Foliar chemical protection against Pantoea ananatis in onion is negated by thrips feeding

Center rot of onion, caused by Pantoea ananatis, is an economically important disease in onion production in Georgia and elsewhere in the United States. Growers rely on frequent foliar applications of bactericides, and in some cases, plant defense inducers to manage this disease. However, regular prophylactic applications of these chemicals is not cost-effective and may not be environmentally friendly. Thrips (Thrips tabaci and Frankliniella fusca) are vectors of P. ananatis, and their feeding may compromise the effectiveness of foliar applications against P. ananatis. In this study, foliar treatments of acibenzolar-S-methyl (Actigard 50WG), cupric hydroxide (Kocide 3000), and Actigard + Kocide were evaluated for their effectiveness in the presence and absence of thrips infestation at two critical onion-growth stages; bulb initiation and bulb swelling. Onion growth stage had no impact on effectiveness of either Kocide or Actigard. In the absence of thrips, Kocide application resulted in reduced center rot incidence compared with Actigard, regardless of the growth stage. However, when thrips were present, the efficacy of both Kocide and Actigard was reduced with bulb incidence not significantly different from the non-treated control. In independent greenhouse studies in the presence or absence of thrips, it was observed that use of protective chemicals (Kocide or Actigard and their combinations) at different rates also affected the pathogen progression into the internal neck tissue and incidence of bulb rot. These results suggest that thrips infestation can reduce the efficacy of protective chemical treatments against P. ananatis.

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Interaction of Onion Cultivar and Growth Stages on Incidence of Pantoea ananatis Bulb Infection

Plant Disease ◽

10.1094/pdis-01-17-0143-re ◽

2017 ◽

Vol 101 (9) ◽

pp. 1616-1620 ◽

Cited By ~ 8

Author(s):

Spencer Stumpf ◽

Ron Gitaitis ◽

Timothy Coolong ◽

Cliff Riner ◽

Bhabesh Dutta

Keyword(s):

Leaf Senescence ◽

Lower Incidence ◽

Growth Stage ◽

Management Strategies ◽

Economic Losses ◽

Growth Stages ◽

Pantoea Ananatis ◽

Bacterial Diseases ◽

Onion Bulbs ◽

Onion Cultivar

Center rot, caused by Pantoea ananatis, has been one of the most important bacterial diseases of onion leading to considerable economic losses. Symptoms can be expressed in the onion foliage and bulb, with the pathogen moving from the infected leaves to bulb scales. However, little is known regarding which growth stage the plant is most susceptible to bulb infection and if there are differences in susceptibility to bulb infection among sweet onion cultivars. In this study, five cultivars of sweet onion (Pirate, Sweet Harvest, 1518, Granex YPRR, and 1407) were inoculated by clipping the tips of onion foliage and depositing 1 ml of 1 × 108 CFU/ml of P. ananatis suspension into the central leaf cavity. The inoculations were done at three growth stages (first leaf senescence, bulb initiation, and bulb swelling). Center rot incidence was assessed for precured and cured onion bulbs. In addition, total bulb incidence of center rot for each cultivar inoculated at three growth stages were also calculated. Total bulb center rot incidence was significantly higher for Granex YPRR (84%) compared with other cultivars. Also, cultivars 1518 (49%) and 1407 (33%) had significantly lower incidence of bulb infection compared with other tested cultivars. Onions were significantly more susceptible to bulb infection when inoculated during first leaf senescence (62%) as compared with bulb initiation (37%) and bulb swelling (31%) stages in precured bulbs (P = 0.041). Significantly higher incidence of center rot was observed for bulbs whose foliage were inoculated during first leaf senescence stage (64%) compared with bulb initiation (55%) and bulb swelling (52%) stages (P = 0.048). Interactions between onion cultivar and inoculation stage on center rot bulb incidence were not significant (P ≥ 0.218), when evaluated at different assessment periods. However, different cultivars displayed significant variability in susceptibility to bulb infection. The outcomes of this study may have implications in devising management strategies aimed at protecting most susceptible onion growth stages against P. ananatis.

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Transmission of Pantoea ananatis and P. agglomerans, Causal Agents of Center Rot of Onion (Allium cepa), by Onion Thrips (Thrips tabaci) Through Feces

Phytopathology ◽

10.1094/phyto-07-13-0199-r ◽

2014 ◽

Vol 104 (8) ◽

pp. 812-819 ◽

Cited By ~ 31

Author(s):

B. Dutta ◽

A. K. Barman ◽

R. Srinivasan ◽

U. Avci ◽

D. E. Ullman ◽

...

Keyword(s):

Immunofluorescence Microscopy ◽

Thrips Tabaci ◽

Mechanical Inoculation ◽

Onion Thrips ◽

Pantoea Ananatis ◽

Exponential Relationship ◽

Frankliniella Fusca ◽

Tobacco Thrips ◽

Relationship Of ◽

The Relationship

Frankliniella fusca, the tobacco thrips, has been shown to acquire and transmit Pantoea ananatis, one of the causal agents of the center rot of onion. Although Thrips tabaci, the onion thrips, is a common pest of onions, its role as a vector of P. ananatis has been unknown. The bacterium, P. agglomerans, is also associated with the center rot of onion, but its transmission by thrips has not been previously investigated. In this study, we investigated the relationship of T. tabaci with P. ananatis and P. agglomerans. Surface-sterilized T. tabaci were provided with various acquisition access periods (AAP) on onion leaves inoculated with either P. ananatis or P. agglomerans. A positive exponential relationship was observed between thrips AAP duration and P. ananatis (R2 = 0.967; P = 0.023) or P. agglomerans acquisition (R2 = 0.958; P = 0.017). Transmission experiments conducted with T. tabaci adults indicated that 70% of the seedlings developed center rot symptoms 15 days after inoculation. Immunofluorescence microscopy with antibodies specific to P. ananatis revealed that the bacterium was localized only in the gut of T. tabaci adults. Mechanical inoculation of onion seedlings with fecal rinsates alone produced center rot but not with salivary secretions. Together these results suggested that T. tabaci could efficiently transmit P. ananatis and P. agglomerans.

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Detection of enteroviruses in marine waters by direct RT-PCR and cell culture

Water Science & Technology ◽

10.2166/wst.1995.0635 ◽

1995 ◽

Vol 31 (5-6) ◽

pp. 323-328 ◽

Cited By ~ 8

Author(s):

K. A. Reynolds ◽

C. P. Gerba ◽

I. L. Pepper

Keyword(s):

Cell Culture ◽

Polymerase Chain Reaction Amplification ◽

Cost Effective ◽

The United States ◽

Water Runoff ◽

Rt Pcr ◽

Marine Waters ◽

Storm Water Runoff ◽

Routine Monitoring ◽

Reaction Amplification

Sewage outfalls and storm water runoff introduces pathogenic human enteric viruses into marine coastal waters, which may pose a potential public health risk. Although members of the enterovirus group have been suggested as possible indicators of sewage pollution in marine waters, the lack of rapid, sensitive and cost effective methods have prevented routine monitoring in the United States. This study compared traditional cell culture and direct RT-PCR (reverse transcriptase-polymerase chain reaction) amplification for detection of an enterovirus. Poliovirus could be recovered from 100 L of artificial seawater with an average efficiency of 77%, using adsorption and elution from electronegative filters. Viruses were eluted from the filters with 1.5% beef extract for viruses (BEV) adjusted to pH 9.5 and reconcentrated by organic flocculation to a volume of 30 mL. Substances which interfered with detection by RT-PCR were removed by treatment of the concentrates with sephadex and chelex resins. Direct RT-PCR could detect 2.5 and 0.025 PFU (plaque forming units) for single (25 cycles) and double PCR (2 × 25 cycles) in 10 μL of pure culture poliovirus samples, respectively. These methods are currently being applied to assess the occurrence of enteroviruses at marine bathing beaches influenced by sewage discharges.

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Growth Stages Classification of Potato Crop Based on Analysis of Spectral Response and Variables Optimization

Sensors ◽

10.3390/s20143995 ◽

2020 ◽

Vol 20 (14) ◽

pp. 3995 ◽

Cited By ~ 3

Author(s):

Ning Liu ◽

Ruomei Zhao ◽

Lang Qiao ◽

Yao Zhang ◽

Minzan Li ◽

...

Keyword(s):

Growth Stage ◽

Spectral Response ◽

Classification Model ◽

Growth Stages ◽

Potato Field ◽

Spectral Bands ◽

Svm Model ◽

Selection Algorithms ◽

Potato Crops

Potato is the world’s fourth-largest food crop, following rice, wheat, and maize. Unlike other crops, it is a typical root crop with a special growth cycle pattern and underground tubers, which makes it harder to track the progress of potatoes and to provide automated crop management. The classification of growth stages has great significance for right time management in the potato field. This paper aims to study how to classify the growth stage of potato crops accurately on the basis of spectroscopy technology. To develop a classification model that monitors the growth stage of potato crops, the field experiments were conducted at the tillering stage (S1), tuber formation stage (S2), tuber bulking stage (S3), and tuber maturation stage (S4), respectively. After spectral data pre-processing, the dynamic changes in chlorophyll content and spectral response during growth were analyzed. A classification model was then established using the support vector machine (SVM) algorithm based on spectral bands and the wavelet coefficients obtained from the continuous wavelet transform (CWT) of reflectance spectra. The spectral variables, which include sensitive spectral bands and feature wavelet coefficients, were optimized using three selection algorithms to improve the classification performance of the model. The selection algorithms include correlation analysis (CA), the successive projection algorithm (SPA), and the random frog (RF) algorithm. The model results were used to compare the performance of various methods. The CWT-SPA-SVM model exhibited excellent performance. The classification accuracies on the training set (Atrain) and the test set (Atest) were respectively 100% and 97.37%, demonstrating the good classification capability of the model. The difference between the Atrain and accuracy of cross-validation (Acv) was 1%, which showed that the model has good stability. Therefore, the CWT-SPA-SVM model can be used to classify the growth stages of potato crops accurately. This study provides an important support method for the classification of growth stages in the potato field.

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Effect of Herbicides on the Management of the Invasive Weed Solanum rostratum Dunal (Solanaceae)

Plants ◽

10.3390/plants10020284 ◽

2021 ◽

Vol 10 (2) ◽

pp. 284

Author(s):

Jackline Abu-Nassar ◽

Maor Matzrafi

Keyword(s):

Growth Stage ◽

Late Summer ◽

Early Spring ◽

Growth Stages ◽

Weed Species ◽

Invasive Weed ◽

Solanum Rostratum ◽

Stage 4 ◽

Chemical Solutions ◽

Late Growth

Solanum rostratum Dunal is an invasive weed species that invaded Israel in the 1950s. The weed appears in several germination flashes, from early spring until late summer. Recently, an increase in its distribution range was observed, alongside the identification of new populations in the northern part of Israel. This study aimed to investigate the efficacy of herbicide application for the control of S. rostratum using two field populations originated from the Golan Heights and the Jezreel Valley. While minor differences in herbicide efficacy were recorded between populations, plant growth stage had a significant effect on herbicide response. Carfentrazone-ethyl was found to be highly effective in controlling plants at both early and late growth stages. Metribuzin, oxadiazon, oxyfluorfen and tembutrione showed reduced efficacy when applied at later growth stage (8–9 cm height), as compared to the application at an early growth stage (4–5 cm height). Tank mixes of oxadiazon and oxyfluorfen with different concentrations of surfactant improved later growth stage plant control. Taken together, our study highlights several herbicides that can improve weed control and may be used as chemical solutions alongside diversified crop rotation options. Thus, they may aid in preventing the spread and further buildup of S. rostratum field populations.

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BioWorma as an Aid for Controlling Ruminant Nematode Parasites

Journal of Animal Science ◽

10.1093/jas/skab096.065 ◽

2021 ◽

Vol 99 (Supplement_2) ◽

pp. 36-36

Author(s):

James E Miller ◽

Joan M Burke ◽

Thomas H Terrill

Keyword(s):

Delivery System ◽

Control Method ◽

Animal Health ◽

Late Pregnancy ◽

Cost Effective ◽

The United States ◽

Gastrointestinal Nematodes ◽

Mineral Supplement ◽

Larval Stages ◽

Nematode Parasites

Abstract Nematode-trapping fungi are biological control agents used against the larval stages of gastrointestinal nematodes in livestock feces. These fungi are normal soil inhabitants where they feed on a variety of non-parasitic soil nematodes. Of the various fungi tested, Duddingtonia flagrans spores (BioWorma, International Animal Health Products, Australia) have been shown to survive passage through the gastrointestinal tract of ruminants. After defecation, the spores germinate and grow in the feces to form sticky, sophisticated traps/loops which are able to trap the developing larval stages in the fecal environment. This form of control has been successfully applied under field conditions and is an environmentally safe biological approach for forage-based feeding systems. BioWorma has recently been approved for use in the United States. The primary delivery system is mixing BioWorma into supplement feedstuffs daily where each animal has the opportunity to consume an adequate amount of the mixture. To achieve optimum control of larvae during the transmission season (May–October), BioWorma needs to be fed for a period of no shorter than 60 days, starting at the beginning of the grazing season (especially young after weaning). Feeding BioWorma to dams during late pregnancy and lactation will also help to reduce pasture contamination, especially for growing young that will graze the same pasture. Another delivery system is mixing BioWorma into loose mineral supplement where animals will consume it free choice. The mineral needs to be kept covered and dry. The spores cannot be incorporated into pellets as the heat of the pelleting process will kill the spores. One drawback in using BioWorma is the relatively high cost. Research is being conducted to evaluate other delivery schemes that could be more cost effective. This product is the only control method that targets nematodes on pasture, where a majority of the total population reside.

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Effect of Growth Stage on Susceptibility of Grape Berry and Rachis Tissues to Infection by Phomopsis viticola

Plant Disease ◽

10.1094/pdis.2001.85.5.517 ◽

2001 ◽

Vol 85 (5) ◽

pp. 517-520 ◽

Cited By ~ 25

Author(s):

O. Erincik ◽

L. V. Madden ◽

D. C. Ferree ◽

M. A. Ellis

Keyword(s):

Growth Stage ◽

Grape Berry ◽

Growth Stages ◽

Phomopsis Viticola ◽

Over Time

Intact ‘Seyval’ grape clusters in the greenhouse and ‘Catawba’ clusters in the field were inoculated with conidia of Phomopsis viticola at seven Eichorn-Lorenz growth stages between 12 (prebloom) and 35 (véraison) in 1998. Five pots (10 clusters) were used per inoculation, and the experiment was repeated three times. Also, 10 to 20 randomly selected Catawba clusters were inoculated in the field for each of three replications at each growth stage. Studies were repeated in 1999. In addition, Chambourcin clusters were also inoculated at four growth stages in the greenhouse in 1999. Results obtained in the greenhouse and field during both years and for all cultivars indicate that berry and rachis infections can occur at all growth stages between 12 and 35 with no evidence of decreasing susceptibility over time. Results disagree with some literature reports that indicate that berry infection occurs primarily during bloom and shortly after bloom, and susceptibility decreases as fruit matures.

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Response to Dr Stone

PEDIATRICS ◽

10.1542/peds.96.4.850 ◽

1995 ◽

Vol 96 (4) ◽

pp. 850-851

Author(s):

Howard A. Pearson

Keyword(s):

Nurse Practitioners ◽

Cost Effective ◽

The United States ◽

Health Maintenance Organizations ◽

Quality Health Care ◽

Quality Cost ◽

Health Maintenance ◽

Effective Care ◽

Quality Health

Dr Elsa Stone, in her usual organized and lucid fashion, has presented the case for inclusion of pediatric nurse practitioners (PNPs) in private pediatric practices. She bases her conclusions on her nearly 10 years of positive experience with a PNP in her own practice in Connecticut. Dr Stone describes the PNP population and demography, describes the training curriculum of PNPs, and discusses the scope of work of these individuals. She concludes that "there is substantial evidence that PNPs provide quality health care and that collaborative teams of pediatricians and PNPs can provide high-quality, cost-effective care to a broader spectrum of children than can be served by either profession alone." The American Academy of Pediatrics (AAP) has insisted for several years that there is a shortage of pediatricians to meet the expanding needs of the children of the United States. Furthermore, pediatricians—because of system changes—will be expected increasingly to provide a variety of time-intensive services. Dr Stone believes that many of these services can be well provided by PNPs. Within the AAP, there have been some concerns about the role of PNPs. Of particular worry seems to be the possibility that PNPs might decide to practice independently, leading to a lower quality of care for their patients. Less often stated, but clearly an issue, is that PNPs are viewed by some pediatricians as potential competitors. Dr Stone's demographic analysis of what PNPs are currently doing is relevant to these concerns. One third of PNPs work in private pediatric practices or health maintenance organizations.

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QS-9000 – Using the Automotive Requirements to Improve Existing ISO 9000 Systems

Thermal Spray 1998: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc1998p0855 ◽

1998 ◽

Author(s):

J.F. Young

Keyword(s):

Continuous Improvement ◽

Cost Effective ◽

Iso 9000 ◽

The United States ◽

Quality System ◽

General Motors ◽

Improvement Program ◽

Quality Initiatives ◽

Cost Of Quality ◽

Improvement Programs

Abstract In this paper, we will discuss how to incorporate several of the QS-9000 quality system requirements into an existing ISO 9000 quality system. This expansion of the existing quality system will be cost effective and ensure that the continuous improvement program will meet its goals. The QS-9000 quality system was developed in 1994 by the "Big Three" automotive and truck producers in Detroit, Michigan. This document, originated in the United States, is based upon the International Standard: ISO 9001-94. It is mandatory that any supplier of goods and/or services to either Chrysler, Ford or General Motors must have their quality system registered to the QS-9000 standard. We believe that there can be benefits to non-automotive organizations if they will incorporate some of the QS-9000 clauses into their current ISO 9000 quality systems. We will discuss actual cases in the following areas: purchasing, safety, process control, training, business management and continuous improvement. We will show how these examples of quality system enhancement are both effective and efficient ways of driving cost reduction and process improvement programs. Cost of quality initiatives can be better managed.

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A Tool for Designing Policy Packages To Achieve India’s Climate Targets: Methods, Data, and Reference Scenario of the India Energy Policy Simulator

10.46830/writn.21.00108 ◽

2021 ◽

Author(s):

Deepthi Swamy ◽

Apurba Mitra ◽

Varun Agarwal ◽

Megan Mahajan ◽

Robbie Orvis

Keyword(s):

Energy Policy ◽

Ghg Emissions ◽

Cost Effective ◽

The United States ◽

Technical Note ◽

Reference Scenario ◽

Low Carbon ◽

Climate Targets ◽

Effective Manner ◽

Business As Usual

India is currently the world’s third-largest emitter of greenhouse gases (GHGs) after China and the United States and is set to experience continued growth in its population, economy, and energy consumption. Exploring low-carbon development pathways for India is therefore crucial for achieving the goal of global decarbonization. India has pledged to reduce the emission intensity of its gross domestic product (GDP) by 33–35 per cent relative to 2005 levels by 2030 through its Nationally Determined Contribution (NDC), among other related targets for the renewable energy and forestry sectors. Further, countries, including India, are expected to respond to the invitation of the Conference of the Parties (COP) to the Paris Agreement to communicate new or updated NDCs with enhanced ambition and long-term low-GHG development strategies for 2050. To design effective policy packages to support the planning and achievement of such climate targets, policymakers need to identify policies that can reduce GHG emissions in a timely and cost-effective manner, while meeting development-related and other national objectives. The India Energy Policy Simulator (India EPS), an open-source, system dynamics model, can enable an integrated quantitative assessment of different cross-sectoral climate policy packages for India through 2050 and their implications for key variables of interest such as emissions, GDP, and jobs. The tool was developed by Energy Innovation LLC and adapted for India in partnership with World Resources Institute. It is available for open access through a Web interface as well as a downloadable application. This technical note describes the structure, input data sources, assumptions, and limitations of the India EPS, as well as the setup and key results of its reference scenario, referred to as the business-as-usual (BAU) scenario in the model. It is intended as an update to the first technical note on the India EPS (Mangan et al. 2019) and accounts for the changes incorporated into the model since the first version.

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