Papers by Dr. Susheel SIngh
ACS Omega
The quorum sensing (QS) system of bacteria helps them to communicate with each other in a density... more The quorum sensing (QS) system of bacteria helps them to communicate with each other in a density-dependent manner and regulates pathogenicity. The concentrations of autoinducers, peptides, and signaling factors are required for determining the expression of virulence factors in many pathogens. The QS signals of the pathogen are regulated by the signal transduction pathway. The binding of signal molecules to its cognate receptor brings changes in the structure of the receptor, makes it more accessible to the DNA, and thus regulates diverse expression patterns, including virulence factors. Degrading the autoinducer molecules or disturbing the quorum sensing network could be exploited to control the virulence of the pathogen while avoiding multidrug-resistant phenotypes. The rhizosphere is a tremendous source of beneficial microbes that has not yet been explored properly for its anti-quorum sensing potential. Lelliottia amnigena causes soft rot diseases in onion, potato, and other species. The present investigation was carried out with the aim of isolating the anti-quorum sensing metabolites and elucidating their role in controlling the virulence factors of the pathogen by performing a maceration assay. The ethyl acetate extracts of various bacteria are promising for violacein inhibition assay using Chromobacterium violaceum MTCC2656 and pyocyanin inhibition of Pseudomonas aeruginosa MTCC2297. Therefore, the extract was used to deduce its role in attenuation of soft rot in potato, carrot, and cucumber. The maximum reduction of macerated tissue in carrot, potato, and cucumber was given by Bacillus cereus RC1 at 91.22, 97.59, and 88.78%, respectively. The concentrationdependent inhibition of virulence traits was observed during the entire experiment. The quorum quenching potential of the bacterial extract was used to understand the regulatory metabolites. The data of the diffusible zone and gas chromatography−mass spectrometry (GC−MS) analysis showed that diketopiperazines, viz. Cyclo(D-phenylalanyl-L-prolyl), Cyclo Phe-Val, Cyclo(Pro-Ala), Cyclo(L-prolyl-L-valine), Cyclo (Leu-Leu), and Cyclo(-Leu-Pro), are prominent metabolites that could modulate the pathogenicity in L. amnigena RCE. The interaction of bacterial extracts regulates various metabolites of the pathogens during their growth in liquid culture compared to their control counterparts. This study might help in exploiting the metabolites from bacteria to control the pathogens, with concurrent reduction in the pathogenicity of the pathogens without developing antibiotic resistance.
Heliyon, 2020
Ashwagandha (W. somnifera Dunal. Linn.), known as Indian ginseng, contains three major bioactive ... more Ashwagandha (W. somnifera Dunal. Linn.), known as Indian ginseng, contains three major bioactive compounds, withaferin-A (WA), 12-deoxywithastramonolide (WO) and withanoloide A (WD). In a field experiment, the impacts of foliar application of growth retardants/promoters was assessed with respect to biomass allocation pattern and major withanoloide content at different phenological stages in W. somnifera. Biomass accumulation pattern showed that foliar application of 500 mg l À1 ethrel at 50, 65, 85, 105, and 120 days after sowing (DAS) restricted phenological progression and reduced berry weight by 61% as comparted to the control at 160 DAS. 500 mg l À1 succinic acid foliar application resulted in maximum plant height (56.4 cm), maximum dry stem weight (DWS) and dry root weight (DRW) whereas 500 mg l À1 ethrel had resulted in minimum plant height and DRW at 180 DAS. During last 50 days of crop growth, the accumulation pattern drastically changed with more than 60% of the biomass allotment to the reproductive part, the berries. The WD in roots ranged between 0.325 mg g À1 and 0.342 mg g À1 during all growth stages. WA content decreased with increase in progression of crop growth and reached the lowest at 180-190 DAS. In a pot experiment, ethrel application up regulated DWF-5 by 2.44, SQE by 3.79 and CYP450s by 1.17 log2fold in roots 8 h after treatment and succinic acid had up regulated the expression of all these genes by nearly 3 log2fold change. This is in accordance with the withanoloide accumulation pattern in field condition under foliar application of these molecules.
Journal of Agrometeorology
Journal of Agrometeorology, 2017
Brinjal is a major solanaceous vegetable crop of India. It contributes about 12.51 per cent of th... more Brinjal is a major solanaceous vegetable crop of India. It contributes about 12.51 per cent of the total production of vegetables in India (Bochalya et al., 2012). The major risk to brinjal cultivation is the susceptible and wide spread attack by fruit and shoot borer. Among16 pest species attacking on brinjal crop, shoot and fruit borer (Leucinodes orbonalis) is most devastating pest in Gujarat (Patel et al., 1970).Weather play a vital role in the biology of any pest.The interaction between pest activity and abiotic factors helps in deriving a predictive model that aids in forecast of pest incidence. To find out the role of weather parameters such on seasonal abundance of brinjal shoot and fruit borer, the experiment was carried out at College farm of N. M. College of Agriculture, Navsari Agricultural University, Navsari during the rabi season of 2012 and 2013. The experiment was laid out in randomized block design with gross plot area of 400 m 2 and spacing of 90 cm x 60 cm. Recommended dose of fertilizers (100: 50: 50 kg NPKha-1) were applied to the crop. The observations of brinjalshoot and fruit borer pest were taken at weekly interval up to harvest of the crop. For recording the observations, 30 plants were selected and tagged from experimental plot area and the observations of shoot and fruit borer were taken and obtained data were converted into per cent of damage.In order to find out the specific impact of different weather parameters on brinjal shoot and fruit borer, the data were correlated with the different meteorological parameters. The averaged data of two years (2012 and 2013) of seasonal occurrence of shoot and fruit borer (Fig. 1) revealed that, the damage due to shoot borer satsted in 44th SMW and reached to its maximum (8%) during 48 and 49 SMW. The occurrence of fruit borer pest appearance was initiated from 46 th SMW (1.6 %) till 21 st SMW (5.3 %). The highest infestation was observed during 6 th , 11 th and 13 th SMW for pest appearance with 34.7, 36.1 and 35.6 per cent fruit damage, respectively. The simple correlation on shoot damage due to shoot borer (Table_2) indicated highly
Journal of Food Science and Technology, 2013
Micronutrients are essential elements needed in small amounts for adequate human nutrition and in... more Micronutrients are essential elements needed in small amounts for adequate human nutrition and include the elements iron and zinc. Both of these minerals are essential to human well-being and an adequate supply of iron and zinc help to prevent iron deficiency anaemia and zinc deficiency, two prevalent health concerns of the developing world. The levels of zinc and, iron were measured in the Banana, Papaya, Rice, Finger millet, Soybean and Urdbean. Standard Atomic absorption spectroscopy (AAS) method was also applied to all the samples for zinc and iron analysis and compared with inductively coupled plasma mass spectroscopy (ICP-MS). It was observed that there was no matrix interference affecting the determination of both elements interested in all the samples analyzed. Average concentration relative standard deviation and standard deviation were used for the statistical evaluation of the results for both elements. Correlation coefficient was used as statistical model to compare both the techniques.
Heliyon, 2021
Pigeonpea (Cajanus cajan L.) is an annually cultivated food and forage crop, attacked by a large ... more Pigeonpea (Cajanus cajan L.) is an annually cultivated food and forage crop, attacked by a large number of pests mainly pod borer (Helicoverpa armigera). For the control of this insect pest, a combination of broad-spectrum insecticides viz., chlorantraniliprole and λ-cyhalothrin have been in use to reduce the pod damage and increase crop production worldwide. Therefore, a field trial was conducted to study dissipation and persistence behavior of insecticides combination (Chlorantraniliprole 9.26 % + λ-cyhalothrin 4.63 % ZC) in/on pigeonpea at the recommended dose (RD) 30 g a.i./ha and double recommended dose 60 g a.i./ha (2RD). The quantitative analysis was performed using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) for chlorantraniliprole and Gas chromatography with electron captured detector (GC-ECD) for λ-cyhalothrin. The Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method was validated for its accuracy, precision and sensitivi...
With a view to study the dissipation of individual insecticide of an effective combination produc... more With a view to study the dissipation of individual insecticide of an effective combination product β-cyfluthrin (9%) and imidacloprid (21%) in brinjal, field experiment was conducted during Rabi 2007–08. The product was applied as foliar spray thrice at weekly interval during flowering stage @ 18 + 42 g a.i. ha−1 and 36+84 g a.i. ha−1. Immediately afterapplication β-cyfluthrin in brinjal fruit was detected below its limit of quantitation (LOQ) at the standard dose. However, at higher dose the initial deposit of 0.037 μg g−1 reached below LOQ on the third day. The corresponding levels for imidacloprid in brinjal fruits one hour after application were 0.035 and 0.062 μg g−1 respectively, which reached below its LOQ on the 5th and 10th day. The half-life (DT50) of imidacloprid in brinjal fruits was 1.67 and 3.82 days at standard and higher dose. Nonetheless, the half-life value of 1.83 days for β-cyfluthrin was obtained only at higher dose. The content of β-cyfluthrin being only 30% of...
Notulae Scientia Biologicae
Sapota, a prominent and economically important fruit crop of India is susceptible to several spec... more Sapota, a prominent and economically important fruit crop of India is susceptible to several species of insect and mite pests. Several pesticides formulations are used to control the pest damage in sapota. The present investigation was aimed to study the dissipation and persistence behaviour of combi-product profenofos 40% + cypermethrin 4% (44EC) at the standard dose (SD) (1162 g a.i. ha-1+106 g a.i. ha-1) and double to standard dose (2×SD) (2324 g a.i. ha-1+212 g a.i. ha-1) in/on sapota under tropical agro-climatic conditions of South Gujarat in India. Prior to quantitative analysis of pesticide residue on Gas chromatography with electron captured detector (GC-ECD), the modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) based method was validated on its accuracy, precision, linearity and sensitivity. Profenofos persisted in sapota up to 30 days with the half-lives of 5.65 and 7.34 days at SD and 2×SD, respectively. Cypermethrin dissipated at a rapid pace and was be...
International Research Journal of Pure and Applied Chemistry
A field experiment was conducted to determine the dissipation kinetics of carbofuran and its meta... more A field experiment was conducted to determine the dissipation kinetics of carbofuran and its metabolite (Carbofuran 3-OH) in the soil and their terminal residue in sugarcane. The experimental plots were subjected to application of carbofuran 3G (1.0 kg a.i./ha) at the time of planting and 60 days after planting of sugarcane variety CoN 07072 grown with recommended agronomic practices. The soil samples were periodically collected at 0 (2 hrs.), 1, 3, 5, 10, 20, 30, 60 and 90 days after last application of carbofuran. QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) based extraction method adopted to quantify the residues of carbofuran on LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry) from soil, sugarcane juice and leaves were found accurate, sensitive and precise enough. Residues of carbofuran and total carbofuran (Carbofuran + Carbofuran 3-OH) were observed upto 30 days after application and reached below quantification level at 60 days after applic...
International Research Journal of Pure and Applied Chemistry
Pesticides are important to the success of agriculture as well as an inevitable factor to maintai... more Pesticides are important to the success of agriculture as well as an inevitable factor to maintain good public health. Over the years, the consumption of pesticides has increased manifold, particularly during the past two decades. However, this increase has caused great concern over the presence of residues or leftover pesticides in the environment. The understanding of adsorption and desorption behavior of different pesticides is an important phenomenon to describe the fate of pesticide in soil and other environmental compartment like water and sediment. The soil is considered as ultimate sink of pesticide as these were reached to soil directly or indirectly from the point/non-point sources. Adsorption–desorption processes are necessary in understanding pesticides retention behavior and its potential mobility within the soil. The behavior of pesticides in the soil depends on factors such as the physico-chemical properties of pesticides, the active surface of mineral, organic compon...
International Journal of Chemical Studies
A study was performed to determine the effect of soil amendments on persistence of hexaconazole a... more A study was performed to determine the effect of soil amendments on persistence of hexaconazole and tebuconazole in soil and its residues in tomato. A typical black cotton soil was amended with FYM, gypsum, biocompost @ 5 tonnes/ha. The amended and unamended soils were treated with hexaconazole and tebuconazole at the rate of 2 mg/kg. Analytical protocol adopted for the analysis of residues of th ese fungicides from unamended and amended soil, and tomato fruits were validated. The linear range of hexaconazole was 0.05-1.0 mg/kg and for tebuconazole was 0.25-5.0 mg/kg on GC-ECD and GCMS-ITD, respectively. The extraction procedure for soil (amended and unamended) and tomato fruits were accurate and precise as the recovery and % RSD of hexaconazole and tebuconazole in amended and unamened clay soil and tomato fruits were in the range of 74.88-112.98 and 1.56-16.0%, respectively. The LOD and LOQ of analytical method was less than 0.1 mg/kg for all the matrices analyzed. The persistence of hexaconazole was highest in soil amended with gypsum (DT50, 77 days) followed by biocompost (DT50, 68 days), FYM (DT50, 57 days) and without amendment (DT50, 45 days) soil. However, persistence of tebuconazole was highest in bio-compost (DT50, 69.31 days) amended soil followed by FYM (DT50, 66.01 days), gypsum (DT50, 43.87days) and unamended (DT50, 37.46 days) soil. The terminal residues of hexaconazole and tebuconazole in soil and tomato were correlated but impact of hexaconazole residues in soil on its terminal residues in tomato is quite high with respect to tebuconazole.
International Journal of Chemical Studies
to study the dissipation behaviour of fipronil and its metabolites in sugarcane grown soil. The f... more to study the dissipation behaviour of fipronil and its metabolites in sugarcane grown soil. The fipronil 0.3 GR was applied at standard and double dose i.e. 100 and 200 g ai ha-1 in gross plot when sugarcane crop was four month old. The soil sampling was done at 0 (2 hrs.), 1, 3, 5, 10, 20, 30, 60 and90 days after application of fipronil. In method verification, acetonitrile based extraction and dispersive cleanup approach adopted to quantify the residues of fipronil and its metabolites with gas chromatography (GC-ECD) from soil was accurate, precise and sensitive enough. Persistence study indicated that residues of fipronil progressively dissipated and reached BQL (<LOQ) at 90 day after application at both doses. The dissipation rate of fipronil was faster in first phase i.e. upto 20 days with respect to second phase (20-60 days). The DT50 and DT90 values of sum total of fipronil and its metabolites was 23.7 and 32.9 days, respectively for single dose and 78.8 and 109.2 days, respectively for double dose.
International Journal of Current Microbiology and Applied Sciences
Following three applications of flubendiamide at 60 and 120 a.i. ha-1 at 10 d interval resulted i... more Following three applications of flubendiamide at 60 and 120 a.i. ha-1 at 10 d interval resulted in average initial deposits of 0.22 and 0.31 mg g-1 respectively. These levels gradually declined and reached below its determination limit of 0.05 µg g-1 after 3 and 5 d at single and double of the recommended doses, respectively. detectable at 3 rd and 5 th d after application in lower and higher dose, respectively. Half-life (t 1/2) of flubendiamide on chilli was observed to be 1.12 and 1.76 d, at single and double dosages, respectively. Desiodo metabolite was BDL on 0 d at 60 g a.i. but its level was 0.08 mg g-1 on d 1 which declined below limit of determination of 0.05 µg g-1 after 3 d. At application rate of 120 a.i. ha-1 desiodo metabolite was detected at the level of 0.07 and 0.08 mg g-1 respectively on 0 d and 1 d and came to BDL on 3 rd d. The application of thiacloprid at 60 and 120 a.i. ha-1 resulted in the residue level of 0.15 and 0.21 mg g-1 respectively, one h after application. The levels gradually declined and reached below detectable at 5 th and 7 th d after application in lower and higher dose, respectively. Half-life (t 1/2) of thiacloprid on chilli was observed to be 2.17 and 2.13 d, at single and double dosages, respectively. Red chilli and soil samples collected after 20 d did not reveal the presence of flubendiamide, its metabolite desiodo and thiacloprid.
Pesticide Research Journal
With a view to study the dissipation of spiromesifen in/on okra, a field experiment was conducted... more With a view to study the dissipation of spiromesifen in/on okra, a field experiment was conducted at the Main Vegetable Research Station, Anand Agricultural University, Anand during kharif, 2008. The foliar application of the insecticide was carried out twice at 10 d interval @ 120 and 240 g a.i. ha-1 at fruiting stage of the crop. Samples of okra fruits were drawn at 0, 1, 3, 5, 7, 10, 15 and 20 d after second spray. Soil samples were also collected on 20 th d after second application. The initial deposits of spiromesifen on okra fruits were 0.964 and 1.819 mg g-1 at standard and double the standard dose of application, respectively. The residues gradually declined and persisted upto 3 rd and 5 th d at lower and higher dose, respectively. The residues reached below quantitation limit of 0.01 µg g-1 on the 5 th and 7 th d at standard and double the standard dose, respectively. Halflife of the insecticide on okra fruits was 1.68 and 1.65 d for standard and higher dose, respectively. Soil samples analyzed on the 20 th d after the last spray revealed residues at below quantitation limit of 0.01 µg g-1 at either dose of application.
Uploads
Papers by Dr. Susheel SIngh