As rice cultivation enters its critical late-season growth phase, which is decisive for final yields, the risk of significant pest and disease outbreaks escalates. Late-season rice, mid-season rice, and ratooning rice crops that have reached canopy closure are now facing a concentrated threat from three primary adversaries: the third-generation Striped Stem Borer, the Rice Planthopper, and Sheath Blight. To secure a successful harvest, a precise and highly effective integrated pest management (IPM) strategy is essential.

1. Core Control Objectives and Critical Timings

A. Broad-Spectrum Pest and Disease Control:

Primary Targets: Focus on suppressing the populations and spread of the Striped Stem Borer (Chilo suppressalis), Rice Planthoppers (Nilaparvata lugens, etc.), and Sheath Blight (Rhizoctonia solani).

Applicable Fields: All late-season, mid-season, and ratooning rice paddies.

B. Stage-Specific Prophylactic Treatments:

Special Focus for Mid-Season Rice:

False Smut Prevention: It is crucial to apply a preventative fungicide 5 to 7 days before the booting and heading stage begins.

Panicle Blast Prevention: Immediate action must be taken at the initial onset of the booting and heading stage to prevent Panicle Blast.

2. Green-First Approach to Pesticide Selection

When developing a treatment plan, biopesticides should be the preferred choice. Applications should be timed precisely to coincide with the optimal control window once pest or disease levels reach the established action thresholds, promoting efficacy while reducing chemical use.

Controlling Striped Stem Borer:

For effective management, rotate between highly effective chemical agents like Emamectin Benzoate and Chlorantraniliprole. However, it is strongly recommended to prioritize bio-based options such as Spinosad and Bacillus thuringiensis (Bt) to conserve natural enemies and delay resistance.

Managing Rice Planthoppers:

To control planthoppers, select from newer, low-resistance insecticides including Triflumezopyrim, Pymetrozine, and Flonicamid. Plant-derived pesticides like Matrine also offer an excellent green alternative.

Treating Sheath Blight:

The key to controlling Sheath Blight is protecting the stem base of the rice plant. Biological fungicides like Jinggangmycin and Shenqinmycin have proven highly effective. For chemical control, Thifluzamide, Hexaconazole, and Difenoconazole + Propiconazole are powerful options.

Preventing False Smut and Rice Blast:

False Smut: Prophylactic applications can include biological agents like Jinggangmycin and Shenqinmycin, or protective chemical fungicides such as Tebuconazole and Epoxiconazole.

Rice Blast: Kasugamycin and Bacillus subtilis are ideal biological control agents. For chemical management, Tricyclazole and Azoxystrobin provide excellent preventative and early curative action.

3. Action Thresholds for Precise Application

To avoid unnecessary pesticide use, initiate treatment only when field scouting indicates the following thresholds have been met:

Striped Stem Borer: At the tillering stage, when the rate of dead heart tillers exceeds 8%, or at the booting stage, when egg mass density reaches 50 per acre.

Rice Planthoppers: When the population exceeds 1,000 insects per 100 hills.

Sheath Blight: From late tillering to booting, when the incidence of infected hills reaches 20%.

Rice Leaf Roller: At tillering, when there are over 150 newly rolled leaves per 100 hills, or over 60 at the booting stage.

Rice Blast: For susceptible varieties, apply preventative treatments during peak tillering or early heading if weather conditions favor disease development. If disease epicenters appear, apply curative treatments immediately.

False Smut: Strictly adhere to the preventative window of 5-7 days before heading. If continuous rainy weather occurs, a second application is recommended 7 days after the first.

4. Key Practices for Enhancing Efficacy and Ensuring Safety

Field Management Best Practices:

Water Level Management: Ensure a standing water layer of approximately one inch is present in the paddy during application and maintained for 3-5 days afterward. This significantly improves the absorption and distribution of the pesticide.

Pesticide Rotation: Avoid the continuous use of a single pesticide. Rotating products with different modes of action is crucial for delaying the development of pest resistance.

Dynamic Monitoring: Regularly scout fields. If Bacterial Blight, Rice Blast, or Rice Leaf Rollers reach action thresholds, conduct targeted treatments immediately. A follow-up application may be necessary after 7-10 days to ensure complete control.

Environmental and Safety Responsibilities:

Pesticide Container Disposal: Every farmer has an environmental responsibility. After mixing pesticides, use the "triple-rinse" method for all containers. Add the rinse water to the spray tank to utilize the residual product and minimize pollution. Properly rinsed, empty containers must be returned to designated collection points, such as the agricultural supply store where they were purchased.

UAV (Drone) Application Standards:

Pre-flight Environmental Assessment: Before application, the operator must survey the surrounding area and clearly define the treatment boundaries to prevent spray drift from harming non-target organisms (e.g., bees, silkworms) or adjacent crops.

Weather Conditions: Strictly adhere to operational guidelines. Cease all spraying activities if wind speeds exceed Level 3 on the Beaufort scale (leaves and small twigs in constant motion). During hot weather, applications should be conducted before 10:00 AM or after 4:00 PM to maximize efficacy and prevent phytotoxicity.