Fungicide

Definition

A pesticide compound formulated to kill or inhibit parasitic fungi, fungal spores, or oomycetes. Fungicides function through contact (surface protection), translaminar (redistribution across leaf surfaces), or systemic (uptake and transport via xylem) modes of action. In entomology and agricultural ecology, fungicides are critical tools in integrated pest management, though their use requires careful timing to avoid harming beneficial entomopathogenic fungi deployed for insect biological control.

Etymology

From Latin fungus (fungus) + -cide (killer), from caedere (to cut, kill)

Example

Beauveria bassiana, an entomopathogenic fungus used to control whiteflies and aphids, can be inadvertently suppressed by preventive fungicide applications in greenhouse systems, necessitating rotation schedules that separate biological and chemical controls.

Synonyms

• fungistat (inhibitory subset)

Related Terms

• entomopathogenic fungus
• Pesticide
• Insecticide
• Integrated Pest Management
• Biological control
• oomycete
• mycoinsecticide

Usage Notes

Specialists distinguish fungicides from fungistats (which inhibit growth without killing). The term is sometimes misapplied to oomycete controls; while oomycetes are Stramenopiles, not true Fungi, they respond to many fungicide chemistries. In arthropod ecology, fungicide-entomopathogen interactions are a key consideration: azole and strobilurin fungicides can reduce fungal pathogen efficacy against pest insects, while some fungicides synergize with insecticides, affecting non-target arthropods in soil food webs.