scholarly journals Evaluation of δ15N analysis to trace the origin of Diaphorina citri (Hemiptera: Liviidae) to citrus orchard fertilization management

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8807
Author(s):  
Francesc Gomez-Marco ◽  
Andrew Yoshimoto ◽  
W. Evan Braswell ◽  
Richard Stouthamer
Keyword(s):  
Laboratory Experiments ◽  
Management Practices ◽  
Diaphorina Citri ◽  
Nitrogen Stable Isotope ◽  
Citrus Orchard ◽  
Laboratory Results ◽  
Citrus Orchards ◽  
Citrus Leaves ◽  
Citrus Disease ◽  
Organic Orchards

We investigated the variability of nitrogen stable isotope ratios 15N/14N (expressed as δ15N) on citrus orchards with different fertilization management practices (organic versus conventional) and its correlation with the δ15N values of the key citrus pest Diaphorina citri Kuwayama (Hemiptera: Liviidae) feeding on such plant material. Tracing the origin of this pest in open field is crucial since the insect is a vector of the incurable and devastating citrus disease known as Huanglongbing. We hypothesized that the origin (natal tree) of the pest may be deduced by correlating the δ15N values obtained from the young citrus leaves and from adults of D. citri raised on them. First, laboratory experiments were performed to understand the acquisition and incorportation of the δ15N values by D. citri. Second, we confirmed the positive correlation between the δ15N values of the young citrus leaves and D. citri. Finally, field sampling was carried out in 21 citrus orchards from Southern California to study the variability on the δ15N values on organic and conventional commercial citrus orchards. Laboratory results suggest that the analyses of the δ15N values can be regarded as a useful method to trace the origin of the pest. However, the high variability in nitrogen resource used in both fertilization management practices (especially in organic orchards) by growers makes the application of this technique unfeasible to pinpoint the origin of D. citri in the citrus agroecosystem.

Evaluating the Biological Potential of Prodigiosin from Serratia Marcescens KH-001 Against Asian Citrus Psyllid

2021 ◽  
Author(s):  
Wei Hu ◽  
Rongkun Zheng ◽  
Yihong Liao ◽  
Fan Kuang ◽  
Zhaolan Yang ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Diaphorina Citri ◽  
Antifeedant Activity ◽  
Control Efficacy ◽  
Egg Hatch ◽  
Biological Potential ◽  
Citrus Orchards ◽  
Citrus Leaves ◽  
Increasing Temperature ◽  
Effective Compound

Abstract The insecticides of microbial origin may be promising biocontrol agents to control pests. In this study, a major metabolite was extracted and purified from Serratia marcescens KH-001 and identified as prodigiosin with a molecule weight of 324.2094, and our primary aim was to evaluate the effects of prodigiosin against Diaphorina citri Kuwayama (Hemiptera: Liviidae) in the laboratory and in the field. Toxicity of purified prodigiosin to nymphs increased with increasing temperature from 25 to 35°C. The laboratory experiment results observed inhibition effects of purified prodigiosin at LC50 on oviposition and egg hatch of D. citri at 30°C. Furthermore, adults that fed on citrus leaves treated with LC20 and LC50 solution of purified prodigiosin at 30°C excreted less honeydew (28–35%) compared with controls, suggesting moderate antifeedant activity of prodigiosin. The results of field experiment showed that 10% prodigiosin emulsifiable concentrate exhibited better control efficacy (70–100%) at three concentrations (100, 200, and 500 mg/liter) in July and August than in October. These data indicate that prodigiosin will be a highly effective compound for the control of D. citri depending on the prevailing temperature conditions and may become a commercially available product to be widely used in citrus orchards.

scholarly journals Impacts of Horticultural Mineral Oils and Two Insecticide Practices on Population Fluctuation ofDiaphorina citriand Spread of Huanglongbing in a Citrus Orchard in Sarawak

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Stephen Chan Teck Leong ◽  
Fatimah Abang ◽  
Andrew Beattie ◽  
Roland Jui Heng Kueh ◽  
Sing King Wong
Keyword(s):  
Polymerase Chain Reaction ◽  
The Other ◽  
Population Fluctuation ◽  
Diaphorina Citri ◽  
Chain Reaction ◽  
Citrus Orchard ◽  
Mineral Oils ◽  
Polymerase Chain ◽  
Citrus Disease

Aspects of the incidence and spread of the citrus disease huanglongbing (HLB) in relation to the vectorDiaphorina citripopulation fluctuation were studied from January 1999 to December 2001 seasons in a 0.8 ha citrus orchard at Jemukan (1° 33′N, 110° 41′E), Southwest Sarawak in Malaysia. In relation to insecticide and horticultural mineral oils (HMOs) use, levels of HLB infection rose quite rapidly over the next 3 years in the unsprayed control and less rapidly in the other treatments such as imidacloprid,nC24HMO, and triazophos/cypermethrin/chlorpyrifos. Levels of HLB as determined by Polymerase Chain Reaction (PCR) were 42.2%, 9.4%, 11.4%, and 22.7%, respectively. The effects ofnC24HMO and conventional pesticides on the citrus psyllid population and parasitoids in citrus orchard were also determined.

Concentration of Impurities during Melting of Snow Made from Secondary Sewage Effluent

1986 ◽  
Vol 18 (2) ◽  
pp. 151-156 ◽  
Author(s):  
R. Zapf-Gilje ◽  
S. O. Russell ◽  
D. S. Mavinic
Keyword(s):  
Potassium Chloride ◽  
Chloride Solution ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Low Cost ◽  
Sewage Effluent ◽  
Potassium Chloride Solution ◽  
Laboratory Results ◽  
Solution Field ◽  
Concentration Of Impurities

When snow is made from sewage effluent, the impurities become concentrated in the early melt leaving the later runoff relatively pure. This could provide a low cost method of separating nutrients from secondary sewage effluent. Laboratory experiments showed that the degree of concentration was largely independent of the number of melt freeze cycles or initial concentration of impurity in the snow. The first 20% of melt removed with it 65% of the phosphorus and 90% of the nitrogen from snow made from sewage effluent; and over 90% of potassium chloride from snow made from potassium chloride solution. Field experiments with a salt solution confirmed the laboratory results.

Factors associated with Diaphorina citri immigration into commercial citrus orchards in São Paulo State, Brazil

2020 ◽  
Author(s):  
Fernando P. F. Zorzenon ◽  
Arthur F. Tomaseto ◽  
Matthew P. Daugherty ◽  
João R. S. Lopes ◽  
Marcelo P. Miranda
Keyword(s):  
Sao Paulo ◽  
São Paulo ◽  
Diaphorina Citri ◽  
Factors Associated ◽  
Paulo State ◽  
São Paulo State ◽  
Citrus Orchards

scholarly journals Deep subsoiling of a subsurface-compacted typical hapludult under citrus orchard

2013 ◽  
Vol 37 (4) ◽  
pp. 911-919 ◽  
Author(s):  
João Carlos Medeiros ◽  
Getulio Coutinho Figueiredo ◽  
Álvaro Luiz Mafra ◽  
Jaqueline Dalla Rosa ◽  
Sung Won Yoon
Keyword(s):  
Hydraulic Conductivity ◽  
Management Practices ◽  
Soil Management ◽  
Penetration Resistance ◽  
Soil Bulk Density ◽  
Soil Samples ◽  
Fruit Yield ◽  
Root Depth ◽  
Citrus Orchard ◽  
Unsaturated Hydraulic Conductivity

Soil management practices which increase the root depth penetration of citrus are important to the longevity and yield maintenance of this plant, especially in regions where long periods of drought are common, even in soil conventionally subsoiled to a depth of 30-40 cm, when the orchard was first established. The objective of this study was to evaluate the efficiency of subsoiling on the physical and hydric properties of a Typical Hapludult and fruit yield in a 14-year-old citrus orchard located in Piracicaba, SP. The treatments consisted of: no-subsoiling (with no tilling of the soil after the orchard was planted); subsoiling on one side of the plant lines (SUB. 1); and subsoiling on both sides of the plant lines (SUB. 2). The subsoiling treatments were carried out 1.5 m from the plant lines and to a depth of 0.8 m. Soil samples were taken 120 days after this operation, at four depths, in order to determine physical and hydric properties. Fruit yield was evaluated 150 days after subsoiling. Subsoiling between the plant lines of an old established citrus orchard alters the physical and hydric properties of the soil, which is reflected in increased soil macroporosity and unsaturated hydraulic conductivity, and reduced soil bulk density, critical degree-of-compactness and penetration resistance. The improvements in the physical and hydric properties of the soil were related to an increase in fruit number and orchard yield.

The chemical composition of the soil in a factorial experiment with citrus. I. Exchangeable metal cations and their effect on the cation content of citrus

1960 ◽  
Vol 11 (2) ◽  
pp. 208 ◽  
Author(s):  
H Groenewegen ◽  
D Bouma
Keyword(s):  
Field Experiment ◽  
Cover Crops ◽  
Laboratory Experiments ◽  
Appreciable Effect ◽  
Exchangeable Calcium ◽  
Cation Content ◽  
Two Factors ◽  
Exchangeable Magnesium ◽  
Citrus Leaves ◽  
Exchangeable Form

In a factorial field experiment with citrus it was found that application of ammonium sulphate caused a greater proportionate reduction in the exchangeable calcium of the soil than in the exchangeable potassium. Short-term laboratory experiments with virgin soil, to which ammonium was added, suggested that at least two factors were involved. If solutions of high electrolyte concentrations were added, a greater release of exchangeable calcium than of potassium occurred, relative to the amounts of these ions originally present in exchangeable form. Secondly, a release of potassium from non-exchangeable to exchangeable form also occurred. In the 0–4 in. layer of the field experiment, exchangeable magnesium was reduced in the same proportion as exchangeable calcium. In the 4–12 in. layer, exchangeable magnesium was reduced relatively more than calcium. The same trend was apparent in laboratory experiments. In one experiment, for example, the original amount of magnesium was reduced by 76 per cent., and calcium by 66 per cent. A comparison between cultural treatments showed that the potassium content of the soil from a bare surface treatment was much lower than that from treatments with cover crops. The changes in soil composition had no appreciable effect on the cation content of citrus leaves, and some reasons for this are discussed.

scholarly journals Development on Infected Citrus over Generations Increases Vector Infection by ‘Candidatus Liberibacter Asiaticus in Diaphorina citri’

Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 469
Author(s):  
Inaiara de Souza Pacheco ◽  
Diogo Manzano Galdeano ◽  
João Roberto Spotti Lopes ◽  
Marcos Antonio Machado
Keyword(s):  
Management Strategies ◽  
Fourth Generation ◽  
Diaphorina Citri ◽  
Candidatus Liberibacter Asiaticus ◽  
Candidatus Liberibacter ◽  
Citrus Huanglongbing ◽  
Liberibacter Asiaticus ◽  
Citrus Orchards ◽  
Vector Efficiency ◽  
Control And Eradication

‘Candidatus Liberibacter asiaticus’ (CLas) is a major causal agent of citrus Huanglongbing (HLB), which is transmitted by Asian citrus psyllid (ACP), Diaphorina citri, causing severe losses in various regions of the world. Vector efficiency is higher when acquisition occurs by ACP immature stages and over longer feeding periods. In this context, our goal was to evaluate the progression of CLas population and infection rate over four ACP generations that continuously developed on infected citrus plants. We showed that the frequency of CLas-positive adult samples increased from 42% in the parental generation to 100% in the fourth generation developing on CLas-infected citrus. The bacterial population in the vector also increased over generations. This information reinforces the importance of HLB management strategies, such as vector control and eradication of diseased citrus trees, to avoid the development of CLas-infected ACP generations with higher bacterial loads and, likely, a higher probability of spreading the pathogen in citrus orchards.

Detection of Candidatus Liberibacter asiaticus from Wampee (Clausena lansium Skeels) by Nested PCR

2007 ◽  
Vol 8 (1) ◽  
pp. 53 ◽  
Author(s):  
Xiaoling Deng ◽  
Gen Zhou ◽  
Huaping Li ◽  
Jianchi Chen ◽  
Edwin L. Civerolo
Keyword(s):  
Nested Pcr ◽  
Southern China ◽  
Diaphorina Citri ◽  
Candidatus Liberibacter Asiaticus ◽  
Term Survival ◽  
Disease Vector ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Citrus Orchards

Wampee (Clausena lansium Skeels) is native to southern China and Southeast Asia. Wampee trees are attractive, with grape-like fruits and a muscat taste and are popular in home gardens. Like other members of Rutaceae, wampee has long been suspected to have yellow shoot disease or Huanglongbing (HLB) and Diaphorina citri, the disease vector, was capable of a long-term survival on Wampee. The authors recommend that eradication of wampee trees surrounding citrus orchards should be part of the overall management of citrus HLB. Accepted for publication 20 December 2007. Published 19 April 2007.

scholarly journals Overlay materials used for increasing lifetime of machine parts working under conditions of intensive abrasion

2013 ◽  
Vol 59 (No. 1) ◽  
pp. 16-22 ◽  
Author(s):  
M. Müller ◽  
P. Hrabě
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Abrasive Wear ◽  
Laboratory Experiments ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Point Of View ◽  
Laboratory Results ◽  
Machine Parts ◽  
Materials Used

We evaluated a degree of the machine part abrasive wear with secondary focus on their hardness. The paper states laboratory results of overlay systems from their wear resistance point of view. Laboratory experiments were carried out by two-body abrasion on bonded abrasive of a P120 granularity. The results proved an increased abrasive wear resistance of martensitic, ledeburitic and stellitic overlays against eleven different original products. The overlay UTP Ledurit 60 reached the optimum values. The GD-OES (Glow Discharge Optical Emission Spectroscopy) method proved the different chemical composition of the overlay from the stated chemical composition of the overlaying electrode.    

scholarly journals SEASONAL FLUCTUATION OF ASIAN CITRUS PSYLLA POPULATIONS IN THE CITRUS ORCHARDS INFECTED WITH HUANGLONGBING IN SARGODHA, PAKISTAN

2017 ◽  
Vol 29 (1) ◽  
pp. 175
Author(s):  
Yasir Iftikhar ◽  
Imran U. Haq ◽  
Waqas Raza ◽  
Muhammad I. Ullah ◽  
Sajjad Ali ◽  
...  
Keyword(s):  
High Temperature ◽  
Environmental Factors ◽  
Minimum Temperature ◽  
Management Strategy ◽  
Integrated Management ◽  
Seasonal Fluctuation ◽  
Diaphorina Citri ◽  
Citrus Production ◽  
Citrus Orchards ◽  
Citrus Psylla

A study on seasonal fluctuation in Citrus psylla (Diaphorina citri) (CP) population in citrus orchards infected with Huanglongbing was carried out in relation to environmental factors in six tehsils of Sargodha district. The population of citrus psylla was reached to the peak twice in a year. Young flushes favored the build-up in psylla population. Minimum temperature and rainfall had highly significant correlation with build-up in population of citrus psylla in all the six tehsils of Sargodha. Although, high temperature also favored the high population of citrus psylla in two tehsils. August and mid-March to April were the two times when population of citrus psylla reached to the peak. Therefore, an integrated management strategy can be formulated with this study that will not only help in reducing the HLB incidence but also increase in citrus production.

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