Slugs are a common pest in greenhouse vegetable production. They are particularly damaging to leafy vegetables grown in high-temperature and high-humidity environments, such as lettuce. So, how can we prevent and control slugs in lettuce cultivation? Let's find out.
Damage Caused by Slugs in Lettuce
Slugs are nocturnal and secretive pests, making early detection challenging. They feed on leaves, causing holes or notches, and contaminate the produce with feces and mucus, resulting in decreased quality and yield of lettuce, thus affecting the profitability of cultivation.
Control Measures for Slugs in Lettuce
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Manual Killing: Slugs are most active for feeding between 11 pm and early morning. Therefore, if the area of lettuce cultivation is small, manual killing during this period is the most environmentally friendly method.
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Physical Attraction: Spread lime powder or strawberry powder on the ground where slugs crawl, causing them to come into contact and perish. Alternatively, set up a container with a solution of sodium hydroxide to attract and kill slugs.
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Enhanced Management: Slugs thrive in moist environments, so controlling humidity is crucial. Avoid excessive watering to keep the soil surface from becoming too wet. Remove weeds, bricks, and debris from the greenhouse promptly, as these can serve as hiding places for slugs during the day. Additionally, using surface mulching can prevent slugs from reaching the soil surface, effectively killing them. Finally, after lettuce harvesting, irrigate the field to kill slugs hiding in the soil.
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Spraying Pesticides: Apply 8% metaldehyde wettable powder at a dilution of 800-1000 times, or 1% copper sulfate wettable powder at a dilution of 1000-1200 times, to treat the stems and leaves of vegetable plants. Alternatively, apply 8% metaldehyde granules at a rate of 400-480g per acre, or 6% molluscicide granules at a rate of 380-500g per acre, along the furrows. It is generally recommended to spray pesticides when the slug population is high.
In conclusion, it is essential to pay close attention to slug control in leafy vegetable greenhouses, such as lettuce. Utilizing a combination of physical and chemical control methods is necessary for effective and scientific pest management to minimize losses caused by slugs.
