Embryonic Developmental Response of Nile Tilapia (Oreochromis niloticus) to Different Aquatic Incubation Media

Application of ready-mix herbicides containing two active ingredients in rice to manage broad group of weeds is in practice currently. Among different ready mix formulations, one comprising pyrazosulfuron-ethyl and pretilachlor have been recently registered in India. Though, the persistence of each herbicide in soil under rice as single formulation was reported, the information on persistence of herbicides from ready-mix formulations is not reported under semi-arid tropical conditions of India. Hence, an experiment was conducted to study the dissipation and fate of these ready-mix formulation herbicides in rice soil, water and in rice grain. Pyrazosulfuron-ethyl and pretilachlor residues were determined using high performance liquid chromatograph (HPLC) and gas chromatograph (GC), respectively. The average recoveries of pyrazosulfuron-ethyl and pretilachlor from matrix ranged from 80.3–103.3% with less than 10% standard deviation and sensitivity up to 0.001 μg/g. Both herbicides showed rapid dissipation in rice field water than soil and the degradation followed first order reaction kinetics. While pyrazosulfuron-ethyl dissipated with a half-life of 2.17–5.45 and 0.77–0.79 days respectively in rice field soil and water, pretilachlor dissipated with a half-life of 5.18–6.68 days in soil and 2.59–3.00 days in field water. Pyrazosulfuron-ethyl has shorter half-life than pretilachlor and both the active ingredients dissipated rapidly in rice field soil than water. At harvest, the residues of both the herbicides in rice grain and straw were below the MRLs set by FSSAI.

Modelling of water and nitrogen balances in the ponded water and soil profile of rice fields in Northern Greece

We investigated the role of an entomogenic gut bacterium Pseudomonas fluorescens on larval development and survival of Culex vishnui Theobald, the mosquito vector of Japanese encephalitis, which breeds exclusively in rice field water in tropical regions. The bacterium could be isolated from the midguts of third and fourth instars of the mosquito. Pseudomonas fluorescens strain 1 (Ps1) was identified as the one vital to C. vishnui larval survival. The phenotypic characteristics of this strain are described. As part of the study, antibiotics were used to cure C. vishnui larvae of Psl; thus cured larvae did not survive when subsequently reared in sterile or antibiotic-treated rice field water or tap water. In contrast, 93.3-100% of cured larvae developed into normal adults when subsequently reared either in unsterile or in sterile rice field water or in tap water containing Psl bacteria (5 X 10 ml). Thus the elimination of Psl from breeding water could be used as a strategy to suppress the mosquito growth, as part of an innovative approach to control Japanese encephalitis.

Copper (II) complexation in northern California rice field waters: an investigation using differential pulse anodic and cathodic stripping voltammetry

Introduction: Agriculture plays an important role in Indonesia's international development, providing rice, corn and wheat to meet the needs of the community. Agricultural development can increase food availability and food security, as well as improve the economy and welfare of the community. One of the villages in Banyuwangi, namely Ketapang Village, is an area where most of the population works in the agricultural sector. KCl fertilizer is one type of fertilizer that is often used in rice fields to increase rice yield. Objective: This study aims to analyze chloride levels in rice field water after fertilization using KCl fertilizer, with the aim of determining the effectiveness of fertilizers that can be absorbed by plants. Methods: This research was conducted at the Chemistry Laboratory of STIKES Banyuwangi in March 2024. Mohr's Argentometric titration method was used for chloride analysis. Rice field water samples were collected from Ketapang Village. Results: The analysis showed significant variation in the percentage of chloride absorbed by plants at eight different paddy field sites after fertilization with KCl. The percentage of chloride absorbed ranged from 49.37% to 97.31%. Conclusions: The analysis showed significant variation in the percentage of chloride absorbed by plants after fertilization with KCl. Sites with a high percentage of chloride content can be considered a good indicator of fertilizer effectiveness, indicating that plants are able to absorb nutrients optimally. This has important implications in evaluating the quality of fertilization applied by farmers and can contribute to increased productivity and health of rice plants.

Molluscicide of fentin acetate (C20H18O2Sn) is commonly used at the present due to effective in terms to control of molluscs in the rice field. The aims of this experiment is to determine toxicity effect of fentin acetate on growth, productivity, and blood glucose on the common carp, Cyprinus carpio cultured at rice field water. A 12 of rice field plots with size of 25m2 each were used. The stocking density of common carp was 25 fish/m2 for each rice plot. The culture period of the common carp was 21 days. The different fentin acetate concentration as treatments were as followed M0) without molluscicide; M1) 0.375 g/L of molluscicide; M2) 0.75 g/L of molluscicide); and M3) 1.5 g/L of molluscicide. Statistical analysis using one-way ANOVA with three replicates for each treatment was performed. The result showed that the treatment of molluscicide at 0.75 g/L was significantly different to the others on survival rate and productivity (p<0.05). Application of 0.75 g/L of molluscicide showed a positive correlation on blood glucose value.

Photodegradation can be a major route of dissipation for pesticides applied to shallow rice field water, leading to diminished persistence and reducing the risk of offsite transport. The objective of this study was to characterize the aqueous-phase photodegradation of clothianidin under simulated California rice field conditions. Photodegradation of clothianidin was characterized in deionized, Sacramento River and rice field water samples. Pseudo-first-order rate constants and DT50 values in rice field water (mean k = 0.0158 min(-1) ; mean DT50 = 18.0 equivalent days) were significantly slower than in deionized water (k = 0.0167 min(-1) ; DT50 = 14.7 equivalent days) and river water (k = 0.0146 min(-1) ; DT50 = 16.6 equivalent days) samples. Quantum yield ϕc values demonstrate that approximately 1 and 0.5% of the light energy absorbed results in photochemical transformation in pure and field water respectively. Concentrations of the photodegradation product thiazolymethylurea in aqueous photolysis samples were determined using liquid chromatography-tandem mass spectrometry and accounted for ≤17% in deionized water and ≤8% in natural water. Photodegradation rates of clothianidin in flooded rice fields will be controlled by turbidity and light attenuation. Aqueous-phase photodegradation may reduce the risk of offsite transport of clothianidin from flooded rice fields (via drainage) and mitigate exposure to non-target organisms. © 2015 Society of Chemical Industry.

SWAGMAN Options: A hierarchical multicriteria framework to identify profitable land uses that minimize water table rise and salinization

Young coconut fibers, often found as waste, contain tannin and anthocyanin compounds that can produce various natural colors, so they can be used as organic dyes. The research method used was an experiment with a focus on testing silk thread dyeing using young coconut fiber extract dissolved in rice field water. This study aims to explore and develop the use of young coconut fibers as a source of environmentally friendly natural dyes. The results showed that young coconut fibers have the potential as organic dyes. Young coconut fiber extract with fermented rice field water solvents produced three color variations depending on the fixator used: brownish black (ferrous sulfate), gray (alum), and brown (lime). Structural tests using Scanning Electron Microscopy (SEM) proved that the dyeing process did not change the cross-sectional shape of the silk thread. In terms of tensile strength, yarn with alum fixation had the highest strength compared to native yarn, ferrous sulfate fixation, and lime fixation. Elongation tests showed the highest elasticity in yarn with alum fixation, followed by lime, ferrous sulfate, and native yarn. The color fastness test against washing at a temperature of 40°C showed a fairly good level of fastness for organic dyes from young coconut fiber

Nitrogen is one of the most deficient plant nutrients in Bangladesh soils. The nitrogenous fertilizer especially prilled urea is a commonly used fertilizer for rice production but its efficiency is very low under traditional broadcast method. Urea is available as prilled urea, urea supergranule and also as NPK briquette for use by the framers. A field experiment was carried out in the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh on Aus rice (May-August) during the cropping season of 2014 to assess the effects of different forms of urea (prilled urea, urea briquette and NPK briquette) on growth, yield, and nitrogen use efficiency of BRRI dhan48. There were six treatments as T1 [check (N0P16K42], T2 [Urea briquette (one-3.4 g) (N52P16K42)], T3 (Urea briquette (one - 2.7 g (N78P16K42)], T4 [NPK briquette (one-3.4g) (N51P13K32], T5 [prilled urea (N78P16K42)] and T6 [NPK briquettes (two - 2.4 g briquettes (N78P15K42)]. The experiment was laid out in a Randomized Complete Block Design with four replications. Prilled urea was applied in two equal splits; at 8 days after transplanting (DAT) and the second split after 38 DAT, while for urea briquettes and NPK briquettes were deep placed (8-10 cm depth) at 8 DAT between four hills at alternate rows. Water samples from each treatment of rice fields were collected after first split application of urea and deep placement of urea briquette and NPK briquette and the second sampling was done after second split of urea. Every sampling was done consecutively for 7 days for measuring NH4+-N. The results showed that the NH4+-N concentration in rice field water reached to maximum on day 2 in PU treated plots and then decreased with time, while in urea briquettes and NPK briquettes treated plots has very low amount of NH4+-N in the rice field water. The highest grain yield of 4.75 t ha-1 (69% over control) was obtained in the treatment T3. The treatment T3 also produced the highest straw yield of 5.49 t ha-1. The maximum apparent N recovery and the maximum N use efficiency were found in the treatment T4. Deep placement of urea briquettes and NPK briquettes reduced N-losses and enhanced the recovery of applied N as well as N use efficiency in comparison with PU application.

The levels of DDTs, HCHs and PCBs in topsoil, cereal and irrigation water from typical industrial and agricultural areas of Jilin Province in Northeastern China were evaluated by using gas chromatography coupled with an electron capture detector. The amount of ∑OCPs and ∑(7)PCBs found in topsoils ranged from 24.7 to 98.0 and 17.2 to 98.7 ng g(-1), respectively. The geometric means of ∑HCHs, ∑DDTs and ∑(7)PCBs in rice stem samples were 28.9, 32.4 and 49.0 ng g(-1), respectively. The average level of total OCPs concentration in rice field water in Meihekou area (0.849 ng g(-1)) is higher than that in Jilin area (0.178 ng g(-1)) and all OCPs concentrations in rice field water met the water quality standards for Grade I regulated by China's national environmental quality standard of surface water.

The rice stink bug (Oebalus pugnax) is the major pest of late-season rice in Louisiana. Prior studies indicate that large populations of mosquitoes are often present in rice fields during the time that rice fields are infested with rice stink bugs. Lambda-cyhalothrin (Karate®) is widely used to control rice stink bugs. The purpose of this study was to determine if application of the insecticide Karate® at a rate of 0.033 kg/ha, for rice stink bug control had an effect on the population of mosquitoes in rice fields. This effect was assessed by monitoring natural populations of mosquitoes before and after applications of Karate® in simulated rice paddies at the LSU AgCenter Rice Research Station (Crowley, Acadia Parish, Louisiana) during the summers of 2003, 2004 and 2005. In 2005, monitoring of native mosquito population was complemented by the use of sentinel cages with Culex quinquefasciatus Say larvae and exposure of Cx. quinquefasciatus larvae to treated rice field water in the laboratory. The number of larvae in Karate® plots decreased after Karate® applications but a significant overall effect was observed only after the first application of 2004 (p=0.034). Mortality of larvae in sentinel cages (p=0.0386) and of larvae exposed to rice field water at 48hrs (p=0.0130) was also observed in some cases. A test conducted in a large rice plot with sentinel cages confirmed the effect of Karate on mosquito larval populations (p=0.0012). An additional effect of foliar Karate residues on adult Cx. quinquefasciatus mosquitoes was observed in the laboratory (2004, 2005). Higher mortality was detected in adults exposed to rice foliage treated with Karate than the untreated control. Another factor that could influence the number of larvae present in rice fields is the oviposition response of mosquitoes to the presence of predatory insects. To test this response, Cx. quinquefasciatus adult mosquitoes were exposed in cages to water conditioned by previous exposure to potential aquatic predators. According to the Oviposition Activity Index (OAI), female mosquitoes preferred to lay eggs in water conditioned water rather than distilled water. The highest OAI was obtained with the Hydrophilidae-conditioned water.

The hydrolysis of chlorantraniliprole (3-bromo-N-[4-chloro-2-methyl-6-(methylcarbamoyl)phenyl]-1-(3-chloro-2-pyridine-2-yl)-1H-pyrazole-5-carboxamide; CAP) was investigated over the pH range of 6-10, reflective of California rice field conditions, with variable additions of Cu2+, Zn2+, Mn2+, or Ni2+. Dissipation accelerated as pH increased with half-lives ranging from 26.9 to 2.2 days with slight inhibition in rice field water. The addition of divalent metals was not observed to catalyze the hydrolysis of CAP at pH 6, indicating that the insecticide is likely to remain recalcitrant to hydrolysis in neutral or acidic surface waters. However, Mn2+ and Ni2+ were observed to inhibit hydrolysis at pH 8 and 9. Attenuated total reflectance Fourier transform infrared analysis supports the conclusion that divalent metals may withdraw electron density from the amide nitrogen via interaction with the amide oxygen, though additional quantum chemical modeling is necessary to provide further mechanistic insights. Overall, the hydrolysis of CAP in California rice fields and their surrounding surface waters will be dominated by pH and inhibited by dissolved metal species.

Benzobicyclon [3-(2-chloro-4-(methylsulfonyl)benzoyl)-2-phenylthiobicyclo[3.2.1]oct-2-en-4-one] is a pro-herbicide used against resistant weeds in California rice fields. Persistence of its active product, benzobicyclon hydrolysate, is of concern. As an acidic herbicide, the neutral species photolyzed faster than the more predominant anionic species ( t1/2 = 1 and 320 h, respectively; natural sunlight), from a >10-fold difference in the quantum yield. Dissolved organic matter in natural waters reduced direct photolysis and increased indirect photolysis compared to high-purity water. Light attenuation appears significant in rice field water and can slow photolysis. These results, used in the pesticides in flooded applications model with other experimental properties, indicate that a floodwater hold time of 20 days could be sufficient for dissipation of the majority of initial aqueous benzobicyclon hydrolysate prior to release. However, soil recalcitrance of both compounds will keep aqueous benzobicyclon hydrolysate levels constant months after benzobicyclon application.

Isoproturon (ISO), an herbicide belonging to the phenyl urea family, is extensively used in modern agriculture to guarantee a bumper harvest. However, it has been evidenced that the ISO has heavy toxicity to the liver system and appears to be a tumor promoter. It is therefore urgent to develop sensitive and selective methods to screen its presence in food resources to meet the ever-increasing pollution restrictions. In this work, an electrochemical sensor based on graphene oxide–modified multi-walled carbon nanotubes hybrid material was firstly developed for the rapid and sensitive detection of ISO via square wave voltammetry (SWV). Under optimized experimental conditions, the sensor exhibits a relatively wide linear range from 0.30 to 15.0 μmol L−1, a low limit of detection (LOD) of 0.10 μmol L−1, as well as good repeatability, high reproducibility, excellent selectivity, and long-term stability. The sensor has also been successfully employed in various real samples such as rice field water, tomato, and lettuce analyses. The obtained recoveries are in the range of 97.33–105.0% with low relative standard deviation (less than 2.5%), which is very close to the results of the high-performance liquid chromatography (HPLC), showing the proposed electrochemical sensor has great potential in practical applications.