scholarly journals Cultivar, Fertilizer, and Irrigation Affect Vegetative Growth and Susceptibility of Chrysanthemum to Western Flower Thrips

1998 ◽  
Vol 123 (4) ◽  
pp. 727-733 ◽  
Author(s):  
Ursula K. Schuch ◽  
Richard A. Redak ◽  
James A. Bethke
Keyword(s):  
Leaf Area ◽  
Frankliniella Occidentalis ◽  
Growth Habit ◽  
Western Flower Thrips ◽  
Dry Mass ◽  
Varietal Resistance ◽  
Flower Thrips ◽  
Irrigation Solution ◽  
Liquid Fertilization ◽  
N Rates

`Fontana', `Iridon', `Pink Lady', `Splendor', `White Diamond', and `White View Time' chrysanthemum (Dendranthema × grandiflorum Ramat.) were grown for 10 weeks with N rates of 80, 160, or 240 mg·L-1 constant liquid fertilization and irrigated at sufficient (high) or deficient (low) amount. Cultivars differed in growth habit, and treatments significantly affected all variables measured. Plants fertilized with 80 mg·L-1 had lower leaf and stem dry mass, less leaf area, and were deficient in leaf N compared with plants fertilized with twice the amount of N. The highest stem dry mass was produced with 160 mg·L-1. Leaf and stem dry mass were reduced 25% for plants receiving low irrigation compared to those receiving high irrigation. In general, leaf area increased when fertilizer was raised from 80 to 160 mg·L-1 but differed by cultivar and irrigation regime when fertilizer was increased to 240 mg·L-1. Three weeks after the experiment started, electrical conductivity (EC) of runoff collected weekly from `White Diamond' plants fertilized with 240 mg·L-1 exceeded the average EC of the irrigation solution. The 240 mg·L-1 treatment also resulted in excessive EC in the growing substrate at the end of the experiment and reduced stem dry mass by 11% compared with the 160 mg·L-1 fertilizer regime. Substrate EC differed between cultivars in response to fertilizer and irrigation. Significantly more adult western flower thrips [Frankliniella occidentalis (Pergrande)], 55% and 52%, were found on the foliage of `Pink Lady' and `Fontana', respectively, than on `Iridon'. `Pink Lady' and `Fontana' had more immature thrips at the end of the experiment than `Iridon' and `White View Time'. Fewer adults and immatures were found on plants fertilized with 80 mg·L-1 than 240 mg·L-1. Fewer adults were detected in plants under high versus low irrigation, while irrigation had no effect on the number of immatures. The simultaneous use of plant varietal resistance and plant cultural growing techniques has the potential to lower thrips populations on chrysanthemum.

scholarly journals Fertility Affects Susceptibility of Chrysanthemum to Western Flower Thrips: Influence on Plant Growth, Photosynthesis, and Ethylene Evolution

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 768E-769
Author(s):  
Fred Davies* ◽  
Chuanjiu He ◽  
Amanda Chau ◽  
Kevin Heinz ◽  
Jay Spiers
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Low Fertility ◽  
High Fertility ◽  
Ethylene Evolution ◽  
Nitrogen Levels ◽  
Flower Thrips ◽  
Vegetative And Reproductive Growth

This research details the influence of fertility on plant growth, photosynthesis and ethylene evolution of chrysanthemum (Dendranthema grandiflora Tzvelev var. Charm) inoculated with western flower thrips (Frankliniella occidentalis (Pergande). We tested the hypothesis that moderate levels of nitrogen would better control western flower thrips on chrysanthemum. While thrips are known to reduce plant quality, there have been few comprehensive studies on plant response to thrips population dynamics—analyzing changes in plant growth and development, plant gas exchange and ethylene evolution. Plants were exposed to four fertility levels that consisted of 0%, 10%, 20% and 100% (375 ppm N) of recommended nitrogen levels. Thrips abundance was greatest at high fertility. Thrips depressed plant vegetative and reproductive growth and altered carbohydrate partitioning. Thrips-inoculated (TI) plants also had reduced leaf area and lower leaf mass than thrips-free (NonTI) plants, but did not differ in specific leaf area [(SLA) leaf area (cm2)/leaf DM (g)]. However, high fertility plants had greater biomass and higher SLA, i.e., thinner leaves than low fertility treatments. Thrips reduced photosynthesis (Pn) and stomatal conductance (gs) in young, mature and older basal leaves, with gs showing greater sensitivity than Pn. Ethylene and chlorophyll levels in thrips damaged leaves did not differ from Non-TI plants.

scholarly journals Effects of Tissue Phosphorus and Nitrogen in Impatiens wallerana on Western Flower Thrips (Frankliniella occidentalis) Population Levels and Plant Damage

HortScience ◽  
2004 ◽  
Vol 39 (3) ◽  
pp. 545-550 ◽  
Author(s):  
Yan Chen ◽  
Kimberly A. Williams ◽  
Brent K. Harbaugh ◽  
Michelle L. Bell
Keyword(s):  
Vegetative Growth ◽  
Growth Stage ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Plant Size ◽  
Flower Thrips ◽  
N Rates ◽  
Nitrogen Rates ◽  
Tissue Phosphorus ◽  
Impatiens Wallerana

Host-plant nutritional status may affect the incidence and development of western flower thrips (WFT; Frankliniella occidentalis Pergande). Two greenhouse experiments were conducted to determine the responses of WFT population levels on impatiens (Impatiens wallerana Hook.f.) when plants were fertilized with commercially practiced rates of nitrogen (N) and phosphorus (P). Impatiens `Dazzler Violet' were grown with nutrient treatment combinations of 2 N rates (8 and 20 mm) by 2 P rates (0.32 and 1.28 mm). Individual plants grown in thrips-proof cages were inoculated with WFT at 2 or 4 weeks after transplant, in separate experiments, representing vegetative or reproductive stages of plant growth, respectively. Plants were destructively sampled weekly for 4 weeks following inoculation. Plant tissue N and P concentrations were significantly different across treatments: 8 and 20 mm N resulted in 4.9% and 6.3% N in tissue, respectively; 0.32 and 1.28 mm P resulted in 0.37% and 0.77% P in tissue, respectively. Nitrogen rates had no effect on WFT population levels. However, 4 weeks after inoculation with adult female WFT during the vegetative growth stage, plants fertilized with 1.28 mm P had more adult WFT than those fertilized with 0.32 mm P. Feeding damage varied depending on whether plants were inoculated in the vegetative stage with adult WFT or during reproductive growth with immature WFT. Plant size and number of flowers were lower in plants inoculated during the vegetative growth stage with adult WFT but were not affected when inoculation with immature WFT occurred during the reproductive stage, as most WFT were found feeding inside the nectariferous spurs of the flowers. Tissue N was lower in WFT-inoculated plants compared to noninoculated plants in both experiments.

scholarly journals Morphological and Chemical Factors Related to Western Flower Thrips Resistance in the Ornamental Gladiolus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer
Keyword(s):  
Host Plant ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Resistance Breeding ◽  
Breeding Programs ◽  
Triterpenoid Saponins ◽  
Flower Thrips ◽  
Highly Correlated

Understanding the mechanisms involved in host plant resistance opens the way for improved resistance breeding programs by using the traits involved as markers. Pest management is a major problem in cultivation of ornamentals. Gladiolus (Gladiolus hybridus L.) is an economically important ornamental in the Netherlands. Gladiolus is especially sensitive to attack by western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera:Thripidae)). The objective of this study was, therefore, to investigate morphological and chemical markers for resistance breeding to western flower thrips in Gladiolus varieties. We measured thrips damage of 14 Gladiolus varieties in a whole-plant thrips bioassay and related this to morphological traits with a focus on papillae density. Moreover, we studied chemical host plant resistance to using an eco-metabolomic approach comparing the 1H NMR profiles of thrips resistant and susceptible varieties representing a broad range of papillae densities. Thrips damage varied strongly among varieties: the most susceptible variety showed 130 times more damage than the most resistant one. Varieties with low thrips damage had shorter mesophylls and epidermal cells, as well as a higher density of epicuticular papillae. All three traits related to thrips damage were highly correlated with each other. We observed a number of metabolites related to resistance against thrips: two unidentified triterpenoid saponins and the amino acids alanine and threonine. All these compounds were highly correlated amongst each other as well as to the density of papillae. These correlations suggest that papillae are involved in resistance to thrips by producing and/or storing compounds causing thrips resistance. Although it is not possible to distinguish the individual effects of morphological and chemical traits statistically, our results show that papillae density is an easy marker in Gladiolus-breeding programs targeted at increased resistance to thrips.

Stability of spinosad resistance inFrankliniella occidentalis(Pergande) under laboratory conditions

2008 ◽  
Vol 98 (4) ◽  
pp. 355-359 ◽  
Author(s):  
P. Bielza ◽  
V. Quinto ◽  
C. Grávalos ◽  
E. Fernández ◽  
J. Abellán ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Selection Pressure ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Laboratory Conditions ◽  
Flower Thrips ◽  
Factors Influencing ◽  
Stability Of Resistance ◽  
The Stability ◽  
Successive Generations

AbstractThe stability of spinosad resistance in western flower thrips (WFT),Frankliniella occidentalis(Pergande), populations with differing initial frequencies of resistance was studied in laboratory conditions. The stability of resistance was assessed in bimonthly residual bioassays in five populations with initial frequencies of 100, 75, 50, 25 and 0% of resistant individuals. There were no consistent changes in susceptibility of the susceptible strain after eight months without insecticide pressure. In the resistant strain, very highly resistant to spinosad (RF50>23,000-fold), resistance was maintained up to eight months without further exposure to spinosad. In the absence of any immigration of susceptible genes into the population, resistance was stable. In the case of the population with different initial frequency of resistant thrips, spinosad resistance declined significantly two months later in the absence of selection pressure. With successive generations, these strains did not change significantly in sensitivity. Spinosad resistance inF. occidentalisdeclined significantly in the absence of selection pressure and the presence of susceptible WFT. These results suggest that spinosad resistance probably is unstable under field conditions, primarily due to the immigration of susceptible WFT. Factors influencing stability or reversion of spinosad resistance are discussed.

Virus Decline of Strawberry in California and the Role of Insect Vectors and Associated Viruses

2015 ◽  
Vol 16 (4) ◽  
pp. 211-215 ◽  
Author(s):  
Surendra K. Dara
Keyword(s):  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Trialeurodes Vaporariorum ◽  
Current Status ◽  
Insect Vectors ◽  
The Past ◽  
Disease Vector ◽  
Flower Thrips ◽  
Purple Coloration

Greenhouse white fly, Trialeurodes vaporariorum (Westwood); western flower thrips, Frankliniella occidentalis (Pergande); and strawberry aphid, Chaetosiphon fragaefolii (Cockerell), are common pests of strawberries in California and are vectors of one or more viruses. Most of the viruses transmitted by these vectors do not cause symptoms on strawberry when the infection occurs individually. However, when one of the viruses (Beet pseudoyellows virus or Strawberry pallidosis-associated virus) transmitted by T. vaporariorum is present along with one of the viruses transmitted by F. occidentalis, C. fragaefolii, or other sources, it results in a virus decline of strawberry, which can cause significant crop losses. Stunted root and plant growth, purple coloration of foliage, and dieback of the plant are some of the symptoms associated with virus decline. Increases in T. vaporariorum infestations during the past few years significantly elevated the risk of whitefly as a crop pest and a disease vector. This article reviews virus decline of strawberry, symptoms of infection, and the current status of insect vectors in California strawberries. Accepted for publication 17 November 2015. Published 20 November 2015.

Spinetoram Is Compatible with the Key Natural Enemy of Frankliniella Species Thrips in Pepper

2008 ◽  
Vol 9 (1) ◽  
pp. 30 ◽  
Author(s):  
Mrittunjai Srivastava ◽  
Lara Bosco ◽  
Joe Funderburk ◽  
Anthony Weiss
Keyword(s):  
Frankliniella Occidentalis ◽  
Field Experiments ◽  
Natural Populations ◽  
Western Flower Thrips ◽  
Central Florida ◽  
Flower Thrips ◽  
Natural Predator ◽  
Wilt Virus ◽  
The Impact ◽  
Reduced Risk

Feeding by the western flower thrips, Frankliniella occidentalis, causes damage to the fruits of pepper, and the species is the key vector of Tomato spotted wilt virus. Effective management integrates conservation of populations of the natural predator, Orius insidiosus, with the use of reduced-risk insecticides, namely spinosad. We conducted field experiments in northern Florida in 2005 and 2006 and in central Florida in 2006 to evaluate the new reduced-risk insecticide spinetoram for control of thrips and to determine the impact on natural populations of O. insidiosus. Spinetoram at 61 g ai/ha was as effective as spinosad at 140 g ai/ha against the western flower thrips and the other common thrips in Florida, Frankliniella tritici and Frankliniella bispinosa. The mean numbers of the predator were very high in all treatments in each experiment, and their numbers relative to the numbers of thrips indicated that predation was sufficient to suppress thrips populations in all treatments. Broad-spectrum insecticides when included in the experiments provided little or no control; sometimes, they flared thrips numbers compared to untreated pepper. Accepted for publication 25 October 2007. Published 18 January 2008.

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