Just like human beings, plants get sick. All plants are susceptible to diseases. A plant becomes diseased when it is disturbed by a causal agent which results in a change in its physiological processes that interfere with the plant’s ability to grow and function normally.
Plant diseases have existed throughout history. In the Bible, diseases such as blight, rust and mildew are mentioned which resulted in famine. Throughout history, certain plant diseases were responsible for hunger and starvation, death, mass migrations and decline in economic activity.
Plant diseases can be fully understood by the ‘Disease Triangle Concept’. This states that plant diseases are formed from the interaction amongst a pathogen (the disease-causing organism: fungus, bacteria, virus), a favourable environment (for the disease to thrive) and a susceptible host (the plant itself).
When all three factors occur simultaneously, then disease is prominent. We can all relate to experiencing symptoms of plant diseases in our ornamental or crop plants. The management of plant diseases will depend on the type of pathogen that is infecting the plant.
Proper identification can be done by an agronomist where a sample of the plant is taken and inspected under a microscope to observe the pathogen. If a virus is present, this can be observed without a microscope.
Controlling plant diseases include eradication (removing the diseased plant or soil by pruning, burning and soil fumigation), protection (usage of a chemical barrier or taking a cultural approach which modifies the environment such as tillage, change in irrigation etc.) and resistance strategies (planting of disease-resistant seeds and plants).
Integrated pest management (IPM) approaches should also be part of the integrated disease management (IDM) plan for the complete control of plant diseases.
If you are having plant disease problems in your garden, please feel free to send an email so we can derive an IDM implementation plan.
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