Journal of Research in Weed Science

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.

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 A field experiment was conducted in pre-monsoon season during 2017 and 2018 at National oil seed research program, Nawalpur, Sarlahi, Nepal, to study the impact of weed management practices in groundnut production. Pendimethalin as pre-emergence, while Metribuzin, Propaquizafop at 100 g per hectare, Quizalofop ethyl at 100 g per hectare, as post emergence was used along with integration with hand weeding and intercultural operation. The result revealed that supplement of the hand weeding after the application of the pre-emergence herbicides pendimethalin was found effective in  reducing  the weed severity and improves the growth and yield attributes and ultimately yielded 2101 kg ha^‑1. This treatment also recorded the highest gross and net return (NRs 168080 and 48470) and benefit cost ratio (1.4) thus, this integrated weed management practice could become effective and economic under southern belt terai agro climatic condition of Nepal.

Abstract Weeds could replace the cultivated fodders in case of fodder shortage. But most of farmers are not aware about the potential of traditional weeds in croplands. Thus, an experiment was conducted to estimate the nutritional quality of some forage weeds with respect to their phonological development. Quantitative and qualitative parameters were recorded and analyzed statistically by analysis of variance technique and means of treatments were compared by least significant difference test. Qualitative traits of selected weeds were determined through the methods developed by The Association of Official Analytical Chemists (AOAC). The results showed that the quantitative traits of weeds differ from each other. It was found that the moisture decreased from vegetative (86.13-90.92%) to post reproductive stage (86.77-73.56%) and crude protein decreased from vegetative (16.95-23.40%) to post reproductive stage (11.52-15.09%) in all weeds. Similarly ash contents decreased from vegetative (13.72-23.40%) to post reproductive stage (9.26-13.11%) in all weeds. The crude fats were nearly similar in all stages (1.75-2.00%). Dry matter and crude fiber increased (9.08-13.87 to 13.23-26.44% and 9.86-21.95 to 21.58-31.63%, respectively) from vegetative to post reproductive stage. Overall results declared that the biomass produced by weeds was a luxurious source for livestock production during the vegetative stage of growth as the nutritional quality decreased from vegetative to post reproductive stages. Further research is needed to explore the forage quality of all common weeds present in croplands.

Abstract The weeds are well accepted source of herbal medicines. However, these plants should be managed and removed from agro ecosystems due to their negative impacts on agricultural production systems. However, it is matter of interest that some of well-known weeds are source of drugs and traditional medicine. The weeds have certain biological phytochemicals viz. alkaloids, flavonoids, phenols, terpenes, and saponins etc. which are used to treat health disorders. The demand and importance of natural occurring herbal drugs is rising globally. This is due to their social contentment, easy accessibility, cheapness, effectiveness and no side effect claims. The use of herbs and weeds is based on empirical treatment and experiences from many generations with info accessible solely in native magazines. These medicines possess numerous biologically active ingredients associated with health disorders. Thus their potential has not been fully explored. There is need to improve the quality and analysis of herbal products to be fabricated with research advancements in their efficacy. This review identifies bioactive or phytochemicals present in different plant parts of weeds and ways to extract them are discussed. In addition, the medicinal beneficial aspects of weed species, their medicinal utility and major concerning issues are also highlighted.

Abstract Most of the people think that weeds are not useful, so they should be eradicated in any case. However weeds have numerous secondary metabolites of medical utility. These secondary metabolites serve as a treatment for many psychological, physical and pharmacological disorders of human body. The essential oils (EOs) extracted from weeds could be utilized as aromatherapy to cure several ailments. This review highlights the role of EOs in aromatherapy, health benefits of aromatherapy by essence or EOs of weeds, methods to extract aroma or EOs, their mode of action, quality and storage issues of EOs, scope and future trends in aromatherapy.

Abstract Glyphosate is an effective post emergence herbicide for weed control in tea. However, dose and timing of any new formulation need to be evaluated before being its recommendation to the growers. The weed flora of the experimental field was composed of Ageratum conyzoides (21.9%), Ageratum houstonianum (21.3%), Chromolaena adenophorum (13.0%), Bidens pilosa (9.6%), Lantana camara (6.2%), Cynodon dactylon (6.0%), Fragaria vesca (5.6%), Imperata cylindrica (5.2%), Polygonum alatum (5.1%) and Erigeron canadensis (5.1%). The new formulation glyphosate 71% SG was found to be comparable to the existing formulation glyphosate 41% SL against Ageratum conyzoides, A. houstonianum, Chromolaena adenophora, Bidens pilosa, Fragaria vesca, Polygonum alatum, Erigeron canadensis, Imperata cylindrica and Cynodon dactylon in reducing their population upto 120 days after application (DAA). Glyphosate 71% SG did not show any toxic symptoms on tea crop and tea leaf yield was similar as under standard formulation used in the present study. Glyphosate 71% SG (ammonium salt) sprayed at 6 kg/ha gave highest tea leaf yield (1940 kg/ha) which was statistically similar to the Glyphosate 71% SG (ammonium salt) applied at the rate of 3 kg/ha (1895 kg/ha). It was also comparable to the market sample. Uncontrolled growth of weeds even for a one season reduced tea leaf yield by 48.5%. The bulk density, water holding capacity, moisture content, soil pH, electrical conductivity, available NPK and organic C were not influenced significantly at harvest. The test herbicide glyphosate 71% SG and the market sample glyphosate 41% SL had increased the population of total bacteria, fungi and actinomycetes at harvest over their initial population. However, there was a slight decrease in the population of this microflora immediately after the application of herbicide not due to the herbicide but owing to seasonal variation as the differences between treatments were not significant.

Abstract The study was conducted with the aim of assessing the distribution and abundance of invasive alien plant species (IAPS) in two administrative Zones (1 and 3) of the Afar region. Data were collected using systematic sampling technique and regular intervals of 10 km were used during the field survey. The following weeds Calotropis procera, Cryptostegia grandiflora, Jatropha curcas, Lantana camara, Opuntia stricta, Parkinsonia aculeata, Parthenium hysterophorus, Prosopis juliflora, Senna occidentalis, and Solanum incanum were recorded in this study. Prosopis was found in 38% of the 91 sample waypoints in the altitude range of 347-1005 meters above sea level whereas C. procera was recorded in 28% of the interceptions between 347 m and 1010 meters above sea level. P. hysterophorus occurred in 15 % of the waypoints in the altitudes ranged from 603 to 1005 meters above sea level. C. grandiflora and P. aculeata were observed respectively in 3% and 6% of the interceptions while L. camara and O. stricta were recorded only at a single waypoint. Higher abundance levels were observed for P. juliflora and C. procera. The majority of the IAPS were found infesting diversified habitats such as road sides, cropland, grazing land, riversides, forest and habitation areas. Awash Fentale district had the highest IAPS richness by possessing all the recorded species. The detailed distribution maps of the identified IAPS were developed and prioritization and ranking of invasive species was made based on abundance levels. The results of this study can be used in invasive weed management or extension programs that aim to tackle major IAPS problems in the region.

Abstract The bio-efficiency of imazethapyr and its ready mix combination products with pendimethalin and imazamox against weeds, their effect on growth, yield and phytotoxic effects on black gram and residual effect on succeeding mustard crop were studied during 2013-14. Significantly lower weed count and dry weight was recorded with application of imazethapyr + pendimethalin (pre-mix) at 800 g/ha, pendimethalin at 1000 g/ha and imazethapyr + pendimethalin (pre-mix) at 900 g/ha. Imazethapyr + pendimethalin (pre-mix) 1000 g/ha and 800 g/ha, pendemethlin 1000 g/ha and imazethapyr 50 and 70 g/ha (pre emergence) behaving statistically similar with pendimethalin 1000 g/ha (pre emergence) and hand weeding at 20 and 40 days after sowing resulted in significantly higher seed yield of black gram. Seed yield of blackgram was negatively associated with total weed count and weed dry weight (P≤0.01). With every one weed increase per square meter, the blackgram seed yield was expected to reduce by 16.8 kg/ha. Net returns, B:C and net returns over weedy check were highest under imazethapyr + pendimethalin 900 g/ha. The economic threshold levels i.e. No m^-2 and g m^-2 with the weed management practices studied varied between 1.7 – 18.0 m^-2 and 1.0-10.0 g m^-2. Imezethapyr + pendimethalin 1000 g/ha and imazethapyr + imazamox 50 g/ha had lowest weed persistence index (WPI). Imazethapyr + pendimethalin 900 g/ha resulted in highest crop resistance index. Weed management index (WMI), Agronomic management index (AMI), and Integrated weed management index (IWMI) were highest following imazethapyr 40 g/ha. Overall impact index (Ii) was highest under imazethapyr 50 g/ha followed by imazethapyr + pendimethalin 900 g/ha, imazethapyr + pendimethalin 1000 g/ha and pendimethalin 1000 g/ha. Weed index (WI) indicated 70.8% loss in yield of blackgram. The residual effects of herbicide treatments on succeeding mustard crop were not observed.

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 experiment was conducted to assess the growth, productivity and profitability of rice (Sukhadhan-3 variety) under different methods of weed management at Bhanu-11 Rupakot, Tanahun during rainy season 2017. The experiment was laid out in randomized complete block design with three replications and ten treatments. The phenological, growth, yield and yield attributing characters were observed in the experiment. Results revealed that maximum grain yield (5.91 ton ha^-1) was obtained in application of butachlor at 4 days after transplanting (DAT) which was statistically at par with all other treatments except single manual weeding, single cono-weeding and non-weeding plots (3.66 ton ha^-1). The highest grain yield obtained from this treatment was might be due to higher number of effective grains per panicle (203 grains), less sterility (6.4%), high test weight (30.7g) with good harvest index (38.4%). Although the single application of butachlor as pre emergence spray showed highest grain yield which seems economically viable and profitable practice to the farmers but it is not environmentally safe to the whole universe.

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 Corn is one of the strategic food commodities in Indonesia which is currently widely used as animal feed ingredient. But the average productivity of national corn is still low. This study aims to determine the dose of herbicide ammonium glufosinate 200 g/L which can maintain the growth potential and yield of corn plants. The experiment was carried out at the Ciparanje Experimental Garden of the Faculty of Agriculture, Padjadjaran University, Jatinangor, Sumedang Regency, West Java, with altitude of 750 meters above sea level in November 2017 to March 2018. The experimental method used was a randomized block design consisting of seven treatments which were repeated four times. The treatments tested consisted of: manual weeding, application of different doses of ammonium glufosinate (450, 600, 750, 900, and 1050 g/ha) and unweeded check. The results of the experiment showed that application of ammonium glufosinate 200 g/L herbicide is able to suppress weed growth in corn cultivation. The application of ammonium glufosinate 200 g/L herbicide starting from a dose of  600 g/ha is effective in suppressing weed growth and suppressing the loss of yield of corn due to the presence of weeds.

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.