Beauveria bassiana Spray Dosage: Complete Guide to Monitoring and Application for Applicator Farmers

Pest control using biological agents such as Beauveria bassiana is increasingly popular among farmers who want to reduce dependence on chemical pesticides. However, the success of Beauveria bassiana spray application depends heavily on the correct dosage and application schedule tailored to the dynamics of pest populations in the field. This article will discuss in depth how to determine the optimal Beauveria bassiana spray dosage, pest population monitoring techniques (trap, scout, threshold), and an effective application schedule based on field data.

Why Pest Population Monitoring is Important Before Application?

Before spraying Beauveria bassiana, farmers must understand the pest population conditions in their fields. Without monitoring, application can be futile due to incorrect timing or dosage. Population monitoring is conducted to:

• Determine the control threshold: Not all pest populations need to be controlled. The control threshold is the pest population density that, if exceeded, will cause economic loss. For Beauveria bassiana, the control threshold is usually lower than for chemical pesticides because its effect is not immediately lethal.
• Choose application timing: Beauveria bassiana works optimally on active larval or nymph stages. Application when the pest population is still low (preventive) or at the peak of attack (curative) requires different dosage strategies.
• Save costs: With monitoring, farmers only spray when necessary, reducing spray frequency and volume.

Monitoring Techniques: Trap, Scout, and Threshold

There are three main techniques that applicator farmers can use:

1. Trap: Use light traps or pheromone traps to monitor adult pests. For example, pheromone traps for Spodoptera litura or Plutella xylostella moths. Count the number of pests caught per night to understand population trends.
2. Scout: Conduct visual observations on sample plants. Take random plant samples (e.g., 10% of the plant population) and count the number of eggs, larvae, or nymphs per plant. Also record symptoms of attack.
3. Control Threshold: Determine threshold values based on pest type and plant growth stage. Example: for armyworm on soybeans, the control threshold is 2-3 larvae per plant. If exceeded, application is necessary.

With monitoring data, farmers can decide when to spray Beauveria bassiana spray and what dosage is needed.

Correct Beauveria bassiana Spray Dosage for Various Conditions

The dosage of Beauveria bassiana spray depends on the product formulation and pest population density. Biosolution products contain Beauveria bassiana and Metarhizium anisopliae with a spore density of 10⁶ CFU/ml per strain. Here is a general dosage guide:

Note: If using a WP (wettable powder) formulation, use 3-5 g/L water. Ensure the suspension is well mixed before spraying.

Higher dosages are needed when pest populations are high to ensure enough spores reach the target. However, do not exceed 3 ml/L as it does not significantly increase efficacy and only wastes product.

Application Schedule Based on Pest Life Cycle and Environmental Conditions

Beauveria bassiana is an entomopathogenic fungus that requires high humidity (RH > 70%) to germinate and infect. Therefore, application timing is crucial.

Best Application Time

• Afternoon (3:00-5:00 PM): When temperature drops and humidity begins to rise. Avoid application during intense sunlight as UV rays can kill spores.
• After light rain: Soil and air humidity are high, spores germinate faster.
• Avoid strong winds: To reduce drift and ensure droplets reach the target.

Application Frequency

• Preventive: Every 7-10 days, especially during the rainy season or when plants are vulnerable.
• Curative: When pest populations are above the threshold, apply every 5-7 days until the population drops. Biosolution products have 80-85% efficacy against target pests, so 2-3 applications are usually sufficient.

Adjustment to Pest Cycle

• Insects with short cycles (e.g., aphids): Apply more frequently (every 5 days) due to rapid reproduction.
• Caterpillars or beetles: Application during active larval or nymph stages (early instar) is more effective because the cuticle is still thin.

Case Study: Monitoring and Application in the Field

Imagine you have a chili field infested with whitefly (Bemisia tabaci) and beet armyworm (Spodoptera exigua). Here are steps you can take:

1. Install yellow sticky traps: To monitor adult whiteflies. If catches exceed 10 per trap per day, conduct scouting.
2. Scouting: Take 20 leaves from 10 random plants. Count the number of whitefly nymphs and armyworm eggs. If the average is >5 nymphs per leaf or >1 egg mass per plant, the threshold is exceeded.
3. Application: Mix 2.5 ml/L of Biosolution product, spray evenly over the entire canopy in the afternoon. Repeat 7 days later if the population has not decreased.
4. Evaluation: 3 days after application, check for pest carcasses covered in white mycelium (sign of Beauveria bassiana infection). If none, check humidity or dosage.

Advantages of Biosolution Products for Beauveria bassiana Spray Application

The Broad-Spectrum Biological Insecticide Formula from Biosolution combines two superior entomopathogenic strains: Beauveria bassiana and Metarhizium anisopliae. Its advantages:

• 80-85% efficacy: Tested against various pests such as aphids, caterpillars, and beetles.
• Residue-free: Safe for vegetables and fruits consumed fresh.
• Compatible with IPM: Does not kill natural enemies if applied correctly.
• Synergistic mechanism: Metarhizium anisopliae complements Beauveria bassiana to control soil pests like grubs.

For optimal results, use the dosage according to the guidelines and conduct routine monitoring. With a data-driven approach, farmers can save costs and increase control effectiveness.

Conclusion

The correct Beauveria bassiana spray dosage (2-3 ml/L of Biosolution product) and application schedule based on pest population monitoring (trap, scout, threshold) are key to successful biological control. By applying these techniques, farmers can reduce chemical pesticide use, lower costs, and produce healthy agricultural products. For further consultation on dosage and application schedule suitable for your field conditions, contact the Biosolution team via WhatsApp or visit the biological pest control product page for complete information.

External references:

• IPM Guidelines from the Indonesian Ministry of Agriculture
• IRRI Publication on Beauveria bassiana