We can diagnose diseases in plants by looking for insects such as aphids, discoloration spots on leaves, stunted growth, decay or abnormal growths, and malformed stems or leaves
Ways to identify plant diseases
1. Use a garden manual or website
2. Take the infected plant to a lab to identify the pathogen
3. Use testing kits containing monoclonal antibodies
Plant ion deficiency diseases

Plant diseases not caused by pathogens
A lack of the nitrate ion causes stunted growth because nitrate is needed for protein synthesis and therefore growth
A lack of the magnesium ion causes chlorosis because magnesium is required to make chlorophyll, causing the leaves to lose their green coloration
