Managing Onion Thrips can Limit Bacterial Stalk and Leaf Necrosis in Michigan Onion Fields

Onion thrips (Thrips tabaci) is a major insect pest of onion and it has been identified as a likely vector of Pantoea agglomerans (bacterial stalk and leaf necrosis), a relatively new pathogen to Michigan’s onion industry. Our objective was to develop an integrated insect and disease management program by examining the efficacy of bactericides and insecticides alone and in combination to limit bacterial stalk and leaf necrosis caused by P. agglomerans. We also examined the association of onion thrips and disease incidence in the field, because thrips are known to transmit this pathogen. In the pesticide trial, insecticides reduced both thrips abundance and bacterial stalk and leaf necrosis incidence whereas bactericides alone did not reduce disease severity. Positive correlations among thrips population density, numbers of thrips positive for P. agglomerans, and bacterial stalk and leaf necrosis incidence in onion fields were determined. This study suggests that onion thrips feeding can facilitate the development of bacterial stalk and leaf necrosis in Michigan’s commercial onion fields, and results from the pesticide trials indicate that thrips feeding damage is positively correlated with disease incidence. Therefore, in order to reduce bacterial stalk and leaf necrosis incidence in onion, management efforts should include reducing onion thrips populations through the use of insecticides and other cultural practices.

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Management of Onion Thrips [Thrips tabaci Lind. (Thysanoptera: Thripidae)] on Onion Using Eco-Friendly Cultural Practices and Varieties of Onion in Central Zone of Tigray, Ethiopia

Journal of Agriculture and Ecology Research International ◽

10.9734/jaeri/2019/v18i230053 ◽

2019 ◽

pp. 1-10

Author(s):

Gebretsadkan Zereabruk ◽

Mulatu Wakgari ◽

Gashawbeza Ayalew

Keyword(s):

Cultural Practices ◽

Agricultural Research ◽

Integrated Management ◽

Block Design ◽

Insect Pest ◽

Central Zone ◽

Thrips Tabaci ◽

Onion Thrips ◽

Untreated Check ◽

Gross Income

Onion thrips, Thrips tabaci (Thysanoptera: Thripidae) is a major insect pest constraining onion production in the Central Zone of Tigray. Therefore, field experiment was conducted at Axum Agricultural Research from November 2015 to April 2016 to manage onion thrips using multiple techniques. The experiment was laid out in a randomized complete block design (RCBD) with split plot arrangement and replicated three times. Onion varieties Bombay Red and Nasik Red were used as main plot treatments and intercropping onion with one or two other vegetables including, cabbage, carrot and lettuce, as subplot treatments. Treating onion with the insecticide lambda-cyhalothrin (Karate) 5% EC and untreated sole onion were included as standard and control checks. Results showed that intercropping onion with cabbage, onion with cabbage + carrot and onion with cabbage + lettuce significantly reduced T. tabaci population by 58.47, 63.81 and 50.51%, respectively at higher infestations. Similarly, intercropping onion with cabbage, onion with cabbage + carrot and onion with lettuce + carrot showed a better effect in reducing thrips damage severity by 23.37, 23.09 and 17.66%, respectively, at higher infestations. Predatory thrips were observed on onion intercrops except the Karate 5% EC treated check. The highest marketable onion yield (35.52 t/ha) was obtained from onion intercropped with carrot and lettuce, though not significantly different from the untreated check. The lowest (23.54 t/ha) was obtained from onion intercropped with cabbage + lettuce. However, onion intercropped with lettuce gave the highest gross income (307344 ETB/ha). The lowest gross income was recorded from the insecticide treated plot (194583 ETB/ha). The study clearly showed that intercropping onion with other vegetables reduced the number of onion thrips and their damage on onion in the central zone of Tigray and hence can form an integral component in the integrated management of thrips on onion.

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Effects of pea (Pisum sativum L.) cultivars on Thrips tabaci Lindeman preference and performance

The Journal of Agricultural Science ◽

10.1017/s0021859613000518 ◽

2013 ◽

Vol 152 (6) ◽

pp. 885-893 ◽

Cited By ~ 2

Author(s):

M. POBOŻNIAK ◽

E. H. KOSCHIER

Keyword(s):

Pisum Sativum ◽

Activity Patterns ◽

Leaf Nitrogen ◽

Thrips Tabaci ◽

Control Measures ◽

Host Use ◽

Onion Thrips ◽

Cultivar Selection ◽

And Performance ◽

Thrips Population

SUMMARYThe polyphagous onion thrips Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a serious pest in many protected and field crops and has recently been found to occur in high numbers in Pisum sativum L. crops. In the present study, the abundance of T. tabaci was compared on two pea cultivars in the field. Data on sweep net catches at different sampling times during the day suggest that peak activity of the thrips is at noon. Significantly more thrips larvae and adults were caught on the early pea cultivar Cud Kelwedonu compared with the very early cultivar Pionier, particularly during and after flowering of the peas. Analysis of primary plant compounds indicated that the higher leaf nitrogen and sucrose contents in the leaves of cvar Cud Kelwedonu promote thrips population growth in pea. The preference of T. tabaci for leaves of cvar Cud Kelwedonu was confirmed in experiments in the laboratory. Thrips tended to settle, caused significantly more feeding damage and laid significantly more eggs on the leaves of Cud Kelwedonu. Knowledge on abundance, activity patterns and host use of T. tabaci in pea may contribute to optimizing cultivar selection, monitoring and timing of possible control measures in the future.

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Distribution and Transmission of Iris yellow spot virus

Plant Disease ◽

10.1094/pdis.2001.85.8.838 ◽

2001 ◽

Vol 85 (8) ◽

pp. 838-842 ◽

Cited By ~ 67

Author(s):

A. Kritzman ◽

M. Lampel ◽

B. Raccah ◽

A. Gera

Keyword(s):

Frankliniella Occidentalis ◽

Thrips Tabaci ◽

Iris Yellow Spot Virus ◽

Yellow Spot ◽

Onion Thrips ◽

Spot Virus ◽

Nucleocapsid Gene ◽

Thrips Species ◽

Mother Plants ◽

Thrips Population

Iris yellow spot virus (IYSV), a new tospovirus associated with a disease in onion (Allium cepa) that is known to growers in Israel as “straw bleaching,” was identified and further characterized by host range, serology, electron microscopy, and molecular analysis of the nucleocapsid gene. The transmissibility of IYSV by Thrips tabaci and Frankliniella occidentalis was studied. IYSV was efficiently transmitted by T. tabaci from infected to healthy onion seedlings and leaf pieces. Two biotypes of F. occidentalis, collected from two different locations in Israel, failed to transmit the virus. Surveys to relate the incidence of thrips populations to that of IYSV were conducted in onion fields. They revealed that the onion thrips T. tabaci was the predominant thrips species, and that its incidence was strongly related to that of IYSV. Forty-five percent of the thrips population collected from IYSV-infected onion and garlic fields in Israel transmitted the virus. IYSV was not transmitted to onion seedlings from infected mother plants through the seed, and was not located in bulbs of infected plants.

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Monitoring onion crops for onion thrips Thrips tabaci

New Zealand Plant Protection ◽

10.30843/nzpp.2006.59.4529 ◽

2006 ◽

Vol 59 ◽

pp. 69-74

Author(s):

N.A. Martin ◽

P.J. Workman ◽

D. Hedderley

Keyword(s):

New Zealand ◽

Insect Pest ◽

Thrips Tabaci ◽

Sampling Strategies ◽

Onion Thrips ◽

Before And After

Onion thrips Thrips tabaci (Thysanoptera Thripidae) is the main insect pest on New Zealand onions The onion industry recommends monitoring 50 or 100 plants in 10 or 20 groups of 5 plants and applying a cluster of insecticides when populations reach 01 thrips/plant The robustness of these guidelines was tested by monitoring six crops before and after the first cluster of insecticides Two people each recorded the numbers of adult and larval thrips in each crop on each occasion using the following strategies (1) 100 randomly stratified plants (2) 20 groups of five plants randomly selected from 1 m2 and (3) 20 groups of five adjacent plants giving a total of 300 plants sampled When sampling 100 plants estimates of thrips/plant were similar for each of the three sampling strategies However to obtain a particular level of precision fewer plants could be sampled using stratified randomly selected plants than groups of five plants

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Distribution et dégâts associés au thrips de l’oignon, Thrips tabaci L. (Thysanoptera : Thripidae) en fonction de la zone agro-climatique au Burkina Faso

International Journal of Biological and Chemical Sciences ◽

10.4314/ijbcs.v14i6.9 ◽

2020 ◽

Vol 14 (6) ◽

pp. 2037-2048

Author(s):

Abdoulaye Savadogo ◽

Boniface Babo Bakouan ◽

Mathieu Wendnéyidé Sawadogo ◽

Karim Nébié ◽

Rémy Dabiré ◽

...

Keyword(s):

Burkina Faso ◽

Crop Production ◽

Insect Pest ◽

Average Density ◽

Thrips Tabaci ◽

Annual Rainfall ◽

Onion Thrips ◽

Average Annual Temperature ◽

Average Annual Rainfall ◽

Plateau Central

L’oignon est le premier légume produit au Burkina Faso. Thrips tabaci constitue son principal insecte ravageur. Ce travail avait pour objectif d’évaluer la distribution, l’incidence et la sévérité des attaques de T. tabaci sur l’oignon. L’étude a été réalisée dans trois bassins de production représentatifs de deux zones agroécologiques du Burkina Faso : la zone sahélienne caractérisée par une pluviosité moyenne annuelle inférieure à 600 mm et une température moyenne annuelle de 35 °C ; contre une pluviosité moyenne annuelle comprise entre 600 et 900 mm et une température moyenne annuelle de 33 °C pour la zone nord soudanienne Nous avons réalisé des prospections dans 45 parcelles paysannes dans les zones de production ciblées. Des plantes d’oignon ont été prélevées dans trois quadrats posés sur une des diagonales de chaque parcelle, et les thrips trouvés sur chaque plante de chaque quadrat comptés. Tous les plants à l’intérieur du quadrat ont été donc observés. La densité moyenne la plus élevée (216 ±385 thrips au m2) a été observée dans la région du Nord tandis que l’incidence moyenne la plus élevée (95,91±8,92%) a été observée dans la Boucle du Mouhoun. La plus faible sévérité (19,29±13,27%) a été enregistrée dans le Plateau central. Cette étude est un premier pas vers le développement de stratégies alternatives de lutte contre les parasites dans le cadre de systèmes de production végétale durables à l’aide de bonnes pratiques agricoles et de l’utilisation des pesticides biologiques.Mots clés : Oignon, Thrips tabaci, incidence, sévérité, répartition, Burkina Faso. English Title: Distribution and damage associated with the onion thrips, Thrips tabaci L. (Thysanoptera: Thripidae) according to the agro-climatic zone in Burkina FasoOnion is the first vegetable produced in Burkina Faso. Thrips tabaci is its main insect pest. We assessed the distribution, incidence and severity of T. tabaci attacks on onion in three-production areas representative of two agroecological zones of Burkina Faso: the the Sahelian zone characterized by an average annual rainfall of less than 600 mm and an average annual temperature of 35 °C; compared to an average annual rainfall of between 600 and 900 mm and an average annual temperature of 33 °C for the northern Sudanian zone. We carried out surveys in 45 farmer plots in the targeted production zones. Thus, onion plants were taken from three quadrats placed on one of the diagonals of each plot, and the thrips found on each plant were counted. All plants within the quadrat were therefore observed. The highest average density (216±385 thrips per m²) was observed in the North while the highest average incidence (95.91±8.92%) was observed in the Boucle du Mouhoun. The lowest severity (19.29±13.27%) was recorded in the Plateau central region. This study is a first step towards the development of alternative pest control strategies within sustainable crop production systems using good agricultural practices and the use of biopesticides.Keywords: Onion, Thrips tabaci, incidence, severity, distribution, Burkina Faso.

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Evaluation of different insecticides for the management of onion thrips (Thrips tabaci Lindeman, 1889) (Thysanoptera, Thripidae) on onion (Allium cepa L.) crops

Polish Journal of Entomology ◽

10.2478/pjen-2018-0012 ◽

2018 ◽

Vol 87 (2) ◽

pp. 165-176

Author(s):

Muhammad Asghar ◽

Mirza Muhammad Qadeer Baig ◽

Muhammad Afzal ◽

Naeem Faisal

Keyword(s):

Cost Benefit ◽

Thrips Tabaci ◽

Onion Bulb ◽

Net Income ◽

Onion Thrips ◽

Allium Cepa L ◽

Before And After ◽

Cost Benefit Ratio ◽

Thrips Population ◽

Bulb Yield

Abstract The efficacy of five insecticides containing a.i. bifenthrin, dimethoate, spinosad, spinetoram and chlorfenapyr was evaluated following RCBD against Thrips tabaci in farmer’s field for two consecutive years. The data were recorded before and after 24 h, 48 h, 72 h and 7 days of spraying. The results showed that all the insecticides reduced thrips populations compared to controls. However, the maximum reduction in thrips population and highest onion bulb yield (34.07 t/ha) was obtained with dimethoate 40EC followed by bifenthrin 10EC (33.14 t/ha). The minimum onion bulb yield (25.71 t/ha) was obtained in the control, where no insecticide was applied against thrips. If onion thrips are not controlled, the damage they cause can reduce bulb yields by 9-25%. The highest incremental return over the control (Rs.83, 600/ha), net income (Rs.82, 913/ha) and maximum cost benefit ratio were also obtained in the treatment with dimethoate 40EC.

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Selection Progress for Resistance to Iris Yellow Spot in Onions

HortScience ◽

10.21273/hortsci13041-18 ◽

2018 ◽

Vol 53 (8) ◽

pp. 1088-1094 ◽

Cited By ~ 1

Author(s):

Neel Kamal ◽

Christopher S. Cramer

Keyword(s):

Disease Severity ◽

First Generation ◽

Disease Incidence ◽

Thrips Tabaci ◽

Yellow Spot ◽

Effective Control ◽

State University ◽

Onion Thrips ◽

Breeding Lines ◽

New Mexico State University

Onion thrips (Thrips tabaci Lindeman)–vectored Iris yellow spot virus (IYSV) causes the disease Iris yellow spot (IYS), which is a major threat to the sustainability of onion production worldwide. An increase in thrips resistance to various insecticides, high costs, and the limited efficacy of insecticides under hot and drier conditions found in various onion-growing regions restrict grower’s options for effective control of thrips and spread of IYSV. Because cultivars resistant to thrips and IYS are lacking, this study was undertaken to measure selection progress for IYS resistance after one selection cycle. In 2009, selections were performed on previously evaluated New Mexico State University (NMSU) breeding lines that showed some reduced IYS disease symptoms, and the selected plants self-pollinated the following year. In 2011 and 2012, plants from the original and selected populations along with a susceptible check, ‘Rumba’, were evaluated under field conditions when onion thrips and IYSV were present. Plants were rated for IYS disease severity and the number of thrips per plant was recorded three times during the study in each year. First-generation material, NMSU 10-776, NMSU 10-782, NMSU 10-785, NMSU 10-807, and NMSU 10-813, had fewer thrips number per plant, lower disease severity, and disease incidence than their original breeding lines on at least one or two rating times in both years. Some first-generation breeding lines performed better with a lower thrips number and disease severity than their original population in 1 year or the other. Most entries exhibited fewer thrips, lower IYS disease severity, and less incidence than the susceptible check ‘Rumba’ at most rating times. Overall, some progress was observed in this first-generation material for reduced IYS disease symptom expression when compared with their original populations.

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Quantitative Trait Loci Controlling Amounts and Types of Epicuticular Waxes in Onion

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.139.5.597 ◽

2014 ◽

Vol 139 (5) ◽

pp. 597-602 ◽

Cited By ~ 8

Author(s):

Steven J. Damon ◽

Michael J. Havey

Keyword(s):

Insect Pest ◽

Epicuticular Wax ◽

Thrips Tabaci ◽

Gas Chromatography Mass Spectrometry ◽

Chromosome 2 ◽

Nucleotide Polymorphisms ◽

Epicuticular Waxes ◽

Onion Thrips ◽

Chromosome 5 ◽

Epicuticular Wax Biosynthesis

Natural variation exists in onion (Allium cepa L.) for amounts and types of epicuticular waxes on leaves. Wild-type waxy onion possesses copious amounts of these waxes, whereas the foliage of semiglossy and glossy phenotypes accumulates significantly less wax. Reduced amounts of epicuticular waxes have been associated with resistance to onion thrips (Thrips tabaci Lindeman), an important insect pest of onion. A segregating family from the cross of waxy and semiglossy onions was used to map single nucleotide polymorphisms (SNPs) and identify chromosome regions affecting amounts and types of epicuticular waxes as measured by gas chromatography–mass spectrometry. The amount of the primary epicuticular wax on onion leaves, hentriacontanone-16, was controlled by one region on chromosome 5. One region on chromosome 2 affected concentrations of several primary fatty alcohols. Results indicate that the region on chromosome 2 may be associated with the acyl reduction pathway, and the region on chromosome 5 may affect the decarbonylation pathway of epicuticular wax biosynthesis. Because lower amounts of epicuticular waxes are recessively inherited, SNPs tagging regions on chromosomes 2 and 5 will be useful for marker-assisted breeding to vary amounts and types of epicuticular waxes on onion foliage with the goal to develop cultivars resistant to onion thrips.

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Evaluating Iris Yellow Spot Disease Incidence and Severity in Onion Germplasm of Varying Leaf Characteristics

HortScience ◽

10.21273/hortsci11770-17 ◽

2017 ◽

Vol 52 (4) ◽

pp. 527-532 ◽

Cited By ~ 1

Author(s):

Christopher S. Cramer ◽

Neel Kamal ◽

Narinder Singh

Keyword(s):

Disease Incidence ◽

Thrips Tabaci ◽

Yellow Spot ◽

State University ◽

Leaf Color ◽

Onion Thrips ◽

Spot Virus ◽

Disease Symptoms ◽

New Mexico State University ◽

Onion Cultivar

Iris yellow spot (IYS) disease, caused by Iris yellow spot virus (IYSV), results in irregular and diamond-shaped, chlorotic, and necrotic lesions on the leaves and seedstalks of onions (Allium cepa L.). These lesions reduce leaf photosynthetic area and ultimately reduce onion bulb size and yield from larger bulb classes. IYSV is vectored by onion thrips (Thrips tabaci L.) that are difficult to control under certain environmental conditions. Currently, no onion cultivar is resistant to the disease symptoms, virus, and/or thrips. Twenty-one cultivars and 17 germplasm lines were evaluated in the field for IYS disease severity and thrips densities at multiple times during the season as well as leaf color, waxiness, and axil openness of these entries. Plants were grown under conditions that favored thrips populations (high temperatures, low moisture, and no insecticidal spray applications), IYSV presence and distribution, and IYS development. Plants of New Mexico State University (NMSU) 07-10-1 had fewer thrips than several entries later in the season in both 2009 and 2010. Several entries exhibited a lower number of thrips per plant early or later in the season; however, these results were not consistent across years and were not associated with a particular foliage characteristic. Lighter leaf color and/or a lesser amount of epicuticular wax did not always result in the fewest number of thrips per plant as has been reported in the literature. Plants of NMSU 09-58 tended to exhibit fewer and less severe IYS symptoms early in the season as compared with plants of other entries.

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Thrips (Thysanoptera) associated with onion (Allium cepa L.) and Welsh onion (Allium fistulosum L.)

Folia Horticulturae ◽

10.2478/fhort-2020-0028 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Marta Olczyk ◽

Maria Pobożniak

Keyword(s):

Allium Cepa ◽

Growing Season ◽

Thrips Tabaci ◽

Allium Fistulosum ◽

Onion Thrips ◽

Welsh Onion ◽

Allium Cepa L ◽

Onion Cultivar ◽

The Relationship ◽

Thrips Population

AbstractWe determined the abundance, species composition, sex ratio and seasonal dynamics of thrips on one cultivar of Welsh onion (Allium fistulosum) and eight cultivars of onion (Allium cepa) in South Poland within three vegetation seasons (2014–2016). Nine species of Thysanoptera were identified on A. cepa and A. fistulosum. Irrespective of the onion cultivar, Thrips tabaci was the dominant species (64.4% of all collected thrips specimens), while Frankliniella intonsa also occurred in high numbers (28.3%). Conversely, Welsh onion was most often inhabited by F. intonsa (62.7%), although T. tabaci was also numerous (28.3%). The predatory Aeolothrips intermedius accounted for 4.5% on A. cepa and 2.9% on A. fistulosum. In the most numerous species, T. tabaci, F. intonsa and A. intermedius populations were formed mainly by females. The cultivar most colonised by thrips was Kroll of A. fistulosum. The tested cultivars of A. cepa demonstrated varying degrees of attractiveness to thrips in the subsequent years. The relationship between populations of T. tabaci, F. intonsa and A. intermedius changed in the subsequent months of the growing season. In June, mainly T. tabaci and F. intonsa occurred on onion plants, while from July, the percentage shares of F. intonsa and the predatory A. intermedius in the thrips population on many onion cultivars increased. The level of attractiveness of A. cepa related to onion thrips, which is reported as a main pest of onion, varies depending on the year and cultivar.

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