What to Do About Herbicide Damage in Corn Fields? A Detailed Guide to Remedies

Corn is a common crop, and during its growth it can suffer from insect pests or diseases, so pesticides need to be sprayed in time. If too much pesticide is applied, herbicide damage can occur. So what should you do about herbicide damage in corn fields?

1. Common types of herbicide damage

1. Nicosulfuron: Herbicide damage from nicosulfuron is most likely to occur when a large dose is used, or when the whorl leaves are re-sprayed, combined with hot and dry weather. After being affected, the corn whorl leaves first turn yellow, then this spreads to the entire leaf and other leaves; corn growth is inhibited, the plant becomes stunted, and some clustering and secondary stems may also appear. In mild cases, it can recover within a week; in severe cases, growth is seriously inhibited and recovery is difficult.

2. Atrazine: Herbicide damage is likely to occur when atrazine is used in too large a dose or under high-temperature weather. The leaf tips lose their green color, turning yellow or pale green, and growth is slow. Generally, the herbicide damage is not serious and can recover in 7-10 days.

3. Mesotrione: Because of its high safety, mesotrione is slightly better at controlling large weeds in the field and is favored by some farmers. Because of its high safety, it can be sprayed over the whole field, which has also led to a reduction in farmers' awareness of herbicide safety precautions. However, use in large doses combined with high-temperature weather can still cause herbicide damage. The main symptoms are whitening of corn leaves (discoloration in the early stage but not drying out, which differs from paraquat herbicide damage), affecting photosynthesis. It also has a fairly obvious inhibitory effect on corn growth, and the larger the dose, the more serious the herbicide damage.

4. MCPA: MCPA has good control efficacy against nutgrass and larger broadleaf weeds in corn fields, and is often used in combination with nicosulfuron. It has a certain sales volume on the market. This type of herbicide belongs to the hormone-type herbicides; they mainly induce crop deformities, with obvious deformation of roots, stems, leaves, flowers and ears.

When corn is sprayed on hot days or when too large a dose is used, the corn leaves curl, the leaves become dark green, the whorl leaves take on a horsewhip-like or scallion-like shape, the stems become flattened and fragile and break easily, short and thick deformed prop roots form above ground, the main root is short, and growth is inhibited; in rainy and highly humid weather it tends to lodge. In the later stage, it mainly affects the developing aerial roots, the root system shrinks, normal nutrient uptake by corn is affected, and there is also a certain effect on corn ears.

2. How to prevent and control it?

1. If herbicide damage has already occurred, rescue it promptly. If the damage is caused by too large a dose of herbicide, spray with clean water in time to remove the residual herbicide liquid on the corn leaf surface, reduce the herbicide concentration in the corn plant, and alleviate the herbicide damage.

2. When the herbicide damage is mild, for corn whose leaves are yellowing and drying but whose whorl leaves are normal, you can spray some foliar fertilizer or regulator to relieve the herbicide damage, such as brassinolide, and strengthen corn fertilizer and water management later, remedying water and fertilizer in time, so that large-scale losses do not occur.

3. You can choose herbicides with high safety, such as the currently popular safe nicosulfuron, or spray with a safener added.

When using pesticides on corn, do not arbitrarily increase the dosage; use them according to the instructions.