Binod Pokhrel
Environmental factors are triggering simultaneous effects on the disease incidence and severity of crop diseases in agriculture. These both aspects are affected by various environmental factors viz. temperature, soil moisture, humidity, light, soil properties (pH and nutrients) and atmospheric carbon dioxide. The effect of environmental constraints on host and pathogen has positive, negative or neutral effects on crop disease incidence. Sometimes sole factor is responsible for profused disease incidence. On the other hand, interaction of various environmental factors causes huge intensity of diseases. Crop disease is the result of three way interaction between susceptible host, virulent pathogen and favourable environment. Elevated CO2 concentration and increased temperature influence the plant disease interaction. This review article focuses the relationship between various environmental factors and crop diseases and their role in increasing or decreasing the disease severity.