Disease Management in Crops and Key Considerations When Using Shade Nets and Insect Screens
Increased humidity in the field can promote the growth of plant pathogens. Shade nets and insect screens supplied by our company may also reduce airflow and, depending on how they are used, increase humidity levels.
This article explains the characteristics of these materials and highlights several important considerations for their proper use.
Why Pathogen Prevention Matters
Like humans, crops can also fall ill. While people often recover naturally or can rely on medication after infection, crops rarely have the ability to self-heal, and treatment options—especially after infection—are extremely limited. For this reason, institutions such as the USDA and the IPM Center emphasize preventive measures rather than post-infection treatment in managing plant pathogens.
Once a crop is infected, treatment becomes difficult, and identifying the full extent of the infection is equally challenging.
A wide variety of diseases can affect agricultural crops. Some are crop-specific, but many are common across multiple species. For example, major tomato diseases include early blight, late blight, Fusarium wilt, Verticillium wilt, bacterial spot, bacterial wilt, Septoria leaf spot, and canker. Among these, early blight, late blight, Fusarium wilt, Verticillium wilt, and Septoria leaf spot can occur in many crops such as other Solanaceae crops, bananas, lettuce, strawberries, cotton, and wheat-related species. Conversely, bacterial spot, bacterial wilt, and canker occur primarily in tomatoes and peppers, with canker being so tomato-specific that cross-species infection is considered quite rare.
Although pathogens vary greatly in their biology and preferred environments, many thrive under different sets of conditions. This means that not all pathogens proliferate simultaneously, and growers can usually identify which pathogens require the most attention based on the crop species and environmental conditions of the field.
Common Preventive Measures
The most widely used preventive measure is the application of agricultural chemicals. Fungicides and bactericides can directly suppress pathogens and are generally effective when appropriately applied.
Another essential strategy is ensuring adequate airflow in the field to prevent excessive humidity. Because humid environments promote pathogen growth, both proper ventilation and good drainage are critical.
If sprinklers or rain are primary sources of irrigation, growers should ensure that moisture on leaves and stems evaporates promptly.
How Shade Nets and Insect Screens Influence Disease Pressure
Although shade nets and insect screens are relatively simple, cost-effective agricultural tools, they interact closely with environmental factors related to disease management—particularly air movement and moisture evaporation.
High-shade shade nets provide a comfortable workspace and reduce heat stress but also increase soil moisture retention and slow evaporation. Fine-mesh insect screens can restrict airflow, raising humidity inside the structure. These characteristics are not ideal in terms of pathogen prevention and must be taken into account when using these materials.
Additionally, certain shade nets are designed to block ultraviolet (UV) radiation. While excessive UV exposure is harmful to both humans and crops, recent studies have highlighted the beneficial role of some UV wavelengths in crop health.
UV-A (315–400 nm): stimulates plant defense responses, enhancing resistance to certain pathogens.
UV-B (280–315 nm): can directly damage the DNA of specific pathogens, contributing to natural sterilization.
Complete UV blocking may therefore reduce these beneficial effects. Many films and shade nets block UV light, but from a disease-management perspective, excessive UV filtering can have unintended negative consequences. Still, because UV-A and UV-B can harm human health, maintaining a balanced level of light transmission is ideal for field environments.
Our Approach to Developing Better Materials
With these considerations in mind, our company has long focused on developing products optimized for modern agricultural practices. Many of our shade nets are designed with high light transmittance in mind, and our insect screens emphasize maintaining airflow as much as possible. Even so, the relationship between disease prevention and these materials will always involve trade-offs.
Regardless of the manufacturer, growers using shade nets or insect screens should always monitor humidity and ventilation conditions in their fields to ensure a healthy growing environment.