Lethal and sublethal effects of Azadirachta indica-based products on Tetranychus neocaledonicus (Acari: Tetranychidae)

2021 ◽  
Author(s):  
Mayara Fernandes dos Santos ◽  
Paulo Roberto Ramalho Silva ◽  
Marcus Eugênio O. Briozo ◽  
Joesley Frazão Silva ◽  
Luiz Carlos de Melo Junior ◽  
...  
Keyword(s):  
Sublethal Effects ◽  
Residual Effect ◽  
Lima Bean ◽  
Phaseolus Lunatus ◽  
Choice Test ◽  
Adult Females ◽  
Average Survival ◽  
History Of ◽  
Ovicidal Effect ◽  
Sublethal Concentrations

The objective of this study is to evaluate the toxicity, repellency, and the ovicidal, residual, and sublethal effects of different neem-based commercial formulations on the red mite Tetranychus neocaledonicus André (1933) reared in the laboratory on lima bean (Phaseolus lunatus L.). To evaluate the toxicity on adult females of T. neocaledonicus, different concentrations of Natural Neem® (NN), Off-Neem® (ON), Nim-I-GO® (NG), and Azamax® (AZ) were defined from preliminary tests. The mortality and toxicity ratio were evaluated 48 h after application of the lethal concentrations (LC50s and LC95s). The repellent effect was verified through a two-choice test. The concentration used was the LC50 of the products calculated in the toxicity test. The number of mites attracted, the repellency index (RI), and the percentage of repellency of each product were calculated. The ovicidal effect after application of the LC50s and LC95s of each product and egg viability were observed. To evaluate the residual efficiency, the plants were sprayed with LC50 and LC95 of the products and the leaves were subsequently harvested at 24, 48, and 96h after the application of the products to evaluate mortality and oviposition reduction (PR - percentage of reduction). The sublethal effects were evaluated by applying the LC30 of the products (AZ, NG) to newly emerged females, whose survival and oviposition were evaluated daily. The determined LC50s were 0.39; 0.48; 0.68; and 1.39% for AZ, ON, NN, and NG, respectively. Considering the LC50, AZ was the most toxic product followed by ON, whereas the established LC95s were 2.20; 3.74; 6.10; and 7.98% for NN, ON, AZ, and NG, respectively. All tested products were classified as repellents for adult females of T. neocaledonicus. The eggs of T. neocaledonicus treated with the LC95s of the products had their viabilities inhibited. However, when using the LC50s, NN provided the lowest viability (8.0%), being considered the most toxic for eggs. The products presented reduced residual effect probably due to their rapid degradation. The mites treated with sublethal concentrations showed an average survival in days of 25.43, 28.35, and 29.20 for the treatments with Azamax®, control (untreated), and Nim-I-GO®, respectively. Relatively high oviposition rates in the first weeks decreased until the end of their life cycle. The life history of T. neocaledonicus is affected by sublethal concentrations of neem-based products. It was concluded that the tested products demonstrated acaricidal potential in the control of T. neocaledonicus on P. lunatus, presenting toxicity and repellent and ovicidal effect, although residual and sublethal effects were less significant.

scholarly journals First Report of Mefenoxam-Resistant Isolates of Phytophthora capsici from Lima Bean Pods in the Mid-Atlantic Region

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 656-656 ◽  
Author(s):  
J. F. Davey ◽  
N. F. Gregory ◽  
R. P. Mulrooney ◽  
T. A. Evans ◽  
R. B. Carroll
Keyword(s):  
Foliar Application ◽  
Phytophthora Capsici ◽  
Crop Protection ◽  
Lima Bean ◽  
Fruit Rot ◽  
Resistant Isolate ◽  
Phaseolus Lunatus ◽  
Atlantic Region ◽  
History Of ◽  
Lima Beans

Phytophthora capsici Leonian, the causal agent of lima bean pod rot, was first identified as a pathogen of lima bean in 2002 (1) and poses a new threat to lima bean (Phaseolus lunatus L.) production in the Mid-Atlantic Region. The phenylamide fungicide mefenoxam (Ridomil Gold; Syngenta Crop Protection) is widely used in the region for controlling foliar and soilborne diseases caused by Oomycetes. Isolates of P. capsici were collected from lima bean pods from production fields in Delaware, Maryland, and New Jersey from 1998 to 2004. These isolates originated from survey samples of lima bean fields for another pathogen, P. phaseoli, in 1999 and 2000 and diagnostic samples were submitted to the Plant Disease Clinic. Isolates were from lima bean, except for one from pepper (basal stem). Identification was made on the basis of morphometric characteristics. No known sensitive or insensitive isolates were included in the evaluation. Single zoospore cultures were evaluated for mefenoxam sensitivity on V8 agar plates amended with 100 ppm of mefenoxam, a previously tested concentration (2). Seven-millimeter-diameter agar plugs of each isolate were cut from the edge of actively expanding cultures of P. capsici with a cork borer and transferred to three V8 agar plates amended with mefenoxam and three unamended V8 plates. The plates were arranged in a completely randomized design and incubated at 25°C in the dark for 3 days. After incubation, colony growth was measured in millimeters and averaged for the three replicate plates of each isolate and percent growth relative to the unamended control was calculated. Mefenoxam sensitivity was assigned according to methods of Lamour et al. (2). The experiment was repeated once, and also run with a treatment of 200 ppm of mefenoxam. Of sixteen isolates screened, nine were rated as sensitive, four were intermediately resistant, and three were resistant. There was no difference between the 100 and 200 ppm results, except for a slight increase in sensitivity for one isolate. A subsequent experiment tested five isolates at concentrations of 1, 10, 100, and 1,000 ppm. Results were consistent with previous tests, with resistant isolates exhibiting some growth at the highest concentration of mefenoxam. One resistant isolate was from a field in Delaware previously cropped to slicing cucumbers with a history of mefenoxam applications. The second was from Caroline County, MD, which is heavily cropped to pickling cucumbers and likely to have been exposed to mefanoxam applications for the control of fruit rot; the origin of the third insensitive isolate from lima bean is unknown. Mefanoxam usage on lima bean is usually limited to one foliar application of mefenoxam+copper hydroxide to control downy mildew in the fall crop in wet seasons. This study indicates that mefenoxam resistance is present in populations of P. capsici in lima bean fields in the Mid-Atlantic Region, presumably as a result of mefenoxam applications to other vegetable crops, principally cucurbits, which are planted in rotation with lima beans or from nearby cucurbit fields. Implementing strategies to minimize fungicide resistance in other vegetables is important to slow resistance development associated with this emerging pathogen on lima beans. Lima bean pod rot continues to be seen sporadically each year in fields with a history of P. capsici and abundant rainfall or excessive irrigation. References: (1) C. R. Davidson et al. Plant Dis. 86:1049, 2002. (2) K. H. Lamour et al. Phytopathology 90:396, 2000.

Accelerating Agricultural Growth—Is Irrigation Institutional Reform Necessary? (Distinguishedl Lecture)

1996 ◽  
Vol 35 (4I) ◽  
pp. 399-417 ◽  
Author(s):  
John W. Mellor
Keyword(s):  
Growth Rates ◽  
Irrigation System ◽  
Institutional Reform ◽  
Residual Effect ◽  
Agricultural Growth ◽  
The Past ◽  
Major Reform ◽  
History Of ◽  
The Right ◽  
Economic Growth Rates

The right to the flow of income from water is vigorously pursued, protected, and fought over in any arid part of the world. Pakistan is of course no exception. Reform of irrigation institutions necessarily changes the rights to water, whether it be those of farmers, government, or government functionaries. Those perceived rights may be explicit and broadly accepted, or simply takings that are not even considered legitimate. Nevertheless they will be fought over. Pakistan has a long history of proposals for irrigation reform, little or none being implemented, except as isolated pilot projects. Thus, to propose major changes in irrigation institutions must be clearly shown to have major benefits to justify the hard battles that must be fought and the goodwill of those who might win those battles for reform. Proponents of irrigation institution reform have always argued the necessity of the reforms and the large gains to be achieved. Perhaps, however, those arguments have not been convincing. This paper will briefly outline the failed attempts at irrigation reform to provide an element of reality to the discussion. It will then proceed to make the case of the urgency of reform in a somewhat different manner to the past. Finally, current major reform proposals will be presented. This paper approaches justification of irrigation reform by focusing on the agricultural growth rate. It does so because that is the critical variable influencing poverty rates and is a significant determinant of over-all economic growth rates. The paper decomposes growth rates and suggests a residual effect of deterioration of the irrigation system that is large and calls for policy and institutional reform. The data are notional, suggesting the usefulness of the approach and paves the way for more detailed empirical analysis and enquiry for the future.

Lethal and Sublethal Effects of Eucalyptus camaldulensis and Mentha piperita Essential Oils on the Khapra Beetle (Coleoptera: Dermestidae) in Terms of Feeding Inhibition, Oviposition, and Seed Damage

2021 ◽  
Author(s):  
Ehsan Borzoui ◽  
Ramin Khaghani ◽  
Gadir Nouri-Ganbalani
Keyword(s):  
Essential Oils ◽  
Sublethal Effects ◽  
Management Strategies ◽  
Eucalyptus Camaldulensis ◽  
Choice Test ◽  
Mentha Piperita ◽  
Growth Stages ◽  
Fumigant Toxicity ◽  
Khapra Beetle ◽  
Wheat Seeds

Abstract Trogoderma granarium Everts, the Khapra beetle, is a major pest of stored products, especially grains. In this study, fumigant toxicity and sublethal effects of Eucalyptus camaldulensis Dehnh. (Myrtaceae) and Mentha piperita L. (Lamiaceae) essential oils (EOs) were investigated against different growth stages of T. granarium. To assess the sublethal effects, insects were exposed to an LC20 or LC50 concentration of each essential oil, and the ability of these oils to deter feeding, oviposition, and damage to wheat seeds and overall mass were surveyed. At LC50 concentrations, M. piperita EO showed higher fumigant toxicity than E. camaldulensis EO against eggs, 2nd instar larvae, 4th instar larvae, and adults of T. granarium. Furthermore, the adults were more sensitive to the tested EOs than immatures. In free-choice tests, both larvae and adults showed a preference for control-treated wheat seeds than for seeds treated with an LC20 or LC50 concentration of EOs from E. camaldulensis or M. piperita. In a no-choice test, adult females exposed to EOs showed lower fecundity and fertility in comparison to control females not exposed to EOs. Treatment of wheat seeds with E. camaldulensis or M. piperita EOs resulted in a dose-specific reduction in the number of damaged seeds and seed weight loss when compared to control. According to our results, both tested EOs, especially EOs extracted from M. piperita, showed good potential for use in integrated pest management strategies against T. granarium.

scholarly journals Sublethal effects of emamectin benzoate on life table parameters of the cotton leafworm, Spodoptera littoralis (Boisd.)

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
El-Sayed Mokbel ◽  
Amal Huesien
Keyword(s):  
Life Table ◽  
Spodoptera Littoralis ◽  
Sublethal Effects ◽  
Lethal Effect ◽  
Reproductive Rate ◽  
Relative Fitness ◽  
Emamectin Benzoate ◽  
Cotton Leafworm ◽  
Sublethal Concentrations ◽  
Preovipositional Period

Abstract Background The cotton leafworm, Spodoptera littoralis (Boisd.), is a serious economic pest in Egypt. Pest control depends mainly on chemical control with several pesticides include conventional and modern insecticides. Comprehensive analysis of pesticides impacts needs to investigate sublethal effects in addition to lethal effect. Results In the current study, the leaf-dip bioassay method was used to evaluate emamectin benzoate (EMB) sublethal concentrations. Results showed that EMB proved high toxicity against S. littorals with LC50 value of 0.019 mg liter−1. Life table analysis showed that treatments with LC5 and LC15 prolonged larval period, mean longevity of males and females, mean generation time (T), doubling time (DT), adult preovipositional period (APOP), and total preovipositional period (TPOP) compared with control. On the contrary, net reproduction rates (R0), intrinsic rates of increase (r), finite rate (λ), fecundity, gross reproductive rate (GRR), and relative fitness were decreased compared to control. Conclusions The current study clarified that sublethal concentrations of EMB induce adverse effects and suppress the population growth of S. littorals. Our results would be useful to assess the overall effects of EMB on S. littorals and can contribute effectively in pest management.

Genetic diversity in accessions of lima bean (Phaseolus lunatus L.) determined from agro-morphological descriptors and SSR markers for use in breeding programs in Brazil

2021 ◽  
Author(s):  
Carolline de Jesús Pires ◽  
Marcones Ferreira Costa ◽  
Maria Imaculada Zucchi ◽  
Regina Lucia Ferreira-Gomes ◽  
José Baldin Pinheiro ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Lima Bean ◽  
Phaseolus Lunatus ◽  
Morphological Descriptors ◽  
Breeding Programs

scholarly journals Metastatic adrenal pheochromocytoma to the thoracic spine

2010 ◽  
Vol 9 (3) ◽  
pp. 343-346 ◽  
Author(s):  
Michael T. Scalfani ◽  
Paul M. Arnold ◽  
Karen K. Anderson
Keyword(s):  
Differential Diagnosis ◽  
Surgical Intervention ◽  
Hepatic Metastases ◽  
Posterior Fixation ◽  
Original Diagnosis ◽  
Average Survival ◽  
Progression Of Disease ◽  
Adrenal Pheochromocytoma ◽  
History Of ◽  
Work Up

To report on a case of pheochromocytoma metastases to the spine occurring more than 20 years after initial diagnosis. A 34-year-old female with a history of metastatic pheochromocytoma diagnosed at age 12 presented with weakness, heart palpitations, and circumferential back pain of five months duration. The patient had undergone multiple laparatomies for abdominal and hepatic metastases. Work-up revealed a destructive lesion at T9. After two weeks of preoperative phenoxybenzamine to control her hypertension, she underwent decompression, posterior fixation and fusion. Surgical intervention was followed by radiation therapy, zoledronic acid, and only one cycle of chemotherapy due to intolerance of side effects. The patient survived 25 years after original diagnosis, which far exceeds the average survival of less than 15 years. The patient died 26 months postoperatively due to progression of disease. Pheochromocytoma with spine metastases occurring more than 20 years after diagnosis is very uncommon, and should be considered in the differential diagnosis of a patient with a history of pheochromocytoma.

scholarly journals Development of Texturized Vegetable Protein from Lima Bean (Phaseolus lunatus) and African Oil Bean Seed [Pentaclethrama crophylla (Benth)]: Optimization Approach

2017 ◽  
Vol 21 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Gibson. L. Arueya ◽  
Bamidele. S. Owosen ◽  
Kazeem. K. Olatoye
Keyword(s):  
Vegetable Protein ◽  
Control Sample ◽  
Lima Bean ◽  
Essential Amino Acids ◽  
Phaseolus Lunatus ◽  
Optimization Approach ◽  
Bean Seed ◽  
Overall Acceptability ◽  
Extrusion Processing ◽  
Feed Moisture

AbstractAs part of measures to combat protein shortages in form of meat analogues, extrusion processing conditions for the development of Texturized Vegetable Protein (TVP) from under-utilized sources (Lima bean and African oil bean seed) are analysed. Optimum parameters for processing were established as being: barrel temperature (92.45°C), screw speed (101.48 rpm), feed moisture (59.63%) and African oil bean seed protein concentrates (AOBSPC) of 1%. Concentrations of essential amino-acids were also found to be significant (0.90-7.3%) with a near absence of anti-nutritional factors (0.0022–1.0008) g/kg. Sensory evaluation showed that TVP5 (100% LBPC) compared favourably with the control sample (cooked meat) in overall acceptability. An Acceptable and nutritious meat analogue had been developed.

ISOLATION AND CHARACTERIZATION OF LIMA BEAN (PHASEOLUS LUNATUS) STARCH

1991 ◽  
Vol 15 (2) ◽  
pp. 117-136 ◽  
Author(s):  
RATNAJOTHI HOOVER ◽  
STEWART C. RORKE ◽  
ANTONIO M. MARTIN
Keyword(s):  
Lima Bean ◽  
Phaseolus Lunatus ◽  
Isolation And Characterization
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