Plant disease and pathogens

• Pathogens are disease-causing viruses, bacteria, fungi or protists which attack plants as well as animals.
• Plants have physical and chemical defences against pathogens.
• Mineral ion deficiencies can cause plant diseases.
• Growth of plants in different nutrient solutions can affect their susceptibility to diseases.
• Plant diseases can be caused by pathogens.
• Farmers and gardeners often use books and the internet to identify plant diseases.
• For diseases that are more difficult to identify, cuttings of the plant may be analysed by scientists in laboratories using testing kits containing monoclonal antibodies.
• Farmers and gardeners can take a small cutting of an infected plant (or a photograph of it) to a local garden centre, which have staff that can often help identify and treat the disease.
• Symptoms of plant diseases and identification of pathogens can be done at a higher level.
• Pathogens can cause diseases with a range of different symptoms.
• The symptoms of common plant infections are shown below.