Plant disease forecasting


Plant disease forecasting

Plant disease forecasting is a management system used to predict the occurrence or change in severity of plant diseases. At the field scale, these systems are used by growers to make economic decisions about disease treatments for control. Often the systems ask the grower a series of questions about the susceptibility of the host crop, and incorporate current and forecast weather conditions to make a recommendation. Typically a recommendation is made about whether disease treatment is necessary or not. Usually treatment is a pesticide application.

Forecasting systems are based on assumptions about the pathogen's interactions with the host and environment, the disease triangle.cite book| last =Agrios | first =George | authorlink = | coauthors = | title =Plant Pathology | publisher =Acadmic Press | date =2005 | location = | pages = | url = | doi = | id = | isbn =978-0120445653 ] The objective is to accurately predict when the three factors - host, environment, and pathogen - all interact in such a fashion that disease can occur and cause economic losses.

In most cases the host can be suitably defined as resistant or susceptible, and the presence of the pathogen may often be reasonably ascertained based on previous cropping history or perhaps survey data. The environment is usually the factor that controls whether disease develops or not. Environmental conditions may determine the presence of the pathogen in a particular season through their effects on processes such as overwintering. Environmental conditions also affect the ability of the pathogen to cause disease, e.g. a minimum leaf wetness duration is required for grey leaf spot of corn to occur. In these cases a disease forecasting system attempts to define when the environment will be conducive to disease development.

Good disease forecasting systems must be reliable, simple, cost-effective and applicable to many diseases. As such they are normally only designed for diseases that are irregular enough to warrant a prediction system, rather than diseases that occur every year for which regular treatment should be employed. [cite book| last =Campbell | first =C. L. | authorlink = | coauthors =Madden, L. V. | title =Introduction to Plant Disease Epidemiology | publisher =Wiley and Sons | date =1990 | location =New York | pages = | url = | doi = | id = | isbn =0471832367 ] Forecasting systems can only be designed if there is also an understanding on the actual disease triangle parameters.

Examples of disease forecasting systems

Forecasting systems may use one of several parameters in order to work out disease risk, or a combination of factors.cite journal| last =Esker | first =P. D. | authorlink = | coauthors =A.H. Sparks, L. Campbell, Z. Guo, M. Rouse, S.D. Silwal, S. Tolos, B. Van Allen, and K.A. Garrett | title =Ecology and Epidemiology in R: Disease Forecasting | journal =The Plant Health Instructor | volume = | issue = | pages = | publisher =APS Press | location = | date= |url= http://www.apsnet.org/education/AdvancedPlantPath/Topics/RModules/Doc1/ | doi =DOI:10.1094/PHI-A-2008-01 | id = | accessdate = ] One of the first forecasting systems designed was for Stewart's Wilt and based on winter temperature index as low temperatures would kill the vector of the disease so there would be no outbreak. [ [http://www.apsnet.org/education/LessonsPlantPath/StewartsWilt/discycle.htm APS Education Centre - Stewart's wilt of corn] ] An example of a multiple disease/pest forecasting system is the EPIdemiology, PREdiction, and PREvention (EPIPRE) system developed in the Netherlands for winter wheat that focused on multiple pathogens. [cite journal| last =Reinink | first =K | authorlink = | coauthors = | title =Experimental verification and development of EPIPRE, a supervised disease and pest management system for wheat | journal =European Journal of Plant Pathology | volume =92 | issue =1 | pages =3–14 | publisher =SpringerLink | location = | date =1986 | url =http://www.springerlink.com/content/u4x6020738401513/ | doi =10.1007/BF01976371 | id = | accessdate = ] Forecasting models are often based on a relationship like simple linear regression where x is used to predict y. Other relationships can be modelled using population growth curves. The growth curve that is used will depend on the nature of the epidemic. Polycyclic epidemics such as potato late blight are usually best modelled by using the logistic model, whereas monocyclic epidemics may be best modelled using the monomolecular model. [cite book| last =Madden | first =Laurence | authorlink = | coauthors =Gareth Hughes, Frank Van Den Bosch | title =Study of Plant Disease Epidemics | publisher =American Phytopathological Society | date =2007 | location = | pages = | url = | doi = | id = | isbn =978-0890543542 ] Correct choice of a model is essential for a disease forecasting system to be useful.

Plant disease forecasting models must be thoroughly tested and validated after being developed. Interest has arisen lately in model validation through the quantification of the economic costs of false positives and false negatives, where disease prevention measures may be used when unnecessary or not applied when needed respectively. The costs of these two types of errors need to be weighed carefully before deciding to use a disease forecasting system.

Future developments

In the future, disease forecasting systems may become more useful as computing power increases and the amount of data that is available to plant pathologists to construct models increases. Good forecasting systems also may become increasingly important with climate change. It will be important to be able to accurately predict where disease outbreaks may occur, since they may not be in the historically known areas.

References


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Plant disease epidemiology — is the study of disease in plant populations. Much like diseases of humans and animals, plant diseases occur due to pathogens such as bacteria, viruses, fungi, oomycetes, nematodes, phytoplasmas, protozoa, and parasitic plants.cite book| last… …   Wikipedia

  • plant disease — ▪ plant pathology Introduction       an impairment of the normal state of a plant that interrupts or modifies its vital functions.       All species of plants, wild and cultivated alike, are subject to disease. Although each species is… …   Universalium

  • Plant pathology — For the journal, see Plant Pathology (journal). Agriculture …   Wikipedia

  • Plant defense against herbivory — Poison ivy produces urushiol to protect the plant from herbivores. In humans this chemical produces an allergic skin rash, known as urushiol induced contact dermatitis …   Wikipedia

  • Alzheimer's disease — Alzheimer redirects here. For other uses, see Alzheimer (disambiguation). Alzheimer s disease Classification and external resources …   Wikipedia

  • agricultural technology — Introduction       application of techniques to control the growth and harvesting of animal and vegetable products. Soil preparation       Mechanical processing of soil so that it is in the proper physical condition for planting is usually… …   Universalium

  • Fungicide — Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores.[1] Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in… …   Wikipedia

  • late blight — Plant Pathol. a disease of plants, esp. potatoes, celery, etc., characterized by spotting, blighting, and withering or decay of the entire plant, caused by any of several fungi, as Phytophthora infestans or Septoria apii. [1900 05] * * * ▪ plant… …   Universalium

  • Phytophthora infestans — Taxobox name = Phytophthora infestans domain = Eukaryota regnum = Chromalveolata phylum = Heterokontophyta classis = Oomycetes ordo = Peronosporales familia = Pythiaceae genus = Phytophthora species = P. infestans binomial = Phytophthora… …   Wikipedia

  • agricultural sciences, the — Introduction  sciences dealing with food and fibre production and processing. They include the technologies of soil cultivation, crop cultivation and harvesting, animal production, and the processing of plant and animal products for human… …   Universalium


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.