Journal of Research in Weed Science

Abstract Weeds are responsible for heavy yield losses in rice, to the extent of complete crop failure under severe infestation conditions. They occur in every field of rice (Oryza sativa) in the world which is the vital food for more than two billion people in Asia. A systematic field study was conducted in paddy field of Devarapalli Mandal, West Godavari District, Andhra Pradesh, India. Infested weeds were collected in paddy field crops for plants identification, observation, and collection. The random quadrant method was adopted for this study. The collected diseased weed plants were carried out for the extensive study on symptoms, isolation and pathogenicity of the organisms that involved in leaf spot diseases. The causal agents of diseased weed plants were isolated. The inoculated fungal pathogens are incubated on PDA for pure cultures. After harvesting of spores they were observed under the microscope. The study is used to know host specificity of isolated fungal pathogens on test plants and also used to identify bio control agents for crop development. Investigator hopes that diseased weeds of rice fields in study area provide good source of information of technical and taxonomic data to the academic institutes and research organizations like Agricultural colleges, Universities, Agricultural Universities and other agricultural agencies

Abstract An experiment was conducted in IAAS, Lamjung research field in 2017 in spring Maize with split plot design to evaluate the effect of weed management practice and tillage system on productivity of spring maize. In tillage system, no-till and conventional tillage were kept as main factor whereas seven weed management practices (viz. sequential application of atrazine at 0.75 kg a.i. ha-1 and 2,4-D at 1.5 kg ha-1; pre-emergence tank mix application of atrazine at 0.75 kg ha-1 and glyphosate at 2.5ml lit-1 of water; pre-emergence tank mix application of atrazine at 0.75 kg ha-1 and pendimethalin at 2ml lit-1 of water; cowpea co-culture; black polythene mulch with control treatment weed free and weedy check as sub-plot. Tillage method had not significant effect on the weed dry matter accumulation in different stages. However, weed dry matter accumulation was varied with different weed management practices. The weed check plot was of highest dry matter accumulation (273.38g m-2, 361.95 g m-2 and 235.95 g m-2 in three different stages (30, 60 and 90 DAS respectively). The highest grain, straw yield and yield attributes was found in plastic mulch plot and no-till system with less severe to weed infestation and index which is statically at par with intercropping with cowpea. Though none of weed management practices completely eliminated weeds, black polythene mulching resulted in best grain yield. Besides the environmental protection, cowpea co-culture treatments yielded almost similar grain yield as compared with common herbicidal weed management practices.

Abstract The study of citrus weeds in the Skikda region during the 2017/2018 crop year included 40 phytoecological surveys of different crops. They were distributed throughout the study area in order to take into account the variability of ecological and Agronomic factors. The results obtained by the Correspondence Factor Analysis (CFA) highlight two groups of surveys including two groups of species. These results explain the distribution of citrus weeds in the Skikda region according to climate and edaphic conditions. The appearance of weed species was selective, for example, Oxalis Latifolia. Kunt. is a very common and abundant species in the more or less humid northern zone, whereas it is almost absent in the southern zone of the study area. On the other hand, Papaver rhoeas. was frequent and abundant in the southern zone, which is a somewhat dry zone, was almost absent in the northern zone.

Abstract A two-year (2017 and 2018) field trials was conducted in the School of Agriculture, Njala University, Sierra Leone, to evaluate weed management practices on weed dynamics and productivity of maize. The experimental trials were laid out in a randomized complete block design (RCBD) with three replications. The treatment combinations comprised of weedy check (Control), two hoe weeding at 4 and 8 weeks after planting (WAP), Double force^® at 4 L ha^-1 plus one hoe weeding at 8 WAP, Gliricidia sepium leaves mulch at 40 kg m^-2 plus one hoe weeding at 8 WAP, weed-free check and Atrazine 500 SC at 3 L ha^-1 plus one hoe weeding at 8 WAP. The results showed that growth and yield physiognomies differ significantly (P<0.05) among weed control practices across both years. The weed-free check treatment recorded the highest growth and yield physiognomies with respect to reduced weed density and increased weed control efficiency followed by herbicidal treatments, while weedy check had the lowest growth and yield attributes across both years. Nonetheless weed-free check required lot of labour force which was not economical to the farmer’s point of judgment. Thus, Double force^® at 4 L ha^-1 plus one hoe weeding at 8 WAP proved to be better in controlling weeds, increasing crop yield and economical compared with other weed management practices. Hence Double force^® at 4 L ha^-1 plus one hoe weeding at 8 WAP was recommended as a pre-emergence herbicide in maize production for effective and environmentally friendly weed control method.

Abstract To evaluate most economical and efficient weed management practices in dry direct seeded rice, a field experiment was conducted at research block of AFU Rampur, Chitwan during the Kharif 2016 season. The treatments consisted of two establishment practices viz., zero till and conventional tillage and eight weed management practices such as weedy check, weed free, Pendimethalin followed by hand weeding at 20 DAS 1 kg a.i ha^-1, Pendimethalin followed by 2, 4-D ethyl ester at  25 DAS 1 kg a.i ha^-1, pendimethalin followed by bispyribac-Na at 25 DAS at 25 g a.i ha^-1, pendimethalin followed by ethoxysulfuron at 25 DAS 25 g a.i ha-¹, pendimethalin followed by penoxsulam at 25 DAS 25 g a.i ha^-1, pendimethalin followed by (ethoxysulfuron + bispyribac-Na. The experiment was conducted in split plot design with three replications. The result of experiment showed that non-significant difference was notice among the establishment method. However, significant difference was observed in weed management practices in all the traits expect number of weeds m^-2, number of weed species m^-2, and dry weight of broad leaf, narrow leaf and sedges weeds. The higher number of weeds m^-2 was found in weedy check plot which resulted in higher weed infestation at all the stages as compared to other weed management practices. Application of pendimethalin followed by hand weeding at 20 DAS recorded higher weed control efficiency which reflected in higher yield of 4202 kg ha^-1 was recorded under this treatment as compared to weedy check plot (1292.13 kg ha^-1) but rest of the treatments are statistically at par with other weed management practices.

Abstract The aim of the present work is to evaluate the herbicidal activity allelopathic extracts of sorghum plants (Sorghum bicolor L.) on wheat and accompanied weeds namely wild oat and canary grass under local conditions in Egypt. The biocidal activity of the aqueous and methanolic extracts of sorghum was compared with two of the most common herbicides used on wheat i.e. diclofop-methyl and clodinafop-propargyl. Application of the tested materials was carried out by using three concentrations of sorghum extracts (5, 10 and 20%) and the recommended dose of each diclofop-methyl (750 ml/fed) and clodinafop-propargyl (140 gm/fed) under laboratory, green house and semi field conditions. The herbicidal and phytotoxic effects of both biochemical agents and conventional herbicides were carried out by measuring germination percentage, seedling shoots and root length, dry weight, chlorophyll content, plant height, plant numbers, spike length and spike weight of the treated wheat. The obtained results indicated that there is no adverse effect of the tested extracts against the measured parameters of productivity and yield of wheat. At the same time promising herbicidal activity of aqueous and methanolic extracts of sorghum was revealed against wild oat and canary grass in particular with aqueous extract of sorghum at concentration of 20%.

Abstract Compare other countries studies associated with field bindweed (Convolvulus arvensis L.) biological control is too short in Iran. Field bindweed is a major weed of several field crops. During a survey, we focus to finding natural enemies of this weed in Khorasan Razavi province for two years. This paper reports the presence of a seed beetle Spermophagus sericeus Geoffroy as a major natural enemy against field bindweed (Convolvulus arvensis L.) in northeast of Iran. Samples of field bindweeds capsules and seeds collected in tomato fields at two locations in that region. Results showed that the reproductive organs of field bindweed were severely damaged, where 76 and 62 percent of capsules and seeds were infested by S. sericeus respectively. Our findings showed the high level control of field bindweed by S. sericeus and this beetle can be considered as a proper bio control agent for this weed in Iran. However more studies about host specificity of this beetle should be performed.

Abstract In Southern Groundnut Basin of Senegal, weed management is one of the biggest challenges for improving upland rice production. This study aimed to evaluate the systematic composition and the infestation of weed species in order to promote a sustainable management in a context of biodiversity decreasing. Thus, phytosociological surveys were carried out during rainy season in upland rice fields. The results revealed that flora consisted of 62 species distributed in 47 genera and 15 families. The families with the highest species richness were Poaceae (24.2%), Fabaceae (12.9%) and Malvaceae (12.9%) which account for half of recorded species. Biological spectrum analysis showed that the flora is largely dominated by therophytes, with 95% of recorded species. Infestation diagram based on weeds abundance and frequency showed eight groups of species reflecting their degree of infestation. Among them, Digitaria horizontalis, Mariscus squarrosus, and Spermacoce stachydea belonged to major weeds and potential general weeds were potentially the most injurious against upland rice because of their high recovery and frequency.

Abstract The experiment was carried out at Umulolo in Okigwe Imo State in 2016 and 2017 seasons. The experiment was laid in randomized complete block design, replicated three times. The treatments were mulching materials (two synthetic materials-polythene sheet, trampoline sheet) while natural or organic materials were 6/ha sawdust and grasses and control treatment (no mulching). Result showed significant difference in all the weed infestation parameters, vegetative growth and yield parameters assessed. In both cropping seasons, the control had significant higher weed density and biomass. Garden egg fruit yield as influenced by different mulching materials was also significantly different (p<0.05) in both cropping seasons. The highest fruit yield; 22.27 and 23.63 t/ha in 2016 and 2017, respectively was from the plot mulched with sawdust. The grasses mulched plot had 21.19 and 22.17 t/ha fruit yield, respectively. The trampoline plot produced 18.77 and 17.18 t/ha fruit, respectively. The least fruit yield was 5.43 and 6.54 t/ha in both cropping seasons in control treatment. The result showed that the plot mulched with sawdust had 7-76% and 6-72% greater fruit yield compared to the other mulching materials in both cropping seasons. The result of indicated that application of grasses and sawdust were more cost effective in weed management and higher economic returns to management compared to trampoline and polythene sheets. Farmers in the study area were advised to mulch their garden egg field during off-season with sawdust. The application of sawdust would reduce weed infestation and also enhances high fruit yield.

Abstract A field study was carried out to evaluate the efficacy of Prioxofop-Propanyl 15% WP (Markclodina) herbicide for wider weeds range in wheat crop during Rabi 2015-16. Six treatments including four herbicides treatments viz. Pendimethalin at 1.0 kg/ha, Clodinafop at 0.060 kg/ha, Markclodina at 0.060 kg/ha, Isoproturon + 2, 4-D at 1.0+0.5 kg/ha along with hand weeding twice (30 and 60 DAS) and one weedy check were used. Avena ludoviciana (34.30 %) and Phlaris minor (25.26 %) were the most dominatinggrassy weeds. New test herbicide Markclodino had better efficacy in controlling Phalaris minor, Avena fatua and Lolium temulentumas evidencedfrom significantly less number of weeds at all the stages of observations. The highest weed control efficiency (80.5 %) was recorded with post emergence application of Markclodina 0.060 kg/ha at 90 DAS. The application of markclodina at 0.06 kg/ha remaining at par with clodinofop propargyl (market sample) at 0.06 kg/ha, isoproturon + 2,4-D at 1.0 + 0.5 kg/ha produced significantly higher grain yield. The magnitude of increase in yield due to Markclodina over weedy check was 68.9 %. Field demonstrations on the performance of Markclodina under various locations showd that there was maximum 19.7 % increase in grain yield over control at distt. Hamirpur (Himachal Pradesh).

Abstract A field experiment was conducted to assess the growth, yield and profitability of wheat under different herbicides application in Kapilvastu and Rupandehi district, Nepal during winter season of 2018. The experiment was laid out in Randomized Complete Block Design (RCBD) with four treatments and five replications. The four treatments comprised of Pendimethalin 30 EC at 3.3 l ha^-1 as a pre emergence herbicide, sulfosulfuron 75 WG at 33.3 g ha^-1 as post emergence, pendimethalin 30 EC at 3.3 l ha^-1 followed by sulfosulfuron 75 WG at 33.3 g ha^-1 and weedy check (control treatment). Results revealed that application of pendimethalin 30 EC at 3.3 l ha^-1 followed by sulfosulfuron 75 WG at 33.3 g ha^-1 significantly reduced the weed population and produced higher wheat grain yield (4487 kg ha^-1). Economic analysis of different herbicides application also showed the highest net returns (NPR. 50,940 ha^-1) for application of pendimethalin followed by sulfosulfuron treatments. Among the tested herbicides, both pendimethalin and sulfosulfuron were found effective to weed management and profitable over weedy check.

Abstract Application of crop residues can be a good option for organic and sustainable weed management in rice. Consequently, the use of crop residues can suppress weed emergence and weed biomass. A study was conducted in two consecutive seasons firstly to optimize the mixture ratio to soil (v/v) of different crop residues on inhibition of common weed species and secondly to evaluate their performance on rice growth and yield. Among the crop residues used in this study sorghum was the most effective followed by mustard, barley, soybean, rice, wheat, triticale, maize, lentil and grasspea. The 50:50 (crop: soil, v/v) treatments incorporation rate of all crop residues suppressed the growth of all weed species in maximum level. The result revealed that broadleaf weed species were more susceptible to crop residues than grass weed species. In this respect, the highest growth inhibition (54.49%) was observed in controlling Monochoria vaginalis. Variety and rate of sorghum residues application significantly influenced weed growth and inhibition. A maximum increment in terms of plant height, dry weight and yield was observed due to sorghum 2.0 t ha^-1 residue applications. Considering yield and yield contributing characters, highest grain and straw yield was obtained from BRRI dhan29. All together, the result depicted that crop residues can effectively control weed along with enhancing growth and yield of rice and it can be successfully used in weed management program in rice.

Abstract This study was carried out to determine the impact of three-year crop rotation in sampling fields on winter wild oat (Avena sterilis L.) populations in Osmaniye wheat sown areas. The study was conducted in Osmaniye province between the years 2013-2015. A total of 103 fields in 7 districts’ wheat sown areas were determined; these sampling fields were visited every year during May-August and effects of different crops sown on winter wild oat populations were observed. Besides determining frequency of occurrence, randomly chosen general coverage in 1 decare and special coverage in 1 m2 in three points were specified. As a result of the study, it was determined that all of the crops except wheat decreased winter wild oat populations and it was found that the changes were related to the crop rotations. It was determined that corn, sunflower, soybean and peanut sown in 2nd and 3rd year instead of wheat decreased the frequency of winter wild oat at 2% and below. Moreover, when the three-year crop rotation system was analyzed, it was revealed that the maximum decrease in winter wild oat population general coverage occurred in 4 crop rotation period. It can be found that populations decrease can be up to more than 90% when compared to 2 and 3 crop rotation systems. It was concluded that crop rotations are sufficient in controlling winter wild oat that are problematic in wheat fields.

Abstract Parthenium hysterophorus L. is a notorious weed, which significantly reduce yield and quality of crops and causes several problems to human health. In, present study an attempt was made to understand the economic value, and survival nature of Parthenium through deep transcriptome analysis. Transcriptome analysis of leaf and root tissue of P. hysterophorus had resulted 7,832,143 reads in case of leaves, and 9,646,830 reads in case of roots sample with longest read length of 300 and 298 nucleotides, respectively. A total of 35,719 contigs were produced with an average length of 548bp after an assembly in all two samples. The Blastn of the above generated contigs with 61,901 sequences of P. argentatum resulted in the identification of 25,947 novel contigs specific to P. hysterophorus. The Kyoto Encyclopedia of Genes and Genomes pathway based analysis showed the expression of genes associated with pathways pertaining to biosynthesis of Glucosinolate, Amino acids, and Aminobenzoate degradation etc. The expression pattern of genes like Artemisinic aldehyde Delta (11(13)) reductase, Codeine O-demethylase, Taraxerol synthase, and Curculin-2 related to biosynthetic of therapeutic importance pathways was also evidenced. Further, the heavy metal accumulator property of P. hysterophorus was also studied. Expression analysis of heavy metal transporters such as ferrous ion transport protein B, and zinc transporter in roots was also validated with its heavy metal transport activity. This investigation provides new insights for functional studies of P. hysterophorus genes involved in biosynthesis of therapeutically important secondary metabolites, and other possible uses such as raw material for rubber industry.

Abstract The survey was conducted in the farmers’ field of Durba Chara village of Gauripur upazilla under Mymensingh district to find out the floristic composition of weeds in three crops i.e. summer rice, potato and winter rice under T. aman-potato-boro cropping pattern. Five farmers’ fields were surveyed by using a quadrat of 0.5m × 0.5m size in four spots from each field randomly. The data were summarized using frequency, field uniformity, mean field density and relative abundance. A total of 27 weed species belonging to 11 families were found in T. aman, potato and boro rice, of which 22 species were under 11 families in T. aman, 15 species under seven families in potato and 20 species were under nine families in boro rice. Echinochloa crusgalli was the most abundant weed in both potato and boro rice while in T. aman, Ludwigia hyssopifolia dominated over others. Echinochloa crusgalli and Polygonum hydropiper were common in both potato and boro rice. The other three dominant weed species i.e. Cyperus rotundus, Cynodon dactylon and Panicum distichum in potato and Eclipta alba, Cyperus difformis, Eleocharis atroperpurea in boro were completely different from each other. In T. aman, five completely different weed species i.e. Ludwigia hyssopifolia, Alternanthera sessilis, Polygonum orientale, Fimbristylis miliaceae and Hedyotis corymbosa were found dominant. Broadleaf weeds were dominant in both T. aman and boro but in potato, grasses dominated over others.

Abstract Sustainable agriculture requires the use of environmentally friendly management practices. Mulching is one of the most effective methods that can play a positive role in weed management, improving soil properties as well as increasing crop production. A field experiment was conducted at the research farm of National Maize Research Program (NMRP), Rampur, Chitwan, Nepal during winter season, 2016. The experiment was carried out in single factor randomized completely block design comprising of nine weed management methods with four replications. Data regarding the weed population, weed dry weight, yield attributes and yield were recorded during the study. Different weed management practices showed significant differences on weed dynamics and weed control efficiencies. Black polythene mulch and silver black mulch was found more effective to reduce total weed density and dry weight during whole crop season and remain comparable with other polythene mulch too. The effect of weed management practices observed on weed density and dry weight were reflected on grain yield. The highest grain yield was recorded in silver black plastic mulch (4537.50 kg ha^-1) followed by black plastic mulch (4068.20 kg ha^-1), clear plastic mulch (4065.22 kg ha^-1), green plastic mulch (3834.84 kg ha^-1) and weed free (3222.74 kg ha^-1) which were comparable to each other. At tasseling-silking stage among plastic mulch treatment, the higher moisture conservation observed on the black plastic mulch followed by clear plastic mulch, green plastic mulch and silver black plastic mulch. While comparing of plastic mulch with dead mulch, moisture on dead mulch remain higher than plastic mulch after 90 DAS. Thus, in humid subtropical region of western Chitwan, Rampur, the maize can be successfully cultivated by using different color of polythene mulch.

Abstract Weeds are among the most harmful factors limiting sorghum production under Sudanian conditions of southern Senegal. Despite, the taxonomic structure of the flora is relatively well known, few studies have focused on crop-weed competition. Field experiment was carried out to determine the critical time for weed competition in grain sorghum. Ten treatments, weedy for initial 15, 30, 45 and 60 DAS and then weed-free, and weed-free for initial 15, 30, 45 and 60 DAS and then weedy, weed-free and weedy up to harvest were assigned in a randomized block design with four replications. The beginning and the end of critical period of weed competition were determined respectively under fertilized and unfertilized conditions. The results showed that more the weeds competition is longer, more sorghum parameters of growth and yield are reduced. Sorghum yield were significantly influenced by many factors such as year, nitrogenous fertilization and weeding periods. The highest plant height, dry matter, and yield were recorded in weed free treatment followed by weed free up to 60 DAS and weedy up to 15 DAS. Plant height, dry matter and yield decreased significantly with each increase in competition period. Therefore, the lowest growth parameters and yield were noticed in weedy check treatment followed by weedy up to 60 DAS and weed free up to 15 DAS. Moreover, our findings showed that sorghum height, dry matter and grain yield increased significantly under fertilized conditions compared to unfertilized conditions, which is widely used in traditional cropping system. The maximum competition between crop and weed was between 15-45 and 15-55 DAS under unfertilized conditions (F0) and 10-55 and 15-55 DAS under fertilized conditions (F1), which can be considered as critical period of crop-weed competition. The weeding practice should be adopted during these periods for getting optimum sorghum production under Sudanian conditions of Senegal.

Abstract Over centuries, agricultural practices have undergone the transition from extensive and traditional to intensive and specialized. Thus, the weeds colonizing cultivated fields are subjected to major shifts due to increased use of herbicides, fertilizers and tillage. There are a total of 176 weed species in Agro-ecosystems of Himachal Pradesh and not less than 46 in maize. Weeds, in maize, are hardier in nature and compete with the crop significantly reducing its yield. Also, slow initial growth and wider spacing favour the growth of weeds even before crop emergence. Commelina benghalensis, Ageratum conyzoides, Echinochloa colona, Panicum dichotomiflorum, Cyperus iria, Digitaria sanguinalis, Polygonum alatum and Aeschynomene indica were dominant weeds observed under Kangra district conditions of Himachal Pradesh. The phytosociological study showed that the species which invaded the non-cropped lands are increasingly infesting the cultivated fields. In 2008, most abundant weed was Fimbristylis miliacea followed by Cyperus difformis, Eragostis tennela, Ageratum conyzoides, Ammannia baciferra, Bidens pilosa and Hackelia uncinata. In 2018, Ageratum conyzoides was the most abundant followed by Phyllanthus niruri, Panicum dichotomiflorum, and Commelina benghalensis. Ageratum conyzoides was the most important weed in 2008 followed by Echinochloa colona, Fimbristylis miliacea, and Digitaria sanguinalis, in that order. The Important Value Index (IVI) for individual weed species in the maize field crop in 2018 indicated that Ageratum conyzoides was again the most important weed species followed by Phyllanthus niruri, Echinochloa colona, Alternanthera philoxeroides, Aeschynomene indica, Commelina benghalensis and Digitaria sanguinalis. The weed species viz. Ammannia baccifera, Bidens pilosa, Brachiaria ramose, B. reptans, Dactyloctenium aegyptium, Fimbristylis miliaceaum, Galinsoga parviflora, Hackelia uncinata, Ipomoea pestgridis, and Physalis minima those recorded in 2008 were not found in the survey of 2018. Aeschynomene indica, Alternanthera philoxeroides, Amaranthus viridis, Echinochloa crusgalli and Oxalis sp. recorded during 2018 were not found in the survey of 2008.

Abstract Growing two or more cultivars of same crop species in mixture reduces intra-specific competition for natural resources and increases competitive ability of crops against weed growth and thus enhances crop yield. The objective of this study was to evaluate the potentiality of growing rice cultivars in mixtures in temporal dimension for minimizing weed pressure and increasing rice yield and to determine the best time of introduction of one cultivar in relation to another cultivar. The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during aman season (July-December) 2017. Two transplanted aman rice cultivars having different plant height and growth duration viz. Binadhan-13 (tall, late- maturing and fine grained aromatic rice cultivar) and BRRI dhan49 (semi-dwarf, mid-maturing and coarse grained rice cultivar) were used in this study. The experiment comprised time of introduction of BRRI dhan49 namely 7 days before Binadhan-13, 7 days after Binadhan-13, same day as Binadhan-13, Binadhan-13 as sole crop, BRRI dhan49 as sole crop and three different weeding regime namely weedy, recommended weeding and weed free. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Both the cultivars showed better growth and higher yield when grown in mixture rather than sole culture. Transplanting of one cultivar before or after another cultivar produced more yield and suppressed weed better than transplanting of two cultivars on the same day. Thus only spatial arrangement produced no advantages over sole culture. Among the weeding regimes, weedy treatment performed the worst, while recommended weeding and weed free treatment performed similarly. Therefore, for better weed suppression and higher production, BRRI dhan49 may be transplanted 7 days before or after Binadhan-13 in 1:1 ratio following recommended weeding.

Abstract Studies were conducted to ascertain the phytotoxic action of aqueous extracts and rhizospheric soils of wasteland weeds such as Parthenium hysterophorus L., Withania somnifera L., Lantana camara L., and Achyranthes aspera L. against four summer crops viz., Gossypium hirsutum L., Helianthus annuus L., Oryza sativa L. and Zea mays L. Experiment was carried out in Agronomy Laboratory, College of Agriculture, University of Sargodha, Punjab-Pakistan. In first experiment, the 5% (w/v) aqueous extract prepared from whole plant of each weed was applied to germinating crop seeds sown in petri plates. In the second experiment soils collected from rhizosphere of these weeds were filled in plastic pots and used as germination medium for seeds of these crops. A constant temperature of 30^oC was maintained in germinator throughout the germination period of 12 days. In first experiment, significantly lower germination percentages (31.7 and 38.3%) and germination indices (4.4 and 6.4) of crops were noted with application of A. aspera and P. hysterophorus extracts, respectively. All weed extracts except L. camara caused significant reduction in shoot length, root length, seedling length and seedling biomass of crops. Root growth of the crop seedlings was influenced more than their shoot growth. In second experiment, germination percentage, shoot dry weight, seedling biomass and seedling vigor index of crops were significantly inhibited by rhizospheric soil of all weeds. Among crops, H. annuus was more susceptible to the deleterious effect of the aqueous extracts as well as rhizospheric soils of weeds. It can be concluded that wasteland weeds especially P. hysterophorus and A. aspera imparted more negative impact on the germination and seedling growth of test crops. Therefore, crop fields and their surroundings should be kept free from these weeds by clean cultivation.

Abstract A field study was conducted at Dr. Balasdaheb Sawant Konkan Krishi Vidyapeeth, Dapoli (Maharashtra) during Kharif seasons (2011 to 2014) on rice crop to evaluate the effect of green manuring with Sesbania rostrata and different herbicides on complex weed flora in transplanted rice. The experimental field was infested with Ludwigia octovalis, Cloem viscosa, Cyperus iria, Amaranthus sessils, Isachne globosa and Eriocaulon hexangularis. Application of pre-emergence fixed herbicide and pre-emergence and post-emergence rotational herbicides reduced the complex weed flora. Pre-emergence application of pretilachlor-S at the rate of 0.75 kg/ha at 3-7 days after treatment (DAT) recorded the highest weed control efficiency, rice grain yield and net returns during all years is the best ways of controlling complex weed flora and enhancing productivity and profitability from transplanted rice.

Abstract A pot experiment was conducted under field conditions in Al-Qizuina district-province of Najaf during the 2017 growing season in order to pre-planting control of field dodder )Cuscuta campestris( by breaking its seed dormancy and reducing seed banks in the soil. The experiment tested 56 treatments (chemical, biological and physical) in a complete randomized design with four replicates. Results showed significant differences between treatments. Gibberelic acid at 800 ppm resulted in the highest germination rates of the dodder seeds (92%), while KNO₃ had the highest speed of seed germination (7.6 days). Some other concentrations of Gibberellic acid, Salicylic acid, Ethrel and KNO₃, and seed extracts of Maize, Barley and Alfalfa as well as the physical treatment of boiling water had significant effects on the dodder seeds in terms of germination rates which ranged from 19 to 51% and germination speed that ranged from 8.4 to 15.4 days compared to the control treatment which resulted in 0.75% and 20.82 days, respectively. The study confirmed that using high efficient treatments in breaking dormancy and increasing seed germination of dodder as pre-planting measurements can be practically applied in the integrate management of this pest. 

Abstract Forests in Mauritius are facing an alarming rate of encroachment by alien plant species which are changing the ecosystem function, equilibrium and composition of species and richness. Mauritius being a small tropical island is one of the recently colonized areas of the world where only a few descriptions of species composition and diversity exist. Invasive plant species are controlled by mechanical, chemical and biological methods. Efficient herbicide and suitable application methods were assessed for the control of Tabebuia pallida (Tecoma) in a forest area managed by the National Parks and Conservation Services (Mauritius). Effectiveness of herbicides to ringed barks showed Round-up (100 %) to be most effective compared to Triclon (73%) and Tordon 101 (40%). Drastic changes were observed with Roundup, irrespective of the application methods used. Significant differences were found among cut stump, ring barking and drilling application methods. Cut stump method was much more effective compared to the other two treatments. Ring barking also proved to be successful to some extent. Application of herbicides through drilling was ineffective. The use of herbicides was a significant factor in the death rate of the invasive species.

Abstract Weeds are among the most harmful factors limiting crop production in savannah zone of Africa. However, they are crucial for biodiversity and ecosystems sustainable management. A field experiment was conducted in savannah zone of Senegal to determine the effect of organic and mineral fertilization on weed flora in peanut crop. The experiment was laid out in randomize complete block design with four replicates and four treatments (Control, Cattle manure, Compost, and Mineral fertilizer). Our findings show that weed density was not significantly affected by the type of fertilization. However, dry matter of grasses and broadleaf weeds was significantly affected by the treatment respectively in forty and sixty days after treatment. The highest dry weight of grasses was observed in forty days after sowing in cattle manure treatment followed by inorganic fertilizer with respectively 23.7 and 15.2 g/m². In sixty days after sowing, the highest dry matter of broadleaf weeds was recorded in cattle manure treatment with 4.5 g/m². It was noticed that Digitaria horizontalis and Mesosphaerum suaveonlens were the dominant species in all treatment. The biodiversity indices were not significantly influenced by the type of fertilization but the highest values of Shannon-Webber and Simpson indices was recorded in cattle manure treatment. Moreover, the linear correlation between grain yield and diversity indices revealed that Shannon index is highly correlated with the peanut yield.

Abstract Two experiments were carried out to study the efficacy of herbicides with different rates for controlling broadleaf and narrow leaves weeds, growth and yield parameters of onion. The treatments of herbicides applied include the single of active ingredient and their combinations. The single of active ingredient such as Oxyfluorfen at the dose of 270; 180; and 90 g a.i./fed, Clethodim at the dose of 93.75; 62.5; and 31.25 g a.i./fed. The combination used the Oxyfluorfen + Clethodim such as 270+93.75; 180+62.5; and 90+31.25 g a.i./fed. Results showed that Weed control efficiency (WCE) for broadleaves species the maximum percent was recorded for Oxyfluorfen (270 g a.i./fed). In controlling narrow leaves weed species, the maximum percent was recorded in Clethodim (93.75 g a.i./fed). While controlling broadleaf and narrow leaves weeds, the maximum percent was recorded in Oxyfluorfen + Clethodim (270+93.75 g a.i./fed). Growth, and yield parameters as plant height, bulb weight and bulb diameters were recorded maximum in Oxyfluorfen + Clethodim (270+93.75 g a.i./fed) compared to rest for the treatments. We suggest that the best treatment was Oxyfluorfen + Clethodim (270+93.75 g a.i./fed) for controlling all species of weeds in the onion plant.