What is essential for fungal infection to occur?

For a fungal infection to occur, the presence of free moisture and high humidity is essential. Fungi require certain environmental conditions to thrive, and moisture is one of the critical factors. This moisture provides an ideal environment for spores to germinate and for fungal colonies to grow. High humidity levels help maintain the necessary water content that supports fungal development and can also inhibit the plant's ability to dry out after rain or irrigation, further facilitating infections.

While high temperatures can promote some fungal activity, it is the combination of adequate moisture and humidity that primarily supports successful infection. Sunlight exposure and high soil pH are generally not conducive to fungal infections, as they do not provide the required conditions for fungal growth and can even inhibit it in some cases. Thus, the presence of free moisture and high humidity is the key condition for the establishment of fungal diseases.