scholarly journals Characterization of favorable weather conditions with powdery mildew disease incidence on pumpkin

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Muhammad Ahmad Zeshan ◽  
Maryam Yousaf ◽  
Romana Anjum ◽  
Safdar Ali ◽  
Muhammad Usman Ghani
Keyword(s):  
Powdery Mildew ◽  
Disease Incidence ◽  
Weather Conditions ◽  
Weather Variables ◽  
Incidence Data ◽  
Powdery Mildew Disease ◽  
Management Approaches ◽  
Favorable Weather ◽  
The Relationship

Weather variables were characterized for the powdery mildew disease caused by Sphaerotheca fuliginea on pumpkin crop. The relationship between airborne conidia and incidence of powdery mildew on pumpkin was studied. Disease incidence data was recorded on weekly basis and correlated with prevailing environmental conditions.  All the environmental factors showed positive relationship with disease incidence except wind speed that exhibited negative correlation. Understanding of favorable environment is helpful to use appropriate management approaches.

scholarly journals Preventive Control of Powdery Mildew Disease of Mango

1999 ◽  
Vol 4 (1) ◽  
pp. 23
Author(s):  
K.P. Akhtar ◽  
I.A. Khan ◽  
M.R. Kazmi ◽  
R.I. Hassan ◽  
B. Fatima
Keyword(s):  
Relative Humidity ◽  
Powdery Mildew ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Optimal Timing ◽  
Positive Trend ◽  
Preventive Control ◽  
Airborne Conidia ◽  
Powdery Mildew Disease ◽  
Favorable Weather

Oidium mangiferae Berthet was found to be associated With the powdery mildew disease of mango. The air- borne conidia are released from the old tissue harboring the dormant fungal hyphae under favorable weather conditions, which produce the disease. Proper forecasting of release of airborne innoculum significantly reduced the required number of sprays needed for chemical control. Spore traps were used to monitor the concentration of airborne conidia during the months of February, March and April 1996 and l997. Daily temperature and relative humidity were noted and the spore counts from the spore traps were correlated to the meteorological data. There was a positive trend between rising temperature, lowering relative humidity and number of spores in the air alter a low temperature, high humidity and cloudy spell of weather. The maximum spore occurrences were noted around 25°C and relative humidity of 40-60%. It took 5-8 days for the emergence of disease symptoms after the first detection of airborne conidia. Ten fungicides were tested on three mango varieties (Langra, Dashehari, and Anwar Retol). The preventive sprays at the stage of first detection of air born conidia were effective in controlling the disease. Optimal timing of two sprays of fungicide were sufficient to provide preventive control (>90%). The susceptibility of inflorescence varied with its developmental stage. Proper forecasting reduced the number of sprays from 7 to 2 or 3. There was no varietal difference in incidence of the disease or response to fungicide applications. During the course of this study, we identified seedling plants which consistently showed resistance to powdery mildew.

scholarly journals Spatial Pattern of Strawberry Powdery Mildew (Podosphaera aphanis) and Airborne Inoculum

Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 43-54 ◽  
Author(s):  
H. Van der Heyden ◽  
M. Lefebvre ◽  
L. Roberge ◽  
L. Brodeur ◽  
O. Carisse
Keyword(s):  
Powdery Mildew ◽  
Power Law ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Disease Incidence ◽  
Data Sets ◽  
Incidence Data ◽  
Airborne Inoculum ◽  
The Relationship

The relationship between strawberry powdery mildew and airborne conidium concentration (ACC) of Podosphaera aphanis was studied using data collected from 2006 to 2009 in 15 fields, and spatial pattern was described using 2 years of airborne inoculum and disease incidence data collected in fields planted with the June-bearing strawberry (Fragaria × ananassa) cultivar Jewel. Disease incidence, expressed as the proportion of diseased leaflets, and ACC were monitored in fields divided into 3 × 8 grids containing 24 100 m2 quadrats. Variance-to-mean ratio, index of dispersion, negative binomial distribution, Poisson distribution, and binomial and beta-binomial distributions were used to characterize the level of spatial heterogeneity. The relationship between percent leaf area diseased and daily ACC was linear, while the relationship between ACC and disease incidence followed an exponential growth curve. The V/M ratios were significantly greater than 1 for 100 and 96% of the sampling dates for ACC sampled at 0.35 m from the ground (ACC0.35m) and for ACC sampled at 1.0 m from the ground (ACC1.0m), respectively. For disease incidence, the index of dispersion D was significantly greater than 1 for 79% of the sampling dates. The negative binomial distribution fitted 86% of the data sets for both ACC1.0m and ACC0.35m. For disease incidence data, the beta-binomial distribution provided a good fit of 75% of the data sets. Taylor's power law indicated that, for ACC at both sampling heights, heterogeneity increased with increasing mean ACC, whereas the binary form of the power law suggested that heterogeneity was not dependent on the mean for disease incidence. When the spatial location of each sampling location was taken into account, Spatial Analysis by Distance Indices showed low aggregation indices for both ACCs and disease incidence, and weak association between ACC and disease incidence. Based on these analyses, it was found that the distribution of strawberry powdery mildew was weakly aggregated. Although a higher level of heterogeneity was observed for airborne inoculum, the heterogeneity was low with no distinct foci, suggesting that epidemics are induced by well-distributed inoculum. This low level of heterogeneity allows mean airborne inoculum concentration to be estimated using only one sampler per field with an overall accuracy of at least 0.841. The results obtained in this study could be used to develop a sampling scheme that will improve strawberry powdery mildew risk estimation.

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

Plant Disease ◽  
2004 ◽  
Vol 88 (8) ◽  
pp. 878-881 ◽  
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.

scholarly journals Perceived Influence of Weather Conditions on Rheumatic Pain in Romania

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Adina-Eliza Croitoru ◽  
Gabriela Dogaru ◽  
Titus Cristian Man ◽  
Simona Mălăescu ◽  
Marieta Motricală ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Pain Intensity ◽  
Air Temperature ◽  
Correlation Matrix ◽  
Great Majority ◽  
Weather Conditions ◽  
Weather Variables ◽  
Rheumatic Pain ◽  
Atmospheric Fronts ◽  
The Relationship

The main objective of this study was to analyze the perception of the influence of various weather conditions on patients with rheumatic pathology. A group of 394 patients, aged between 39 and 87 years and diagnosed with degenerative rheumatic diseases, were interviewed individually by using a questionnaire created specifically for this study. Further on, to assess the relationship between pain intensity and weather conditions, a frequency analysis based on Pearson’s correlation matrix was employed. The most important results are as follows: the great majority of the participants (more than 75%) believe that their rheumatic pain is definitely or to a great extent influenced by different weather conditions; most of the patients reported intensification of their pain with weather worsening, especially when cloudiness and humidity suddenly increase (83.8% and 82.0%, respectively), air temperature suddenly decreases (81.5%), and in fog or rain conditions (81.2%). In our research, alongside simple meteorological variables, we established that complex weather variables such as atmospheric fronts, in particular, the cold ones and winter anticyclonic conditions, greatly intensify the rheumatic pain, whereas summer anticyclonic conditions usually lead to a decrease in pain severity. In terms of relationships between pain intensity and weather conditions, we found the strongest correlations (ranging between 0.725 and 0.830) when temperature, relative humidity, and cloudiness are constantly high.

scholarly journals Modeling Infection of Strawberry Flowers by Botrytis cinerea Using Field Data

2000 ◽  
Vol 90 (12) ◽  
pp. 1367-1374 ◽  
Author(s):  
Xiangming Xu ◽  
David C. Harris ◽  
Angela M. Berrie
Keyword(s):  
Vapor Pressure ◽  
Botrytis Cinerea ◽  
Vapor Pressure Deficit ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Gray Mold ◽  
Weather Variables ◽  
Infection Models ◽  
The Relationship ◽  
Field Plots

The incidence of strawberry flower infection by Botrytis cinerea was monitored in unsprayed field plots in three successive years together with meteorological data and numbers of conidia in the air. There were large differences in conidia numbers and weather conditions in the 3 years. Three sets of models were derived to relate inoculum and weather conditions to the incidence of flower infection; by inoculum only, by weather variables only, and by both inoculum and weather variables. All the models fitted the observed incidence satisfactorily. High inoculum led to more infection. Models using weather variables only gave more accurate predictions than models using inoculum only. Models using both weather variables and inoculum gave the best predictions, but the improvement over the models based on weather variables only was small. The relationship between incidence of flower infection and inoculum and weather variables was generally consistent between years. Of the weather variables examined, daytime vapor pressure deficit and nighttime temperature had the greatest effect in determining daily incidence of flower infection. Infection was favored by low day vapor pressure deficit and high night temperature. The accuracy and consistency of the weather-based models suggest they could be explored to assist in management of gray mold.

scholarly journals Analysis of biochemical changes in cultivars of Black gram, Green gram and Pea against powdery mildew

2019 ◽  
Vol 2 (1) ◽  
pp. 5-10
Author(s):  
P P Waghmare ◽  
Sahera Nasreen
Keyword(s):  
Powdery Mildew ◽  
Disease Incidence ◽  
Field Studies ◽  
Biochemical Changes ◽  
Antimicrobial Compounds ◽  
Black Gram ◽  
Incidence Data ◽  
Major Constraint ◽  
Visual Screening ◽  
Defence Enzymes

Powdery mildew disease of the Black gram, Mung bean and Pea are a major constraint in the production. The resistance of plants to various pathogens depends on synthesis and level of various defence enzymes like hydrolases; peroxidases and antimicrobial compounds like phytoalexins (Kuc, l991 et al Kauffmann et al. l987; Boiler, l987; Mauch et al., l988; Kale and Choudhary 200l, Koche and Choudhary, 2005). The present study focused on visual screening of selected crop cultivars against the powdery mildew and its biochemical correlation with chlorophyll content, sugars, phenols content, PR-proteins and Phytoalexin activities. From the field studies, it was observed that selected crop was found with powdery mildew incidence. This disease incidence data was correlated with biochemical changes and level of chlorophyll, sugars, phenols, PR-protein and Phytoalexin activities. 

scholarly journals Whole Genome Re-Sequencing and Characterization of Powdery Mildew Disease-Associated Allelic Variation in Melon

PLoS ONE ◽  
2016 ◽  
Vol 11 (6) ◽  
pp. e0157524 ◽  
Author(s):  
Sathishkumar Natarajan ◽  
Hoy-Taek Kim ◽  
Senthil Kumar Thamilarasan ◽  
Karpagam Veerappan ◽  
Jong-In Park ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Allelic Variation ◽  
Whole Genome ◽  
Powdery Mildew Disease

scholarly journals Management of Okra Yellow Vein Mosaic Virus (OYVMV) Through Selected Insecticides and Light Reflecting Colored Mulches

2021 ◽  
Vol 3 (1) ◽  
pp. 161-165
Author(s):  
Md. Belal Hossain ◽  
Suraiya Jitu ◽  
Sanjana Akter ◽  
Md. Ariful Islam
Keyword(s):  
Mosaic Virus ◽  
Disease Incidence ◽  
Negative Relationship ◽  
Yellow Vein ◽  
Insect Vector ◽  
Yellow Vein Mosaic Virus ◽  
Red Color ◽  
Management Approaches ◽  
The Relationship ◽  
Black Color

A field experiment was conducted to evaluate the effect of light reflecting colored mulches and only one time spraying with selected insecticides to control the insect vector of Okra Yellow Vein Mosaic Virus (OYVMV) whitefly (Bemisia tabaci) at the central farm of Sher-e-Bangla Agricultural University, Dhaka-1207. The experiment was carried out in three blocks layouted with RCBD comprising eight treatments viz. T0 (control/no spray), T1 (1 time spray with imitaf), T2 (1 time spray with protect), T3 (1 time spray with tiddo plus), T4 (1 time spray with terbine), T5 (light reflecting silver color mulch), T6 (light reflecting red color mulch) and T7 (light reflecting black color mulch) with three replications. The mulches were used before sowing and insecticides were sprayed at 30 DAS. It was observed that among the light reflecting colored mulches, the lowest disease incidence (11.48%) was recorded in the plots which mulched with red color mulch (T6). Among the insecticides, the lowest disease incidence (30.17%) was recorded in plots that was sprayed with terbine (one time). Yield and yield contributing characters, morphological and physiological features of okra plant that changes due to disease infection which cause damages in okra production and reduce the fruit quality as well as market value was also the part of this study. Yield and yield contributing characters showed significant variance among the selected treatments. In the relationship study, it was noticed that the yield and plant height was showed negative relationship with disease incidence. However, considering all measuring parameters, spraying with terbine (one time) and used red color mulch may be recommended as good management approaches that will give higher okra production and lower disease incidence of Okra Yellow Vein Mosaic Virus (OYVMV).

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