scholarly journals Determining the Spatial Pattern of Blackleg Diseased Potato Plants in the Field and Simulated Post-Harvest Tuber Infections in Potato Crates

2021 ◽  
Author(s):  
Thomas H. Been ◽  
Johanna E. Beniers ◽  
Jan M. van der Wolf
Keyword(s):  
Spatial Pattern ◽  
Disease Incidence ◽  
Random Pattern ◽  
Field Surveys ◽  
Infected Seed ◽  
Seed Potatoes ◽  
Potato Plants ◽  
Global Positioning ◽  
Before And After ◽  
Random Distributions

Abstract Experiments were carried out in 2012 and 2013 to answer two basic questions in the testing of potato blackleg causing agents before and after harvest. Firstly, what is the spatial distribution of symptomatic plants in the field. Secondly, what is the distribution of infected tubers over the crates and the resulting detection probability using the standard method of collecting 200 tubers from the top crates in storage. In both years, ten farmers were equipped with a global positioning system (Garmin GPSMAP 62) and asked to register the position of blackleg diseased plants every time they scouted their potato lot for diseases. To answer the second question, potatoes marked with four nails (only visible internally after harvest) and potatoes with a different skin colour were added to one-hectare (ha) fields of seed potatoes in different patterns of aggregation ranging from random, to aggregated distribution, up to one big hotspot prior to harvest. The invisibly marked tubers were used for the unbiased collection of twenty 200-tuber samples from the storage crates, while the coloured skin tubers were used to ascertain, when the potatoes were graded, the distribution of ‘infected’ potatoes over the storage crates. The experiment was carried out with 0.05 and 0.1% disease incidence, in 2012 and 2013, respectively. Twenty two out of 26 fields proved to have a random pattern of diseased plants at harvest, which indicates that the blackleg diseased plants came into the field as infected seed potatoes. Two of the four aggregated patterns detected, started out as random distributions but became aggregated later in time, indicating spread in the field. A random spatial pattern in the field at harvest proved to result in a uniform distribution of infected tubers in the crates and, consequently, sampling of only the top crates for the 200-tuber sample does not introduce any bias. Fifty percent of the infected farmer lots were detected by the Nederlandse Algemene Keuringsdienst inspectors performing their official field surveys, which was a better performance than the 18% detection obtained by the standard 200-tuber sampling method. Only 6 out of 80 samples from the ‘infected’ lots with 0.05% disease incidence level, and 22 out of 80 samples at the 0.1% disease incidence level were detected by the latter method. It was concluded that intensifying the field survey would be cheaper and more successful than enlarging the tuber sample size to increase the probability for detection of infected seed lots.

scholarly journals Sugarcane Mosaic Distribution, Incidence, Increase, and Spatial Pattern in Louisiana

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 2051-2056
Author(s):  
J. L. Rice ◽  
J. W. Hoy ◽  
M. P. Grisham
Keyword(s):  
Spatial Pattern ◽  
Disease Incidence ◽  
Aphid Transmission ◽  
Field Surveys ◽  
Reverse Transcription Pcr ◽  
Single Leaf ◽  
Disease Surveys ◽  
Low Incidence ◽  
Mosaic Distribution ◽  
Production Areas

Sugarcane mosaic is a historically important disease in Louisiana currently caused by sorghum mosaic virus (SrMV). Successful breeding for resistance reduced the disease to low incidence in commercial cultivars. However, mosaic was detected in experimental clone evaluations at multiple locations, leading to uncertainty concerning the current distribution and incidence in the state. Field surveys were conducted from 2016 to 2018 in breeding program yield trials and experimental clone seed cane increase fields. Mosaic symptomatic plants were observed in a newly released cultivar, HoCP 09-804, in three of five production areas, with incidences ranging from 0 to 10%. Mosaic also was observed in nine additional experimental clones. Single leaf samples were tested for SrMV using reverse transcription PCR. All symptomatic samples and a low percentage (0.3%) of asymptomatic samples tested positive for SrMV, confirming that it continues to be the causal species. Runs analysis detected aggregation of infected plants within at least 70% of rows in 94% of surveyed fields. The spatial pattern and geographical distribution of disease incidence suggested that infected seed cane was the source of the disease. Surveys conducted in the same fields of HoCP 09-804 through two subsequent crops detected disease incidence increases in some fields and decreases in the others in first ratoon, but observed incidence was lower compared with plant cane in all fields in second ratoon. The results indicated that disease increase owing to aphid transmission did not occur under the prevailing conditions.

scholarly journals New tools for old problems — comparing drone- and field-based assessments of a problematic plant species

2021 ◽  
Vol 193 (2) ◽  
Author(s):  
Jens Oldeland ◽  
Rasmus Revermann ◽  
Jona Luther-Mosebach ◽  
Tillmann Buttschardt ◽  
Jan R. K. Lehmann
Keyword(s):  
Image Analysis ◽  
Plant Species ◽  
Just In Time ◽  
Post Processing ◽  
Tall Grass ◽  
Field Surveys ◽  
Distribution Maps ◽  
Object Based Image Analysis ◽  
Object Based ◽  
Before And After

AbstractPlant species that negatively affect their environment by encroachment require constant management and monitoring through field surveys. Drones have been suggested to support field surveyors allowing more accurate mapping with just-in-time aerial imagery. Furthermore, object-based image analysis tools could increase the accuracy of species maps. However, only few studies compare species distribution maps resulting from traditional field surveys and object-based image analysis using drone imagery. We acquired drone imagery for a saltmarsh area (18 ha) on the Hallig Nordstrandischmoor (Germany) with patches of Elymus athericus, a tall grass which encroaches higher parts of saltmarshes. A field survey was conducted afterwards using the drone orthoimagery as a baseline. We used object-based image analysis (OBIA) to segment CIR imagery into polygons which were classified into eight land cover classes. Finally, we compared polygons of the field-based and OBIA-based maps visually and for location, area, and overlap before and after post-processing. OBIA-based classification yielded good results (kappa = 0.937) and agreed in general with the field-based maps (field = 6.29 ha, drone = 6.22 ha with E. athericus dominance). Post-processing revealed 0.31 ha of misclassified polygons, which were often related to water runnels or shadows, leaving 5.91 ha of E. athericus cover. Overlap of both polygon maps was only 70% resulting from many small patches identified where E. athericus was absent. In sum, drones can greatly support field surveys in monitoring of plant species by allowing for accurate species maps and just-in-time captured very-high-resolution imagery.

scholarly journals 545. The Impact of COVID-19 on African Americans’ Health Attitudes and Information Seeking Behavior

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S338-S339
Author(s):  
Katherine Kricorian ◽  
Ozlem Equils ◽  
Karin Kricorian ◽  
Brianna Rochebrun
Keyword(s):  
African Americans ◽  
Information Seeking ◽  
Disease Incidence ◽  
Family Members ◽  
National Sample ◽  
Health Attitudes ◽  
Health News ◽  
Before And After ◽  
Science And Government ◽  
The Impact

Abstract Background African-Americans suffer a disproportionate impact from COVID-19, comprising about 24% of deaths while representing 13% of the US population. We conducted a study to understand COVID-19’s impact on African-Americans’ health attitudes. Methods In April 2020, we surveyed online a national sample of US adults on their health attitudes and behaviors before and after the COVID-19 outbreak. Comparisons were analyzed using chi-squared tests. Results A total of 2,544 individuals completed the survey: 473 African-Americans, 282 Hispanics and 1,799 Caucasians responded. The mean ages of each group were 41.4 ± 11 years, 38.0 ± 11 years and 45.7 ± 13 years, respectively. Before COVID-19, African-Americans were least likely to report they had trust in science (53% vs. 68% for Hispanics and 77% for Caucasians; p< .01) and government (16% vs. 27% and 28%; p< .01). After COVID-19, the percentage of African-Americans who had trust in science and government fell further to 44% (p< .01) and 9% (p< .01), respectively, and remained significantly lower than the other two groups. Twice as many African-Americans vs. Caucasians stopped following science and health news after COVID-19 (9% vs. 4%, p< .01). The percentage of African-Americans who reported anxiety about their health rose from 30% pre-COVID to 53% after the outbreak (p< .01), and the percentage who reported anxiety about their family members’ health rose from 35% to 61% (p< .01). Only 25% of African-Americans surveyed agreed that if they contracted COVID-19, they were confident they would get the healthcare needed. Conclusion After COVID-19, African-Americans’ trust in science and government fell and a meaningful percentage stopped following science and health news, possibly reducing access to important health information. The percentage of African-Americans reporting anxiety about the future, about their health and about their family members’ health all increased significantly after COVID-19. Only a minority of African-Americans agreed they would get the needed healthcare if they contracted COVID-19. These findings have implications for the mental health and behavioral impacts of COVID-19 on African-Americans and for the development of health communications to high-disease-incidence populations. Disclosures All Authors: No reported disclosures

scholarly journals In-Furrow Applications of Metalaxyl and Phosphite for Control of Pink Rot (Phytophthora erythroseptica) of Potato in New Brunswick, Canada

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1305-1309 ◽  
Author(s):  
Khalil I. Al-Mughrabi ◽  
Rick D. Peters ◽  
H. W. (Bud) Platt ◽  
Gilles Moreau ◽  
Appanna Vikram ◽  
...  
Keyword(s):  
New Brunswick ◽  
Disease Incidence ◽  
Field Trials ◽  
Russet Burbank ◽  
Viable Option ◽  
Potato Plants ◽  
Pink Rot ◽  
Phytophthora Erythroseptica ◽  
Sensitive Isolate ◽  
The Mean

The efficacy of metalaxyl-m (Ridomil Gold 480EC) and phosphite (Phostrol) applied at planting in-furrow against pink rot (Phytophthora erythroseptica) of potato (Solanum tuberosum) ‘Shepody’ and ‘Russet Burbank’ was evaluated in field trials conducted in 2005 and 2006 in Florenceville, New Brunswick, Canada. Inoculum made from a metalaxyl-m-sensitive isolate of P. erythroseptica from New Brunswick was applied either in-furrow as a vermiculite slurry at planting or as a zoospore drench in soils adjacent to potato plants in late August. After harvest, the number and weight of tubers showing pink rot symptoms were assessed and expressed as percentages of the total tuber number and total weight of tubers. Metalaxyl-m applied in-furrow was significantly more effective against pink rot than phosphite. The mean percentage of diseased tubers as a percentage of total tuber weight was 1.5% (2005) and 1.2% (2006) for metalaxyl-m-treated plots and 9.6% (2005) and 2.8% (2006) for phosphite-treated plots, a percentage similar to that obtained in inoculated control plots with no fungicide treatment. The mean percentage of diseased tubers expressed as a percentage of the total number of tubers was 1.7% (2005) and 1.3% (2006) for metalaxyl-m-treated plots and 10.1% (2005) and 3.1% (2006) for phosphite-treated plots. Disease incidence was significantly higher using the late-season inoculation technique (respective means in 2005 and 2006 were 9.9 and 3.8% diseased tubers, by weight, and 10.6 and 3.9%, by number) than with the in-furrow inoculation method (respective means in 2005 and 2006 were 3.3 and 0.7% by weight, and 3.7 and 1.3%, by number). The potato cv. Shepody was significantly more susceptible to pink rot (9.9 and 3.3% diseased tubers, by weight, in 2005 and 2006, respectively, and 10.6 and 3.9%, by number) than Russet Burbank (respective means in 2005 and 2006 were 3.4,% and 1.2%, by weight, and 3.7,% and 1.2%, by number). Our findings indicate that metalaxyl applied in-furrow at planting is a viable option for control of pink rot caused by metalaxyl-sensitive strains of P. erythroseptica, whereas phosphite was ineffective.

scholarly journals Feasibility of Using Global Positioning Systems (GPS) With Diverse Urban Adults: Before and After Data on Perceived Acceptability, Barriers, and Ease of Use

2012 ◽  
Vol 9 (7) ◽  
pp. 924-934 ◽  
Author(s):  
Shannon N. Zenk ◽  
Amy J. Schulz ◽  
Angela M. Odoms-Young ◽  
JoEllen Wilbur ◽  
Stephen Matthews ◽  
...  
Keyword(s):  
Ethnically Diverse ◽  
Ease Of Use ◽  
Global Positioning Systems ◽  
Pilot Studies ◽  
Positioning Systems ◽  
Comfort Levels ◽  
Lower Socioeconomic ◽  
Global Positioning ◽  
Before And After ◽  
Urban Adults

Background:Global positioning systems (GPS) have emerged as a research tool to better understand environmental influences on physical activity. This study examined the feasibility of using GPS in terms of perceived acceptability, barriers, and ease of use in a racially/ethnically diverse sample of lower socioeconomic position (SEP).Methods:Data were from 2 pilot studies involving a total of 170 African American, Hispanic, and White urban adults with a mean (standard deviation) age of 47.8 (±13.1) years. Participants wore a GPS for up to 7 days. They answered questions about GPS acceptability, barriers (wear-related concerns), and ease of use before and after wearing the GPS.Results:We found high ratings of GPS acceptability and ease of use and low levels of wear-related concerns, which were maintained after data collection. While most were comfortable with their movements being tracked, older participants (P < .05) and African Americans (P < .05) reported lower comfort levels. Participants who were younger, with higher education, and low incomes were more likely to indicate that the GPS made the study more interesting (P < .05). Participants described technical and wear-related problems, but few concerns related to safety, loss, or appearance.Conclusions:Use of GPS was feasible in this racially/ethnically diverse, lower SEP sample.

scholarly journals Evaluation of garlic, BAU-biofungicide, bion and chemical fungicides in controlling leaf spot of Taro

2017 ◽  
Vol 28 (3) ◽  
pp. 167-173
Author(s):  
MAS Sohag ◽  
MT Hossen ◽  
MS Monjil
Keyword(s):  
Field Experiment ◽  
Plant Height ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Foliar Spray ◽  
Leaf Spot Disease ◽  
Spot Disease ◽  
Maximum Reduction ◽  
Before And After ◽  
Chemical Fungicides

The field experiment was conducted to evaluate the efficacy of Garlic extract @ 10%, BAU-Biofungicide @ 2%, Bion@ 0.2%, Bavistin DF (Carbendazim) @ 0.1% and Proud 250EC (Propiconazole) @ 0.1%  for controlling leaf spot disease of taro (Colocasia esculenta). Performance of these treatments was assessed by applying as cormel treatment and foliar spray. Cormel treatment under field experiment was found effective for BAU-Biofungicide and Proud 250EC. Bavistin DF and Proud 250EC was more effective than other treatments in increasing plant height and healthy leaves, and in decreasing spotted and dead leaves. Before foliar spraying, BAU-Biofungicide as cormel treatment reduced the disease incidence (46.19%) and severity (25.28%) of taro leaf spot at 180 days after sowing. As foliar spray all the treatments has significant effect on taro leaf spot. Among the treatments BAU-Biofungicide was found superior to control leaf spot of taro. BAU-Biofungicide resulted maximum reduction of disease incidence and severity and increase in number of healthy leaf followed by Bion and Proud 250EC. BAU-Biofungicide showed enhanced results in terms of disease incidence and severity of leaf spot of Taro before and after foliar spraying.Progressive Agriculture 28 (3): 167--173, 2017

A survey of a low-density koala population in a major reserve system, near Sydney, New South Wales..

2001 ◽  
Vol 23 (2) ◽  
pp. 135 ◽  
Author(s):  
A Curtin ◽  
D Lunney ◽  
A Matthews
Keyword(s):  
National Park ◽  
Field Survey ◽  
New South ◽  
Specific Information ◽  
Vegetation Types ◽  
Field Surveys ◽  
South Wales ◽  
Before And After ◽  
Recreation Area ◽  
Reserve System

cinereus) in Yengo National Park and Parr State Recreation Area, which together form a major reserve system where P. cinereus were known to be scarce. The first, a community survey which was distributed to 823 residences adjoining the reserves, yielded 139 responses. Of these, 31 responses provided information that allowed 26 P. cinereus locality records to be verified. A further eight P. cinereus locality records were obtained from interviews with neighbours. Most records were road-based. The second, a field survey based on scat searches, produced an additional 13 P. cinereus localities. P. cinereus scats were found under 11 tree species. Eucalyptus punctata was most frequently recorded with scats of those that were adequately sampled. A range of vegetation types and both ridges and gullies were used by P. cinereus. During field surveys, P. cinereus was found to be sparse and occurring throughout much of the survey area, concentrated in the eastern, southern and central parts of the reserve system. Both methods identified P. cinereus to be present before and after the extensive fires of January 1994, which burnt 60 % of the area. An appraisal of the methods revealed that they are complementary. The survey of residents provided recent and historical information and an indication of initial search areas for P. cinereus. The field survey yielded specific information about local P. cinereus habitat. The combination increased the number of P. cinereus records for the area more than four-fold. This study has provided the reserve managers with a clearer picture of the location of the local P. cinereus population.

scholarly journals Sustainability of Public Transportation: An Examination of User Behavior to Real-Time GPS Tracking Application

2020 ◽  
Vol 12 (22) ◽  
pp. 9541 ◽  
Author(s):  
Wei Chiang Chan ◽  
Wan Hashim Wan Ibrahim ◽  
May Chiun Lo ◽  
Mohamad Kadim Suaidi ◽  
Shiaw Tong Ha
Keyword(s):  
Real Time ◽  
Global Positioning System ◽  
Public Transport ◽  
Public Transportation ◽  
User Behavior ◽  
Mobile App ◽  
Gps Tracking ◽  
Inaccurate Information ◽  
Global Positioning ◽  
Before And After

Public transportation is an effective method of mobility that promotes cost-saving and is environmentally friendly. Poor public transport ridership in Malaysia is due to the unsatisfactory attitude of public transport users and inaccurate information on departure and arrivals. Sarawak, a state of Malaysia, is especially poor in ridership of public transport. A real-time Global Positioning System (GPS) tracking application (app) was found to be an effective tool to increase the ridership of public transport. Hence, a mobile app named UniBus was developed to enhance the ridership of public transport in Sarawak. The determinants that affect satisfaction and customer loyalty such as accessibility, reliability, comfort, safety, and security were all examined before and after the use of real-time GPS tracking app. The data was collected in Kuching, and targeted public transport users who used the UniBus app. The result indicated that all the mentioned variables were improved after using a real-time GPS tracking app. It is suggested that future studies can consider other factors such as service quality, availability, and perceived value as well as cover other states of Malaysia.

Spatial Patterns of Microsclerotia of Verticillium dahliae in Soil and Verticillium Wilt of Cauliflower

1997 ◽  
Vol 87 (3) ◽  
pp. 325-331 ◽  
Author(s):  
C. L. Xiao ◽  
J. J. Hao ◽  
K. V. Subbarao
Keyword(s):  
Spatial Patterns ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Binomial Distribution ◽  
Disease Incidence ◽  
Soil Samples ◽  
Random Pattern ◽  
Parameter Estimates ◽  
Regular Pattern ◽  
Vascular Discoloration

The spatial patterns of microsclerotia of Verticillium dahliae in soil and wilt symptoms on cauliflower were determined at three sites in each of two fields in 1994 and 1995. Each site was an 8 × 8 grid divided into 64 contiguous quadrats (2 by 2 m each). Soil samples were collected to a depth of 15 cm with a probe (2.5 cm in diameter), and samples from four sites in each quadrat were bulked. Plants in each quadrat were cut transversely, and the number of plants with vascular discoloration and the number without discoloration were recorded. The soil was assayed for microsclerotia by the modified Anderson sampler technique. Lloyd's index of patchiness (LIP) was used as an indicator to evaluate the aggregation of microsclerotia in the field. Spatial autocorrelation and geostatistical analyses were also used to assess the autocorrelation of microsclerotia among quadrats. The LIP for microsclerotia was greater than 1, indicating aggregation of propagules; however, the degree of aggregation at most sites was not high. Significant autocorrelation within or across rows was detected in some spatial autocorrelograms of propagules, and anisotropic patterns were also detected in some oriented semivariograms from geostatistical analyses for microsclerotia, indicating the influence of bed preparation in the fields on pathogen distribution. The parameter estimates p and θ in the beta-binomial distribution and the index of dispersion (D) associated with the distribution were used to assess the aggregation of diseased plants at each site. A random pattern of wilt incidence was detected at 7 of 12 sites, and an aggregated pattern was detected at 5 of 12 sites. The degree of aggregation was not high. A regular pattern of wilt severity was detected at all sites. The high disease incidence (77 to 98%) observed at 11 of the 12 sites could be explained by high inoculum density.

Quantifying Explosive Actions in International Women’s Soccer

2017 ◽  
Vol 12 (3) ◽  
pp. 310-315 ◽  
Author(s):  
César Meylan ◽  
Joshua Trewin ◽  
Kelly McKean
Keyword(s):  
High Speed ◽  
Movement Analysis ◽  
Match Analysis ◽  
Change Of Direction ◽  
National Team ◽  
Global Positioning ◽  
Before And After ◽  
The Mean ◽  
The Right ◽  
Women's Soccer

The aims of the current study were to examine the external validity of inertial-based parameters (inertial movement analysis [IMA]) to detect multiplanar explosive actions during maximal sprinting and change of direction (COD) and to further determine its reliability, set appropriate magnitude bands for match analysis, and assess its variability during international women’s soccer matches. Twenty U20 female soccer players, wearing global positioning system (GPS) units with a built-in accelerometer, completed 3 trials of a 40-m sprint and a 20-m sprint with a change of direction to the right or left at 10 m. Furthermore, 13 women’s national-team players (157 files; 4–27 matches/player) were analyzed to ascertain match-to-match variability. Video synchronization indicated that the IMA signal was instantaneous with explosive movement (acceleration, deceleration, COD). Peak GPS velocity during the 40-m sprint showed similar reliability (coefficient of variation [CV] = 2.1%) to timing gates but increased before and after COD (CV = 4.5–13%). IMA variability was greater at the start of sprints (CV = 16–21%) than before and after COD (CV = 13–16%). IMA threshold for match analysis was set at 2.5 m · s–1 · s–1 by subtracting 1 SD from the mean IMA during sprint trials. IMA match variability (CV = 14%) differed from high-speed GPS metrics (35–60%). Practitioners are advised that timing lights should remain the gold standard for monitoring sprint and acceleration capabilities of athletes. However, IMA could be a reliable method to monitor explosive actions between matches and assess changes due to various factors such as congested schedule, tactics, heat, or altitude.

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