Field Efficacies and Joint Actions of Beta-cyfluthrin Mixed With Thiamethoxam or Tolfenpyrad Against Diaphorina citri (Hemiptera: Liviidae)

2020 ◽  
Vol 113 (6) ◽  
pp. 2793-2799
Author(s):  
Tao Tang ◽  
Mingping Zhao ◽  
Pei Wang ◽  
Yi Xiao ◽  
Shengkong Huang ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Foliar Spray ◽  
Diaphorina Citri ◽  
Mass Ratio ◽  
Negative Effects ◽  
Joint Actions ◽  
Citrus Greening Disease ◽  
Foliar Sprays ◽  
The Given ◽  
Capsule Suspension

Abstract The Asian citrus psyllid, Diaphorina citri Kuwayama, is the most serious pest of citrus because it is a vector for the highly destructive citrus greening disease (huanglongbing, HLB). Currently, insecticide applications are being used widely to control psyllid populations, thereby suppressing the spread of HLB. In the present study, topical application bioassays were performed to detect the joint actions of beta-cyfluthrin and thiamethoxam or tolfenpyrad against D. citri adults in the laboratory. In 2019, a field plot experiment was conducted to evaluate the control efficacies of beta-cyfluthrin+thiamethoxam 22% capsule suspension and beta-cyfluthrin+tolfenpyrad 30% microemulsion against D. citri using foliar sprays. For the former, a 9:13 mass ratio had the highest synergistic effect, with a cotoxicity coefficient of 188.64. For the latter, a 5:25 mass ratio had the highest synergistic effect, with a cotoxicity coefficient of 153.94. A one-time foliar spray of the former at 30–40 mg/kg or of the latter at 40–60 mg/kg effectively controlled D. citri, with control efficacies varying from 80.1 to 99.4% or 80.4 to 100.0%, during the 3–30 d after treatment, respectively. Moreover, field observations indicated that these foliar sprays at the tested rates had no negative effects on citrus trees. Thus, foliar sprays of beta-cyfluthrin+thiamethoxam or beta-cyfluthrin+tolfenpyrad under the given conditions may control D. citri.

scholarly journals Innovative aerodynamic grain separation system for plant harvesting in sloped areas: problems, research and optimization of parameters

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jerzy Bienek ◽  
Piotr Komarnicki ◽  
Jerzy Detyna
Keyword(s):  
Monte Carlo ◽  
Separation System ◽  
Indicator Values ◽  
Negative Effects ◽  
The Monte Carlo Method ◽  
Longitudinal Slope ◽  
Combine Harvester ◽  
The Given ◽  
Transverse Slope ◽  
Plant Harvesting

AbstractThis article presents the main problems associated with cereal harvesting in sloping areas. The presented innovative aerodynamic system supporting the separating unit of combine harvester can be one of the ways to counteract the negative effects of harvesting machines work on slopes. The Monte Carlo numerical method, presented in this article, was applied in the optimization of an aerodynamic sieve separation process on an inclined terrain. The given variables are the transverse slope of separator α (of the sieve), longitudinal slope β and the output of the main and side fans. The Monte Carlo method makes it possible to determine an optimized set of parameters (α = 10°, β = 2.8°, δ = 9°), the output of the main fan (0.67 m3 s−1) and the output of the side fan (1.86 m3 s−1), allowing to obtain the best indicator values of 2.1% grain loss and 97.5% grain purity.

scholarly journals Evaluation of Foliar Sprays of Bacteriophages for the Management of Bacterial Canker in Greenhouse Tomatoes

2009 ◽  
Vol 10 (1) ◽  
pp. 19 ◽  
Author(s):  
David M. Ingram ◽  
Shi-En Lu
Keyword(s):  
Total Yield ◽  
Foliar Spray ◽  
Bacterial Canker ◽  
Symptom Development ◽  
Plant Mortality ◽  
Greenhouse Tomato ◽  
Disease Progress ◽  
Foliar Sprays ◽  
Greenhouse Tomatoes

AgriPhage applied as a preventative foliar spray significantly reduced severity of bacterial canker of greenhouse tomato in two of three years. Area under the disease progress curves (AUDPC) indicated that AgriPhage slowed the progression of bacterial canker symptom development by 50% and 59% in 2006 and 2007, respectively. Plant mortality was significantly reduced by 76% in 2006 as compared to the inoculated control. AgriPhage-treated plants produced significantly greater total yield in 2006 only. Copper and Kasumin sprays also significantly reduced severity (AUDPC) of bacterial canker in 2007 as compared to the inoculated control. However, none of these treatments reduced symptom development or increased yield in 2008. Accepted for publication 9 April 2009. Published 12 May 2009.

scholarly journals PEDESTRIANS’ PERSPECTIVES ON ENVIRONMENTAL PROBLEMS, AWARENESS AND WILLINGNESS IN CHANGING CURRENT MODE TO WALKING IN A POSSIBLE WAY TO REDUCE EXPOSURE OF O3 CONCENTRATIONS TO SCHOOLCHILDREN

2018 ◽  
Vol 80 (5) ◽  
Author(s):  
Nazatul Syadia Zainordin ◽  
Nor Azam Ramli ◽  
Ahmad Zia Ul-Saufie Mohamad ◽  
Muhammad Rizal Razman ◽  
Ahmad Shukri Yahya ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Air Pollutants ◽  
Current Mode ◽  
Ground Level ◽  
Environmental Problems ◽  
Negative Effects ◽  
Ground Level Ozone ◽  
Distance Travel ◽  
The Given ◽  
Level Of Agreement

Increasing ground level ozone has become an important issue because of its adverse effects on health and the environment. Increasing numbers of vehicles is known to be one of the sources of its precursors where gas emissions from vehicle exhausts lead to the production of ground level ozone.  Active transports, mainly walking have been found to be the most effective way to reduce the use of private vehicles especially for short-distance travel.  In this study, pedestrians’ perspectives on the existence of environmental problems and awareness regarding negative effects of these issues and their perceptions towards changing the current mode to active mode were evaluated. According to the surveys conducted at the four selected schools, by referring to the gender, as compared to male respondents, female respondents mostly testified that there were local environmental problems occurred at their area and are aware  of the adverse effects of air pollutants exposed to human. As for types of respondents, teachers were much concern with the environmental problems as they spent more time in schools compared than other types of respondents. In terms of race, Indian and Malay respondents were more aware of the negative effects of air pollutants and most willingly to change from current mode to walking. From the analysis of one-way ANOVA and independent t-test, respondents’ level of agreement with environmental problems, awareness and potential in changing the current mode to walking were related to the gender, types of respondents and race. Nevertheless, factor of travel distance did not influence the given level of agreement by respondents.

scholarly journals Ubiquitin Proteasome Pathway annotation in Diaphorina citri can reveal potential targets for RNAi based pest management

2021 ◽  
Author(s):  
Will Tank ◽  
Teresa Shippy ◽  
Amanda Thate ◽  
Crissy Massimino ◽  
Prashant S Hosmani ◽  
...  
Keyword(s):  
Management Strategies ◽  
Bacterial Pathogen ◽  
Diaphorina Citri ◽  
Ubiquitin Proteasome Pathway ◽  
Citrus Greening Disease ◽  
Pathway Annotation ◽  
New Information ◽  
Genomic Studies ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway

Ubiquitination is an ATP-dependent process that targets proteins for degradation by the proteasome. In this study, we annotated 15 genes from the ubiquitin-proteasome pathway in the Asian citrus psyllid, Diaphorina citri. This psyllid vector has come to prominence in the last decade due to its role in the transmission of the devastating bacterial pathogen, Candidatus Liberibacter asiaticus (CLas). Infection of citrus crops by this pathogen causes Huanglongbing (HLB or citrus greening disease) and results in the eventual death of citrus trees. The identification and correct annotation of these genes in D. citri will be useful for functional genomic studies that aid in the development of RNAi-based management strategies aimed at reducing the spread of HLB. Investigating the effects of CLas infection on the expression of ubiquitin-proteasome pathway genes may provide new information regarding the role that these genes play in the acquisition and transmission of CLas by D. citri.

Competition and the Winner's Curse in B2B Reverse Auctions

2011 ◽  
pp. 150-165
Author(s):  
Indranil K. Ghosh ◽  
John L. Fizel ◽  
Ido Millet ◽  
Diane H. Parente
Keyword(s):  
Theoretical Background ◽  
Procurement Auctions ◽  
Future Research ◽  
Winner's Curse ◽  
Negative Effects ◽  
Diverse Range ◽  
Winner’S Curse ◽  
Managerial Implications ◽  
The Given ◽  
The Relationship

The Winner’s Curse is a common phenomenon mostly in auctions, even though it has applications in a diverse range of fields. We define the idea of a Winner’s Curse and specify the types of auctions in which this could be prevalent. We look at the data provided by a major multinational corporation on online procurement auctions conducted by them. We specify the relationship that the prevalence of the Winner’s Curse would have on the success of such procurement auctions. Using this theoretical background, we analyze the given data and show that in some cases, the presence of the Winner’s Curse and the subsequent need for bidders to show caution in the presence of the Winner’s Curse could lead to lower auction success for the firm. We specify the particular cases where this is true. This leads to Managerial Implications for firms wishing to conduct procurement auctions online and we spell them out. We also provide some examples of how firms might try and lower the negative effects of the Winner’s Curse. Finally we provide some future research ideas that may be pursued and some additional readings for the curious reader.

scholarly journals Interaction of zinc and IAA alleviate aluminum-induced damage on photosystems via promoting proton motive force and reducing proton gradient in alfalfa

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Liantai Su ◽  
Jianping Xie ◽  
Wuwu Wen ◽  
Jiaojiao Li ◽  
Peng Zhou ◽  
...  
Keyword(s):  
Energy Production ◽  
Foliar Spray ◽  
Quantum Yields ◽  
Zn Deficiency ◽  
Negative Effects ◽  
Transfer Rates ◽  
Apical Buds ◽  
Zn Addition ◽  
Photosynthetic Machinery ◽  
Al Treatment

Abstract Background In acidic soils, aluminum (Al) competing with Zn results in Zn deficiency in plants. Zn is essential for auxin biosynthesis. Zn-mediated alleviation of Al toxicity has been rarely studied, the mechanism of Zn alleviation on Al-induced photoinhibition in photosystems remains unclear. The objective of this study was to investigate the effects of Zn and IAA on photosystems of Al-stressed alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or100 μM AlCl3 combined with 0 or 50 μM ZnCl2, and then foliar spray with water or 6 mg L− 1 IAA. Results Our results showed that Al stress significantly decreased plant growth rate, net photosynthetic rate (Pn), quantum yields and electron transfer rates of PSI and PSII. Exogenous application of Zn and IAA significantly alleviated the Al-induced negative effects on photosynthetic machinery, and an interaction of Zn and IAA played an important role in the alleviative effects. After removing apical buds of Al-stressed alfalfa seedlings, the values of pmf, gH+ and Y(II) under exogenous spraying IAA were significantly higher, and ΔpHpmf was significantly lower in Zn addition than Al treatment alone, but the changes did not occur under none spraying IAA. The interaction of Zn and IAA directly increased Y(I), Y(II), ETRI and ETRII, and decreased O2− content of Al-stressed seedlings. In addition, the transcriptome analysis showed that fourteen functionally noted genes classified into functional category of energy production and conversion were differentially expressed in leaves of alfalfa seedlings with and without apical buds. Conclusion Our results suggest that the interaction of zinc and IAA alleviate aluminum-induced damage on photosystems via increasing pmf and decreasing ΔpHpmf between lumen and stroma.

scholarly journals Asian citrus psyllid adults inoculate huanglongbing bacterium more efficiently than nymphs when this bacterium is acquired by early instar nymphs

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
El-Desouky Ammar ◽  
Justin George ◽  
Kasie Sturgeon ◽  
Lukasz L. Stelinski ◽  
Robert G. Shatters
Keyword(s):  
Latent Period ◽  
Salivary Glands ◽  
Emerging Adults ◽  
Citrus Greening ◽  
Asian Citrus Psyllid ◽  
Diaphorina Citri ◽  
Citrus Greening Disease ◽  
Early Instar ◽  
Liberibacter Asiaticus ◽  
Greening Disease

Abstract The Asian citrus psyllid (Diaphorina citri) transmits the bacterium ‘Candidatus Liberibacter asiaticus’ (CLas), which causes huanglongbing (citrus greening) disease, in a circulative-propagative manner. We compared CLas inoculation efficiency of D. citri nymphs and adults into healthy (uninfected) citron leaves when both vector stages were reared from eggs on infected plants. The proportion of CLas-positive leaves was 2.5% for nymphs and 36.3% for adults. CLas acquisition by early instar nymphs followed by dissections of adults and 4th instar nymphs revealed that CLas bacterium had moved into the head-thorax section (containing the salivary glands) in 26.7–30.0% of nymphs and 37–45% of adults. Mean Ct values in these sections were 31.6–32.9 and 26.8–27.0 for nymphs and adults, respectively. Therefore, CLas incidence and titer were higher in the head-thorax of adults than in nymphs. Our results suggest that following acquisition of CLas by early instar D. citri nymphs, emerging adults inoculate the bacteria into citrus more efficiently than nymphs because adults are afforded a longer latent period necessary for multiplication and/or translocation of CLas into the salivary glands of the vector. We propose that CLas uses D. citri nymphs mainly for pathogen acquisition and multiplication, and their adults mainly for pathogen inoculation and spread.

Bayleton® Seed Treatment Combined with Foliar Spray Improves Fusiform Rust Control in Nurseries

1984 ◽  
Vol 8 (1) ◽  
pp. 51-54
Author(s):  
S. J. Rowan
Keyword(s):  
Seed Germination ◽  
Seed Treatment ◽  
Disease Incidence ◽  
Foliar Spray ◽  
Artificial Inoculation ◽  
Fusiform Rust ◽  
Complete Control ◽  
Infection Period ◽  
Foliar Sprays ◽  
Forest Nurseries

Abstract Bayleton foliar sprays eradicated all fusiform rust infections when applied up to 7 days after artificial inoculation and eradicated a significant number of infections when applied 28 days after inoculation. A combination of seed treatment and foliar spray provided complete control when the spray was applied up to 14 days after inoculation and further reduced disease incidence when the foliar spray was applied 28 days after inoculation. Foliar sprays applied before inoculation prevented infections up to four weeks after application but sprays applied to nongerminated seed did not prevent infections in seedlings originating from these seed. Seed treatment would, therefore, significantly improve fusiform rust control in forest nurseries. Without seed treatment, applications of both ferbam and Bayleton during the period of seed germination may be necessary to adequately control the disease in high rust-hazard nurseries. When seed are treated with Bayleton, the first foliar spray must be applied 14 days after germination begins or no later than 7 days after the first infection period following the first 14 days of seed germination. Thereafter, sprays should be applied at intervals not to exceed 35 days.

Sign in / Sign up

Export Citation Format

Share Document