Experimental Research on the Application of Water Hyacinths to the Ecological Restoration of Water Bodies with Eutrophication

[Objective] The study aims to discuss the application of water hyacinths to the ecological restoration of water bodies with eutrophication through simulation experiments. [Method] In this study, water hyacinths were used to restore the simulated eutrophic water with green algae as the dominant algae species, and then the restoration effect of the simulated eutrophic water by water hyacinths was analyzed. [Result] In the simulation test without sediment, the peak chlorophyll concentration was 434.6 mg/m3 in the tank without water hyacinths, which decreased to 285 and 119 mg/m3 respectively in the tanks with 1 and 4 water hyacinths. In the experiment with sediment, compared with the control tank without water hyacinths, a 58% reduction in chlorophyll concentration could be observed in the tank with 4 water hyacinths planted (with a coverage of 51%). The results showed that water hyacinths could inhibit alga growth notably, but there was likely a density threshold (51% coverage), and no significant eco-restoration effect was observed in the simulated eutrophic water with too few water hyacinths planted. [Conclusion] The research could provide scientific references for the ecological restoration of eutrophic water bodies.

Integrated biological control of water hyacinths, Eichhornia crassipes by a novel combination of grass carp, Ctenopharyngodon idella (Valenciennes, 1844), and the weevil, Neochetina spp.

The efficacy of grass carp Ctenopharyngodon idella （Cyprinidae） and weevils Neochetina spp. （Curculionidae） to control the aquatic weed, water hyacinth, is investigated in a square net cage （happas） setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within ll0 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed biomass is reduced from 5 kg （day 1） to 0.33 kg （day 110） when exposed to grass carp and weevils. The number of plants is reduced to 0.75 in grass carp and weevil exposed happas, while it is 741.5 in the control. The mean number of leaves per plant is also reduced. In addition, the chlorophyll a and b are significantly reduced in happas exposed to the combination of fish and insects when compared to the other treatments. Based on the results of this study, we consider the combined use of grass carp and weevils to be more efficient and sustainable for managing water hyacinths than the use of these organisms individually.

Assessment of Electric Power Generation via Water Hyacinths and Agricultural Waste

The importance and the necessary of researches on renewable energy have become a hot topic in recent years due to climate change and global warming. In addition, the fossil fuel reserves is facing rapid depletion on the earth. Currently, most researches have concentrated on producing biogas for heating, lighting, drying, cooking but lack in researching on electricity production because the possibility of producing biogas at households are common at small scale. Studying on alternative energy sources to replace traditional fuel for electric power generation brings new chances and great opportunities for development. This study presents an assessment electric power generation via water hyacinths and agricultural waste. In this paper, the evaluation electric power is generated by operating internal combustion engines which use biogas fuel to replace traditional fuel （diesel, gasoline）. The results of the studies were demonstrated by experiments on the renewable energy production system at Hoa An Biotechnology Research and Experimental Center of Cantho University.

Catalytic Hydrothermal Liquefaction of Water Hyacinth Using Fe3O4/NiO Nanocomposite: Optimization of Reaction Conditions by Response Surface Methodology

This research aimed at optimizing the reaction conditions for the catalytic hydrothermal liquefaction (HTL) of water hyacinth using iron oxide/nickel oxide nanocomposite as catalysts. The iron oxide/nickel oxide nanocomposite was synthesized by the co-precipitation method and used in the hydrothermal liquefaction of water hyacinth. The composition and structural morphology of the synthesized catalysts were determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic absorption spectroscopy (AAS). The particle size distribution of the catalyst nanoparticles was determined by the Image J software. Three reaction parameters were optimized using the response surface methodology (RSM). These were: temperature, residence time, and catalyst dosage. A maximum bio-oil yield of 59.4 wt% was obtained using iron oxide/nickel oxide nanocomposite compared to 50.7 wt% obtained in absence of the catalyst. The maximum bio-oil yield was obtained at a temperature of 320°C, 1.5 g of catalyst dosage, and 60 min of residence time. The composition of bio-oil was analyzed using gas chromatography-mass spectroscopy (GC-MS) and elemental analysis. The GC-MS results showed an increase of hydrocarbons from 58.3% for uncatalyzed hydrothermal liquefaction to 88.66% using iron oxide/nickel oxide nanocomposite. Elemental analysis results revealed an increase in the hydrogen and carbon content and a reduction in the Nitrogen, Oxygen, and Sulphur content of the bio-oil during catalytic HTL compared to HTL in absence of catalyst nanoparticles. The high heating value increased from 33.5 MJ/Kg for uncatalyzed hydrothermal liquefaction to 38.6 MJ/Kg during the catalytic HTL. The catalyst nanoparticles were recovered from the solid residue by sonication and magnetic separation and recycled. The recycled catalyst nanoparticles were still efficient as hydrothermal liquefaction (HTL) catalysts and were recycled four times. The application of iron oxide/ nickel oxide nanocomposites in the HTL of water hyacinth increases the yield of bio-oil and improves its quality by reducing hetero atoms thus increasing its energy performance as fuel. Iron oxide/nickel oxide nanocomposites used in this study are widely available and can be easily recovered magnetically and recycled. This will potentially lead to an economical, environmentally friendly, and sustainable way of converting biomass into biofuel.

Ultrafast Spectral Studies of the Primary Processes of Photosynthesis in Spinach and Water Hyacinth Leaves

The authors have studied the spectroscopic characteristics and the fluorescence lifetime for the chloroplasts from spinach (Spinacia oleracea L.) and water hyacinth (Eichhornia crassipes (Mart) Solms.) plant leaves by absorption spectra, low temperature steady_state fluorescence spectroscopy and single photon counting measurement under the same conditions. The absorption spectra at room temperature for the spinach and water hyacinth chloroplasts are similar, which show that different plants can efficiently absorb light of same wavelength. The low temperature steady_state fluorescence spectroscopy for the water hyacinth chloroplast reveals a poor balance of photon quantum between two photosystems. The fluorescence decays in PSⅡ measured at the natural Q A state for the chloroplasts have been fitted by a three_exponential kinetic model. The slow lifetime fluorescence component is assigned to a collection of associated light harvesting Chl a/b proteins, the fast lifetime component to the reaction center of PSⅡ and the middle lifetime component to the delay fluorescence of recombination of P + 680 and Pheo -. The excited energy conversion efficiency (η) in PSⅡ RC is 87% and 91% respectively for the water hyacinth and spinach chloroplasts calculated on the 20 ps model. This interesting result is not consistent with what is assumed that the efficiency is 100% in PSⅡ RC. The results in this paper also present a support for the 20 ps electron transfer time constant in PSⅡ RC. On the viewpoint of excitation energy conversion efficiency, the growing rate for the water hyacinth plan is smaller than that for the spinach plant. But, authors' results show those plants can perform highly efficient transfer of photo_excitation energy from the light_harvesting pigment system to the reaction center (approximately 100%).

Invasion and control of water hyacinth (Eichhornia crassipes)in China

By the time of primary 21st century, water hyacinth had become a serious environmental problem in China. Water hyacinth contributes to the major part of ecological hazards from the invasion of foreign plant species, which is estimated about USD 7 billion a year in values. In the past 10 years, herbicides glyphosate, 2,4-D and paraquat have been used in controlling water hyacinth in China. Al- though the herbicides provided effective control on the weed in some areas, they could not provide the sustainable inhibition on the weed population, while would lead to pollution on water at various levels. At present, the herbicide application on water hyacinth is forbidden in many areas of China such as Shanghai. In this situation, the asexual reproduction inhibitor, KWH02, was invented for controlling water hyacinth and it provided about 70% of growth inhibition without any risk of dead plant pollution. It has been about 10 years for bio-control of water hyacinth in China. Works focused on mainly the efficacy and safety of the utilization of foreign insects. Researches on microorganism herbicides to control water hyacinth were started and obtained primary achievements in recent years. Although there are different opinions on how to face the water hyacinth problem in China, it is accepted widely that the control methods should be high efficient and safe with low cost. Some practical measures for integrated management of water hyacinth are suggested.

Performance of a water hyacinth(Eichhornia crassipes)system in the treatment of wastewater from a duck farm and the effects of using water hyacinth as duck feed

Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 mz was constructed on an egg duck farm, and water hyacinth （Eichhornia crassipes） was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks＇ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand （COD）, 21.78% of total nitrogen （TN） and 23.02% of total phosphorus （TP）. Both dissolved oxygen （DO） and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the differences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group （P 〈 0.05）, but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth. We concluded that a water hyacinth system was effective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.

Sorption of Manganese （II） and Chromium （III） Ions from Aqueous Solution Using Water Hyacinth Biomass （Eichhornia crassipes）

The use of water hyacinth biomass as adsorbent for Cr3＋ and Mn2＋ ions from aqueous solution by means of batch-adsorption technique was investigated to determine the potential ability of the biomaterial for metal ion removal. The equilibrium isotherm study showed that the maximum monolayer coverage on the biomass surface was 0.933 mg·g-1 and 0.874 mg·g-1 for Mn2＋ and Cr3＋ ions respectively. The highest percentage of Cr3＋ and Mn2＋ ions adsorbed by the biomass was 86.4% and 82.6% at the optimum pH of 4.0 and 6.0 respectively. The results also showed that the highest percentage removal 82.5% and 78.3% was obtained at 30 and 20 minutes respectively for Cr3＋ and Mn2＋ ions. The sorption process was examined by means of the Langmuir model. The adsorption equilibrium data were found to follow the Langmuir isotherm model with high coefficients of determination （R2 = 0.990 and 0.999） for Cr＋ and Mn2＋ ions respectively. The adsorption capacity of water hyacinth showed that water hyacinth will be useful in recovering chromium （III） and manganese （II） ions from solution and their subsequent removal from industrial effluents.

Extraction and Application of Natural Mordant Dyes from Eichhornia Crassipes(Water Hyacinth)

Metallic salts are often added as extra mordant when dyeing the fabrics with natural dyes. Eichhornia crassipes,namely water hyacinth( WH),is an environmentally problematic aquatic weed with high affinity for metals. In this paper,WH was selected as the source of natural mordant dyes,and extracted by absolute ethyl alcohol using a soxhlet apparatus. The colorants in WH were extracted and separated by column chromatography and thin layer chromatography( TLC). UV-visible spectrophotometer( UV-VIS),mass spectrometry, chemical identification with chromogenic reaction,and Fourier transform infrared spetroscopy( FTIR) were used to identify the main components of each pigment band. The total metal contents before and after extracting of the WH were determined by using an inductively coupled plasma atomic emission detector. The WH extracts were then used to dye wool fabric. The dyeing properties of WH extracts with and without metal mordant were investigated and compared. The results show that the main components of WH extracts are pheophytin and phyllins. The major metallic elements identified in WH are magnesium, manganese,zinc,and iron. Samples dyed with WH extracts without metal mordant exhibits high K / S values and good dyeing properties. This study indicates that the WH extracts can be used as a natural mordant dye on wool fabrics directly.

Adsorption of Caffeine and Ciprofloxacin onto Pyrolitically Derived Water Hyacinth Biochar： Isothermal, Kinetic and Thermodynamic Studies

In this work, the adsorptive features of water hyacinth （Eichhornia crassipes） derived biochar for sequestration of ciprofloxacin and caffeine from aqueous solution is reported. The isothermal behaviour, adsorption kinetics, mechanisms and thermodynamic parameters were investigated in batch mode. Langmuir and Freundlich models described the equilibrium adsorption data with regression values 〉 0.9. The kineticsdata obeyed the pseudo-second-order kinetic law while intraparticle pore diffusion was not the only rate controlling step. The computed thermodynamic parameters, namely change in Gibbs free energy （AG）, change in enthalpy （AH） and change in entropy （AS） indicated that the adsorption processes were spontaneous and exothermic with less randomness, pH dependence studies depicted multi-mechanistic adsorption for both compounds and is hypothesized to involve hydrophobic interactions besides other non-coulombic interactions. The findings demonstrate that water hyacinth biochar presents an excellent low cost and environmentally benign adsorbent for mitigation of pharmaceuticals from water with a removal efficiency of above 60 % for caffeine and ciprofloxacin.

Ethanol Production Process by Lignocellulosic Material Fermentation from Water Hyacinth Biomass

In order to take advantage of the lignocellulosic material in water hyacinth （Eichhornia crassipes）, dehydration pretreatment in the first step and then sodium hydroxide and hydrogen peroxide pretreatment was performed. The microorganism used for the fermentation process was Zimomonas mobilis. Batch fermentation experiments were carried out with four tests using 22 factorial design with two levels leadings to evaluate the effect of NaOH concentration, conditioning salts as independent variables and ethanol produced as a dependent variable. The optimum condition with higher amount of glucose hydrolyzed and ethanol was： substrate conditioning cellulases, it was pretreated 10% NaOH, with 92.38% conversion of glucose to ethanol and yield of 0.47 g ethanol per g of glucose and 0.018 g ethanol per g of biomass.

Influence of pH on Water Hyacinth Ponds Treating and Recycling Wastewater

This work has examined the effects of pH on the treatment efficiency and biomass production rate of water hyacinth ponds (WHP) treating domestic wastewater. Experiments were carried out outdoor in WHP, working under batch and subtropical environmental conditions, using pre-treated sewage with pH varying from 5 to 9. It was observed that the plants regulated the pH of the medium to within 6.4 to 7.1 during the treatment processes independently of influent wastewater pH ranges. This adjustment reduced the treatment performances and the biomass production in ponds, the alkaline conditions in ponds being less favorable to the activities of the plants. The optimal removal and biomass production was achieved with influent pH of 7 lying in the above interval. So the optimum influent pH for the growth of plants and the removal of nutrients and organic matters in WHP is within pH 6.4 to pH 7.1.

The Effect of Water Hyacinth （Eichhornia Crassipes） Infestation on Phytoplankton Productivity in Lake Naivasha and the Status of Control

The paper presents data collected in an assessment of the effects of water hyacinth （Eichhornia crassipes） infestation on phytoplankton productivity in Lake Naivasha. A summary of the status of control and strategies used is given. The ecological effects of water hyacinth on the lake have received little attention compared to the large body of work available on the weed＇s socioeconomic impact. This study was conducted to determine the effect of hyacinth infestation on the phytoplankton productivity. Several sampling stations were set up in the lake at sites containing floating mats of the weed and at sites where the weed was absent. Phytoplankton chlorophyll-a concentration and dissolved oxygen were measured at each station and used as proxies for phytoplankton productivity. The findings show that phytoplankton productivity in weed covered areas is reduced with significant change in species composition and biodiversity suggesting that water hyacinth can alter the ecology of the lake. Although water hyacinth has continued posing serious ecological consequences, the control strategies already adopted will continue to reduce deleterious impacts and allow sustained development in the Lake Naivasha Basin. There is need however to undertake research to quantify the level of ecological damage and the costs of control. There are other effects such as livelihood loss, diseases, and disruption of normal operations that also need to be quantified.

Separated Hydrolysis and Fermentation of Water Hyacinth Leaves for Ethanol Production

Water hyacinth is a raw material for long-term sustainable production of cellulosics ethanol. In this study, the acid pretreatment and enzymatic hydrolysis were used to evaluate to produce more sugar, to be fermented to ethanol. Separated hydrolysis and fermentation （SHF） studies were carried out to produce ethanol from water hyacinth leaves. Dilute sulfuric acid pretreatment and enzymatic hydrolysis were conducted to select the optimum pretreatment conditions. The optimum pretreatment conditions included T = 135 ℃, t = 30 min, and sulfuric acid concentration = 0.1 M. The residue was enzymatically hydrolyzed using the mixture of enzymes cellulase, xylanase and pectinase. The maximum enzymatic saccharification of cellulosic material （76.8%） was achieved. SHF by mono-culture of Saccharomyces cerevisiae KM1195 achieved the highest yields of ethanol. Furthermore, ethanol production was accomplished with the co-culture ofS. cerevisiae TISTR5048 and Candida tropicalis TISTR5045 which produced the highest increase in ethanol Yield. In this case, the ethanol concentration of 3.42 （g/L）, percentage of the theoretical ethanol yield of 99.9%, the ethanol yield of 0.27 g/g and the productivity of 0.22 g/L/h were obtained. This suggested that mild acid pretreatment and co-cultureare promising methods to improve enzymatic hydrolysis and ethanol production from water hyacinth.

Silage Feeding with Water Hyacinth in the Tropics: A Research Note

Water hyacinth has ecological significance in addition to its agricultural and energy uses. Lower quality silage is defined in this paper as requiring nitrogen supplementation and treatment to improve nutritive value (NV). Ensilage of water hyacinth as a test case centers largely around the process to optimize protein nitrogen retention in silage-based regimens. A previous hypothesis proposed earlier by the author of that of functional amino acid ratios [tyrosine (TYR): large neutral amino acids (LNAA), tyrosine (TYR): phenylalanine (PHE)] were subsequently found to be counter to what the given schemata predicts. And subsequently with another study there was no corroborative evidence for it to support the espoused hypothesis using the same schemata. The role of N status is still the most viable option among factors from studies continuing how amino acids like histidine (HIS) and arginine (ARG) and their growth-related endocrine functions play a role. There are other schemas illustrating non-homeostatic type regulation with protein intake. To focus on molecular-level mechanisms to ruminal protein digestion it is becoming clear what factors in feed and microbial cell fermentation contribute to optimizing microbial cell protein (MCP) synthesis from ATP with organic matter (OM) digestibility and preformed amino acids (PFAA) from peptides and free amino acids in addition to non-protein nitrogen (NPN), the former more efficiently assimilated in MCP than NPN in the rumen. Accordingly, it has been recommended that soluble proteins fed to dairy cows not exceed microbial requirements along with high dietary escape protein fed with a sufficient amino acid profile to meet dairy production.

GIS Based Approach to Determine the Changes of Water Hyacinth (Eichhornia crassipes) Cover and Relation with Lesser Whistling Teal (Dendrocygna javanica) Assemblage at Santragachi Wetland, West Bengal

The present investigation is conducted to study the year wise (2011to 2018) changes of water hyacinth (Eichhornia crassipes) cover atSantragachi Lake a Wetland under National Wetland ConservationProgramme of India. Further the relationship between water hyacinthcover and the most abundant migratory waterbirds of Satragachi, LesserWhistling Teal (LWT;Dendrocygna javanica) is assessed because this birdspecies is prefer depending on water hyacinth mat for their roosting. Thestudy comprises of eight satellite images procured from Google earth (2011to 2018) to explore this relationship. A marked decline in the number ofLWT at Santragachi wetland is observed in the year of 2017 and 2018. Itis very interesting fact that from 2017-2018, the water hyacinth mat of thiswetland is almost cleared before winter and the result of cluster analysissupports this fact. Significant positive correlation is also observed withinLWT number and water hyacinth cover area (r = 0.7481 at p< 0.05) alongwith the total perimeter (r = 0.8648 at p< 0.05) of the water hyacinthislands at Santragachi wetland. However, open water area is also neededfor diving, swimming, food searching for the LWT and other waterbirds.Therefore, more study is needed to optimize the clearing operations,focused on optimizing the shape and size of water hyacinth islands forproper management of the waterbirds habitat.

Study on Aerobic Composting of Mixed Municipal Sludge, Kitchen Waste and Water Hyacinth

In this study, a in vessel aerobic composting method is adopted to investigate the variation rules of various evaluation parameters （temperature, moisture content, pH, organic matter, water soluble ammonia nitrogen, water soluble nitrate nitrogen and germination index） in cocomposting of municipal sludge, kitchen waste and water hyacinth at different proportions. The results show that, in composting, the parameters of moisture content, pH, water soluble ammonia nitrogen and water soluble nitrate nitrogen demonstrate marked dynamic change rules during composting process; the temperature of three groups of compost materials rapidly rise to above 55 ~C within 96h, and last for 3 - 7d, meeting the harmless requirements, and their organic matter degradation rate excess 30%, the GI index is higher than 83%, in line with the requirements on maturity, which proves that the co-composting of municipal sludge, kitchen waste and water hyacinth can realize harmlessness and resource reutilization after composting.

Hydrothermal Liquefaction of Water Hyacinth: Effect of Process Conditions and Magnetite Nanoparticles on Biocrude Yield and Composition

In this work, an efficient way of converting the water hyacinth to biocrude oil using magnetite nanoparticles (MNPs) as potential catalysts was demonstrated for the first time. MNPs were synthesised by co-precipitation and used in the hydrothermal liquefaction (HTL) of water hyacinth at different reaction conditions (temperature, reaction time, MNPs to biomass ratio and biomass to water ratio). The best reaction conditions were as follows: temperature— 320, reaction time—60 minutes, MNPs to biomass ratio – 0.2 g/g and biomass to water ratio – 0.06 g/g. HTL in presence of MNPs gave higher biocrude yields compared to HTL in absence of MNPs. The highest biocrude yield was 58.3 wt% compared to 52.3 wt% in absence of MNPs at similar reaction conditions. The composition of biocrude oil was analysed using GC-MS and elemental analysis. GC-MS results revealed that HTL in presence of MNPs led to an increase in the percentage area corresponding to hydrocarbons and a reduction in the percentage area corresponding to oxygenated compounds, nitrogenated compounds and sulphur compounds. Elemental analysis revealed an increase in the hydrogen and carbon content and a reduction in the nitrogen, oxygen and sulphur content of the biocrude when HTL was done in presence of MNPs compared to HTL in absence of MNPs. The nanoparticles were recovered from the biochar by sonication and magnetic separation and recycled. The recycled MNPs were still efficient as HTL catalysts and were recycled five times. The application of MNPs in the HTL of water hyacinth increases the yield of biocrude oil, improves the quality of biocrude through removal of hetero atoms, oxygen and sulphur compounds and is a potentially economical alternative to the traditional petroleum catalysts since MNPs are cheaper, widely available and can be easily recovered magnetically and recycled. This will potentially lead to an economical, environmentally friendly and sustainable way of producing biofuels from biomass.

Evaluation of Sunlight and Humidity Protection of a Bioherbicide for Eichornia crassipes Biocontrol

C. piaropi （Cercospora piaropi） and A. zonatum （Acremonium zonatum） have proved to be effective in reducing water hyacinth growth. However, efficacy of these fungi in field is limited by the effect of solar UV （ultraviolet） light and desiccation. In this study, three compounds used as sunscreens and one seed plant that produce mucilage were tested for their effects on the infection produced by C. piaropi and A. zonatum inoculum under laboratory and field conditions. In laboratory conditions, TiO2 （titanium dioxide） and metamucil did not inhibit C. piaropi and A. zonatum viability. Moreover, the addition of TiO2 and metamucil to the inoculum suspension increased fungi infection. The protective effect of TiO2 and metamucil was more evident when the inoculum suspension was applied 4 h before sunset. These results suggest that addition of TiO2 and metamucil provides necessary humidity and solar protection for increasing C piaropi and A. zonatum infection on water hyacinth plants.

Influence of Organic and Inorganic Fertilizers on Floating Bed Cultivation of Okra and Cucumber during Summer Season in Southern Part of Bangladesh

Some trails were carried out with a view to evaluate the performances of organic and inorganic fertilizers on growth and yield of okra (Abelmoschus esculentus L.) and cucumber (Cucumis sativus L.) in floating bed cultivation applying water hyacinth in 2014 and 2015 at Gopalpur union under Tungipara upazila of Gopalganj district in Bangladesh. The single factor experiment was conducted following Randomized Complete Block Design (RCBD) involving four treatments with three replications viz. T1: control (without organic and inorganic fertilizer), T2: cow dung, T3: recommended dose of NPK and T4: 50% cow dung + 50% recommended dose of NPK. Different growth parameters in respect of okra grown in 2014 and 2015, the longest plant height (171.73 cm and 164.03 cm), maximum number of branches (5.67 and 5.67) and leaves (60.33 and 69.67) were found in the treatment T3. Regarding yield parameters, significantly higher number of fruits plant-1, fruit length (cm), fruit diameter (cm), individual fruit weight (g), fruits weight plant-1 (g) and yield (t·ha-1) were 24.00 & 23.33, 16.61 & 16.59 cm, 6.01 & 6.17 cm, 23.47 & 24.74 g, 617.33 & 660.33 g, 13.01 & 13.21 t·ha-1 obtained respectively grown in 2014 and 2015 by applying the treatment T3 were identically similar with those in receiving the treatment T4. The lowest output was recorded in control in both seasons for all the cases. Similar trend of growth and yield were also observed during the cultivation of cucumber under the same treatment conditions in both the seasons. Results revealed that there was no identical differences in growth and yield attributes in between the treatments T3 and T4, where as the production cost was subjected to lower in T4 compare to T3. However, from the economic point of view, the treatment T4 i.e. application of 50% cow dung + 50% recommended dose of NPK fertilizers in floating bed cultivation was exposed to be more feasible and suitable as cost effective for the growth and yield of okra and cucumber in the experimental area.