Understanding Biotic Stress in Crops

Biotic stress refers to the stress experienced by plants due to the adverse effects of living organisms. These organisms can harm crops, leading to reduced yield and quality. Identifying the sources of biotic stress is crucial for effective crop management.

Differentiating Biotic and Abiotic Stress

It's important to distinguish biotic stress from abiotic stress. Abiotic stress is caused by non-living environmental factors, such as:

• Extreme temperatures (heat or cold)
• Water issues (drought or waterlogging)
• Soil conditions (salinity, nutrient deficiency, pH)
• Light intensity
• Wind

Biotic stress, on the other hand, originates specifically from living entities.

Analyzing the Options for Biotic Stress Causes

Let's examine each option provided in the context of crop production:

• Option 1: water logging and drought

  Waterlogging (excess water) and drought (lack of water) are environmental conditions. These fall under abiotic stress, not biotic stress.

• Option 2: insects, pathogens and other living organisms

  This option correctly identifies living organisms. Insects (pests), pathogens (like fungi, bacteria, viruses causing diseases), and other living organisms (like parasitic weeds) are all biotic factors that directly interact with and harm crops. Therefore, this is the correct cause of biotic stress.

• Option 3: farming machinery and tools

  Farming machinery and tools are inanimate objects used in agriculture. While they can cause physical damage, they are not living organisms and thus do not cause biotic stress.

• Option 4: poor fertiliser application

  Incorrect or poor application of fertilisers relates to nutrient management. Imbalances in nutrients or excessive application can harm plants, but this is typically classified under abiotic stress or poor agricultural practices, not stress caused by living organisms.

Based on the analysis, biotic stress in crop production is directly caused by living organisms like insects and pathogens.