Damage Characteristics and Control Methods of Snails in Corn Fields

Currently, it is the critical period for summer corn management. Many snails have been found on corn plants. In recent years, the damage caused by snails has shown a trend of spreading, which requires attention. So how to control snails in corn fields?

Symptoms of snail damage to corn

When snails damage corn, strip-like cracks appear on the corn leaves. On leaves bitten by snails, often only a layer of transparent epidermis remains at the cracks. In severe cases, it leads to missing seedlings and twisted leaves in corn, thereby affecting photosynthesis. In general fields, the rate of damaged plants is 10-15%, and in severely affected fields, the rate of damaged plants is above 50%, posing a threat to the normal growth of corn.

How to control snails in corn fields?

(1) Agricultural control

Regularly clean the field to destroy the habitat and egg-laying sites of snails and reduce the source of pests. Deep plowing in autumn and winter can turn eggs and overwintering adults to the soil surface, so that they are dried to death by the sun or eaten by natural enemies. In places where snail disasters are relatively serious, when plowing the land in winter, spring, and autumn, leave a small patch of weedy grass to attract snails, and then eliminate them in a concentrated manner.

(2) Physical control

Promptly spread a layer of quicklime around the plants, but do not spread it on the upper surface of crop leaves, so as not to affect photosynthesis. When snails come out at night to feed and touch the quicklime, they lose water and die. Alternatively, spread quicklime along field ditches and between ridges to form a barrier belt, using 5-7 kg of quicklime per mu; the effect is poor when the ground is wet.

(3) Manual capture

Before sunrise in the early morning or on rainy days, when snails are active and causing damage, promptly carry out manual capture on the ground and on the plants.

(4) Chemical control

During the peak occurrence period of snails, use 600 g of 10% snail bait (metaldehyde) granules per mu, evenly broadcast on the bed surface in the evening, or apply the granules on the ground at the lower part of the plants; alternatively, select 30-60 g of 80% metaldehyde per mu and spray with water. For fields with severe snail occurrence, carry out a second control after 10-15 days, which can effectively control snail damage