Three principles of spraying pesticides during the rainy season
September 01 03:13:08, 2025
When applying pesticides, it's essential to consider the weather conditions. The best time for application is before rain, as the effectiveness of treatment is generally higher when the medicine is applied prior to rainfall, rather than during or after the rain. Rain can wash away the pesticide, reducing its efficacy.
Choosing the right type of pesticide is also crucial, especially during the rainy season. Opt for systemic, fast-acting, rain-resistant, and microbial pesticides. These types are more effective in wet conditions and ensure better coverage and longer-lasting results.
Systemic pesticides like carbendazim, triadimefon, fenbuconazole, thiophanate-methyl, methomyl, carbofuran, chlorpyrifos, dimethoate, omethoate, and phosphorodithioic acid esters are absorbed into the plant within 4 to 5 hours after application. This absorption reduces the risk of the active ingredients being washed away by rain.
Fast-acting insecticides such as dichlorvos, acephate, chlorpyrifos, cypermethrin, and other pyrethroids work quickly—killing pests within 1 to 2 hours or up to 4 to 5 hours after application. These products are less affected by rain and provide rapid control.
Fungicides and bactericides like Jinggangmycin, trimethoprim, tetracycline, and kelpin have strong resistance to water. Even after a heavy shower lasting 1 to 5 hours, they remain effective without significant loss of potency.
Microbial pesticides, such as *Beauveria bassiana* and *Penicillium* species, thrive in high humidity. Applying them during rainy periods can enhance their germination and effectiveness, making them ideal for wet conditions.
To improve the adhesion of the pesticide solution to plants and pests, adding an adhesive agent like a small amount of detergent can be beneficial. This helps the pesticide stick better and last longer on the surface.
Method: Mix 50–75 grams of detergent powder into 50 liters of pesticide solution. Stir well and apply immediately. It’s best to use the mixture right away, as prolonged storage may reduce its effectiveness.
Always check the label instructions and follow local regulations when using pesticides. Proper timing, selection, and application techniques can significantly improve pest control outcomes, even during the rainy season.