scholarly journals Laboratory evaluation of the effectiveness of some chemical pesticide and biopesticides and their combinations in the control of tomato leafminer Liriomyza bryoniae

2019 ◽  
Vol 24 (3) ◽  
pp. 1
Author(s):  
Safaa Zakaria Baker ◽  
Zahraa Khalaf Hassan

A laboratory study was carried out to evaluate the effectiveness of the chemical pesticides Actara, Abamectin, Oxymatrim, and two bioformulation Varanestra (V. lecanii) and Almite (H. thompsonii) and their combination on adults and pupae of the Liriomyza bryoniae. The results showed that the most compatibility pesticide with  V.lecanii   and   H.thompsonii  were Actara, while  Abamectin and Oxymatrine  did not showed compatibility with these fungi. The treatment of Abamectin was superior in adult mortality  55.56% at the half-field concentration (FC-50%), followed by Actara was 46.67%, while the lowest mortality percentage of Oxymatrine treatment was 38.89%. The treatment of Varunestra was significantly higher in mortality percentage of adults was  55.60%, while the lowest mortality percentage for Almite  treatment was 42.20%. There was no significant difference in adults mortality percentage for both the mixture (Actara + Varunestra) and the mixture (Actara + Almite), which reached 56.66% and 52.22%, respectively. The treatment of the mixture (Actara + Varunestra) was superior In reducing adults emergence percentage from pupae  of 8.88%, which did not differ significantly from the treatment of the mixture (Actara + Almite), which reached to 12.22%.Results showed that Actara was compatibility with two bioformulation Varanestra (V.lecanii) and Almite (H. thompsonii) to control adults and pupae of the Liriomyza bryoniae.  http://dx.doi.org/10.25130/tjps.24.2019.041

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Jinan Malik Kalaf

"The study was carried out to effect of some pesticidesand microwave in red flour beetle in plant protection Department of Agriculture, Basrah University. it was observed that there was a significant difference between the exposure of chemical pesticides and the treatment of control ,as the effect of the larvae death was Deltamethrin pesticide affected the percentage of the destruction of the last larva age and adults stage . The percentage of larval 88.66% compared with the Alpha-cypermethrin and Vapcocidinwere their percentage in which the rate 72.2%and 64.2% respectively. The effect of exposure on the percentage of adult mortality 85.0, 68.8 .53.9% for both Deltamethrin, Alpha-cypermethrin and Vapcocidin respectively. Was superior to the Deltamethrin the mortality rate for larvae and adults 93.53% and 91.5% respectively. The study showed that percentage of mortality of larval and adult increased with increase exposure time and increase intensity of microwave and the highest percentage was at exposure time 20 second, where the mortality rate 100% for the last larva age and adults when the intensity of 800 watts, and did not affect the levels of microwave in the proportion of germination of wheat grain treated as the results of the statistical analysis showed no significant different between treatments and control."


2018 ◽  
Vol 4 (3) ◽  
pp. 165 ◽  
Author(s):  
Nikmatul Maula Nur Rahmadani ◽  
Dwita Aryadina Rachmawati ◽  
Ulfa Elfiah

Many farmers still use chemical pesticides. Chemical pesticides inside the body will form free radicals that will bind to unsaturated fatty acids (cell membrane structures) that cause increased levels of malondialdehyde (MDA). Organic pesticides can be used as an alternative to control pests. Organic pesticides leave no residues to plants and the environment. This study aims to determine the difference of plasma malondialdehid (MDA) levels in farmers who use chemical pesticides in Dawuhan Village, Tenggarang Subdistrict, Bondowoso Regency and farmers who use organic pesticides in Lombok Kulon Village, Wonosari Sub-district, Bondowoso District. This was an observational analytic research with cross sectional research design conducted on 30 farmers who use chemical pesticides and 30 farmers who use organic pesticides. Blood sampling was taken from Mediana cubiti vein. Measurements of plasma malondialdehyde (MDA) were performed using the TBARS method. Based on the result of Unpaired T-test, it was found that p < 0.001 which showed significant difference in plasma malondialdehyde (MDA) level in farmers using chemical pesticides and farmers using organic pesticides. The plasma malondialdehyde (MDA) level average were higher in farmers using chemical pesticides. Keywords: Chemical Pesticide, Organic Pesticide, Plasma Malondialdehyde          


1988 ◽  
Vol 120 (4) ◽  
pp. 297-305 ◽  
Author(s):  
W. A. Charnetski

AbstractThree methods—tube chambers (ventilated and unventilated), petri dish chambers, and field cages—were used to evaluate the toxicity of deltamethrin, trichlorfon, and methoxychlor deposits on alfalfa, Medicago sativa L., to 1- to 7-day-old alfalfa leafcutter bees, Megachile rotundata (F.), 24 and 48 h after exposure. In unventilated tube chambers, all three insecticides were significantly toxic to male bees after 24 and 48 h, but only deltamethrin and trichlorfon were significantly toxic to female bees after 24 h. In ventilated tube chambers, only deltamethrin was significantly toxic by contact and then only to male bees at 24 h. Significant vapor action was observed only for trichlorfon and only in unventilated tube chambers. By the petri dish method, only deltamethrin caused significant mortality to male and female bees. However, bee mortality increased significantly between 24 and 48 h. By the field cage method, there was no significant difference in mortality among treatments and controls within the 24- and 48-h evaluations. Bee mortality in the controls was much higher in the petri dish and field cage methods than in either of the two variations of the tube chamber method. The three evaluation methods are compared and the need for a standardized laboratory evaluation procedure is discussed.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 246-252
Author(s):  
Devon A Hansen ◽  
Brieann C Satterfield ◽  
Matthew E Layton ◽  
Hans P A Van Dongen

ABSTRACT Introduction Military operations often involve intense exposure to stressors combined with acute sleep deprivation, while military personnel also experience high prevalence of chronic sleep deficiency from insomnia and other sleep disorders. However, the impact of acute and chronic sleep deficiency on physiologic stressor responses is poorly understood. In a controlled laboratory study with normal sleepers and individuals with chronic sleep-onset insomnia, we measured responses to an acute stressor administered in a sleep deprivation condition or a control condition. Methods Twenty-two adults (aged 22-40 years; 16 females)—11 healthy normal sleepers and 11 individuals with sleep-onset insomnia—completed a 5-day (4-night) in-laboratory study. After an adaptation day and a baseline day, subjects were assigned to a 38-hour total sleep deprivation (TSD) condition or a control condition; the study ended with a recovery day. At 8:00 PM after 36 hours awake in the sleep deprivation condition or 12 hours awake in the control condition, subjects underwent a Maastricht Acute Stress Test (MAST). Salivary cortisol was measured immediately before the MAST at 8:00 PM, every 15 minutes after the MAST from 8:15 PM until 9:15 PM, and 30 minutes later at 9:45 PM. Baseline salivary cortisol was collected in the evening of the baseline day. Additionally, before and immediately upon completion of the MAST, self-report ratings of affect and pain were collected. Results The MAST elicited a stressor response in both normal sleepers and individuals with sleep-onset insomnia, regardless of the condition, as evidenced by increases in negative affect and pain ratings. Relative to baseline, cortisol levels increased immediately following the MAST, peaked 30 minutes later, and then gradually returned to pre-MAST levels. At the cortisol peak, there was a significant difference across groups and conditions, reflecting a pronounced blunting of the cortisol response in the normal sleepers in the TSD condition and the sleep-onset insomnia group in both the TSD and control conditions. Conclusions Blunted stressor reactivity as a result of sleep deficiency, whether acute or chronic, may reflect reduced resiliency attributable to allostatic load and may put warfighters at increased risk in high-stakes, rapid response scenarios.


QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Faten Mohammed Mahmoud Kamel ◽  
Hazem Ibrahim Abdel Rahman ◽  
Amany Sayed Khaleel Ahmed Elkhayat

Abstract Background Vertebral collapse is a common problem due to benign conditions (trauma, infection, osteoporosis) or malignant process. And although the spine is the most common site of bone metastases (39% of bony metastases in patients with primary neoplasms) benign vertebral fractures due to osteopenia occur in one third of cancer patients, making it essential to determine whether the cause of vertebral collapse is benign or malignant. Aim of the Work To establish the role of DWI in differentiating benign from pathologic vertebral fractures using ADC values in comparison with histopathology report /laboratory evaluation and clinical follow-up. Patients and Methods A cross sectional study is approved by the ethics review board of Ain Shams University Hospital (Al Demerdash). All patients provided informed consent for the MR imaging examinations and for inclusion of their data in this analysis. From April 2020 to october 2020, 25 cases with previous imaging with vertebral compression underwent conventional MRI study on the affected region. Diffusion weighted imaging and ADC was added. Results We performed DWI using maximum b-values 600, and quantitative analysis, named apparent diffusion coefficient (ADC). We correlated the ADC number to histopathology, laboratory finding and clinical follow up. In our study there was significant difference (p &lt; 0.04) between DWI of the benign and malignant groups. Also the ADC value showed significant difference &lt;0.001. The mean ADCs of benign VCFs were higher significantly than those of pathological fractures. Conclusion DWI with ADC value was helpful when added to conventional MRI to differentiate benign from pathological (malignant) vertebral compression. It should be a routine sequence in patients with vertebral compression fractures for accurate diagnosis and successful management also can decrease no of biopsies.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.


2021 ◽  
Author(s):  
Lili Guo ◽  
Andi Cao ◽  
Minjun Huang ◽  
Houjian Li

Abstract Recently, serious haze pollution has not only threatened the human health and food security, but also seems to have aggravated the unscientific use of pesticides by rice farmers in rural area of China. Using original data on haze pollution across China, combined with rural household survey data collected from 2014 to 2018, we conducted a detailed empirical study on the effects of haze pollution on pesticide use by rice farmers based on the theory of risk aversion. The empirical results revealed that haze pollution with higher levels of PM2.5 positively impacted the use of chemical pesticides in the rice cultivation. More precisely, with 1% increases in PM2.5 concentration, the amount of pesticide application per mu increased by 7.9%, and the average pesticide fee per mu increased by 2.3%, respectively. The results were robust to a series of tests that addressed potential endogeneity concerns, including omitted variable bias, measurement error and reverse causality. We then examined the heterogeneous effects of haze pollution increase on the use of chemical pesticides and found that the effects of haze pollution on the use of chemical pesticides to be weaker for rice farmer with more rice-planting experience, those with smaller cultivated area of rice, however, the effects on the amount of chemical pesticide application per mu to be weaker for those with rice insurance, but the effects on the average chemical pesticide fee per mu to be stronger for those with rice insurance. Our findings provide important policy implications for pesticide risk management in rural areas of developing countries.


2021 ◽  
Vol 25 (8) ◽  
pp. 1547-1550
Author(s):  
O.A. Majekodunmi ◽  
I.O. Abiola ◽  
A.M. Aderemi ◽  
J.O. Adedipe ◽  
O.G. Ogunwale ◽  
...  

This study investigated the effect of sowing media on the seed germination and subsequent seedling growth of Senna fistula L. Treatments were T1 (Top soil), T2 (River sand), T3 (Grinded coconut husk) and T4 (weathered sawdust), replicated two times for seed germination. The treatments were arranged in a Completely Randomized Design (CRD) and the data generated was subjected to analysis of variance (ANOVA) at 5% level of significance, while mean separation where appropriate was done using Least Significant Difference (LSD). The different sowing media used had positive effect on the seed emergence, the seeds planted in river sand had the highest emergence percentage of 70%. The different sowing media used did not have any significant effect on the vegetative growth parameters, statistically, they had same effect on the parameters measured. Nonetheless, seedlings from river sand produced highest number of leave (20.4), seedlings from topsoil produced highest plant height and largest leaf area of l0.62 cm and 37.l4 cm2 respectively. The seedlings from weathered sawdust produced the highest stem diameter of 0.79 mm, while seedlings from grinded coconut husk had lowest values for all the growth parameters measured. Therefore, it is recommended that river sand or weathered sawdust can be used to propagate Senna fistula seeds.


2018 ◽  
Vol 34 (4) ◽  
pp. 281-290 ◽  
Author(s):  
Benjamin E. McMillan ◽  
Jake E. Bova ◽  
Carlyle C. Brewster ◽  
Nicola T. Gallagher ◽  
Sally L. Paulson

ABSTRACT The effect of 5 plant species (arborvitae [Thuja occidentalis], boxwood [Buxus sp., Japanese honeysuckle [Lonicera japonica], rhododendron [Rhododendron sp.], and zebra grass [Miscanthus sinensis]) and 2 rates of lambda-cyhalothrin (3.13 ml and 6.25 ml active ingredient [AI]/liter) on knockdown (1 h) and mortality (24 h) of adult female Aedes albopictus was evaluated over an 8-wk period. A significant difference in knockdown was observed between the 2 rates of lambda-cyhalothrin on the 5 plant species, with the highest proportion of knockdown observed on zebra grass and rhododendron treated at the higher rate. Although mortality was ≥60% and 85% on the 5 plant species at the low and high rates of lambda-cyhalothrin, respectively, a significant difference between the 2 rates was only observed on boxwood and Japanese honeysuckle (P &lt; 0.0001). We also tested the residual toxicity of 3 barrier sprays (lambda-cyhalothrin, bifenthrin, and deltamethrin) and evaluated the efficacy of a short (5-min) exposure to the insecticides on knockdown and mortality of adults over time. Significantly higher knockdown was observed with lambda-cyhalothrin compared with bifenthrin and deltamethrin (P &lt; 0.0001). Mean knockdown was ∼98%, 92%, and 20% for lambda-cyhalothrin, bifenthrin, and deltamethrin, respectively, at week 2, and ∼98%, 0%, and 44%, respectively, 8 wk after treatments were applied. Adult mortality from the 3 chemical treatments, however, remained above 90% throughout the study. Lastly, the trends in mean proportion of knockdown were similar for mosquitoes exposed for either 5 min or 24 h to the 3 chemicals. An overall decline in mean mortality over time, however, was observed for mosquitoes exposed for 5 min to the chemicals compared with mortality from the 24-h exposure. The results suggest that lambda-cyhalothrin can be an effective barrier spray treatment against Ae. albopictus adults because its efficacy is limited little by plant species, it has long residual toxicity, and it is effective following only 5 min of exposure.


2001 ◽  
Vol 28 (6) ◽  
pp. 565 ◽  
Author(s):  
Richard E. Major ◽  
Greg Gowing

To determine relative survival rates of small birds occupying small, linear strips of woodland compared with large patches of woodland, marked populations of red-capped robins were monitored over a two-year period. In total, 196 male robins were banded with unique colour combinations in 10 woodland remnants and censused by song playback at half-yearly intervals. The Cormack–Jolly–Seber method was used to calculate half-yearly survival probabilities for birds in the two habitat configurations and the strongest model included separate survival parameters for summer (36.2% 5.1) and autumn (88.9% 13.5) half-years, but a constant recapture probability (50.5% 7.2). The inclusion of separate parameters for the large and linear habitat configurations reduced the strength of the model, indicating that there was no significant difference between the survival rates of birds occupying small, linear strips of woodland and birds occupying large patches of woodland. The mean annual survival, determined by multiplying the half-yearly survival probabilities, was 32%, which is low, compared with the annual survival of other Petroica robins. Although no banded birds were located away from the banding site, we suspect that much of the ‘mortality’ represented emigration during the summer half-year. Under this scenario a better estimate of annual survival (79%) might be achieved by extrapolation of survival over the winter half-year. This study provides no data to support the contention that adult mortality is higher in small, linear strips of habitat, although further data on the fate of birds that disappear from remnants is required before this is conclusive. In addition, to detect a 20% difference in survival using similar methods to the present study, with their accompanying sources of variation, at least 10 times the number of birds would need to be monitored. This might most effectively be done as a co-operative banding project.


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