During the growth of green onions, you may notice symptoms such as white spots, dry leaves, curling, and stunted growth. In some cases, pesticides fail to show any effect. How can you deal with this? According to **China Pesticide Network**, here are some effective solutions.
There are several pests and diseases that can cause yellowing and withering in green onions, including downy mildew, gray mold, blight, viral infections, and onion fly infestations. If the usual treatments for downy mildew, gray mold, or blight are ineffective, it's likely that the issue is caused by a virus or an onion fly infestation. The appropriate pesticide should be chosen based on the specific symptoms observed.
Viral infections typically present with mottled yellow and green streaks on the leaves, which may become twisted, thin, and gradually turn yellow at the tips. As the infection worsens, the growth of the plant slows down or even stops entirely. To manage this, you can spray a 1.5% phytopathogenic emulsion diluted 1000 times, 20% mancozeb wettable powder diluted 500 times, or a 10% mixed fatty acid emulsion diluted 100 times. Apply these solutions every 7 to 10 days, repeating 2 to 3 times for best results.
Onion fly infestations occur when the larvae burrow into the roots underground, causing rot and decay. This leads to wilting above ground, yellowing leaf tips, or entire plants turning yellow. In severe cases, the green onions may stop growing or die. To control the larvae, you can apply a 75% imidacloprid wettable powder diluted 3000 times, 40% chlorpyrifos emulsifiable concentrate diluted 3000 times, 48% chlorpyrifos emulsifiable concentrate diluted 3000 times, or 5% hexaflumuron emulsifiable concentrate diluted 3000 times directly to the roots.
It’s important to identify the exact cause of the problem before applying any treatment. Regular monitoring and timely intervention can help prevent further damage and ensure healthy growth of your green onions. Always follow the manufacturer’s instructions when using any pesticide to avoid overuse or harm to the environment.
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