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Several national rice centers in Indonesia have used acetolactate synthase herbicide inhibitors for years, especially in several regions of Lampung and West Java provinces. This practice has led to the failure of the application of bensulfuron-methyl herbicide to control Monochoria vaginalis (Burm. f.) C. Presl. The purposes of this study were to confirm that the failure of herbicide application in several areas of the provinces of Lampung and West Java was caused by weed resistance, and to determine the level of resistance. A resistance test of M. vaginalis was performed using the whole plant pot test method and split plot design with three replications. Monochoria vaginalis which indicated resistance was sampled from several regions, namely Sapto Mulyo, Ramadewa, Sarijaya, and Kalentambo. The susceptible samples of M. vaginalis as a control were taken from Cibodas and Sumberagung. The six levels of doses of herbicide bensulfuron-methyl used were: 0, 80, 160, 320, 640 and 1,280 g ∙ ha–1. The experimental results show that M. vaginalis from Sapto Mulyo, Ramadewa, Kalentambo and Sarijaya was confirmed to have developed into weeds resistant to bensulfuron-methyl herbicide. Monochoria vaginalis from Saptomulyo, Kalentambo and Sarijaya were included in the high resistance category with a resistance ratio of more than 12, while M. vaginalis from Ramadewa was included in the moderate resistance category with a resistance ratio of 9.39.

Rice bran application is practically used by Japanese organic rice farmers as a common measure in controlling Monochoria vaginalis, a known weed in organic rice production. To elucidate the inhibitory mechanisms of rice bran application on M. vaginalis germination, we focused on volatile fatty acids (VFAs) and aromatic carboxylic acids (ACAs) as organic acids produced through rice bran decomposition in the soil, which can possibly suppress M. vaginalis germination. Both solo solutions of 1 mM VFAs (propionic or isobutyric acid) and 0.2 mM ACAs (3-phenylpropionic or 4-phenylbutyric acid) exhibited M. vaginalis germination suppression, especially at pH 4.6, the lowest pH tested. In the 0.5–3 mM VFA solutions at pH 4.6, germination was strongly suppressed in the order of isobutyric > propionic > butyric > acetic acid. With the 0.05–0.2 mM ACA solutions at pH 4.6, the germination was strongly suppressed in the order of 3-phenylpropionic > 4-phenylbutyric > 2-phenylpropionic acid. Benzoic acid did not exhibit significant germination suppression. The solutions of 0.5 mM VFAs and 0.05 mM ACAs exhibited no suppression when applied separately; however, the certain mixture of a VFA and an ACA at the aforementioned concentration, for example, 0.5 mM isobutyric acid and 0.05 mM 3-phenylpropionic acid, exhibited significant germination suppression. These results showed the several combinations of VFAs and ACAs at even non-effective concentrations synergistically suppressed M. vaginalis germination. Abbreviations:2PPA: 2-phenylpropionic acid; 3PPA: 3-phenylpropionic acid; 4PBA: 4-phenylbutyric acid; ACA: aromatic carboxylic acid; EC: electrical conductivity; M. vaginalis: Monochoria vaginalis; VFA: volatile fatty acid

Organic paddy rice (Oryza sativa L.) cultivation can be negatively impacted because of the weeds growth like Monochoria vaginalis. Although the rice bran application is useful in combating weed, its performance is not consistent. In this study, laboratory experiments were conducted to elucidate the effects of rice bran on the suppression and promotion of germination of M. vaginalis. Suppression experiments involved incubating mixtures of flooded soil and rice bran. This was followed by a germination experiment in the collected soil solutions. A negative and significant correlation was observed between germination and the electric conductivity (EC) of the solution. None of the seeds germinated when the EC of the Gray Lowland soil was over 130 mS m−1. Conversely, the seeds in the Andosols’ solution germinated even when EC was over 130 mS m−1. Thus, the solutions of the Andosols had different mechanisms of suppression than the Gray Lowland soils. To understand the promotion of germination, air-dried soil was prepared after the flooded incubation of rice bran and soil mixture, simulating a long-term application of rice bran. Germination was analyzed in a filtrate of the mixture of air-dried soil and distilled water. The addition of rice bran significantly promoted germination. There was a negative and significant correlation between germination and dissolved oxygen (DO) suggesting that hardly decomposable components like antioxidants in rice bran decreased O2 and stimulated germination because the seeds of M. vaginalis require very little O2 for germination.

The experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University during the period from July to December 2017 to evaluate the effect of barley crop residues on weed management and yield of transplant aman rice. The experiment consisted of three time of crop residue application viz. one week before transplanting, at the time of transplanting, at one week after transplanting and five doses of barley crop residues such as no crop residues, barley crop residues @ 0.5 t ha-1, barley crop residues @ 1.0 t ha-1, barley crop residues @ 1.5 t ha-1, and barley crop residues @ 2.0 t ha-1. The experiment was laid out in a split plot design with three replications. Weed population and weed dry weight were significantly affected by the dose and time of barley crop residues application. The minimum weed growth was noticed with the application of barley crop residues @ 2.0 t ha-1 at one week after transplanting and the maximum one was observed in no crop residues treatment at one week before transplanting. The highest values of percent weed inhibition was found with the application of barley crop residues @ 2.0 t ha-1 which were 48.13%, 41.39%, 39.71%, 39.88% and 38.73% for panikachu (Monochoria vaginalis), shama (Echinochloa crusgalli), chesra (Scirpus juncoides), amrul (Oxalis corniculata) and sabujnakful (Cyperus difformis), respectively. Rice grain yield and the yield contributing characters produced by the application of crop residues at one week before transplanting was the highest among different times of application and the highest reduction of rice grain yield was obtained in no crop residue treatment. The highest number of effective tillers hill-1, number of grains panicle-1, 1000-grain weight, rice grain and straw yields were observed when barley crop residues were applied @ 2.0 t ha-1 at one week before transplanting. Results of this study indicate that application of barley crop residues @ 2 t ha-1 at one week before transplanting showed the maximum suppression of weed growth. Therefore, barley crop residues might be used as an alternative tool for weed management in transplant aman rice. Progressive Agriculture 31 (2): 119-129, 2020

This study aims to determine the ability of water hyacinth, heartshape false pickerelweed, and water lettuce as phytoremediation of chlorine in water; to determine the ability of those plants, as well as to accumulate and translocate chlorine in water, bioconcentration factor (BCF), and translocation factor (TF). The research method was used, namely the experimental design method to find the effect of certain treatments on controlled conditions. The results of the study concluded that water hyacinth (Eicchorniacrassipes (Mart.) Solms), heart shape false pickerelweed (Monochoria vaginalis (Burm.F) Presi), and water lettuce (Pistia stratiotes L.) have the ability as phytoremediating agents for chlorine in water, with absorption respectively 79.58% for water hyacinth, 73.60% heartshape false pickerelweed, and 87.39% for water lettuce. These plantsare hyperaccumulators if the absorption / accumulation rate is at least 1000 ppm of contaminants. Thus, the three types of plants (Eichhorniacrassipes, Monochoria vaginalis, and Pistia stratiotes) can be categorized as hyperaccumulator plants for chlorine because their accumulation levels are respectively 1492.35 ppm (E.crassipes), 1374 ppm (M. vaginalis), and 1631.28 ppm (P. stratiotes).

To investigate the effect of different plant residues on weed inhibition and yield of transplant aman rice, an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during June 2017 to December, 2017. The experiment comprised of three rice cultivars i.e. BR11, BRRI dhan34 and BRRI dhan49 and five different plant residues treatment viz., no crop residues (control), soybean, wheat, bishkatali and sorghum crop residues @ 2.0 t ha-1 of each. The experiment was laid out following randomized complete block design with three replications. Weed population and weed dry weight were significantly affected by cultivars and crop residues treatment. The highest percent inhibition of 58.31%, 46.84%, 66.85%, 66.94% and 57.6% was in Panikachu (Monochoria vaginalis), Shama (Echinochloa crusgalli), Chesra (Scirpus juncoides), Sabujnakful (Cyperus difformis) and Amrul (Oxalis corniculata), respectively caused by sorghum crop residues. The grain yield, as well as the yield contributing characters produced by BR11,was the highest among the studied varieties. The highest number of effective tillers hill-1 (8.41), number of grains panicle-1(118.08) and 1000-grain weight (20.54 g) were observed in sorghum crop residues. BR11 under sorghum crop residues @ 2.0 t ha-1 produced the highest grain (5.76 t ha-1) and straw yield (6.39 t ha-1). So, to reduce herbicide use in the present situation of Bangladesh, natural herbicide or crop residues like sorghum might be used as an alternative way for weed management for effective and sustainable rice production.

Introduction: Numerous locally accessible plants in Nepal are left unseen. So, exploring their antioxidant activity for medicinal purposes can be beneficial in treating various diseases. Antioxidants have great importance in terms of reducing oxidative stress that causes damage to biological molecules. The qualitative analysis of chemical constituents using a chromatographic technique like TLC plays a pivotal role in this aspect. The present study aimed at performing chemical profiling using thin-layer chromatographic technique and evaluation of the antioxidant activity of selected medicinal plants. Methods: Firstly, TLC profiling of 70% methanolic extracts of eighteen medicinal plants was done using preparative TLC plate in two different ratio of chloroform, methanol and water. Then, antioxidant activity was tested by DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging assay by using a 96 well plate method at wavelength 510 nm in which Trolox was taken as standard. Results: Flavonoids, tannins, saccharides, and phenols were identified from TLC profiling. The yield value of Sapium insigne leaves extracts i.e. 20.52% was highest and Monochoria vaginalis leaves possess the least i.e. 3.93%. Solena heterophylla leaves extract with IC50 amount i.e. 21 µg/ml was found most potent among all the plant extracts. Conclusion: The results imply that the extract of ethnomedicinal plants is rich with a variety of phytochemicals, which can be used as natural antioxidants. However, further studies are warranted to isolate and identify the chemical and biological properties of obtained extracts for the provision of scientific evidence for traditional uses.

There were many types of macrophyta present in the swamp area of the Sawah Village, but there was no information about the types of macrophyta in that area. To understand the type of macrophyta presence in that area, a research has been carried out in February 2019. The method usedz is a the survey method, where the swanp area of the Sawah Village used as the location of the research and macrophytes as the object of research. Sampling was done once during the study. The plants were then identified based on Steenis (1981). There are 10 types of macrophytes found in the swanp area of the Sawah Village namely: Colocasia esculenta, Eichhornia crassipes, Eleocharis dulcis, Paspalum comersonii, Azolla pinnata, Utricularia aurea, Salvinia natans, Nepbrolepis biserrata, Monochoria vaginalis, Panicum repens.

Coal mining activities could potentially interfere with the environment. One of the environmental disturbances in coal mining activities is theformation of acid mine drainage (AMD). AMD management can be done passively through the construction of swamp forest. The constructed swampforest system uses organic material in the form of cow manure which serves as a growing plants’ medium. Phytoremediation is an attempt to usevplant species in the accumulation of heavy metals. This study was aimed to know the AMD management system passively and identify the diversity ofplants in artificial swamp forests. Purposive sampling method with a sample size of 2 x 2m in 10 plots/compartments was used to identify the plantdiversity in constructed swamp forest. The observation was made both before and after AMD flowed. Constructed swamp forest consist of 6compartments (2 sediment pond compartments and 4 swamp compartments). The results of the vegetation analysis found that before the AMD flowed,21 species are still capable growing naturally in constructed swamp forest, however, it became 15 after the AMD flowed. Cyperus iria, Fimbristylisgriffithii, Scirpus juncoides, Ludwigia hyssopifolia, Cyperus platystylis and Monochoria vaginalis are six dominant species that can be used asphytoremediation agent in constructed swamp forest.Keywords: Acid Mine Drainage, constructed swamp forest, phytoremediation

Water pollution caused by excessive nutrient and biological invasion is increasingly widespread in China, which can lead to problems with drinking water as well as serious damage to the ecosystem if not be properly treated. Aquatic plant restoration (phytoremediation) has become a promising and increasingly popular solution. In this study, eight native species of low-temperature-tolerant aquatic macrophytes were chosen to construct three combinations of aquatic macrophytes to study their purification efficiency on eutrophic water in large open tanks during autumn in Guangzhou City. The total nitrogen (TN) removal rates of group A (Vallisneria natans + Ludwigia adscendens + Monochoria vaginalis + Saururus chinensis), group B (V. natans + Ipomoea aquatica + Acorus calamus + Typha orientalis), and group C (V. natans + L. adscendens + Schoenoplectus juncoides + T. orientalis) were 79.10%, 46.39%, and 67.46%, respectively. The total phosphorus (TP) removal rates were 89.39%, 88.37%, and 91.96% in groups A, B, and C, respectively, while the chemical oxygen demand (COD) removal rates were 93.91%, 96.48%, and 92.78%, respectively. In the control group (CK), the removal rates of TN, TP, and COD were 70.42%, 86.59%, and 87.94%, respectively. The overall removal rates of TN, TP, and COD in the plant groups were only slightly higher than that in CK group, which did not show a significant advantage. This may be related to the leaf decay of some aquatic plants during the experiment, whereby the decay of V. natans was the most obvious. The results suggest that a proper amount of plant residue will not lead to a significant deterioration of water quality.

Waterlily aphid Rhopalosiphum nymphaeae is one of the aphids that have many hosts, including Azolla filiculoides , Limnobium laevigatum , Monochoria vaginalis and Spirodela polyrhiza . The aim of this study was to study the effect of host shift and confirm the results of previous studies on the effect of nitrogen and carbon factors among A. filiculoides, L. laevigatum, M. vaginalis and S. polyrhiza on the level of aphid preference and number of offspring. Analysis of the nitrogen and carbon content of plants was also carried out to confirm the preference and number of offspring produced by aphids. The study began with maintaining aphids on the four tested hosts, up to the 4th generation. Twenty five individuals were randomly selected from each host, then released on the inner wall of the plastic container (14 x 7.5 x 15 cm 3 ) which was filled with four hosts arranged side by side. Observations were made every 24 hours up to 97 hours starting from the first hour after treatment. Observations after 97 hours showed that waterlily aphids imago preferred L. laevigatum the most (49.28%), then on M. vaginalis (20.43%), S. polyrhiza (16.33%), and A. filiculoides (1.75%). Meanwhile, the number of offspring produced by each group of aphids that selected on four hosts were: 46.65 individuals on L. laevigatum , 37.8 individuals on M. vaginalis , 19 individuals on S. polyrhiza , and 0.6 individuals on A. filiculoides . The analysis showed that the highest nitrogen content was found in M. vaginalis (4.16%), followed by S. polyrhiza (3.71%), L. laevigatum (2.33%), and A. filiculoides (2.08%).

Herbicides are used successfully for weed control in rice fields for rapid effect, easier to application and low cost involvement in comparison to the traditional methods of hand weeding. Sulfentrazoneis a new pre-planting herbicide in Bangladesh. Field trials were conducted at Bangladesh Rice Research Institute (BRRI), Gazipur during Aman 2014 and Boro 2014-15 to evaluate the efficacy of sulfentrazone 48 SC on weed suppression and performance of transplanted rice. Treatments were Sulfentrazone 48 SC @ 150, 200 and 250 ml ha-1, pretilachlor 500 EC @ 1000 ml ha-1, weed free and unweeded control. Visual assessment indicated that this herbicide possesses high selectivity and not toxic to rice plants. The results revealed that the major weed flora associated with the transplanted rice was mainly comprised of two grasses, two sedges and four broadleaves in Aman 2014 and two grasses, two sedge and two broadleaves in Boro 2014-15. The most dominant weeds were Cyperus difformis, Echinochloa crus-galli, Scirpus maritimus and Monochoria vaginalis in both the growing seasons. Application of Sulfentrazone 48 SC @ 200 ml ha-1 was most effective to suppress weed density and dry masses in both the seasons resulting increased grain yield more than 50% as compared to unweeded control. Therefore, Sulfentrazone 48 SC @ 200 ml ha-1 should apply two or three days before plantingfor effectively control weeds in riceBangladesh Rice j. 2017, 21(1): 67-76

Different weeding frequencies (WFs)―0WF, 2WF, 4WF, 6WF, and 8WF―were adopted in an organic rice field to investigate their influence on weed types, rice and weed biomass, rice tiller and weed number, N concentration, and N uptake. The study field was located in Tsuruoka, Yamagata, Japan. Rice (cv. Sasanishiki) was planted from May to September 2019, and all weeding events were carried out until 49 days after transplantation (DAT) using a rotary weeder. Rice and weed samples were collected at 60, 88, and 110 DAT. Echinochloa crus-galli (E. crus-galli), Schoenoplectus juncoides, and Monochoria vaginalis (Burm. f.) were the most commonly found weeds. High weed diversity was observed at both 6WF and 8WF, E. crus-galli was the dominant weed at 0WF. Compared to 0WF, 2WF displayed a significantly decreased weed biomass. However, at 8WF, the weed biomass was reduced by 79.0%, the rice biomass was increased by 277%, and the rice tiller number was almost three times higher than that at 0WF and 110 DAT. Compared to 0WF, a significantly increased rice N uptake was observed at 4WF, and rice N uptakes achieved at 6WF and 8WF were two and four times higher than those at 0WF, respectively. Higher weeding frequencies provide notable benefits in suppressing weeds and supporting rice growth, especially in N uptake competition with weeds.

Allelopathy plays an important role in weed control because it reduces dependence use on synthetic herbicide and labor. Some rice varieties release chemical compounds that can inhibit weed growth. The objective of this research was to identify compounds and to determine the rice allelopathic potential of rice root extract. The experiment was conducted in Regional Health Laboratorium Jakarta and ICRR’s greenhouse, West Java. Identification of metabolite compounds in 10 rice root extracts used GCMS. The experiment in the greenhouse used a split plot design with four replications. The main plot was weeds (Echinochloa crus-galli and Monochoria vaginalis), while the subplot was the roots of 10 swamp rice varieties and control. The rice roots were extracted by the maceration method using 80% methanol and evaporated by a rotary evaporator. The root extract was diluted distilled water at a 50% concentration (w/v) and applied to weeds. The experimental unit was 3 pots planted with 5 weed seeds. The research identified 88 compounds in rice root extract and the highest peak area was stigmasterol compound. The inhibitory of growth and dry weight of weeds varied, between 27-44%. Inpara-3, Inpara-4, Inpara-7, Inpara-8, and Inpara-10 were able to inhibit weeds greater and belong to one cluster. The five swamp rice can be chosen to be developed in paddy fields that were dominated by Echinochloa crus-galli and Monochoria vaginalis.

Experiment was carried out at the Agronomy field of Bangladesh Rice Research Institute, Gazipur, during the period from December 2014 to May 2015 to investigate the response of different levels of N and methods of weeding on weed abundance and grain yield of BRRI hybrid dhan3 under alternate wetting and drying (AWD) irrigation condition. The treatments consisted of five N levels viz.,0, 60, 120,180 and 240 kg N ha-1 and four different weed control methods viz., Pre-emergence herbicide followed by 1HW, Pre-emergence followed by post emergence herbicide, Weed free by 3 hand weedings and Unweeded (control). The experiment was laid out in factorial RCB design with three replication. Pre-emergence application of prefer 18WP (Bensulfuran Methyl + Acetachlor) and post emergence herbicide Dhaman 300wp (Bispyribac sodium 18% + Bensulfuran methyl 12%) followed by one hand weeding effectively control all weeds (78-93%). In the experimental field, sedges and grass weeds were highly dominant over treatments. Based on summed dominance ratio (SDR), the most dominant weed species could be arranged in the order of Echinochloa crus-galli > Scirpus juncoides > Cynodon dactylon > Cyperus difformis > Marselia minuta > Monochoria vaginalis. Interaction of nitrogen levels and weeding methods had significant response on yield and yield components of hybrid rice. The highest (7.61 t ha-1) grain yield was obtained from the combination @ 180 kg N ha-1 with weed free treatments. Comparable higher grain yield was obtained from the combination of pre emergence herbicide of bensulfuranm methyl + acetachlor) + one hand weeding with 180 kg N ha (7.48 t ha-1) and the combination of pre + post-emergence herbicide (Bispyribac sodium 18% + Bensulfuran methyl 12%) with 180 kg N ha-1 (7.56t ha-1). The estimated optimum dose of nitrogen for Pre EH, Post EH and 3HW (weed free) were 173, 189.1 and 189.4 kg N ha-1 respectively for BRRI hybrid dhan3 under AWD irrigation system.Bangladesh Agron. J. 2017, 20(1): 13-24

A weed survey was conducted in Agronomy Field Laboratory, BAUFarm and farmers’ fields of Sutiakhali Natunchar village in Mymensingh district during the period from December 2015 to March 2016 to study the weed vegetation in wheat and boro rice. Ten fields were selected for each crop from each location. A quadrat of 0.25 m 2 was placed randomly at four places in each plot and the weeds within the quadrat were identified and counted species-wise. The results revealed that the composition of weed species in two different crops was different and the composition of weed flora in each crop under different locations was also different. In wheat, a total number of 29 weed species belonging to 16 families were found from all three locations. The infesting weed species were 18 in Agronomy Field Laboratory, 16 species in BAU Farm and 19 species in farmers’ fields. From the five most dominant species, Polygonum hydropiper had the highest relative abundance value in both Agronomy Field Laboratory and BAU Farm and on the other hand, in farmers’ field, a new weed species, Eleusine indica was in the top most of the dominant list. The other weed species which were present in the dominant list of three locations were Cynodon dactylon, Cyperus rotundus, Paspalum distichum, Chenopodium album, Marsilea quadrifolia and Leucas aspera . In boro rice fields, among the three locations, 25 weed species were observed in total belonging to 13 families. Of which, 20 weed species were found in both Agronomy Field Laboratory and BAU Farm whereas in farmers’ fields, 21 weed species were identified. In both Agronomy Field Laboratory and BAU Farm, Eleocharis atropurpurea had the highest abundance value but in farmers’ field, Cyperus difformis occupied the highest value . The other dominant weed species were Leersia hexandra, Monochoria vaginalis, Echinochloa crusgalli, Paspalum distichum and Alternanthera philoxeroides found in three locations. Many common weeds were present in three locations in a crop but their frequency, uniformity, density and relative abundance value were different. The similarity index of weed species between wheat and boro rice indicated that the infesting weed species between the two crops was less associated. Thus the weed divergence in boro rice with wheat was high. From this study it was clear that the weed infestation was changed by crop and locations. In this study a little bit divergence and ranking of five most abundant weed species and low similarity index value of weed species in different crops under a specific area or among the area indicated that weed control measure should be adopted on crop basis in a specific area considering the dominant weed species. J. Bangladesh Agril. Univ. 15(2): 148-157, December 2017

In this research we discussed the brief introduction of natural fibers and different plants were collected and by chemical method lignocelluloses sheet was fabricated which further can be used for many different applications such as in textile industry also it can be used with nanomaterials for flexible energy devices. Lignocellulosic fibers were attained by mechanical separation from monochoria vaginalis and Typha Angustifolia plants, and then after drying of fibers, fibers sheet fabricated by bleaching of fiber with different concentration, the lignocellulose fiber sheets were so flexible that can twist into any geometrical shape and can cut with the help of scissor.

Rice is an important food crop for Indonesia, but its productivity is still low, which is 5.11 tons/ha. One of the factors causing the low productivity of rice is pickerelweed (Monochoria vaginalis) which can reduce yields by 80%. This research was aimed to determine the physio-morphological character of pickerelweed at various soil moisture levels and obtain soil moisture levels which can suppress the growth of pickerelweed. The research was conducted with a single factor experimental method that was arranged in a Completely Randomized Design. The treatments were soil moisture levels that consisting of 4 levels, i.e. field capacity, muddy, waterlogged 2 cm, and waterlogged 5 cm, and additional treatment is rice cultivation according to Good Agricultural Practice as a control. The results of the research showed that the moisture level of the field capacity and the muddy can reduce height, the number of leaves, plant growth rate, root length, shoots dry weight, and roots of pickerelweed, while the moisture level of waterlogged 2 cm and 5 cm increase height, the number of leaves, leaf area, weed growth rate, root length, fresh weight and dry weight of pickerelweed.

We investigated the effect of poultry manure (PM) on the occurrence and early growth of Monochoria vaginalis in relation to soil solution electrical conductivity (SSEC). PM was applied at rates corresponding to 0 g of nitrogen (N) m−2 (PM-0), 1 g N m−2 (PM-1), 3 g N m−2 (PM-3), and 5 g N m−2 (PM-5). At 7 d post-seeding, the soil solution was sampled to measure EC, and also the emergence and growth of M. vaginalis were evaluated. The emergence rate of M. vaginalis decreased with increasing application rate of PM and SSEC. SSEC was significantly negatively correlated with the emergence rate of M. vaginalis seedlings. The average leaf number and length of M. vaginalis did not differ between PM-0, PM-1, and PM-3, but were significantly lower in PM-5. In summary, PM would allow to better control the emergence and early growth of M. vaginalis.

Invasive species benefit from advantageous trait values and/or trait plasticity in their invasion process when facing changing environments. However, few studies explored this mechanism on invasive macrophytes. The effects of soil on the invasion of macrophytes were studied little by previous researches. In the measurement of several traits related to resource utilization, we studied the plant responses to three representative types of riparian soil in Liangzi Lake, China. Using multi-species comparison, we explored the differences of trait values and trait plasticity among Eichhornia crassipes (Mart.) Solms and its non-invasive confamilial counterparts all in emergent life-form—exotic Pontederia cordata L. and native Monochoria vaginalis (Burm. f.) Presl ex Kunth. We measured leaf-level and root-level traits after harvest. We found that E. crassipes mainly showed trait value advantages in root-level traits in infertile soils, while some advantages of leaf-level traits were present but not obvious compared to the two confamilials. Besides, E. crassipes showed higher plasticity in several traits especially in some root-level traits than the two confamilials. We concluded that both trait values and trait plasticity especially in belowground traits play a crucial role in the invasion success of emergent E. crassipes.

The purpose of study was conducted to examine factors that influence on germination of Monochoria vaginalis, a major and problematic weed in paddy fields. It was found that seed coats of barnyardgrass and Monochoria itself strongly promoted germination of Monochoria seeds. Germinating rice seeds caused germination induction of Monochoria, but dehulled rice and rice hulls did not play a role. In general, rice root exudates from 2 to 22 day after germination did not exert significant influence on germination and initial growth of Monochoria. The increase of rice seeds showed no remarkable impact on germination, root length and shoot length of Monochoria. In conclusion, it is suggested that coats of weed seeds, residues of rice and other plants in paddy fields may play a critical role in promoting germination of Monochoria seeds. Therefore, the incorporation of these residues in paddy fields may provide negative impact to weed control as germination of Monochoria is much accelerated.

Field experiments were conducted to analyze the relationship between the settled soil volume in water (SSVW) and the growth of Monochoria vaginalis (Burm. f.) Kunth under organic farming conditions. SSVW corresponds to the mud volume per dry matter weight. Soil was sampled from the superficial layer of the topsoil (

Surveys of weed species in paddy fields were conducted to identify weed occurrence on July 2013. Total 237 sites of paddy fields in 9 City/Gun, Jeonnam Provinces in Korea were investigated. From the survey, 45 weed species in 18 families were identified and classified to 33 annuals and 15 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (9 species) and 8 and 4 weed species belonged to Cyperaceae and Scrophulariaceae, respectively. These 21 weed species in the most four families accounted for 46% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (18.5%), followed by Monochoria vaginalis (12.3%), Lemna perpusilla (8.2), Eleocharis kuroguwai (5.2%) and Scirpus juncoides (5.2%). The most dominant weed species in machine transplanting paddy fields were Echinochloa spp. (14%), followed by Monochoria vaginalis (12%) and in water seeded rice paddy fields were Echinochloa spp. (25%), followed by Monochoria vaginalis (11%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields.

This study was conducted to establish the effective weed management methods in rice field simultaneously dominated by the herbicide resistant Echinochloa oryzicola, Monochoria vaginalis and Scirpus juncoides. Herbicides registered for use before transplanting, oxadiazon 12% EC, pyrazolate 36% SC, pretilachlor 14% EC and thiobencarb 50% EC were effective until 0.5 leaf stage of herbicide resistant Echinochloa oryzoides. Herbicides registered for use after transplanting, fentrazamide 1% GR and mefenacet 18% SC were effective until 2 leaf stage of herbicide resistant Echinochloa oryzicola and triafamone 0.98% SC was possible to control up to 4 leaf stage. HPPD inhibitors, benzobicyclon, mesotrione and tefuryltrione SC, were simultaneously effective to SU herbicide-resistant Monochoria vaginalis and Scirpus juncoides. Herbicides registered for use before transplanting, benzobicyclon + oxadiargyl EC out of the tested herbicide was most effective in rice field simultaneously dominated by the herbicide resistant Echinochloa oryzicola, Monochoria vaginalis and Scirpus juncoides. Its effectiveness rises in proportion to flooding duration. Mazosulfuron GR, a herbicides registered for use after transplanting was most effective without phytotoxicity until 60 days after transplanting in rice field simultaneously dominated by the herbicide resistant Echinochloa oryzicola.

Combined applications of rice bran with pine leaves were tested to examine the inhibitory effects to paddy weeds and increased yield of rice for developing techniques of environment-friendly weed management in paddy rice fields. Weed control efficacy at 60 days after treatment was improved to 88.8% by combined application of rice bran with pine leaves, while weed control efficacy by single application of rice bran showed 67.5%. The other weed control efficacy combined with chestnut leaves and barley straws were 76.3% and 69.9% respectively. Combined application of rice bran with pine leaves was more effective to broadleaf weeds such as Monochoria vaginalis. Weed control efficacy by combined application with pine leaves was 100% until 70 days after rice transplanting and maintained weed control effect up to 90 days after transplanting. Rice yield by combined application of rice bran with pine leaves was 526 kg/10 a, which was higher yield than by combined application with barley straws, single application of rice bran, natural snail application and hand weeding.

Bioaccumulation potential of six ecotypes, collected from six different industrial zones of lower Indo-Gangetic basin of West Bengal, India,of Monochoria vaginalis, commonly known as oval-leafed pondweed has been investigated based on chromium (Cr), cadmium (Cd) andCopper (Cu) accumulation pattern in different plant organs. Bioaccumulation potential was assessed by bioaccumulation factors (BFs-leavesmetal concentration/soil metal concentration), bioconcentration factors (BCFs- roots metal/soil metal), transfer factors (TFs-leaves +rhizomes/roots) and enrichment factors (EFs-metals in edible parts/soil metal). Accumulation pattern significantly differed among ecotypes,and accumulation in plant organs was highly metal-specific. BFs for Cr and Cd were >>1 in most of the ecotypes while high TFs (>>1) werenoticed in six ecotypes for Cr and Cu. BCFs was >>1 in all the ecotypes for Cd accumulation only. EFs values for the three metals hoveredaround 1 but it was > 1.0 for Cu in all the six ecotypes. The results suggested that Cr and Cu predominantly accumulated in leaves and rhizomeswhile Cd was predominantly sequestered in roots of M. vaginalis ecotypes. Cu, a redox active metal, showed higher capability than Cd and Crto accumulate in edible parts. In the present study, potential plant parts in M. vaginalis have been identified as bioaccumulation organs withoutany apparent symptoms of toxicity which can be used as phytoremediation of heavy metal contamination in aquatic ecosystems of lower Indo-Gangetic basin of India.DOI: http://dx.doi.org/10.3126/ijasbt.v3i1.12193 Int J Appl Sci Biotechnol, Vol. 3(1): 9-15

This paper analyzes optimal weed control management strategies under static and dynamic decision rules. Seed bank is taken into account to introduce dynamics into the model. We present a numerical example of controlling Sheathed Monochoria (Monochoria Vaginalis) in Korean rice paddy fields. Our results show that producers benefit from dynamic decision rules; higher income and more control of weed density can be obtained with the same amount of herbicide. In order to illustrate the magnitude of differences between static and dynamic models, a numerical example is presented using a data set from Korean rice production. When it comes to controlling weed density, Korean rice farmers are found to be better off under the dynamic model, and the magnitude of advantages are found to be more sensitive to herbicide efficacy and less sensitive to initial seed banks and germination rates in terms of weed density.

The number of aquatic plants along the river flow outside the village of Lambur becomes a barrier to water traffic so that these plants are classified to be weeds or a nuisance for local people. This study aims to determine and document the types of weeds found in the village of Lambur and explore locals’ knowledge about the types of existing water weeds and their use. This research was conducted in the Village of Lambur Luar Tanjung Jabung Timur District by using the roaming method to collect existing Weed samples. Data collection is done by observation, interviews, documentation and literature studies, the data are analysed descriptive qualitative design. The results showed that there were 19 species and 13 families of water weeds, namely: Fimbristylis sp1, fimbristylis sp2, Cyperus sphacelatus Rottb, Blyxa aubertii Rich, Lindernia sp, Glinus oppositifolius (L.) Aug.DC, Melastoma malabathticum L, Nymphaea nouchali Burn, Ludwigia hyssopifolia (G.Don) Exell, Ludwigia repens JR Forst, Scoparia dulcis, Hippochaete debilis (Roxb.ex Vaucher) Ching, Panicum repens L, Oryza sativa, Persicaria hydropiper L, Monochoria vaginalis (Burm.f.) C.Presl, Borreria alata (Aubl.) DC, Borreria repens DC, and Xyris sp. Of the 19 species found, only 12 species, the locals know the name of the water weed, 7 species are only referred to as grass only by the locals, this water weed is not used by the them but mostly weeds are used for animal feed, the researchers provide education to the community that actually weed water can be used for treatment and to find out the quality of a waters or be used as an indicator of the biological condition of a river in wheteher good condition or not. Keywords: Knowledge Studies, Lambur Luar, Water Weeds

This study was conducted to obtain basis information for effective weed control by the fact-finding survey of herbicides use at farmer’s level and distribution of herbicide resistant weeds in paddy field of Jeonbuk province, Korea. The distributions of major paddy field weeds and frequently used herbicide according to the survey were as follows. The dominant weeds in rice paddy field were Echinochloa crus-galli, Eleocharis kuroguwai, Scirpus juncoides, Monochoria vaginalis, etc.. Preferred herbicides widely used by farmers were ranked in the following order, early and middle treatment (48.0%), treatment before transplanting (36.7%) and foliar treatment (15.3%). The occurrence of herbicide-resistant weeds according to collected paddy soils was as follows. The occurring area of herbicide-resistant weeds was 24,413 ha, approximately 18.4% of rice cultivation area. Herbicideresistant weeds were occurred in four species. The order of occurrence were Scirpus juncoides (39.0%) ＞ Monochoria vaginalis (27.8%) ＞ Echinochloa crus-galli (16.6%) and Cyperus difformis (16.6%). This information could be useful for estimation of future herbicide-resistant weed and establishment of herbicide-resistant weed control methods in Jeonbuk province, Korea.

A phytosociological survey of weed species was conducted during the rainy season in 2008 in paddy fields at different distances from the main irrigation canal in the Kamping Puoy Irrigation Rehabilitation Area in northwestern Cambodia. The spatial variation in water depth was large between upstream (shallower) and downstream (deeper) paddies, which resulted in different weed, with many Poaceae and Cyperaceae species observed on levees in upstream and aquatic herbs in downstream paddies. Chemical fertilizer input levels were generally small and average rice yield was relatively low (ca. 2.3 t/ha). Traditional and less intensive weed management options such as hand weeding, mid-season tillage, and post-harvest straw burning were common, while the herbicide 2,4-D was also widely used. Weed species in the paddy ecosystem used by villagers included Ipomoea aquatica, Nymphaea nouchali, and Monochoria vaginalis (occasional, for human consumption) and graminoid species (frequent, for cattle feed in addition to rice straw). Greater inorganic fertilizer input was associated with a lower diversity of weed species, but grain yield and weed diversity indices had no negative relation among different locations. This survey revealed relatively small extent of intensification in the irrigation rehabilitation area in Cambodia, which led to high weed diversity, including numerous plant species available for use to support farmers’ livelihoods in the area.

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh during the period from July to December 2012 to find out the effect of herbicide Prechlor 500 EC on weed control and performance of transplant aman rice. The experiment was laid out in a randomized complete block design with four replications. The experiment consisted of two varieties viz., BRRI dhan41 and Nizershail, and four levels of Prechlor @ 0, 0.5, 1.0 and 1.5 L ha -1 . Monochoria vaginalis , Nymphaea nouchali , Paspalum scrobiculatum , Echinochloa crusgalli and Scirpus juncodies were the major weeds in the experimental plots. Prechlor 500EC @ 1.5 L ha -1 showed the best performance in reducing weed density, weed dry weight and increased weed control efficiency but reduce grain yield. Variety had significant influence on all the yield and yield contributing characters of rice. Higher grain yield (3.09 t ha -1 ) was obtained from BRRI dhan41. Different levels of Prechlor also had significant effect on yield and yield contributing characters such as number of total tillers hill -1 , number of effective tillers hill -1 , panicle length, spikelets panicle -1 , grains panicle -1 , grain yield, straw yield and harvest index. Prechlor @ 1.5 L ha -1 showed best performance with respect to most yield attributes, grain and straw yields and the lowest grain yield was obtained from Prechlor @ 0 L ha -1 . The interaction effects of variety and herbicide Prechlor had significant effect on all yield attributes except plant height, effective tillers hill -1 , panicle length, 1000-grain weight and harvest index. The highest grain yield (3.62 t ha -1 ) was obtained from variety BRRI dhan41 with Prechlor @ 1.5 L ha -1 . The results suggest that farmers can be advised to use herbicide Prechlor @ 1.5 L ha -1 to boost up the production of BRRI dhan41 controlling weeds during aman season under the agro-climatic condition of the study area. DOI: http://dx.doi.org/10.3329/jbau.v11i2.19923 J. Bangladesh Agril. Univ. 11(2): 257-264, 2013

Surveys of weed species in paddy fields were conducted in Korea to identify weed occurrence from June to September 2013. Total 3,434 sites of paddy fields in 155 City/Gun, eight Provinces were investigated. From the nation-wide survey, 90 weed species in 28 families were identified and classified to 52 annuals, 3 biennials and 35 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (18 species). 17, 8 and 6 weed species belonged to Cyperaceae, Scrophulariaceae and Polygonaceae, respectively, and these 49 weed species in the most four families accounted for 54% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (17.4%), followed by Monochoria vaginalis (12.4%), Eleocharis kuroguwai (7.8%), Bidens tripartite (9.27%), Scirpus juncoides (6.2%) and Sagittaria sagittifolia (6.1%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields of Korea.

Survey was carried out in paddy fields to investigate the dominance of weed species and weed occurrence on 200 fields of southern Gyeonggi region in Korea during the year 2013. We observed 3 species of grass, 5 species of sedge, and 11 species of broadleaf and other weeds. The most dominant weed species was Eleocharis kuroguwai, followed by Echinochloa crus-galli, Sagittaria trifolia, Monochoria vaginalis, Scirpus juncoides and Bidens tripartita. The dominance value of E. kuroguwai and B. tripartita decreased compared to the survey results performed in 2005 but that of M. vaginalis, S. juncoides, S. trifolia and E. crus-galli increased. Weed occurrence increased from 2.83 g in 2005 to 3.51 g in 2013 based on weed dry weight per m². Occurrence ratio of annual weeds to perennial weeds changed from 45.2% : 54.8% in 2005 to 45.8% : 54.2% in 2013. If we analyze dominance of weed species based on the rice transplanting timing, E. kuroguwai and E. crus-galli were the most dominant weed species at mid-May transplanting, and M. vaginalis and S. juncoides were the most dominant weed species at late-May transplanting, and M. vaginalis and E. kuroguwai were the most dominant weed species at early-June transplanting. Since paddy weeds resistant to sulfonylurea herbicides are expected to be continuously increased, the regular monitoring of their occurrence and efficient control methods should be considered in future.