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

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.

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Seed production of lemon balm and the quality of its seeds in the middle of the Volga region

The Agrarian Scientific Journal ◽

10.28983/asj.y2019i8pp34-36 ◽

2019 ◽

pp. 34-36

Author(s):

Ilya Alexandrovich Khapugin

Keyword(s):

Seed Production ◽

Weather Conditions ◽

Mineral Fertilizers ◽

Small Scale ◽

Melissa Officinalis ◽

Seed Productivity ◽

Lemon Balm ◽

Maximum Productivity ◽

Scale Experiment

The influence of mineral fertilizers on seed productivity and quality of obtained seeds of lemon balm (Melissa officinalis L.) was studied in the field small-scale experiment under conditions of unstable moistening of the Mordovia Republic. As a result, it was found that seed productivity varied depending on weather conditions and the types of fertilizers introduced. It was shown that the maximum productivity of Melissa officinalis plants was on the variant with the use of phosphorus-potassium fertilizers at a dose of P60K90 (71.2±78.5 g/m2 in 2017 and 48.8±4.3 g/m2 in 2018), while it exceeded the control variant by 74-91 %. The total germination of seeds of Melissa officinalis practically did not change over the years, and was in the range of 37-39 %. Separation of seeds according to the degree of aging allowed to increase germination 11.4-13.3 %.

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Effective Biomass Reduction of the Invasive Weed Species Banana Poka by Septoria Leaf Spot

Plant Disease ◽

10.1094/pdis.2001.85.4.357 ◽

2001 ◽

Vol 85 (4) ◽

pp. 357-361 ◽

Cited By ~ 7

Author(s):

Eduardo E. Trujillo ◽

Chris Kadooka ◽

Victor Tanimoto ◽

Steve Bergfeld ◽

Glenn Shishido ◽

...

Keyword(s):

Leaf Spot ◽

Disease Incidence ◽

Severe Disease ◽

Disease Spread ◽

Leaf Spot Disease ◽

Native Forest ◽

Invasive Weed ◽

Disease Epidemics ◽

Biomass Reduction ◽

Septoria Leaf Spot

Inoculations of Septoria passiflorae for biological control of banana poka (Passiflora tripartita var. tripartita) at different forest sites in Hawaii, Kauai, and Maui resulted in successful establishment of the Septoria leaf spot disease at all sites during 1996. Semi-annual monitoring of sites in 1997 revealed low disease incidence and no disease spread to adjacent non-inoculated plants. Site inspections in March 1998 revealed light disease epidemics causing visible defoliation at inoculated sites on Kauai and Maui. Banana poka biomass reduction at sites with light epidemics of the disease in Kauai and Maui were estimated to be less than 10% in 1998, whereas in 1999 biomass reduction ranged from 50 to 95%. Five of 11 inoculation sites in 1996 on the island of Hawaii showed no disease. These five sites on Kaloko had frequent acid rainfall averaging 3.2 pH, which inhibited spore germination and infection. Six sites, free of acid rain, three at Hilo Forest Reserve and three at Puuwaawaa Wildlife Sanctuary, had severe disease epidemics by 1998, and vine defoliation was >90%. Widespread epidemics of the disease occurred in 1999, resulting in estimated 80 to 95% biomass reductions in more than 2,000 hectares of native forest infested with banana poka.

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Temporal Progress of Septoria Leaf Spot on Rabbiteye Blueberry (Vaccinium ashei)

Plant Disease ◽

10.1094/pd-89-1090 ◽

2005 ◽

Vol 89 (10) ◽

pp. 1090-1096 ◽

Cited By ~ 7

Author(s):

P. S. Ojiambo ◽

H. Scherm

Keyword(s):

Disease Severity ◽

Leaf Spot ◽

Developmental Stages ◽

Disease Incidence ◽

Disease Onset ◽

Parameter Estimates ◽

Vaccinium Ashei ◽

Leaf Emergence ◽

Temporal Progress ◽

Septoria Leaf Spot

Septoria leaf spot, caused by Septoria albopunctata, is an important disease on blueberry in the southeastern United States, yet its epidemiology is largely unknown. Disease severity and dissemination of pycnidiospores were monitored from 2002 to 2004 in a planting of susceptible Premier rabbiteye blueberry to characterize the temporal progress of the disease and determine the effect of inoculum dynamics and selected leaf attributes on disease development. Disease onset was observed between late April and mid-June, followed by a rapid increase in disease severity until mid- to late September; thereafter, disease severity decreased until the end of the season due to abscission of severely infected leaves. A logistic model was fitted to disease severity data using nonlinear regression, and parameter estimates were used to compare the effects of leaf position on the shoot and shoot location in the canopy on disease progress. Based on this model, the highest absolute rate of disease increase and the highest upper asymptote of disease severity were predicted for leaves in intermediate positions on the shoot and for shoots in the lower canopy. Data collected with funnel spore samplers showed that splash-dispersed pycnidiospores of S. albopunctata were available throughout most of the period from April through late October. Final disease severity on individual leaves was more strongly correlated with cumulative spore numbers throughout the entire season (from leaf emergence to the end of the assessment period in November) than with cumulative spore numbers during shorter periods around the time of leaf emergence; this suggests that infection is not limited to young, expanding leaves, but rather that leaves at all developmental stages can become infected by S. albopunctata seasonlong. Disease incidence on leaves of potted trap plants exposed to natural inoculum in the field during rain events in 2003 and 2004 was >70.0% irrespective of leaf developmental stage at the time of exposure. Taken together, the results of this study indicate that inoculum of S. albopunctata is present throughout most of the growing season and that infection can occur season-long on leaves of any age, giving rise to a polycyclic epidemic.

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Effect of Planting Population on Stem Diseases of Soybean in Iowa and Wisconsin

Plant Health Progress ◽

10.1094/php-07-20-0062-rs ◽

2021 ◽

Author(s):

Yuba R. Kandel ◽

Xavier A. Phillips ◽

John M. Gaska ◽

Shawn P. Conley ◽

Daren S. Mueller

Keyword(s):

Disease Incidence ◽

Weather Conditions ◽

Field Trials ◽

The Other ◽

Seeding Rate ◽

Late Season ◽

Stem Blight ◽

Similar Yield

Farmers may adjust seeding rate across or within fields for a variety of reasons. The objectives of this study were to determine if seeding rate affected two late-season stem diseases, anthracnose stem blight (ASB) and pod and stem blight (PSB), and yield of soybean. Disease incidence, severity, and yield were collected from eight field trials in Iowa and Wisconsin during 2016 to 2018. ASB incidence exceeded 80% in most of the trials and significantly differed across years with the highest incidence in 2016 and 2018 compared with 2017, the year with the least precipitation. A similar trend across years was observed for ASB severity. The incidence and severity of PSB also differed across years, although PSB incidence and severity were always less than ASB. PSB was greatest in 2017 compared with the other two years. Seeding rate did not affect either disease. A seeding rate of 198,000 to 395,000 seeds/ha provided statistically similar yield. Weather conditions each year affected late-season stem diseases.

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

Plant Health Progress ◽

10.1094/php-2007-0726-06-rs ◽

2007 ◽

Vol 8 (1) ◽

pp. 69 ◽

Cited By ~ 1

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.

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

Plant Disease ◽

10.1094/pd-90-1239 ◽

2006 ◽

Vol 90 (9) ◽

pp. 1239-1246 ◽

Cited By ~ 13

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.

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Biological control of important fungal diseases of potato and raspberry by two Bacillus velezensis strains

PeerJ ◽

10.7717/peerj.11578 ◽

2021 ◽

Vol 9 ◽

pp. e11578

Author(s):

Anzhela Asaturova ◽

Margarita Shternshis ◽

Vera Tsvetkova ◽

Tatyana Shpatova ◽

Vladislava Maslennikova ◽

...

Keyword(s):

Biological Control ◽

Western Siberia ◽

Plant Protection ◽

Disease Incidence ◽

Weather Conditions ◽

Small Scale ◽

Biological Control Agents ◽

Bacterial Strains ◽

Red Raspberry ◽

Bacillus Velezensis

Stem canker and black scurf caused by Rhizoctonia solani are the important diseases in potato, while spur blight caused by Didymella applanata is a major disease in red raspberry. In Western Siberia, both crops are grown predominantly in small-scale farming that requires maximal usage of biological products for plant protection instead of chemicals. We evaluated two promising Bacillus velezensis strains BZR 336 g and BZR 517 isolated in the south of Russia (45°1′N, 38°59′E) for their biological control potentials against the potato and red raspberry diseases under the more severe weather conditions of Western Siberia (55°1′N, 82°55′ E). We tested two techniques to apply biocontrol agents: (1) coating the seeds (potato tubers) and (2) spraying over the plants (raspberry canes). In each case, we estimated B. velezensis strains on two plant cultivars differed by the disease resistance. The degree of B. velezensis influence on disease incidence and severity depended on the bacterial strain, the protected plant, and its cultivar. We also demonstrated that two B. velezensis strains significantly stimulated plant growth of potato, which contributed to the plant productivity on both cultivars. The BZR 336 g strain affected the potato productivity more than the BZR 517 strain. Under the influence of both bacterial strains, raspberry yield was significantly higher compared to the control on the susceptible cultivar. These findings indicated that two southern B. velezensis strains had proved their efficacy as biological control agents in the control of the serious fungal infection of potato and raspberry plants under the more severe ecological conditions of Western Siberia. For the first time, we demonstrated B. velezensis strains potential for use as biological control agents against R. solani on potato, and against D. applanata on red raspberry.

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Relationship Among Concentrations of Sphaerotheca macularis Conidia in the Air, Environmental Conditions, and the Incidence of Powdery Mildew in Strawberry

Plant Disease ◽

10.1094/pdis.2004.88.8.878 ◽

2004 ◽

Vol 88 (8) ◽

pp. 878-881 ◽

Cited By ~ 17

Author(s):

C. Blanco ◽

B. de los Santos ◽

C. Barrau ◽

F. T. Arroyo ◽

M. Porras ◽

...

Keyword(s):

Powdery Mildew ◽

Disease Incidence ◽

Weather Conditions ◽

The Other ◽

Diurnal Pattern ◽

Airborne Conidia ◽

Sphaerotheca Macularis ◽

The Relationship ◽

Atmospheric Concentrations

Atmospheric concentrations of Sphaerotheca macularis conidia were monitored for 2 years on a strawberry crop in Huelva (southwestern Spain). The presence of airborne conidia was determined to assess the role of weather conditions on conidial release. The relationship between airborne conidia and incidence of powdery mildew on fruit was also studied. Concentrations of conidia were estimated with a Burkard volumetric spore sampler. The presence of conidia was related to temperature, relative humidity, and rainfall, with a positive correlation for the first factor and a negative correlation with the other two. The presence of conidia in the air was positively correlated with disease incidence. A diurnal pattern of conidia release was observed.

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Suppression of Septoria Leaf Spot Disease of Tomato Using Aerated Compost Tea

HortScience ◽

10.21273/hortsci.39.4.831d ◽

2004 ◽

Vol 39 (4) ◽

pp. 831D-831

Author(s):

Chandrappa Gangaiah* ◽

Edward E. Carey ◽

Ned A. Tisserat

Keyword(s):

Leaf Spot ◽

Disease Incidence ◽

Foliar Spray ◽

Plant Diseases ◽

Leaf Spot Disease ◽

Compost Tea ◽

Plastic Mulch ◽

Tomato Cultivar ◽

Spot Disease ◽

Septoria Leaf Spot

Compost teas, made using an aerated brewing process, have been reported to have potential for controlling a range of plant diseases and improving crop health. Septoria leaf spot of tomato, caused by the fungus Septoria lycopersici, is a common and destructive disease of tomato in Kansas. A field trial was conducted at Wichita, Kansas during Summer 2003 to evaluate the potential of pre-plant compost, and compost tea applied as a foliar spray or through drip fertigation, to control Septoria leaf spot of tomato. The experimental design included three factors: Pre-plant application of 13N-13P-13K or vermicompost; fertigation with CaNO3 or compost tea; and foliar spray with compost tea, fungicide (Dithane) or water. A split plot design was used with fertigation treatments as main plots and the other two factors as sub-plots. There were 3 replications. Tomato cultivar Merced was used and individual plots consisted of 5 plants grown on beds covered with red plastic mulch and supported by stake and weave system. Aerated compost tea was brewed weekly using a vermicompost-based recipe including alfalfa pellets, molasses, humic acid, fish emulsion and yucca extract and applied to plots starting 2 weeks after transplanting. Disease incidence and severity were recorded weekly for 3 weeks following the appearance of disease. Plots were harvested twice weekly and counts of No. 1, No 2 and cull grade tomatoes were recorded. There were no effects of pre-plant or fertigation treatments on Septoria leaf spot disease, but there was a significant effect due to foliar sprays, with mean severity of compost-tea-sprayed plots (26.3%) and fungicide-sprayed plots (31.9%) significantly lower than water-sprayed plots (45.9%) at trial termination.

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Management of Septoria leaf spot disease in tomato at Bhaktapur.

10.31220/agrirxiv.2021.00059 ◽

2021 ◽

Author(s):

S. Khyaju ◽

G. K. C. ◽

R. Timila ◽

S. Shrestha

Keyword(s):

Leaf Spot ◽

Management Practices ◽

Disease Incidence ◽

Agricultural Practices ◽

Viral Disease ◽

Leaf Spot Disease ◽

Spot Disease ◽

Randomized Design ◽

Cow Urine ◽

Septoria Leaf Spot

Abstract A farmers' field survey was conducted during 2014 in Bhaktapur district to study socioeconomic status, agricultural practices and occurrence of Septoria Leaf Spot (Septoria lycopersici Mill.) of tomato and its management practices using random sampling of 25 respondents. Field experiment on management of Septoria Leaf Spot was conducted in a completely randomized design (CRD) with six treatments and four replications. The six treatments were (i) Astha Killer 15 (Azadirachta indica) 1500 ppm, (ii) Cow Urine (@ 5% concentration of cow urine; solar activation for 48 hours), (iii) Neem (2 ml/l water) + cow urine (5%) (1:1 ratio; final solution of 2 ml/l water), (iv) Chlorothalonil @ 2.5 gm/lt water, (v) Mancozeb (@ 2.5 gm/lt water), and (vi) control (water). Majority of farmers (70%) raised seedlings by themselves. Septoria Leaf Spot disease was the third important disease after Late Blight and viral disease. Septoria Leaf Spot disease was found in farms of 84% respondents. Septoria Leaf Spot symptom was found in leaf and both in leaf and stem in 47.62% and 52.38% respondents respectively. The disease incidence in field of 85.71% respondents was since 1-2 years. Higher relative humidity, higher precipitation and higher temperature were congenial for disease development. 80% of the respondents used synthetic fungicides for controlling the disease, where Mancozeb and Chlorothalonil were used by 44% and 20% respectively. Mancozeb was found most effective in controlling disease, followed by Chlorothalonil. Among the botanical treatments, Neem (2 ml/l water) + Cow urine (5%) was found effective in disease control than other two botanical treatments.

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