scholarly journals Understanding Yield Loss and Pathogen Biology to Improve Disease Management: Septoria Nodorum Blotch - A Case Study in Wheat

Plant Disease ◽  
2018 ◽  
Vol 102 (4) ◽  
pp. 696-707 ◽  
Author(s):  
Andrea Ficke ◽  
Christina Cowger ◽  
Gary Bergstrom ◽  
Guro Brodal
Keyword(s):  
Disease Management ◽  
Plant Pathogens ◽  
Management Practices ◽  
Yield Loss ◽  
Control Measures ◽  
Crop Loss ◽  
Yield Losses ◽  
Disease Epidemiology ◽  
Economic Thresholds ◽  
Host Pathogen

The estimated potential yield losses caused by plant pathogens is up to 16% globally and most research in plant pathology aims to reduce yield loss in our crops directly or indirectly. Yield losses caused by a certain disease depend not only on disease severity, but also on the weather factors, the pathogen’s aggressiveness, and the ability of the crop to compensate for reduced photosynthetic area. The yield loss-disease relationship in a certain host-pathogen system might therefore change from year to year, making predictions for yield loss very difficult at the regional or even at the farmer’s level. However, estimating yield losses is essential to determine disease management thresholds at which acute control measures such as fungicide applications, or strategic measures such as crop rotation or use of resistant cultivars are economically and environmentally sensible. Legislation in many countries enforces implementation of integrated pest management (IPM), based on economic thresholds at which the costs due to a disease justify the costs for its management. Without a better understanding of the relationship between disease epidemiology and yield loss, we remain insufficiently equipped to design adequate IPM strategies that will be widely adapted in agriculture. Crop loss studies are resource demanding and difficult to interpret for one particular disease, as crops are usually not invaded by only one pest or pathogen at a time. Combining our knowledge on disease epidemiology, crop physiology, yield development, damage mechanisms involved, and the effect of management practices can help us to increase our understanding of the disease-crop loss relationship. The main aim of this paper is to review and analyze the literature on a representative host-pathogen relationship in an important staple food crop to identify knowledge gaps and research areas to better assess yield loss and design management strategies based on economic thresholds.

scholarly journals Estimating Yield and Economic Loss from Constriction Canker of Peach

Plant Disease ◽  
2000 ◽  
Vol 84 (9) ◽  
pp. 941-946 ◽  
Author(s):  
Norman Lalancette ◽  
Dean F. Polk
Keyword(s):  
Yield Loss ◽  
Disease Incidence ◽  
Economic Loss ◽  
Control Measures ◽  
Economic Losses ◽  
Crop Loss ◽  
Friedman Test ◽  
Yield Losses ◽  
Yield Level ◽  
Total Crop

Constriction cankers, caused by Phomopsis amygdali, girdle and kill fruiting twigs which results in a direct crop loss. To quantitatively determine this loss from 1996 to 1998, the number of fruit lost per infected shoot was estimated as a function of disease incidence in 21 severely infected orchards in New Jersey. For each cultivar in 1997 and 1998, the distribution of fruit sizes at harvest and prices at shipping were used to calculate total crop value for typical expected yields. Economic loss was then calculated from yield loss and crop value estimates. The overall percent yield loss mean across all sites and cultivars, unadjusted for fruit remaining on infected shoots, was 22.2, 30.7, and 23.7% for 1996, 1997, and 1998, respectively. The frequency of these losses were not normally distributed, and the nonparametric Friedman test indicated that yield loss was significantly different among years. Assuming the remaining fruit on infected shoots were harvested, yield losses for 1997 and 1998 were 28.5 and 21.0%, which translated into average economic losses of $4,009 and 2,803/ha, respectively, for an expected yield level of 14,010 kg/ha. These loss values justify control measures for management of constriction canker in severely infected orchards.

scholarly journals Impact of Weather on Sigatoka Leaf Spot of Banana (Musa spp. L.) and its Ecofriendly Management

2016 ◽  
Vol 13 (2) ◽  
pp. 44-53
Author(s):  
M A H Khan ◽  
I Hossain ◽  
M U Ahmad
Keyword(s):  
Disease Management ◽  
Leaf Spot ◽  
Management Practices ◽  
Management Practice ◽  
Foliar Spray ◽  
Control Measures ◽  
Environment Friendly

A study was carried out during July 2010 to April 2012 to understand the effect of weather prevalence on sigatoka disease of banana suckers in different areas of Bangladesh and to develop an environment friendly disease management practice.  Four locations viz. Dinajpur, Bogra, Rangpur and Madhupur were surveyed. To find out suitable and ecofriendly management practices for  controlling sigatoka disease of banana, seven  treatments were used viz. i) Soil drenching with BAU- Biofungicide (2%), ii) BAU-Biofungicide as foliar spray (2%), iii) Soil drenching with BAU-Biofungicide (2%) plus foliar spray (2%), iv) Bavistin (carbendazim) spray (0.2%), v) Dithane M-45 (mancozeb) spray (0.2%), vi) Soil drenching with BAU-Biofungicide (2%) plus Bavistin spray (0.2%); and vii) control. The average highest incidence (26.42%) and severity (22.84%) of sigatoka disease of banana suckers were recorded during October at Bogra, while the lowest incidence (9.75 %) and severity (8.51%) were recorded during January at Dinajpur. Out of the control measures employed, BAU-Biofungicide (2%) either alone or in combination with Bavistin (0.2%) was found as an excellent biocontrol means for controlling sigatoka disease of banana suckers.DOI: http://dx.doi.org/10.3329/agric.v13i2.26587The Agriculturists 2015; 13(2) 44-53

The Critical Period of Bengal Dayflower (Commelina Bengalensis) Control in Peanut

Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 359-364 ◽  
Author(s):  
Theodore M. Webster ◽  
Wilson H. Faircloth ◽  
J. Timothy Flanders ◽  
Eric P. Prostko ◽  
Timothy L. Grey
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Plant Pathogens ◽  
Yield Loss ◽  
Maximum Yield ◽  
Field Studies ◽  
Yield Losses ◽  
Competitive Effects ◽  
Peanut Crop ◽  
The Relationship

Bengal dayflower (also known as tropical spiderwort) is one of the most troublesome weeds in peanut in Georgia, United States. Field studies conducted in 2004 and 2005 evaluated the relationship between the duration of Bengal dayflower interference and peanut yield in an effort to optimize the timing of weed control. In 2004, the critical period of weed control (CPWC) necessary to avoid greater than 5% peanut yield loss was between 316 and 607 growing degree days (GDD), which corresponded to an interval between June 8 and July 2. In 2005, the CPWC ranged from 185 to 547 GDD, an interval between May 30 and July 3. Maximum yield loss in 2005 from season-long interference of Bengal dayflower was 51%. In 2004, production of peanut pods was eliminated by interference with Bengal dayflower for the initial 6 wk (495 GDD) of the growing season. Robust Bengal dayflower growth in 2004 shaded the peanut crop, likely intercepting fungicide applications and causing a reduction in peanut yield. Therefore, the competitive effects of Bengal dayflower are likely complicated with the activity of plant pathogens. In spite of higher Bengal dayflower population densities, greater Bengal dayflower growth, and greater peanut yield losses in 2004 than in 2005, the CPWC was a relatively similar 4-wk period that ended during the first week of July, for peanut that was planted in the first week of May.

scholarly journals Yield loss and economic thresholds of yellow nutsedge in irrigated rice as a function of the onset of flood irrigation

Bragantia ◽  
2014 ◽  
Vol 73 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Nixon da Rosa Westendorff ◽  
Dirceu Agostinetto ◽  
André da Rosa Ulguim ◽  
Lais Tessari Perboni ◽  
Bruno Moncks da Silva
Keyword(s):  
Competitive Ability ◽  
Control Measures ◽  
Economic Damage ◽  
Hyperbolic Model ◽  
Yield Losses ◽  
Flood Irrigation ◽  
Irrigated Rice ◽  
Weed Population ◽  
Yellow Nutsedge ◽  
Economic Thresholds

Yellow nutsedge (Cyperus esculentus) is adapted to flooding and reduces yield in irrigated rice. Information on the competitive ability of this weed with the crop and the size of the economic damage caused is lacking. Mathematical models quantify the damage to crops and support control decision-making. This study aimed to determine yield losses and economic thresholds (ET) of this weed in the culture according to weed population and time of onset of irrigation of the crop. The field study was conducted in the agricultural year of 2010/2011 in Pelotas/RS to evaluate the competitive ability of BRS Querência in competition with different population levels of yellow nutsedge and two periods of onset of flood irrigation (14 and 21 days after emergence). The hyperbolic model satisfactorily estimated yield losses caused by yellow nutsedge. Population of yellow nutsedge was the variable most fitted to the model. The delay of seven days for the beginning of rice irrigation causes decrease in competitive ability of BRS Querência, and based on the ET calculated to the price paid for rice, it is necessary between two and thirteen plants m-2 weed to justify the control in the first and second period of irrigation, respectively. Increases in yield, price paid for rice and control efficiency of the herbicide, besides reduction of costs of controlling promote reduction of ET of yellow nutsedge in rice crops, justifying the adoption of control measures even at smaller weed population.

YIELD LOSSES IN WHEAT DUE TO WEED COMMUNITIES DOMINATED BY GREEN FOXTAIL [Setaria viridis (L.) BEAUV.]: A MULTISPECIES APPROACH

1989 ◽  
Vol 69 (2) ◽  
pp. 521-529 ◽  
Author(s):  
L. HUME
Keyword(s):  
Yield Loss ◽  
Triticum Aestivum L ◽  
Crop Loss ◽  
Setaria Viridis ◽  
Yield Losses ◽  
Degree Days ◽  
Relative Time ◽  
Weed Communities ◽  
Green Foxtail ◽  
Multispecies Competition

A model was developed to predict wheat (Triticum aestivum L.) loss due to interference by multi-species weed communities dominated by green foxtail [Setaria viridis (L.) Beauv.], 3–4 wk after seeding. Results indicated that green foxtail-dominated weed communities averaging 427 plants m−2 over 4 yr reduced yield by about 7.8%. When plots were kept free of green foxtail, different species became important components of a second model developed to predict the yield loss. The combined effect of precipitation and growing degree days was an important component of both models. It is postulated that these environmental variables reflected the relative time of emergence of the weeds and the crop. Advantages of models based upon multispecies tests over those determined from one-weed one-crop tests are discussed as they relate to crop loss in multispecies situations.Key words: Setaria viridis, green foxtail, crop loss, multispecies competition, weed communities, modeling

scholarly journals Suitability of the MODIS-NDVI Time-Series for a Posteriori Evaluation of the Citrus Tristeza Virus Epidemic

2020 ◽  
Vol 12 (12) ◽  
pp. 1965
Author(s):  
Daniela Vanella ◽  
Simona Consoli ◽  
Juan Miguel Ramírez-Cuesta ◽  
Matilde Tessitori
Keyword(s):  
Time Series ◽  
Plant Pathogens ◽  
Management Practices ◽  
Citrus Tristeza Virus ◽  
Plant Diseases ◽  
Control Measures ◽  
Ndvi Time Series ◽  
The Impact ◽  
Tristeza Virus ◽  
Citrus Tristeza

The technological advances of remote sensing (RS) have allowed its use in a number of fields of application including plant disease depiction. In this study, an RS approach based on an 18-year (i.e., 2001–2018) time-series analysis of Normalized Difference Vegetation Index (NDVI) data, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and processed with TIMESAT free software, was applied in Sicily (insular Italy). The RS approach was carried out in four orchards infected by Citrus tristeza virus (CTV) at different temporal stages and characterized by heterogeneous conditions (e.g., elevation, location, plant age). The temporal analysis allowed the identification of specific metrics of the NDVI time-series at the selected sites during the study period. The most reliable parameter which was able to identify the temporal evolution of CTV syndrome and the impact of operational management practices was the “Base value” (i.e., average NDVI during the growing seasons, which reached R2 values up to 0.88), showing good relationships with “Peak value”, “Small integrated value” and “Amplitude”, with R2 values of 0.63, 0.70 and 0.75, respectively. The approach herein developed is valid to be transferred to regional agencies involved in and/or in charge of the management of plant diseases, especially if it is integrated with ground-based early detection methods or high-resolution RS approaches, in the case of quarantine plant pathogens requiring control measures at large-scale level.

scholarly journals The brown rot fungi of fruit crops (Monilinia spp.): III. Important features of disease management (Review paper)

2004 ◽  
Vol 10 (4) ◽  
Author(s):  
I. J. Holb
Keyword(s):  
Disease Management ◽  
Chemical Control ◽  
Management Practices ◽  
Brown Rot ◽  
Control Measures ◽  
Fruit Crops ◽  
Monilinia Fructigena ◽  
Brown Rot Fungi ◽  
Monilia Polystroma ◽  
Rot Disease

In the third part of this review, important features of disease management are summarised for brown rot fungi of fruit crops (Monilinia fructigena, Monilinia laxa, Monilinia fructicola and Monilia polystroma). Several methods of brown rot disease management practices were collected and interpreted in five main chapters. In these chapters, details are given about the legislative control measures, the cultural, physical, biological and chemical control methods. Chemical control is divided into two parts: pre-harvest and post-harvest chemical control. In addition, host resistance and fungicide resistance statuses are also included in this part of the review. Finally, future aspects of brown rot disease control are discussed.

scholarly journals Status of Rice Brown Spot (Helminthosporium oryza) Management in India: A Review

2021 ◽  
Author(s):  
M. Surendhar ◽  
Y. Anbuselvam ◽  
J. Johnny Subakar Ivin
Keyword(s):  
Disease Management ◽  
Yield Loss ◽  
Disease Incidence ◽  
Control Measures ◽  
Brown Spot ◽  
Strong Impact ◽  
Management Protocol ◽  
Current Scenario ◽  
Helminthosporium Oryzae ◽  
Historic Significance

Rice is one of the most widely consumed staple food for more than half of the population in the world. Brown spot caused by Helminthosporium oryzae accounts for 5% yield loss worldwide annually. Adversely affected fields show yield loss as high as 45%. The present study focuses on the several management aspects that are currently used to curb out the disease incidence and measures to be taken in near future for designing effective disease management protocol. The disease is of historic significance and a devasting outbroke in the Bengal Province during 1943 ended as the Great Bengal Famine resulting in starvation and an estimated demise of 2.1 to 3 million people. Brown spot is still devastating on looking the present scenario of damage to rice. Different approaches have been adopted ranging from the use of brown spot resistant rice cultivars, chemical ameliorations and biological control measures for the management of the disease. But, still the disease seems to be chronic and adverse in the current scenario. In this review, we have highlighted epidemiology, control measures practiced and several quantitative and qualitative gaps with respect to disease management, which if rectified, would lead to a strong impact on crop disease control and the sustainable Rice production that are pertinent to the present situation of farmers.

Phytophthora in Australia

1995 ◽  
Vol 46 (7) ◽  
pp. 1311 ◽  
Author(s):  
JAG Irwin ◽  
DM Cahill ◽  
A Drenth
Keyword(s):  
Genetic Structure ◽  
Population Genetic Structure ◽  
Agricultural Production ◽  
Population Genetic ◽  
Plant Pathogens ◽  
Current Control ◽  
Control Measures ◽  
Case Histories ◽  
Phytophthora Spp ◽  
Host Pathogen

Phytophthora spp. are one of Australia's most serious plant pathogens, causing well in excess of $200 million in lost production annually across all of our plant-based industries. Of the more than 50 species of Phytophthora recorded worldwide, over 20 are present in Australia. All species, along with their hosts, distribution and current control measures have been tabulated. Use of molecular markers to analyse population genetic structure has shown that most of these pathogens have been introduced from overseas, and become widely distributed in Australia within relatively short periods of time. The review highlights the general biology of Phytophthora spp. and their impact on agricultural production in Australia, with particular emphasis on the genetics of host/pathogen interactions, population genetic structure and reproduction of Phytophthora populations in Australia. The review highlights the role molecular technologies may play in developing an understanding of host-pathogen recognition and pathogenesis in Phytophthora. Three case histories, involving P. sojae, P. medicaginis and P. cinnamomi, have been developed to provide insights into current levels of understanding, and to identify gaps in our knowledge. Current control measures are summarized and possible new avenues of control discussed.

scholarly journals Soybean yield loss and economic thresholds due to glyphosate resistant hairy fleabane interference

2018 ◽  
Vol 84 (0) ◽  
Author(s):  
Dirceu Agostinetto ◽  
Diecson Ruy Orsolin da Silva ◽  
Leandro Vargas
Keyword(s):  
Yield Loss ◽  
Development Stage ◽  
Control Measures ◽  
Economic Threshold ◽  
Economic Management ◽  
Soybean Yield ◽  
Weed Density ◽  
Economic Thresholds ◽  
Soybean Price ◽  
Hairy Fleabane

ABSTRACT: The interference of glyphosate resistant hairy fleabane (Conyza bonariensis) has caused yield losses in soybean crop. Knowledge of the economic threshold is an important aspect for the economic management of resistant weeds. Because of it, the interference of the glyphosate resistant hairy fleabane density on the soybean yield loss was evaluated, as well as to estimate the economic threshold. Two experiments were conducted to verify the effect of different weed densities on the yield of two soybean cultivars (BRS Estância and BMX Turbo). Weed density ranged from 0 to 124 plants m-2. The yield of the BRS Estância decreased by 1.4% to the increase of one single plant, while for the BMX Turbo the loss was 25.9%. Soybean yield and economic threshold were lower for the BMX Turbo cultivar compared to the cultivar BRS Estância, which can be attributed to the genotype, competitive ability, weed development stage and/or environment. Increases in crop yield expectation, soybean price and herbicide efficiency reduce the economic threshold, indicating that the adoption of control measures should be taken when the weed density is low. Due to the high cost of hairy fleabane control, it is only feasible at high densities.

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