scholarly journals Pathogen Dispersal and Glomerella Leaf Spot Progress Within Apple Canopy in Brazil

Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3209-3217 ◽  
Author(s):  
Natasha Akemi Hamada ◽  
Rafaele Regina Moreira ◽  
Cristiano Nunes Nesi ◽  
Louise Larissa May De Mio
Keyword(s):  
Leaf Spot ◽  
Weather Conditions ◽  
Water Runoff ◽  
Initial Inoculum ◽  
Colletotrichum Species ◽  
Primary Inoculum ◽  
Species Complexes ◽  
Glomerella Leaf Spot ◽  
Favorable Weather ◽  
Temporal Progress

Glomerella leaf spot (GLS) of apple is caused by three different Colletotrichum species complexes. This study evaluated the dispersal of Colletotrichum spores related to GLS temporal progress and defoliation. Spores were monitored by air and water runoff in different plant heights, and the temporal progress of GLS and defoliation were assessed. Spores of the pathogen were first cached in the lower part of the tree closer to the ground, confirming the importance of dead leaves on the ground as main source of primary inoculum. In plots with high primary inoculum, the disease increases exponentially during favorable weather conditions. The highest initial inoculum was found in the lower part of the tree, but the highest rate of the disease progress in the upper.

Unraveling Colletotrichum species associated with Glomerella leaf spot of apple

2018 ◽  
Vol 44 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Aline Cristina Velho ◽  
Marciel J. Stadnik ◽  
Matthew Wallhead
Keyword(s):  
Leaf Spot ◽  
Colletotrichum Species ◽  
Glomerella Leaf Spot

Comparative epidemiology of three Colletotrichum species complex causing Glomerella leaf spot on apple

2020 ◽  
Vol 158 (2) ◽  
pp. 473-484
Author(s):  
Rafaele Regina Moreira ◽  
Armando Bergamin Filho ◽  
Walmes Marques Zeviani ◽  
Louise Larissa May De Mio
Keyword(s):  
Leaf Spot ◽  
Species Complex ◽  
Colletotrichum Species ◽  
Comparative Epidemiology ◽  
Glomerella Leaf Spot

scholarly journals Ascospore Infection and Colletotrichum Species Causing Glomerella Leaf Spot of Apple in Uruguay

2019 ◽  
Vol 35 (2) ◽  
pp. 100-111 ◽  
Author(s):  
Sandra Alaniz ◽  
Vanessa Cuozzo ◽  
Valentina Martínez ◽  
Marciel J. Stadnik ◽  
Pedro Mondino
Keyword(s):  
Leaf Spot ◽  
Colletotrichum Species ◽  
Glomerella Leaf Spot

scholarly journals Models and applications for risk assessment and prediction of Asian soybean rust epidemics

2006 ◽  
Vol 31 (6) ◽  
pp. 533-544 ◽  
Author(s):  
Emerson M. Del Ponte ◽  
Cláudia V. Godoy ◽  
Marcelo G. Canteri ◽  
Erlei M. Reis ◽  
X.B. Yang
Keyword(s):  
Disease Modeling ◽  
Weather Conditions ◽  
Epidemiological Studies ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Spatial And Temporal Scales ◽  
Asian Soybean Rust ◽  
New Development ◽  
Glycine Max L ◽  
Favorable Weather

Asian rust of soybean [Glycine max (L.) Merril] is one of the most important fungal diseases of this crop worldwide. The recent introduction of Phakopsora pachyrhizi Syd. & P. Syd in the Americas represents a major threat to soybean production in the main growing regions, and significant losses have already been reported. P. pachyrhizi is extremely aggressive under favorable weather conditions, causing rapid plant defoliation. Epidemiological studies, under both controlled and natural environmental conditions, have been done for several decades with the aim of elucidating factors that affect the disease cycle as a basis for disease modeling. The recent spread of Asian soybean rust to major production regions in the world has promoted new development, testing and application of mathematical models to assess the risk and predict the disease. These efforts have included the integration of new data, epidemiological knowledge, statistical methods, and advances in computer simulation to develop models and systems with different spatial and temporal scales, objectives and audience. In this review, we present a comprehensive discussion on the models and systems that have been tested to predict and assess the risk of Asian soybean rust. Limitations, uncertainties and challenges for modelers are also discussed.

scholarly journals Influence of hydrothermal conditions on the productivity of perennial grasses in South Steppe of Ukraine

2019 ◽  
pp. 27-36 ◽  
Author(s):  
V. F. Petrychenko ◽  
L. K. Antypova ◽  
N. V. Tsurkan
Keyword(s):  
Weather Conditions ◽  
Bromus Inermis ◽  
Perennial Grasses ◽  
Hydrothermal Conditions ◽  
Green Mass ◽  
Melilotus Albus ◽  
Perennial Legume ◽  
Favorable Weather ◽  
Perennial Legumes ◽  
Similar Yield

The purpose is to determine the productivity of perennial legume and cereal grasses under conditions of natural moisture supply in South Steppe of Ukraine. Method. The studies were conducted during 2016—2018 using conventional methods, and the output of feed units, digestible protein per unit of area was determined by reference books. Results. On average over three years of research, the highest yield of leaf-stem mass of cereals was formed by Bromus inermis and Elytrigia medium tender – 11.6 and 11.2 t/ha, respectively. The lowest yield was formed by Agropyrum pectiniforme – 7.6 t/ha. Among the all legume grasses, Melilotus albus prevailed (14.8 t/ha). Medicago sativa and Onobrychis arenaria were able to form a similar yield (14.5 and 13.5 t/ha, respectively) under the arid conditions of South Steppe of Ukraine. Insufficient rainfall in 2017 caused a decrease in the productivity of the studied crops. Thus, in 2017 the average yield of green mass in the experiment was 10.3 t/ha, while in 2016 under more favorable weather conditions this figure was 13.2 t/ha or 28.2 % more. The highest output of feed and protein units (FPU) per unit of area under cereal grasses was provided by Bromus inermis (2.35 t/ha). The lowest one was recorded in Agropyrum pectiniforme (1.60 t/ha). FPU output per unit of area under legume grasses increased respectively. Lotus corniculatus provides less green mass and therefore dry matter and forage and protein units. Perennial cereals grasses do not prevail over legume grasses, so they do not spread in South Ukraine. Conclusions. The productivity of perennial grasses in the south of Ukraine significantly depends on the type of plants, weather (hydrothermal) conditions of the year. The most effective is the cultivation of perennial legumes, namely Melilotus albus, alfalfa, Onobrychis arenaria. Bromus inermis and Elytrigia medium prevail among cereal grasses.

Studying Driving Behavior on Horizontal Curves using Naturalistic Driving Study Data

2018 ◽  
Vol 2672 (17) ◽  
pp. 83-95 ◽  
Author(s):  
Bashar Dhahir ◽  
Yasser Hassan
Keyword(s):  
Data Collection ◽  
Weather Conditions ◽  
Driving Behavior ◽  
Study Data ◽  
Output Analysis ◽  
Horizontal Curves ◽  
Naturalistic Driving Study ◽  
Naturalistic Driving ◽  
Design Consistency ◽  
Favorable Weather

Many studies have been conducted to develop models to predict speed and driver comfort thresholds on horizontal curves, and to evaluate design consistency. The approaches used to develop these models differ from one another in data collection, data processing, assumptions, and analysis. However, some issues might be associated with the data collection that can affect the reliability of collected data and developed models. In addition, analysis of speed behavior on the assumption that vehicles traverse horizontal curves at a constant speed is far from actual driving behavior. Using the Naturalistic Driving Study (NDS) database can help overcome problems associated with data collection. This paper aimed at using NDS data to investigate driving behavior on horizontal curves in terms of speed, longitudinal acceleration, and comfort threshold. The NDS data were valuable in providing clear insight on drivers’ behavior during daytime and favorable weather conditions. A methodology was developed to evaluate driver behavior and was coded in Matlab. Sensitivity analysis was performed to recommend values for the parameters that can affect the output. Analysis of the drivers’ speed behavior and comfort threshold highlighted several issues that describe how drivers traverse horizontal curves that need to be considered in horizontal curve design and consistency evaluation.

Near Optimal Receding Horizon Control of Thermal Energy Storage

2021 ◽  
pp. 1-13
Author(s):  
Omer Ahmed Qureshi ◽  
Peter R. Armstrong
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Energy Savings ◽  
Search Algorithm ◽  
Cost Savings ◽  
Weather Conditions ◽  
Receding Horizon Control ◽  
Receding Horizon ◽  
Favorable Weather

Abstract Efficient plant operation can be achieved by properly loading and sequencing available chillers to charge and discharge a thermal energy storage (TES) reservoir at optimal rates and times. TES charging sequences are often determined by heuristic rules that typically aim to reduce utility costs under time of use rates. However, such rules of thumb may result in significantly sub optimal performance on somedays. Rigorous optimization, on the other hand, is computationally expensive and can be unreliable as well if not carefully implemented. Receding Horizon Control (RHC) using the novel finite search algorithm is reliable and can reach ~80% of achievable energy efficiency and/or peak shifting capacity has been our target. A novel algorithm is developed to reliably achieve near optimal control for charging the stratified sensible cool storage reservoir of a chiller plant. The algorithm provides a constant COP (or cost per ton-hour) for 24-hr dispatch plan under which chillers operate during most favorable weather conditions. Analysis of four hot climates, ranging from humid to dry, indicates 2.4~2.6% energy savings under a flat electricity rate relative to the same plant operating without TES. Annual cost savings from 6% to 9% was found for electricity billed under a simple (10am-10pm) time-of-use rate with no demand charge and no ratchet component.

scholarly journals Techniques for screening Cercospora leaf spot resistant fenugreek genotypes

2019 ◽  
Vol 99 (3) ◽  
pp. 324-337
Author(s):  
U. Subedi ◽  
S. Acharya ◽  
S. Chatterton ◽  
J. Thomas ◽  
D. Friebel
Keyword(s):  
Leaf Spot ◽  
Weather Conditions ◽  
Disease Spread ◽  
Temperature Sensitive ◽  
Cercospora Leaf Spot ◽  
Legume Crop ◽  
Whole Plant ◽  
Crop Field ◽  
Plant Assays ◽  
Trigonella Foenum Graecum L

Cercospora leaf spot (CLS) caused by Cercospora traversiana is an important phyto-pathological problem of fenugreek (Trigonella foenum-graecum L.), a multiuse legume crop. Field screenings for resistant plants, although accurate and effective, demand significant time and a sizable workforce to accomplish. Also, weather conditions in the field may not always be favourable for uniform disease spread, which eventually may lead to failure of the overall experiment. Whole-plant assays (WPA) and detached leaf assays (DLA) with artificial inoculation not only help in scaling up the number of plants screened but also reduce the space, time, and amount of inoculum needed for the experiment. The results from our two experiments indicate that both the WPA and DLA methods can be used reliably to differentiate resistant and susceptible genotypes of fenugreek. In addition, the correlation coefficient between WPA and DLA (r = 0.875, P < 0.01), derived from the mean disease score of each genotype, shows that they can be used interchangeably while screening fenugreek for CLS. DLA was found to be temperature-sensitive for the development of CLS symptoms and wounded leaves developed symptoms faster than non-wounded leaves. These indoor methods can be used for the development of CLS-resistant fenugreek cultivars in areas where disease development is difficult under field conditions.

scholarly journals Forecasting system for infection risk of phoma stem canker in selected regions of the Czech Republic in 2009–2011 

2014 ◽  
Vol 50 (No. 1) ◽  
pp. 8-16 ◽  
Author(s):  
J. Poslušná ◽  
E. Plachká
Keyword(s):  
Czech Republic ◽  
Leaf Spot ◽  
Weather Conditions ◽  
Stem Canker ◽  
Infection Risk ◽  
Risk Of Infection ◽  
The Czech Republic ◽  
Phoma Stem Canker ◽  
Ascospore Release ◽  
Forecasting System

In the period 2009&ndash;2011 monitoring of the incidence of phoma stem canker was carried out at selected sites of the Czech Republic (&Scaron;umperk and Opava regions in North Moravia). The risk of infection was evaluated by assessing the autumn release of&nbsp;Leptosphaeria&nbsp;spp. ascospores and with the proPlant prediction model. In recent years, the incidence of phoma stem canker has been relatively low and this corresponded with the total count of ascospores released in the autumn period but not with an increased level of infection risk announced by the proPlant model. During the monitored period the ascospore concentration reached maximally 2 ascospores/1 m<sup>3</sup>&nbsp;per day. Maximum ascospore release was recorded in 2010 as a result of favourable weather conditions. The first incidence of phoma leaf spot has been observed in mid-October. The higher values of ascospores concentration were recorded in the Opava region, but the total number of the trapped ascospores was more often higher in the &Scaron;umperk region.&nbsp;

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