Evaluations of New and Current Management Strategies to Control Phomopsis Cane and Leaf Spot of Grape

2007 ◽  
Vol 8 (1) ◽  
pp. 69 ◽  
Author(s):  
Mizuho Nita ◽  
Michael A. Ellis ◽  
Leslie L. Wilson ◽  
Laurence V. Madden
Keyword(s):  
Leaf Spot ◽  
Early Stage ◽  
Disease Incidence ◽  
Management Strategies ◽  
Warning System ◽  
Weather Conditions ◽  
Early Spring ◽  
System Control ◽  
Stage Of Development ◽  
Significant Difference

To extend our understanding of the epidemiology and control of Phomopsis cane and leaf spot of grape, caused by Phomopsis viticola, studies were conducted to: (i) determine efficacy of a dormant fungicide spray program for controlling the disease in its early stage of development (e.g., spring); (ii) evaluate a disease warning system by applying fungicides and fungicide-adjuvant combinations in response to predicted infection periods based on weather conditions; and (iii) correlate commercial control practices and environmental conditions with disease incidence based on a state-wide survey of commercial fields. With the warning system, control was equal to that obtained with a 7-day protectant fungicide program, but with fewer fungicide applications per season. A dormant application provided consistent, yet only moderate, control of the disease. Growers who applied a dormant-season application or early spring protectant fungicides tended to have lower disease incidence than those who did not. There was high variability in disease incidence within vineyards and farms, but no significant difference in incidence among regions of the state. Overall, early season application of protective fungicides was shown to be a key factor for successful management of P. viticola. Accepted for publication 29 March 2007. Published 26 July 2007.

scholarly journals Evaluation of a Disease Warning System for Phomopsis Cane and Leaf Spot of Grape: A Field Study

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1239-1246 ◽  
Author(s):  
M. Nita ◽  
M. A. Ellis ◽  
L. L. Wilson ◽  
L. V. Madden
Keyword(s):  
Leaf Spot ◽  
Shoot Growth ◽  
Disease Incidence ◽  
Warning System ◽  
Field Evaluation ◽  
Weather Conditions ◽  
Relative Difference ◽  
Phomopsis Viticola ◽  
The Mean ◽  
Vitis Spp

A field evaluation of a warning system for Phomopsis cane and leaf spot of grape (Vitis spp.), caused by Phomopsis viticola, was conducted in Ohio over 3 years (2002 to 2004) by applying fungicides and fungicide-adjuvant combinations based on predicted infection events. Three different criteria for risk—light, moderate, and high—were evaluated with the warning system. The warning system is based on measured weather conditions (temperature and wetness duration following rain) and a model for risk of leaf and internode infection. Vines were sprayed with fungicides based on either the warning system or a calendar-based 7-day protectant program, from 2.5-cm shoot growth (Eichhorn-Lorenz [E-L] stage 7) to the end of the broom (E-L stage 27). Fungicides were tested with or without an adjuvant (JMS Stylet-Oil or Regulaid). In the controls, the mean percentage of leaves and internodes with infections ranged from 36 to 100%, the number of lesions per leaf ranged from 1 to 28, and percentage of internodes covered by lesions ranged from 1 to 12%. Both the calendar-based protectant treatment (based on use of mancozeb) and the warning system treatment based on spraying in response to light or moderate predicted infection events (especially with mancozeb + Regulaid) resulted in significantly less disease incidence and severity compared with the controls. The mean percent control (relative difference in disease between a treatment and the control) was higher for the protectant schedule (˜55% and ˜80% for incidence and severity, respectively, based on application of mancozeb) than for the warning system (˜36% and ˜60% for incidence and severity, respectively, based on application of mancozeb + Regulaid), but there were two to three times more fungicide applications with the protectant schedule than with the warning system.

scholarly journals SUSCEPTIBILITY OF LEMON BALM (Melissa officinalis L.) VARIETIES TO SEPTORIA LEAF SPOT (Septoria melissae Desm.) IN HUNGARY

2019 ◽  
Vol 18 (1) ◽  
pp. 47-56
Author(s):  
Gergő Kovács ◽  
Éva Zámbori-Németh ◽  
Géza Nagy
Keyword(s):  
Leaf Spot ◽  
Plant Protection ◽  
Disease Incidence ◽  
Weather Conditions ◽  
The Other ◽  
Melissa Officinalis ◽  
Lemon Balm ◽  
Protection Method ◽  
Cultivated Plant ◽  
Septoria Leaf Spot

Lemon balm (Melissa officinalis L.) is a widely cultivated plant in Europe. Septoria melissae Desm. is the most important pathogen of lemon balm crops, which may cause serious yield loss by the severe leaf fall. As chemical control of the pathogen is restricted, alternative plant protection methods, like the use of tolerant varieties, should be taken under consideration. The goal of our work was to evaluate the susceptibility of three lemon balm varieties to Septoria leaf spot in field. The trials were carried out in 2016 and 2017 in Budapest-Soroksár, Hungary. Dynamics of infection showed characteristic sharp increase from the beginning of August in both years. The lowest infection levels were observed in cultivar ‘Lemona’. The disease incidence in the middle of August was 19% in the first year and 59% in the second year, while these values were over 40% and 70% in the other cultivars ‘Soroksári’ and ‘Quedlinburger Niederliegende’, respectively. The manifestation of symptomps was also significantly lighter on the ‘Lemona’ plants and they had the highest ratio of healthy leaves (81%) compared to the other cultivars. According to the data, weather conditions might modify the range of the differences among the cultivars. It was concluded that appropriate selection of varieties could be an effective and enviromental friendly plant protection method in the practice of lemon balm cultivation.

scholarly journals Screening of oil palm (Elaeis guineensis Jacq.) varieties for resistance to Curvularia leaf spot disease

2019 ◽  
Vol 13 ((04) 2019) ◽  
pp. 507-512
Author(s):  
Jittra Kittimorakul ◽  
Anurag Sunpapao ◽  
Saowapa Duangpan ◽  
Jakarat Anothai ◽  
Theera Eksomtramage
Keyword(s):  
High Resistance ◽  
Oil Palm ◽  
Leaf Spot ◽  
Elaeis Guineensis ◽  
Disease Incidence ◽  
Leaf Spot Disease ◽  
Spot Disease ◽  
Resistant Varieties ◽  
Significant Difference ◽  
Hybrid Lines

Leaf spot disease, particularly Curvularia leaf spot (CLS), can devastatingly damage both quality and quantity of oil palm seedlings in Thailand. Chemical fungicides have been intensively applied to control transmission of this disease. However, this has relatively low efficiency as the causative pathogen gains resistance to fungicides with selection pressure. An alternative or complementary cost-effective and environmentally friendly approach is necessary to find the resistant varieties for disease management. In this present study, a total of 122 lines of Dura female plant, 2 lines of Pisifera male plant, and 4 Tenera commercial varieties (A, B, C and SUP-PSU1) were screened by Curvularia inoculation using detached leaf method. Two weeks after inoculation, the results showed 13 Dura lines as highly resistant to CLS (0% disease incidence), whereas one line (129) and the commercial variety B were highly susceptible (100% disease incidence). Nine Tenera hybrid lines from 13 Dura highly resistant lines were selected to test for high resistance and subjected to Curvularia inoculation in greenhouse conditions, and compared with the susceptible and highly susceptible lines. Three Tenera hybrid lines (138, 187 and 203) showed high resistance to CLS significant difference from susceptible lines. These were the most highly resistant varieties to CLS and should be considered for breeding programs of oil palm stock among the cases tested.

scholarly journals Deep-Learning and Vibration-Based System for Wear Size Estimation of Railway Switches and Crossings

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5217
Author(s):  
Taoufik Najeh ◽  
Jan Lundberg ◽  
Abdelfateh Kerrouche
Keyword(s):  
Deep Learning ◽  
Short Term Memory ◽  
Early Stage ◽  
Warning System ◽  
Weather Conditions ◽  
Size Estimation ◽  
Vibration Data ◽  
University Of Technology ◽  
Railway Infrastructure ◽  
Processing Techniques

The switch and crossing (S&C) is one of the most important parts of the railway infrastructure network due to its significant influence on traffic delays and maintenance costs. Two central questions were investigated in this paper: (I) the first question is related to the feasibility of exploring the vibration data for wear size estimation of railway S&C and (II) the second one is how to take advantage of the Artificial Intelligence (AI)-based framework to design an effective early-warning system at early stage of S&C wear development. The aim of the study was to predict the amount of wear in the entire S&C, using medium-range accelerometer sensors. Vibration data were collected, processed, and used for developing accurate data-driven models. Within this study, AI-based methods and signal-processing techniques were applied and tested in a full-scale S&C test rig at Lulea University of Technology to investigate the effectiveness of the proposed method. A real-scale railway wagon bogie was used to study different relevant types of wear on the switchblades, support rail, middle rail, and crossing part. All the sensors were housed inside the point machine as an optimal location for protection of the data acquisition system from harsh weather conditions such as ice and snow and from the ballast. The vibration data resulting from the measurements were used to feed two different deep-learning architectures, to make it possible to achieve an acceptable correlation between the measured vibration data and the actual amount of wear. The first model is based on the ResNet architecture where the input data are converted to spectrograms. The second model was based on a long short-term memory (LSTM) architecture. The proposed model was tested in terms of its accuracy in wear severity classification. The results show that this machine learning method accurately estimates the amount of wear in different locations in the S&C.

scholarly journals Incidence of two leaf fungal diseases in two plum training systems

2018 ◽  
Vol 24 (3-4) ◽  
Author(s):  
B. Molnár ◽  
M. Varga ◽  
A. Vámos ◽  
I. J. Holb
Keyword(s):  
Fungal Pathogens ◽  
Disease Incidence ◽  
Weather Conditions ◽  
Fungal Diseases ◽  
Susceptible Cultivar ◽  
Training Systems ◽  
Leaf Disease ◽  
Significant Difference

In a two-year study, we aimed to determine the susceptibility of four plum cultivars to two fungal pathogens of plum (Stigmina carpophila and Polystigma rubrum) in two training systems with tree spacings of 4 x 1.5m and 6 x 3m. Results showed that shothole symptoms were not detected on cvs ’Bluefre’ and ’Stanley’ in August, 2016. Disease incidence was above 50% in the case of ’Čačanska lepotica’ in both training systems in 2016. There were no significant difference between the two training systems. Shot hole incidence was lower in the 6 x 3m spacings compared to the 4 x 1.5m spacings on cv ’President’ in 2016. Cultivar ’Čačanska lepotica’ showed the highest incidence of Stigmina carpophila in the 4 x 1.5m spacing in 2017. Disease incidence of Stigmina carpophila was significantly lower in the 6 x 3m spacing compared to the 4 x 1.5m spacing. Shothole incidences on cv ’President’ were similar to the values in 2016 ranging from 40% to 60%. Leaf disease incidence was higher in the 4 x 1.5m spacing compared to the 6 x 3m plot. Low disease incidence (below 10%) was observed on cv ’Stanley’ in 2017 and only in the 4 x 1.5m spacing. There were no visible symptoms of blackhorn dotty in 2016 due to inadequate weather conditions for the Polystigma rubrum fungus. However, all the four cultivars were infected by Polystigma rubrum in 2017. The most susceptible cultivar was cv ’Čačanska lepotica’ with the highest disease incidence in the 4 x 1.5m spacing. Disease incidence of this cultivar was lower in the 6 x 3m spacing which was significantly less than in the 4 x 1.5m spacing. The least susceptible cultivar was ’Bluefre’ and symptoms were observed only in the spacing of 4 x 1.5m. The disease incidence of cv ’President’ was similarly low to cv ’Stanley’ in both spacings.

scholarly journals Farmer Perceptions on Vegetable Diseases and Their Control in Sub-Humid Areas in Zimbabwe

2019 ◽  
Vol 5 (1) ◽  
pp. 1-11
Author(s):  
Maria Goss ◽  
Paramu. L. Mafongoya ◽  
Augustine Gubba ◽  
Obert Jiri
Keyword(s):  
Disease Management ◽  
Production Systems ◽  
Disease Incidence ◽  
Management Strategies ◽  
Disease Outbreaks ◽  
Weather Conditions ◽  
Cultural Control ◽  
Bacterial Disease ◽  
Vegetable Production ◽  
Control Methods

Abstract The monoculture vegetable production systems practiced by Zimbabwean farmers has resulted in major disease outbreaks, causing major production constraints. There is need to determine the intensity of pesticides usage and methods of alternative disease management strategies. This study was carried out using 250 randomly selected vegetable farmers by administering questionnaires. The study objectives were to determine farmers’ perceptions on vegetable disease incidence and severity in relation to prevailing weather conditions, and determine common control methods practiced to manage fungal and bacterial disease outbreaks. The results indicated significant increases in fungal and bacterial disease incidence of 84.6% (within community cropping fields) and severity of 73.1% (within individual farmer fields) over the past 5-10 years (P £ 0.05). It also revealed disease incidence being highest [30.8%] during winter (May – July) and rainy months [23.1%] (November – February). Results further indicated 96.2% of the respondents relied on chemical methods, 53.8% used cultural control, and 11.5% used natural control methods. However, none of the farmers used bio-pesticide/biological control methods. In conclusion: farmers are aware of the disease shifts in response to different climate variability but seem unaware of the negative effects of extensive chemical use, nor existence of alternative bio-pesticide/biological disease management strategies.

scholarly journals Comparison of Two Intravenous Fluid Management Strategies in COVID-19 Patients in Hubei, China: A Retrospective Multicenter Study

2020 ◽  
Author(s):  
Yaping Yuan ◽  
Jionghe Wu ◽  
Runsheng Wang ◽  
Zhanling Wu ◽  
Lei Pan ◽  
...  
Keyword(s):  
Disease Progression ◽  
Intravenous Infusion ◽  
Early Stage ◽  
Fluid Management ◽  
Management Strategies ◽  
Laboratory Findings ◽  
Conservative Group ◽  
Significant Difference ◽  
Liberal Group ◽  
Duration Of Hospitalization

Abstract Background Optimal fluid management in patients with COVID-19 has not been reported. This retrospective, multicenter study investigated the impact of intravenous infusion volume in the early stage of COVID-19 on clinical outcomes. Methods 127 patients from two tertiary hospitals were separated into the “conservative” and “liberal” groups based on average daily intravenous infusion volume within the first seven days after admission. Basic information, demographic and epidemiological characteristics, laboratory findings, treatments, and outcome measures were retrieved from medical records. The disease progression and prognosis were analyzed and compared. Results The average daily intravenous infusion volume within 7 days was 500 (150–700) ml/day in the conservative-strategy group (n = 87), and 1100 (1000–1288) ml/day in the liberal-strategy group (n = 40) (p < 0.001). There were no statistical differences in median age, male-to-female ratio, epidemiology, laboratory findings on admission, comorbidities, and average daily urine output within the seven days (p > 0.05). The final K+ in the liberal group was slightly higher than that at admission, and the final hematocrit level in the conservative group had a significant difference than that at admission (p < 0.05). The mean (± SD) duration of hospitalization was 22.41 ± 11.99 days in the conservative group and 25.28 ± 12.08 days in the liberal group (p = 0.120). However, compared to the liberal group, conservative group had statistically lower rates of disease progression (9.3% vs 37.5%, p < 0.001), mechanical ventilation (2.3% vs 27.5%, p < 0.001) and in-hospital mortality (2.3% vs 15.0%, p = 0.012). Conclusions Although there appeared to be no significant difference in the duration of hospitalization between using conservative and liberal fluid management strategies, the former was associated with lower rates of disease progression, mechanical ventilation and in-hospital mortality without increased nonpulmonary-organ dysfunction. These results support the importance of implementing conservative intravenous fluid infusion in the early stage of COVID-19.

scholarly journals Research on the Innovation of Management Strategies of Enterprises in Different Stages of Development

2020 ◽  
Vol 4 (4) ◽  
pp. 122
Author(s):  
Pu Dai
Keyword(s):  
Management Strategy ◽  
Development Process ◽  
Early Stage ◽  
Management Strategies ◽  
International Competition ◽  
Enterprise Development ◽  
Stages Of Development ◽  
Stage Of Development ◽  
Start Ups ◽  
Statistical Results

With the development of China’s enterprises, many enterprises gradually go abroad to participate in international competition. However, some research and statistical results show that only 30% of newly established start-ups can survive, and most of them fall into unsustainable situation at the early stage of development. Based on this, this article studies the management strategy and innovation of enterprises in different stages of development, in order to provide useful reference for the development of enterprises in different stages. This article firstly analyses the characteristics of different stages of enterprise development process, and then gives corresponding management strategies and innovation methods based on different stages of enterprise development.

scholarly journals First Report of Leaf Spot Caused by Cladosporium oxysporum on Greenhouse Eggplant in China

Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 566-566 ◽  
Author(s):  
C. Zheng ◽  
Z.-H. Liu ◽  
S.-S. Tang ◽  
D. Lu ◽  
X.-Y. Huang
Keyword(s):  
Leaf Spot ◽  
Early Stage ◽  
Disease Incidence ◽  
Solanum Melongena ◽  
Morphological Characteristics ◽  
Liaoning Province ◽  
Control Treatment ◽  
Pathogenicity Test ◽  
Potato Dextrose Broth ◽  
First Report

Eggplant (Solanum melongena L.) is an important vegetable crop that has significant economic value in northern regions of China, especially in Liaoning Province. In April 2013, a leaf spot was discovered on the eggplant cultivar 706 in ten 1-ha commercial greenhouses in Huludao, Liaoning Province, with 30% of the eggplants infected, resulting in reduced eggplant yield and quality. By July 2013, disease incidence was 35%. Spots were found mainly on the leaves. At the early stage of infection, small, chlorotic spots appeared on leaves and gradually expanded into brown, irregular spots with a diameter of 1 to 7 mm. Dark green mold developed in the spots on both sides of the leaves at high humidity, and the spots led to leaf yellowing and defoliation. Conidiophores in the lesions were straight or slightly flexuous with 1 to 7 septa, brown and smooth, with typical swellings at the junction of septa, and 45 to 670 × 3.0 to 5.3 μm. Conidia were oval or obpyriform with a smooth surface, brown or dark brown, with 0 to 2 septa and 5.5 to 14.8 × 2.5 to 4.0 μm. The pathogen was consistent morphologically with Cladosporium oxysporum (1). To identify the pathogen, leaf pieces (3 to 5 mm2) taken from the edge of lesions so that each leaf section included both infected and healthy leaf tissue, were surface-disinfested in 75% ethanol for 30 s, then transferred to a 0.1% aqueous mercuric chloride solution for 30 to 60 s, and rinsed with sterilized water three times. The sections were cultured on potato dextrose agar (PDA) at 25°C in the dark for 7 days. Three pure cultures were obtained from single spores. The conidia on PDA were oval or obpyriform, and 5.4 to 14.7 × 2.4 to 4.2 μm with 0 to 1 septa, and were smaller than the conidia examined directly from infected eggplant leaves. Two isolates were grown on synthetic nutrient agar (SNA) in slide cultures. The conidiophores on SNA were straight or slightly flexuous with swellings at the junctions of septa. On the grounds of these morphological characteristics, the pathogen was identified as C. oxysporum (1,3). For DNA extraction, cultures were grown in potato dextrose broth and the internal transcribed spacer (ITS) region of ribosomal DNA (rNDA) was amplified using primers ITS1 and ITS4 (2). Sequence analysis showed that the ITS sequences of the two isolates were 99% identical to that of C. oxysporum (GenBank Accession No. EF029816). Two isolates were tested for pathogenicity on eggplant using 1 × 107 conidia/ml in sterilized water atomized onto each of six 7-week-old plants of the cultivar Xi'an Green Eggplant. Sterilized water was applied similarly to another six plants as the control treatment. The plants were incubated at 25°C with 85% relative humidity for 8 to 10 days. After 10 days, light brown, irregular spots were found on inoculated leaves, whereas no symptoms were observed on control plants. The pathogen was re-isolated from lesions on inoculated plants but not from control plants. The re-isolates were confirmed to be C. oxysporum based on morphological characteristics. The pathogenicity test was repeated and the same results obtained. Therefore, the pathogen causing leaf spot on eggplant in these greenhouses was identified as C. oxysporum. This is the first report of C. oxysporum causing leaf spot on greenhouse eggplant in China. C. oxysporum is a known pathogen of pepper and tomato. Additional studies are needed to provide management recommendations for this pathogen on Solanaceae crops. References: (1) K. Bensch et al. Stud. Mycol. 67:1, 2010. (2) Q. Li and G. Wang. Microbiol. Res. 164:233, 2009. (3) W. T. H. Peregrine and K. B. Ahmad. Phytopathol. Pap. 27:1, 1982.

scholarly journals First report of Alternaria longipes causing leaf spot on tea in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Qiaoxiu Yin ◽  
Xiaoli An ◽  
Xian Wu ◽  
Dissanayake Saman Pradeep Dharmasena ◽  
Dongxue Li ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Early Spring ◽  
Guizhou Province ◽  
Leaf Spot Disease ◽  
Control Group ◽  
Post Inoculation ◽  
First Report ◽  
Spot Disease ◽  
Light Yellow

Tea [Camellia sinensis (L.) Kuntze)] have been widely planted in Guizhou Province in recent years, and the cultivation area in the region ranks first among all the provinces or cities in China. Leaf spot disease was an important disease of tea in Kaiyang county, Guizhou Province, which mainly damaged young leaves and shoot of tea and led to a huge loss of the production of tea. The spots initially represented brown and round, and then the diameter of the spot was 4-6 mm during later period, with the color of the center in the spot changing white. Tea leaf spot disease always occurs in early spring and the region with 1300 m altitude. From 2016 to 2019, disease incidence of leaves was estimated at 84% to 92%, and the disease severity on a plant basis was determined to be 64% to 76%, depending on the field. To identify the causal agent of the foliar disease, pieces of the lesion margins were surface sterilized with 75% ethanol for 30 s, followed by 0.5% sodium hypochlorite for 5 min, rinsed with sterile water three times, plated on potato dextrose agar (PDA) and incubated in the dark at 25C for 3 to 5 d. The hyphal tips from the margins of the growing colonies were successively picked and transferred to fresh PDA plates to purify the isolates. The result indicated that the isolates on PDA represented initially round form, and white mycelium. The reverse sides of the isolates firstly displayed light yellow on PDA. Conidiophores represent dark brown, geniculate. Brown conidia, narrow ovoid, length: 22.9 ± 4.5 μm, width: 11.1 ± 1.7 μm, with 4 to 8 transverse septa and with conspicuously ornamented walls. The gene of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (Berbee et al. 1999) and the Alternaria allergen 1 (Alt a1) (Hong et al. 2005) of three strains were amplified, sequenced and deposited in Genbank. Maximum parsimony phylogenetic analysis based on concatenated sequences of combined GAPDH (1-583) and Alt a 1 (588-1065) indicated that the strain AXLKY_2019_010 was identical to reference strain Alternaria longipes strain EGS 30-033, and the clade was supported by 96% bootstrap values. According to the Koch’s postulate, the tea leaves were inoculated with PDA plugs with actively growing mycelia using the methods of the puncture, cut and unwound under the laboratory conditions and the natural conditions. Slight yellow spots were gradually formed after 2 d post-inoculation on the inoculated leaves, and the color of the center of the spot changed to be white. With the prolonging of inoculation time, the size of lesion represented to be slightly enlarged. PDA plugs without mycelia were used as a control, and the control group showed no symptoms. The same isolates were consistently reisolated from inoculated leaves. A. longipes can cause leaf blight of carrots in Israel (Vintal et al. 2002), leaf spot of potato in Pakistan (Shoaib et al. 2014) and leaf spot of Atractylodes macrocephala in China (Tan et al. 2012). To our knowledge, this is the first report of A. longipes causing leaf spot on tea in China and our findings will be useful for its management and for further research.

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