000 g/ha recorded lowest weed density and weed biomass of both broad-leaved and grassy-weeds and significantly highest dry matter accumulation, number of pods/plant, pod, haulm and biological yield in groundnut over all the other herbicidal treatments.

The study was conducted at G.B. Pant University of Agriculture and Technology, Pantnagar during rainy seasons of 2012-13 and 2013-14 to evaluate the efficacy of halosulfuron 12% + metribuzin 55% WG ready-mix (RM) coded as CPL-1255 in sugarcane, and its carry over impact on succeeding lentil. The maximum weed suppression and the highest weed control efficiency were obtained with application of halosulfuron + metribuzin (RM) at higher doses (600 and 900 g/ha) applied as post-emergence, and were significantly better than the alone application of atrazine 50% WP and 2,4-D amine salt 50% SL at recommended doses. Combination of halosulfuron + metribuzin (RM) even applied at 600 g/ha was also found superior over atrazine 50% WP at 2000 g and 2,4-D amine 58% SL at 3500 g/ha while execution of twice hoeing (30 and 60 day after planting (DAP)) was also comparable to combination of halosulfuron + metribuzin at lower and higher doses at 450 and 900 g/ha, respectively, during 2012 and only to lower dose during 2013 with respect to cane yield. The ready mix application of halosulfuron + metribuzin at any dose did not pronounce any phytotoxic effect on sugarcane as well as carry over effect on the succeeding lentil in respect to germination, growth and grain yield. Overall microbial population was higher before application and decreased after application of herbicide at harvest. Herbicidal treated plots had no significant effect on bacterial counts. There was drastic reduction in microbial population at 7 day after application (DAA) of herbicide and increased thereafter. At harvest overall population of actinomycetes varied from 43.7% to 20.1% over weedy check.

A field experiment was conducted during Kharif 2014 and 2015 at Agriculture and Horticulture Research Station, Kathalagere, Davanagere district of Karnataka state, to study the effect of various weed management practices on weed density, weed dry weight, growth, yield and economics of turmeric. Pre-emergence (PE) application of pendimethalin at 1.0 kg/ha fb two hand weeding on 45 and 75 DAP recorded the highest rhizome yield, weed control efficiency, net returns and B:C ratio (23.2 t/ha, 89.2%, ` 1,45,309/ha and 2.50, respectively) in 2014. Whereas, PE application of oxyflourfen at 0.30 kg/ha fb 2 hand weeding on 45 and 75 DAP recoded the highest rhizome yield, weed control efficiency, net returns and B:C ratio (21.9 t/ha, 89.1%, ` 133236/ha and 2.60, respectively) in 2015. Integrated weed management using a broad-spectrum PE herbicide like pendimethalin or oxyflourfen fb 2 hand weedings on 45 and 75 DAP was effective in controlling weeds and obtaining higher yield and economic returns in turmeric.

The comparative efficacy of orchard soil management practices like mulching (paddy straw, white polythene, black polythene) and weed control methods (mechanical and chemical) were evaluated for managing weeds growth in guava orchard. A weedy plot was also kept as control for comparative assessment of different orchard floor management practices. The results revealed a significant effect of different treatments on grassy as well as broad-leaf weeds in the orchard. Although the black polythene mulch kept the area weed free throughout the season, the paddy straw mulch exhibited promising results, with 69.1 and 93.2% reduction in total weed biomass during first and second year of application, respectively. The white polythene was poor performer as it resulted in heavy weed growth under the mulch and tearing of polythene sheet. Chemical weed management as well as mechanical weeding also reduced the intensity of weeds but resurgence of weeds resulted significantly higher weed biomass compared to paddy straw mulch. The paddy straw mulch exhibited potential to manage weeds in guava orchard.

A field experiment was conducted during rainy season of 2010-11 and 2011-12 at Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh to evaluate the efficacy of post-emergence herbicides alone and as tank mixtures on weed control, growth and fibre yield of roselle (Hibiscus sabdariffa). The post-emergence treatments applied at 20 days after sowing (DAS) include, fenoaxaprop-ethyl 56, quizalofop-ethyl 50, pyrithiobac 63 g/ha alone and tank mixtures of fenoxaprop-ethyl 56 + pyrithiobac 63 g/ha, quizalofop-ethyl 50 + pyrithiobac 63 g/ha in comparison with standard herbicide, pendimethalin 750 g/ha (pre-emergence), hand weeding at 20 and 40 DAS and weedy check. All the treatments were replicated thrice in a randomized block design. Results indicated that post-emergence (PoE) tank mix application of pyrithiobac 63 g/ha with quizalofop-ethyl 50 or fenoxaprop-ethyl 56 g/ha reduced weed growth at par with pre-emergence (PE) application of pendimethalin 750 g/ha both at 60 DAS and harvest. Post-emergence application of pyrithiobac 63 g/ha either alone or as tank mixture with fenoxaprop-ethyl 56,or quizalofop-ethyl 50 g/ha caused upto 40% injury to roselle crop at 14 days after application. All the weed control treatments significantly influenced crop growth and fibre yield. Among the weed control treatments, maximum fibre yield (2.36 t/ha) and benefit cost ratio (1.65) was obtained with pre-emergence application of pendimethalin 750 g/ha and was at par with alone PoE application of fenoxaprop-ethyl 56 g/ha (2.11 t/ha) and quizalofop-ethyl 50 g/ha (2.03 t/ha). None of the treatments could reach the level of hand weeding at 20 and 40 DAS, which significantly recorded the highest fibre yield (2.91 t/ha). Season long weed competition caused 46% reduction in fibre yield of roselle. It was concluded that the pre-emergence application of pendimethalin 750 g/ha was found to be effective and economical in controlling weeds in roselle.

A field experiment was conducted at Kendrapara, Odisha to find out suitable and cost effective weed management practices for jute. Different doses of pre-emergence butachlor (both liquid and granule formulation) and post-emergence (quizalofop-ethyl) herbicides followed by (fb) one hand weeding (HW) were tested in jute crop and the treatment effects were compared with unweeded and two hand weeding treatments. Application of quizalofop-ethyl 60 g/ha at 20 days after crop emergence (DAE) followed by one HW at 15-20 days after herbicide application recorded higher weed control efficiency (78.3%), plant height (351 cm), basal diameter (1.40 cm) and fiber yield (2.9 t/ha) of jute as well as higher B:C ratio (2.13) compared to other weed control treatments. Values of the said parameters recorded with the quizalofop-ethyl treatment were statistically at par with those recorded with two hand weeding. Butachlor 1.5 kg/ha fb one HW at 20 DAE was the next best treatment with respect to weed control efficiency (68.7%), plant height (341.0 cm), basal diameter (1.39 cm), fibre yield (2.64 t/ha), and B:C ratio (1.99). Thus application of pre-emergence herbicide butachlor 1.5 kg/ha or post-emergence herbicide quizalofop-ethyl 60 g/ha in combination with one manual weeding may be recommended to the jute growers as more effective and economic weed control practices compared to the existing manual weeding practice.

Wrinkle grass (Ischaemum rugosum Salisb.) is a highly competitive weed in rice production that can cause huge yield reductions. Information on germination ecology of this weed is essential for the development of effective integrated weed management systems. No information is available on germination ecology for populations of this weed from Indo-Gangetic plain region of India. This study was conducted to generate information on effects of major environmental factors, viz. light, temperature, burial depth, moisture, salinity and pH on germination/emergence of this weed. Seed germination was independent of light and more than 50% germination was recorded under a wide temperature range of 20/10 to 35/25 °C day/night (12/12 h). Maximum emergence was observed when seeds were placed on surface or buried up to 1 cm; but considerable emergence was also observed from deeper soil layers (up to 6 cm depth). Germination was above 75% at 160 mM but completely inhibited at 320 mM of NaCl. Germination was sensitive to moisture stress and was completely inhibited at water potential of -0.8 MPa. Seeds were able to germinate under wide pH range of 3-10.

The present experiment was conducted with an objective to reveal the photochemical behaviour of isoproturon on different soil surfaces, viz. red, black and alluvial soil under sunlight. The half-life values of isoproturon on glass surface was  found as 25.38 days. But on soil surfaces, the rate of photolysis was changed with half-life values of 20.76, 27.38 and 28.02 days under sunlight for red, black and alluvial soil, respectively. The slower reaction rate on the surfaces of black and alluvial soil was due to the quenching effect imparted by humic substances, which were absent on glass surface and less in red soil. The sunlight-irradiated extracts of isoproturon and its degradation products were analysed by LC-MS/MS using electrospray interfacing technique and the structures of six different photoproducts were characterised by their respective spectra as 3-(4-isopropyl-2/3-hydroxyphenyl)-1-methyl-1-hydroxymethylurea (I), 3-(4-isopropyl-2/3-hydroxyphenyl)-1-methyl-1-(N,N-dimethylcarbamoyl)urea (II), 3-(4-isopropyl-2/3-hydroxyphenyl)-1-methyl-1-(N-methylcarbamoyl)urea (III), 3-(4-isopropyl-2/3-hydroxyphenyl)-1-methyl-1-carbamoyl urea (IV), N-dimethyl-N-methyl urea (V), N-dimethyl-N-dimethyl urea (VI). The products were mainly formed through demethylation, ring oxidation and rearrangement. Thus, sunlight induced photodegradation may contribute in the dissipation of isoproturon in soil minimising the load of environmental hazards.

Effect of three herbicides namely 2,4-D, metsulfuron-methyl and glyphosate was evaluated on fish mortality and water quality in relation to control of aquatic form of alligator weed (Alternanthera philoxeroides; Family, Amaranthaceae). All herbicides caused fish mortality and affected water quality after application, but it was highest in 2,4-D treated tanks followed by glyphosate and metsulfuron-methyl. Herbicide did not cause fish mortality at 1 DAA (days after application) but it caused at 7 DAA and increased corresponding to increase in concentration and days. Fish mortality was recorded lowest in herbicides treated tanks that were having only water but no weeds. Significantly higher fish mortality occurred in 2,4-D treated tanks having weeds. This reflected that fish mortality was more due to decaying of weeds, which decreased dissolved oxygen drastically in the water tanks. Herbicides did not affect fish development because growth and weight of fish was highest in water tanks treated with herbicides having no weeds. All the herbicides significantly decreased pH in treated tanks than control at 0 and 1 DAA, however, it was resumed towards normalisation in due course. The decrease in pH was least in the tanks having weeds and treated with metsulfuron-methyl followed by glyphosate and 2,4-D. Further, decrease in pH was less in water tanks having no weeds than having weeds. All the herbicides significantly decreased the dissolved oxygen (DO) at 0 day in water tanks with and without weeds except metsulfuron-methyl in the tanks having no weeds. Decrease in DO was more prominent in 2,4-D treated tanks followed by glyphosate and metsulfuron-methyl. Dissolved oxygen was least affected in tanks having no weeds.

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Experiment was carried out during Kharif, 2015 at Agricultural College Farm, Bapatla.  Among the herbicides tested, pre-emergence application of atrazine 1.0 kg/ha + post-emergence application of halosulfuron-methyl 90 g/ha registered the lowest density (no./m2) and biomass of weeds (g/ha) and highest weed control efficiency (%) and yield of maize and this was statistically at par with pre-emergence application of pendimethalin 1.5 kg/ha + post-emergence application of halosulfuron-methyl 90 g/ha.

Application of pendimethalin PE 1.0 kg/ha or oxyfluorfen PE 0.1 kg/ha fb pyrithiobac-sodium PoE 75 g/ha at 45 DAS + one inter culturing through mechanical weeder 60 DAS in Bt. cotton recorded significantly lowest total weed density, weed biomass, weed index and weed persistence index while higher WCE, herbicide efficiency index, crop resistance index also higher seed cotton, lint, stalk yield, net returns and B:C ratio.

Field experiment was conducted during Rabi season of 2014-15 and 2015-16 at agricultural research farm of Banaras Hindu University, Varanasi (Uttar Pradesh) to study the bio-efficiency of flurochloridone on narrow and broad-leaved weeds in carrot. Flurochloridone 500, 625 and 750 g/ha, pendimethalin 1000 g/ha and metribuzin 525 g/ha were applied as pre-emergence. Maximum reduction in different weed species biomass was observed with flurochloridone 750 g/ha followed by flurochloridone 625 g/ha. Weed control efficiency was highest with flurochloridone at 750 g/ha for all the weed species. Carrot yield was maximum with two hand weeded treatment (31.14 t/ha) and was comparable to flurochloridone 750 g/ha and flurochloridone 625 kg/ha.

A number of phytopathogenic fungi are known to be associated with horse purslane. Three new fungal pathogens have been found to be associated with horse purslane, which may be used for the preparation of mycoherbicide. There may be possibility to prepare cultural blends with suitable adjuvants. One of the fungal pathogen, Gibbago trianthema, has shown the potential to be used as successful biological control agent. New phytopathogenic fungal genera reported during this study, can be further exploited for the biological control of horse purslane.

Agricultural system in India is an amalgamation of various sub-systems where information need is very critical at various stages starting from input supply and production till finally reaching to consumer doorsteps. The farming system faces a plethora of problems including weed management and to solve these problems, Weed Manager – a mobile App can provide real time weed management information to farmers and other agriculture stakeholders to improve decision making ability to manage weeds to increase their production and productivity.

Presence of air microbes such as bacteria is reported to be associated with a number of illnesses. Chemical based cleaning products and fumigants available in the market have their limitations and sometimes pose severe ill effects on health of mankind.  In order to explore the potential of weeds as bio-fumigant to reduce microflora in indoors, experiments were conducted with the fumes of three weeds namely purple fleabean Vernonia cinerea (Compositae), coat buttons Tridax procumbens (Asteraceae), Lantana camara (Verbenaceae) and oleo-gum resin of guggul  Commiphora wightii (Burseraceae), an important ingredient of Yajnya ‘Havan samigri’ (composition of different herbal ingredients). The study revealed significant reduction in bacterial colonies (cfu/15 m) after fumigation in Petri-plates exposed to the air. Per cent reduction of bacterial count over control (before fumigation) was recorded as 79.7, 83.7, 67.3 and 82.3% and 76.7, 80.7, 61.0 and 77.3% by V. cinerea, T. procumbens, L.camara and C. wightii after 24 and 48 hours, respectively. The findings of the present study highlights that these weeds can be utilized as an ingredient in preparation of herbal fumigants for cleaning the indoors.