A field experiment was conducted during the Kharif season of 2006 and 2007 at G.B. Pant University of Agriculture and Technology, Pantnagar to find out the most effective weed control method under different sowing dates in direct-seeded unpuddled rice. Highest grain yield (2.5-2.7 t/ha) was recorded from 20 June sowing. The grain yield was the highest in mechanical weedings at 20 and 40 DAS. Pendimethalin 1.0 kg/ha + anilophos 0.4 kg/ha (pre-emergence) produced significantly higher grain yield (3.1-3.3 t/ha) over rest of the herbicidal treatments. Uncontrolled weeds reduced the grain yield of rice by 67-70%.

Efficacy of pyrazosulfuron-ethyl against weeds in transplanted rice was studied during 2008 and 2009 at Regional Research Sub-station, Chakdaha under Bidhan Chandra Krishi Viswavidyalaya, West Bengal. The experiment was laid out in randomized block design with seven treatments replicated thrice. The major associated weeds were: Echinochloa colona, Cyperus difformis, Ammania baccifera, Ludwigia octovalvis and Monochoria vaginalis. Pyrazosulfuron-ethyl at 42.0 g/ha applied at 3 DAT was most effective in managing associated weed species and yielded maximum grain yield (3.3 t/ha) of rice with lower weed index (10.8%).

A field experiment was conducted at Ludhiana during 2009-10 and 2010-11, study the effect of sowing methods and herbicides on weed dynamics and productivity of wheat (Triticum aestivum L.). Sowing methods, viz. bed planting, zero till, conventional till and stubbled sowing did not influence densities and dry matter accumulation of narrow- and broad-leaved weeds. Averaged over two seasons, bed planting, zero till and conventional till sowing methods recorded similar wheat grain yield and were statistically superior to stubbed sowing. Wheat grain yield under bed planting, zero till and conventional till methods was 25.4, 46.2 and 40.8% higher as compared to stubbled sowing. Among weed control, post-emergence application of carfentrazone + sulfosulfuron 45 g, metsulfuron + sulfosulfuron 30 g and fenoxaprop-p-ethyl + metribuzin 275 g/ha recorded complete control of all the narrow- and broad-leaved weeds. Mesosulfuron + iodosulfuron 12 g, sulfosulfuron 25 g, pinoxaden 50 g and clodinafop 60 g/ha recorded effective control of narrow-leaved weeds only. All these herbicidal treatments, except fenoxaprop-p-ethyl + metribuzin 275 g/ha, recorded significantly higher wheat grain yield as compared to unsprayed control. Fenoxaprop-p-ethyl + metribuzin was phototoxic to wheat plants and wheat grain yield was at par to weedy check.

In this study, response of 20 Phalaris minor Retz. (little seed canary grass) populations against sulfosulfuron and its ready–mix formulation sulfosulfuron + metsulfuron and mesosulfuron + iodosulfuron was studied. Out of 20 populations, 12  showed high resistance, 8 showed  medium resitance and none were susceptible to sulfosulfuron (25 g/ha). GR50 value was in the range of 30-110 g/ha in P. minor populations  tested. In wheat, it was more than 200 g/ha. Eleven populations showed resistance to ready mix formulation of sulfosulfuron + metsulfuron, 8 populations  were medium R/medium S and one population was susceptible. Similarly, 11 showed resistance to ready mix formulation of mesosulfuron +  iodosulfuron, 7 populations  were medium R/medium S and one biotype was susceptible. GR50 values tested were in the range of 30-110 g/ha in contrast to 5 g/ha at the time of recommendation.

A field experiment was conducted during 2010-11 and 2011-12 to evaluate the efficacy of pinoxaden alone and in combination with other herbicides against complex weed flora in wheat. Pinoxaden 50 g/ha alone and as tank mixture with and before metsulfuron-methyl 4 g/ha, carfentrazone-ethyl 20 g/ha and 2,4-D 500 g/ha was compared to isoproturon + 2,4-D, clodinafop fb 2,4-D, weed free and weedy check for weed control and grain yield. Phalaris minor and Anagallis arvensis were the major weeds constituting 59.1 and 20.8% of the total weed population during 2010-11 and 67.6 and 16.9% during 2011-12, respectively. Avena ludovician, Lolium temulentum, Poa annua and Vicia sativa were the other important weeds found in association with wheat. Weeds reduced grain yield of wheat by 39.5%. Pinoxaden + metsulfuron-methyl (50 + 4 g/ha) and pinoxaden fb metsulfuron-methyl (50 fb 4 g/ha) were comparable to weed free treatment in reducing the density of Phalaris minor and Anagallis arvensis. Pinoxaden alone was not effective against broad-leaved weeds, while carfentrazone, metsulfuron-methyl and 2,4-D were not effective against grasses. Combined application of pinoxaden with metsulfuron-methyl/carfentrazone (as tank mixed or as followed by) resulted in significantly lower total weed density and weed biomass. Combined application of pinoxaden with metsulfuron-methyl, carfentrazone and 2,4-D resulted in significantly higher tillers, grains/spike and 1000-seed weight and grain yield as comparable to in weed free.

A field experiment was conducted at Research Farm of MPUAT, Udaipur for two consecutive years during 2008-09 and 2009-10 to evaluate the efficacy of different doses of quizalofop-ethyl as post-emergences (at 4-6 leaf stage of weeds) in blackgram and residual effect thereof on succeeding Rabi crops (wheat, gram and mustard). The experiment comprising five weed control treatments, viz. quizalofop-ethyl at 37.5 and 50 g/ha as post-emergence, pendimethalin 750 g/ha as pre-emergence, farmers practice of two hand weedings at 20 and 35 days after sowing (DAS) and weedy check, was conducted in randomized block design with four replications. To study phytotoxicity, quizalofop-ethyl 100 g/ha was also included in addition to above treatments. In the experimental field, more than 50% weeds were dominated by Echinochloa spp. Results revealed that among the herbicidal treatments, quizalofop-ethyl 50 g/ha recorded the lowest narrow-leaved weed density and dry weight at 30 DAS and at harvest during both the years. Quizalofop-ethyl irrespective of its doses was not effective against broad-leaved weeds. The weed control efficiency of quizalofop-ethyl 50 g/ha was 81.3% than the highest (85.6%) under two hand weedings against grassy weeds at harvest. Number of branches and pods/plant, seeds/pod and grain and stover yields of blackgram were also superior in plots treated with quizalofop-ethyl 50 g/ha or two HW. Quizalofop-ethyl was found safe to blackgram, and did not cause any residual toxicity to succeeding crops.

A field experiment was conducted to find out the most effective control measure for weeds in sesame (Sesamum indicun L.) under rainfed condition. Result showed that two hand weeding (weed free) recorded lowest weed population and dry weight which was significantly superior over rest of the treatments. Application of quizalofop-ethy l0.05 kg/ha + 1 HW proved most effective and also recorded lower population and dry weight of weeds followed by trifluralin 0.75 kg/ha + 1 HW and  pendimethalin  0.75 kg/ha + 1 HW. Weed control efficiency and seed yield was higher under quizalofop-ethyl 0.05 kg/ha + 1 hand weeding as compared to other weed control treatments.

Experiments were conducted to standardize duration and level of senescence required to enhance translocation of glyphosate in Cyperus rotundus. Senescence was induced by paraquat (500 g/ha) or glyphosate (1.312 kg/ha). Decrease in total chlorophyll and membrane damage was more in herbicide treatments than ethephon. Periodic leaf RWC remained unchanged in control but decreased periodically in ethephon and paraquat. Significantly higher RWC was observed at 72 h in glyphosate than paraquat. Maintenance of membrane integrity and high RWC in glyphosate at 72 h than paraquat facilitated mobility of glyphosate. Total biomass reduction bioassay indicated that senescence induced by glyphosate (1.312 kg/ha) pre-treatment 48 hr followed by (fb) glyphosate (1.312 kg/ha) showed significantly more  efficacy (7%)  than pre-treatment with benzyl adenine  (synthetic cytokinin) fb glyphosate which reduced  efficacy by 9% compared to glyphosate alone.

Study on adsorption of oxadiargyl and butachlor was carried out on soil particle size separates of four type of soils from different agroclimatic zones of Andhra Pradesh using batch equilibration technique. Irrespective of the particle size, the per cent adsorption was more in vertisols than alfisols. Among four soils studied, maximum adsorption (59.7 µg/g) was observed in 0.05 mm soil separate of vertisol-2, whereas minimum adsorption of 4.5 µg/g was observed in 2 mm soil of alfisol-1. The amount adsorbed increased with increase in initial concentration and reached a plateau. The isotherms were mainly parabolic in nature with ‘S’ shaped tendency. The S-shape reflected the initial resistance to the adsorption of herbicides, to overcome later by the cooperative effect of adsorbed molecules. Soil low to medium in organic carbon, has a tendency to give S-shaped isotherms on account of their hydrophilic nature as compared to soil high in organic carbon which tend to be hydrophobic. The adsorption maxima was positively and significantly correlated with organic carbon content. Freundlich ‘Kf’ values which indicate the extent of binding of herbicide to the soil constituents were positively and significantly correlated with organic carbon, clay content and clay + organic carbon.

Concentration of heavy metals like Cd, Pb, Ni, Co, Zn, Mn and Fe were tested in medicinal weeds growing at heavy metal contaminated site around Jabalpur during winter season of 2008. Except Vicia  sativa, higher concentration of Cd was observed in weeds like Sonchus arvensis (3.07 µg/g), Alternanthera viridis (1.56 µg/g), Anagalis arvensis (1.5 µg/g), Melilotus indica (1.30 µg/g), Eclipta alba (1.14 µg/g), Chenopodium album (1.15 µg/g), Cichorium intybus (1.05 µg/g), Lathyrus sativa (0.77 µg/g). Copper concentrations in plant was higher than prescribed standard limit, viz. Amaranthus viridis (46 µg/g), Ageratum conyzoides (22 µg/g), Polygonum persicaria (37 µg/g), Commelina communis   (30 µg/g), Alternanthera sessilis (22 µg/g), Solanum nigrum (22 µg/g) and Ipomoea aquatica (21 µg/g) . Ni and Zn contents exceeded the permissible limit in shoots of Polygonum persicaria (19,265 µg/g), Commelina communis (17,192 µg/g), Alternanthera sessilis (14,216 µg/g), Amaranthus viridis (17,488 µg/g), Ipomoea aquatic (15,238 µg/g), Heliotropicum indicum (16,89 µg/g), Ageratum conyzoides (15,127 µg/g),  Blumea lacera (3,218 µg/g), Solanum nigrum (16, 191 µg/g), Convolvulus arvensis ( 15,125 µg/g) and Cyperus iria (15,177 µg/g) respectively. Calotropis procera (21 µg/g) exhibited higher Pb concentration exceeding prescribed standard limit. Conversely, Co content was found within prescribed limit in Melilotus indica, Lathyrus sativa, Heliotropicum indicum, Cyperus iria, Convolvulus arvensis, Blumea lacera, Pb below standard limit in Hyptis suaveolens, Cichorium intybus, Lantana camara and Datura stramonium, and no Pb was detected in Alternanthera sessilis, Abutilon indicum, Xanthium strumarium, Anagalis arvensis.  

A field experiment was conducted at BCKV, Mohanpur during the pre-Kharif season of 2010 and 2011 to observe the weed smothering ability of different crops and also to evaluate the bio-herbicidal potential of plant extracts on weeds. The study revealed that among the crops, significantly lowest population of different categories of weeds were found under black gram while highest population was recorded under sesame. Among the weed management practices, hand weeding at 20 DAS resulted in lowest population of all categories of weeds at 30 DAS. Among the botanical plant extracts, Ageratum conyzoides extract 5% (w/v) recorded lowest sedge and broad-leaved weed population while lowest grassy weed population was recorded under Ocimum sanctum extract 5% (w/v). The highest weed control efficiency was recorded under hand weeding treatment followed by fenoxaprop-p-ethyl while among the botanical plant extract, Ageratum conyzoides recorded the highest.

A field experiment was conducted at the research farm of the General Company for industrial crops in the province of Tikrit (Dhuluiya), Iraq to evaluate chemical herbicides, viz. fluazifop-butyl, glyphosate, paraquat and Chevalier in sugarcane variety ‘QD12’. Results showed that use of paraquat helped in controlling weeds to the extent of 86.8% over weedy check. As a result, weed density was very less and reduction in dry weight of green weeds was up to 87.7%. The number of canes increased by 20.5%, green leaves by 56% and leaf area by 45%, which was reflected in the highest increase in cane yield (44.9%). Cane length and diameter were not significantly affected by herbicide application.

A field experiment was carried out at weed science research center, MKV, Parbhani during 2011 and 2012 to evaluate the performance of post emergence herbicides for weed control in soybean  showed that Grain yield as well as straw yield was highest with 2 Hand weeding and hoeing treatments, which was on par with T4 and T1 and significantly higher than rest of the treatments during both the years of experimentation. Two hand weedings at 20 and 40 DAS significantly reduced weed density and dry weed weight at 30 DAS and 60 DAS respectively over weedy check, and was at par with imazethapyr + imazimox 30 g/ha and imazethapyr 0.1 kg/ha as PoE at 20 DAS.

A field experiment was conducted during rainy season of 2009-10 at Research Farm, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur to study the bio-efficacy of post-emergence herbicides on weeds in soybean. Early post-emergence applications of imazethapyr with adjuvant and ammonium sulphate (100 g + 750 ml + 1 kg/ha) was most effective in paralyzing the weed growth and producing significantly higher yield attributing characters and seed yield (2.6 t/ha). The same treatment recorded the maximum net monetary returns ( 39,109/ha) and B:C ratio (3.20). The minimum seed yield (1.3 t/ha) was recorded under weedy check.

A study was undertaken at AICRP (VC), MPKV., Rahuri during Kharif  season of 2011 using different herbicides and their time of application. It was found that the maximum weed control efficiency (87%) was recorded in oxyfluorfen  (425 ml/ha) application before planting and second application at 15 days after transplanting.  For controlling weed flora in Kharif  onion, the oxyflourfen  (625 ml/ha) at 15 days after transplanting and one hand weeding at 45 days after transplanting was found effective followed by oxyflourfen (425 ml/ha) application before planting and second application at 15 days after transplanting.

The experiment was conducted at Annamalai University, Tamilnadu, India to study the possibility of interaction between botanical herbicide Coleus amboinicus/aromaticus with insect agents Neochetina eichhorniae/bruchi. Single control options was found inefficient for managing the worlds worst aquatic weed water hyacinth. The integrated approach of releasing the insect agents Neochetina spp. onto the weed and spraying the aqueous extract of leaf powder of Coleus spp. showed synergistic interaction in reducing the fresh weight and chlorophyll content of water hyacinth. Among the three inoculation loads of insect agents,viz. three, two and one insects/plant, three/plant followed by spraying the extract of Coleus spp. leaf powder at 25% proved significantly superior in reducing the fresh weight and chlorophyll content to on 60 and 50 days after releasing the insects, respectively. Among the different interludes or time lag compared for evolving a standardized method of integrating foliar spray of leaf powder extract, viz. 10, 20 and 30 days, 10 days performed superior by achieving fresh weight and chlorophyll content reduction and least weed nutrient content of water hyacinth. No insect mortality was observed in any of the treatments.

A field experiment was conducted at Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal, Puducherry to evaluate the efficacy of different weed management practices in managing weeds of aerobic rice in the coastal areas of Karaikal. The     experiment involved eleven weed management treatments laid out in randomized block design with three replications. Treatments included: four pre-emergence (pendimethalin 0.75 kg/ha, pretilachlor + safener 0.50 kg/ha, Butachlor 1.00 kg/ha and  anilophos 0.40 kg/ha) and three early post-emergence herbicides (cyhalofop 0.10 kg/ha, pyrazosulfuron ethyl 0.20 kg/ha, metamifop 0.075 kg/ha, metamifop 0.100 kg/ha) followed by one hand hoeing at 40 DAS. Aerobic rice under these treatments was compared with transplanted rice given two hand weeding at 20 and 40 days after transplanting. The predominant weed flora observed in the experimental field were Echinochloa colona, Cynodon dactylon, Panicum repens, Cyperus rotundus, Trianthema portulacastrum, Cleome viscosa, Aeschynomene indica and Eclipta alba. Herbicides tested were effective in reducing the weed density and biomass and increasing the rice grain yield significantly. Pre-emergence application of pendimethalin  0.75 kg/ha + HH at 40 DAS recorded significantly higher grain and straw yields with  lower weed density, weed biomass  and higher weed control efficiency.