Integrated Pest Management in Protected Structures I: Basic Principles and Scouting
The fundamentals of managing pests in protected structures are very similar in many respects to managing pests in field crops. The grower must still develop a management plan, assembling pertinent information for identifying, monitoring and controlling specific pests before planting. Integration of several pest management strategies into a comprehensive program is still critical. Recognition of seasonal patterns and anticipation of associated pests are important for timing control measures. Unlike field pest management, conditions within a protected structure can be modified to a certain degree to prevent, delay, or even mitigate pest issues. However, it’s important to recognize that conditions that discourage one group of pests can often favor another. Protected structures can be screened to physically exclude many insect pests (Figure 1), but screens also shelter insect pests inside the structure from enemies. Structures with non-porous tops like greenhouses (Figure 2) and high tunnels (Figure 3) can mitigate the effect of rain on many bacterial and fungal pathogens that require free moisture for infection and movement, but without proper ventilation these same structures will increase humidity to a degree that offsets these gains or encourages other diseases such as Botrytis and powdery mildew. While the use of soilless media can eliminate many detrimental soil-borne pests and pathogens that plague field production, some soil-borne pathogens produce spores that can still be problematic in a protected structure even when the pathogen source is outside the structure.