Imidacloprid Insecticide Slows Development of Pierce's Disease in Bunch Grapes

2002 ◽  
Vol 37 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Gerard Krewer ◽  
J. D. Dutcher ◽  
C. J. Chang

Six cultivars of bunch grapevines Vitis labrusca (L.) and V. vinifera (L), ‘Cabernet Franc’, ‘Canadice’, ‘Flame Seedless’, ‘Johannesburg Riesling’, ‘Mars’ and ‘Reliance’ when treated at planting and for 3 yrs with two (early spring and mid-summer) applications of imidacloprid (Admire®, Bayer Corp., Kansas City, MO) in a 1 to 2 liters aqueous solution (0.70 g active ingredient per vine per application) as drench to the base of the vine, had lower incidence of Pierce's Disease (PD) than untreated grapevines. Apparent PD symptoms were evident on the control vines in mid-summer of the second season. By the fall of the second season and spring of the third season, some control vines were dead. ELISA tests in July of the third season, indicated that similar proportions of treated and control vines contained the PD bacteria. ELISA tests in August of the third season, indicated that significantly more control vines than treated vines contained PD bacteria. Vines treated with imidacloprid showed PD symptoms in June of the third season, and the rate of disease development was slower than in the control vines. After 3 yrs, 18% of the control vines were dead while all the treated vines were alive. ‘Carbernet Franc’ and ‘J. Riesling’ vines treated with imidacloprid had higher yields that the untreated vines within the two cultivars in the third season. ‘Reliance’ vines had higher soluble solids in vines treated with imidacloprid than in untreated vines. Survival at bud break of the fourth year was higher in treated than in untreated vines. Homalodisca coagulata (Say), H. insolita (F.), Oncometopia orbona (Walker) and Graphocephala versuta (Say) were the more abundant leafhopper vectors of PD in the experimental plot and in the surrounding fruit crops. Overall, this research suggests that under severe PD pressure vineyard life can be extended by about 1 yr by application of imidacloprid.

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 511c-511 ◽  
Author(s):  
Gerard Krewer ◽  
Jim Dutcher ◽  
C. J. Chang

Pierce's Disease is the major limiting factor in the production of European and American bunch grapes in the Coastal Plain and Lower Piedmont of the Southeastern United States. Pierce's Disease is also a significant problem in some areas of California. The disease has been impossible to control with insecticide sprays up to this point, because the leaf hopper vectors are xylem feeders and have minimal plant/insecticide contact. Admire was cleared for use on grapes 3 years ago, and an experiment was started near Tifton, Ga. Cultivars of European and American bunch grapes in this experiment include `Flame Seedless', `J. Riesling', `Cabernet Franc', `Reliance', `Mars' and `Canadice'. Experimental design is a randomize complete block with two replications and six vines per replication and treatment for a total of 72 vines in the experiment. Treatments are untreated control and vines treated with Admire (3.26 g/vine per application) in an aqueous solution of 1 to 2 L applied as a basal drench. Vines were planted in Mar. 1996 and applications of Admire have been applied in the early spring and mid summer of each year. Apparent Pierce's Disease symptoms became evident on some of the control vines in mid-summer 1997. By Fall 1997, some of the control vines were dead. This trend has continued in Spring 1998. Some vines treated with Admire show slight Pierce's Disease symptoms, but rate of disease development is much slower than in the control vines. Based on company research with virus transmission on other crops, even better results can be expected when large blocks are treated with Admire. Current results on this experiment will be presented. Larger scale experiments are underway as well as experiments to determine the effect of Admire on the development of phony peach disease and plum leaf scald disease.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 343
Author(s):  
Carolina Ballesteros ◽  
Alda Romero ◽  
María Colomba Castro ◽  
Sofía Miranda ◽  
Jan Bergmann ◽  
...  

Pseudococcus calceolariae, the citrophilous mealybug, is a species of economic importance. Mating disruption (MD) is a potential control tool. During 2017–2020, trials were conducted to evaluate the potential of P. calceolariae MD in an apple and a tangerine orchard. Two pheromone doses, 6.32 g/ha (2017–2018) and 9.45 g/ha (2019–2020), were tested. The intermediate season (2018–2019) was evaluated without pheromone renewal to study the persistence of the pheromone effect. Male captures in pheromone traps, mealybug population/plant, percentage of infested fruit at harvest and mating disruption index (MDI) were recorded regularly. In both orchards, in the first season, male captures were significantly lower in MD plots compared to control plots, with an MDI > 94% in the first month after pheromone deployment. During the second season, significantly lower male captures in MD plots were still observed, with an average MDI of 80%. At the third season, male captures were again significant lower in MD than control plots shortly after pheromone applications. In both orchards, population by visual inspection and infested fruits were very low, without differences between MD and control plots. These results show the potential use of mating disruption for the control of P. calceolariae.


EDIS ◽  
1969 ◽  
Vol 2004 (18) ◽  
Author(s):  
Tracy Conklin ◽  
Russell F. Mizell, III

The glassy-winged sharpshooter, Homalodisca coagulata (Say), is a large leafhopper species native to the southeastern United States. It is one of the main vectors of the bacterium Xylella fastidiosa, a plant pathogen that causes a variety of plant diseases, including phony peach disease of peach and Pierce's disease of grape. Though usually not a serious pest in the area of its native distribution, the glassy-winged sharpshooter has recently been introduced into southern California, where it has become a serious threat to viticulture due to its ability to vector Pierce's disease.  This document is EENY-274, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: October 2002. Revised: July 2004. EENY-274/IN552: Glassy-Winged Sharpshooter, Homalodisca vitripennis (=coagulata) (Germar) (Insecta: Hemiptera: Cicadellidae: Cicadellinae) (ufl.edu)


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 826B-826
Author(s):  
Xia Xu* ◽  
Zhongbo Ren ◽  
Jiang Lu

Pierce's Disease (PD) is a major factor limiting grape production in the southeast United State. This disease is caused by a bacterium, Xylella fastidiosa Wells et al., which is transmitted to the xylem system of the grapevines primarily by glassy-winged sharpshooters (Homalodisca coagulata Say). Once it is in the xylem, the X. fastidiosa will use the xylem sap as a nutrient source to multiply, colonize, and eventually plug the xylem vessels and cause the PD in susceptible cultivars. On the other hand, symptoms of PD in tolerant cultivars do not appear until fruit maturation, and symptoms are rarely observed in PD resistant cultivars. In order to understand the correlation between X. fastidiosa and PD symptom development, a study was initialed to monitor X. fastidiosa in xylem of resistant, tolerant, and susceptible vines on a monthly basis. Presence of X. fastidiosa was detected directly from xylem sap of field-grown vines by medium culture and confirmed by polymerase chain reaction (PCR). Xylella fastidiosa was detectable throughout the growing season in PD susceptible cultivar `Chardonnay', PD tolerant Florida hybrid grape `Blanc du Bois', and muscadine cultivar `Carlos'. The bacteria were also appeared in the dormant vines with high density in cultivars `Chardonnay' and `Blanc du Bios'. Although X. fastidiosa was also found in dormant canes of `Carlos', the density decreased throughout the late fall and winter months, and they were hardly found before June. The results indicated that X. fastidiosa were carried over from previous season in cultivars `Chardonnay' and `Blanc du Bois', while in PD tolerant cultivar `Carlos', they were newly acquired from the sharpshooter feedings during the growing season.


2004 ◽  
Vol 94 (10) ◽  
pp. 1136-1144 ◽  
Author(s):  
K. M. Tubajika ◽  
E. L. Civerolo ◽  
M. A. Ciomperlik ◽  
D. A. Luvisi ◽  
J. M. Hashim

The incidence of Pierce's disease (PD), caused by Xylella fastidiosa, was monitored in 11 naturally infested commercial vineyards to determine the presence of an X. fastidiosa vector, Homalodisca coagulata (glassy-winged sharpshooter [GWSS]), to examine the spatial patterns of the disease and elucidate possible influences of surrounding environments. Disease incidence ranged from <1 to 65% among vineyards in 2001. Our efforts to trap or capture potential disease vectors have indicated that the GWSS is the most likely vector. Disease incidence doubled in most vineyards during the 2002 production season. Spatial patterns of symptomatic vines in 2001 and 2002, as determined by ordinary runs analysis, showed strong evidence for within- and across-row aggregation of infected vines. In most fields, they were no disease gradients observed relative to GWSS source (e.g., citrus). Within fields, however, disease incidence displayed strong spatial dependence and a high degree of anisotropy, indicating strongly aggregated patterns of disease with distinct directional orientation. The within-row (0°) and across-row (90°) orientations generally were the predominant directions of increased disease incidence, consistent with vine-to-vine spread of X. fastidiosa. We concluded that the distribution of PD in vineyards reflected the feeding pattern of vectors carrying X. fastidiosa. Based on these results, effective PD management is likely to be based on practices that reduce significant insect vector populations and remove infected vines as soon as identified and on the use of resistant cultivars.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1127E-1128
Author(s):  
Jiang Lu ◽  
Elvis Clarke ◽  
Zhong-bo Ren

Although some of the American native Vitis species and their hybrids, particularly those originated from the southeastern United States, have been known for resistance to Pierce's disease (PD), their resistant status against the glassy-winged sharp shooter [GWSS, Homalodisca coagulata (Say)], the vector transmitting PD pathogen (Xylellafastidiosa Well), has not been reported. To determine GWSS feeding preferences on different grape species/cultivars and correlations of feeding to Pierce's disease development, a survey was conducted at Florida A&M University, Tallahassee. The feeding preference of GWSS on different species/cultivars was evaluated in two different ways: 1) count the number of GWSS on different grapevines in the field; and 2) determine the feeding preference by measuring the excretion of the GWSS feeding on difference grape species/cultivars, including highly susceptible V. vinifera cultivars, native American grape species and hybrids, and muscadine grapes. Results from this study indicated that the frequency of GWSS visits on different grapevines varied among the species/cultivars investigated. For example, PD-resistant grape V. rotundifolia (muscadine grape) had significantly fewer GWSS visits than did the PD-susceptible V. vinifera grape. The frequency of GWSS visits to V. labrusca, the native American grape susceptible to PD, was intermediate between those found on V. rotundifolia and V. vinifera. Similarly, the GWSS sucked more xylem sap when they fed on PD-susceptible grapevines than on PD-resistant ones. Overall, there is a positive correlation between the GWSS visits/feeding and the status of grapevine resistance/susceptibility to Pierce's disease.


Author(s):  
Meryanti Napitupulu And Anni Holila Pulungan

This study was conducted as an attempt to discover the effect of applying Demonstration Method on students’ achievement in speaking skill. It was an experimental research. The subject was students of Grade XII, Vocational High School (Sekolah Menengah Kejuruan: SMK), which consisted of 79 students. The research was divided into two groups: experimental and control groups. The instrument used to collect the data was speaking test. To obtain the reliability of the test, the writer applied Kuder Richardson 21 formula. The result of the reliability was 0.7, and it was found that the test was reliable. The data were analyzed by using t-test formula. The analysis showed that the scores of the students in the experimental group were significantly higher than the scores of the students in the control group at the level of significant m = 0.05 with the degree of freedom (df) 77, t-observed value 8.9 > t-table value 1.99. The findings indicate that using Demonstration Method significantly affected the students’ achievement in speaking skill. So, English teachers are suggested to use Demonstration Method in order to improve students’ achievement in speaking skill.


Author(s):  
A.G. Filipova ◽  
A.V. Vysotskaya

The article presents the results of mathematical experiments with the system «Social potential of childhood in the Russian regions». In the structure of system divided into three subsystems – the «Reproduction of children in the region», «Children’s health» and «Education of children», for each defined its target factor (output parameter). The groups of infrastructure factors (education, health, culture and sport, transport), socio-economic, territorial-settlement, demographic and en-vironmental factors are designated as the factors that control the system (input parameters). The aim of the study is to build a model îf «Social potential of childhood in the Russian regions», as well as to conduct experiments to find the optimal ratio of the values of target and control factors. Three waves of experiments were conducted. The first wave is related to the analysis of the dynam-ics of indicators for 6 years. The second – with the selection of optimal values of control factors at fixed ideal values of target factors. The third wave allowed us to calculate the values of the target factors based on the selected optimal values of the control factors of the previous wave.


2021 ◽  
pp. 053901842199956
Author(s):  
Gerard Delanty

This essay is a comment on the research program launched by Frank Adloff and Sighard Neckel. My comment is specifically focused on their research agenda as outlined in their trend-setting article, ‘Futures of sustainability as modernization, transformation, and control: A conceptual framework’. The comment is also addressed more generally to the research program of the Humanities Centre for Advanced Studies ‘Futures of Sustainability’. I raise three issues: the first relates to the very idea of the future; the second concerns the notion of social imaginaries and the third question is focused on the idea of social transformation.


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