Additionally, understanding the responses of the immune system in plants will further benefit and limit the loss of crops.
Typically successful intervention will lead to a low enough level of disease to be acceptable, depending upon the value of the crop.
Plant disease epidemiology is often looked at from a multi-disciplinary approach, requiring biological, statistical, agronomic and ecological perspectives.
Native species of plants may serve as reservoirs for pathogens that cause disease in crops.
Using this framework we can now model and determine thresholds for epidemics that take place in a homogeneous environment such as a mono-cultural crop field.
An epidemic of potato late blight, caused by Phytophthora infestans, led to the Great Irish Famine and the loss of many lives.
[5] Commonly the elements of an epidemic are referred to as the “disease triangle”: a susceptible host, pathogen, and conducive environment.
Polycyclic epidemics are caused by pathogens capable of several infection cycles a season.
[citation needed] Epidemics under these conditions are called polyetic; they can be caused by both monocyclic and polycyclic pathogens.
They are techniques where sample preparation and/or repetitive processes are not necessary for measuring and observing the conditions of the plants’ health.
[7] Non-destructive approaches may include image processing, imaging-based, spectroscopy based, and remote sensing.
[8] Plants can show many signs or physical evidence of fungal, viral or bacterial infections.
[9] Symptoms which are visible effects of diseases on the plant consist of changes in color, shape or function.
[9] These changes in the plant coordinates with their response to pathogens or foreign organisms that is negatively effecting their system.
[11] On the other hand, the second branch responds to pathogen virulence factors, either directly or indirectly to the host.
[11] In addition, R genes also known as Effector-Triggered Immunity is activated by specific pathogen “effectors” that can trigger a strong antimicrobial response.
[11] Both PTI and ETI assist in plant defense through activation of DAMP which is Damage-associated Compounds.