Latest Technical Methods for Pest and Disease Control During Corn Sowing and Seedling Stages

Seed Treatment

Before sowing corn, seed treatment can increase the germination rate of seeds, promote seedling growth, and also kill pathogens on the seed coat, reduce pest and disease damage, and promote full, timely, and strong seedlings. Seed treatment methods include:

1. Sunning seeds: Spread the selected seeds on the ground or on a mat, 5-6 cm thick, and turn and sun them continuously for 2-3 days. Never spread the seeds directly on cement or metal plates, to avoid scalding the seeds due to excessive temperature.

2. Chemical seed dressing: To control corn virus diseases, use 100 ml of 1.5% Zhibingling II, mix with an appropriate amount of water to dress 50 kg of corn seed. To control root rot and smut, use 100-150 g of 50% carbendazim or 25% triadimefon wettable powder to dress 50 kg of seed; to control underground pests, use 100 ml of 50% phoxim emulsifiable concentrate, mix with an appropriate amount of water, and dress 100 kg of corn seed. After mixing evenly, dry and sow. For areas where underground pests and corn diseases occur together, a mixed pesticide dressing can be used. When dressing seeds, first mix the insecticide, dry, and then mix the fungicide.

3. Coating with special seed coating agent. The dosage is 50 ml to coat 5-7 kg of seeds, which both prevents disease and controls pests.

Seedling Stage Control Measures

1. Corn weed control

Weed control can reduce breeding sites for pests and diseases. Choose high-quality, appropriate herbicides, grasp the optimal application period, appropriately increase the amount of water when spraying, avoid high temperatures and windy weather, spray evenly on the ground, and ensure no repeated spraying or missed spraying. Strictly follow the herbicide instructions to prevent phytotoxicity. Commonly used herbicides include: 1. Use 150-200 ml of 40% acetochlor-atrazine mixture per mu, mixed with 50-80 kg of water, sprayed after corn sowing and before emergence. 2. Use 80-100 ml of 18% nicosulfuron per mu, mixed with 50-80 kg of water, directed spray at the 2-3 leaf stage of corn. 3. Use 150 ml of 50% acetochlor-atrazine mixture per mu, mixed with 50-80 kg of water, directed spray before the 4-leaf stage of corn.

2. Seedling stage pest and disease control:

(1) Small brown planthoppers and aphids are virus-transmitting insects of corn. Spray with 1000 times dilution of 10% imidacloprid.

(2) To control corn virus diseases: At the one-leaf-one-heart stage of corn, use 800-1000 times dilution of 1.5% Zhibingling II per mu, spray once every 7-10 days, for 2 consecutive times, spraying evenly on both sides of the leaves.

(3) Pay attention to the occurrence of armyworms to prevent armyworms from attacking after wheat lodging. Since the armyworm is a migratory pest, closely monitor its occurrence dynamics. Before the third instar of armyworm larvae, when transparent small spots appear on the corn whorl leaves, apply pesticide for control. Use 30-50 g of 25% diflubenzuron suspension concentrate or NPV virus preparation per mu, mixed with 40-50 kg of water for spraying, which can also simultaneously control pests such as caterpillars and cotton bollworms. The spraying time should be based on the armyworm's habit of hiding by day and emerging at night, choosing before 10 AM or after 4 PM.