What Causes Crop Diseases?

Crop diseases usually occur depending on certain factors such as  pathogens, environmental conditions, and variety of crops planted. In general, they are spread according to the very nature of the agent that caused them.

There are two (2) types of causal agents:

  1. Non-infectious Disease Agents  (Abiotic)
  2. Infectious Disease Agents (Biotic)

Crop Disease Causal Agents

Non-infectious Disease Agents

This type of agent is also known as Abiotic agents, comprising of non-living causal factors such as environmental conditions and inappropriate farm management. Crop diseases that are solely caused by Abiotic factors are not transmissible to other or neighboring plants.

Here is a list of some of the most widely recognized abiotic agents:

  • Chemical injuries caused by pesticides
  • Improper Water Management
  • Seasonal Change
  • Extreme Temperature
  • Nutrient Deficiency
  • Frequent Heavy Rain
  • Soil Compaction
  • Drought
  • Moisture
  • Wind

Infectious Disease Agents

This is also referred to as Biotic agents, which are comprised of living organisms that serve as pathogens capable of spreading from one host to another, transmitting the specific type of disease.

The most common type of pathogens are:

  • Fungi – the most common pathogen, causing around 85% of crop diseases.
  • Viruses – this type of pathogen is usually transmitted from a vector (ex. tick, insect, etc.).
  • Nematodes – this pathogen targets the roots of plants, causing galls on them.
  • Bacteria – this kind of pathogen quickly mutates and multiplies. They usually enter through a wound or opening in a plant.


The truth behind crop diseases is that they are not caused solely by either abiotic or biotic factors. Together, these causal agents create a special condition conducive for disease development. However, it is still vital that farmers or gardeners are able to identify causes of crop diseases to protect their crops.

Understanding the disease and its origin is the first step towards successful disease management. When aware and familiar with these diseases, farmers are more likely to be prepared and equipped to handle and counter them.

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