What are the main diseases of corn? Detailed explanation of control methods

In daily life, corn is a grain we can eat almost every day. Many people's hometowns grow corn, and besides eating it themselves, most of the corn is sold. The income from growing corn is also quite good, but in recent years there have been more and more corn diseases. So below, Shuaishuai will introduce some common corn diseases and teach everyone how to prevent and control these diseases. Let's take a look together!

I. Northern corn leaf blight

1. Symptoms

This disease mainly harms the leaf portion of corn. If the condition is severe, it will infect the leaf sheath and husk leaves of corn. At the very beginning of this virus, it mainly starts by infecting the lower leaves of the plant, then spreads from bottom to top. In the end, all the leaves turn brown, then mold begins to grow on the surface, and finally the leaves die. The incidence rate of summer corn is generally heavier than that of spring corn.

2. Control methods

Select good disease-resistant varieties. When corn is first planted, appropriately strengthen its planting density, then apply more organic fertilizer and phosphorus-potassium fertilizer. In the early stage of northern corn leaf blight, chemical drugs can be used for treatment, such as carbendazim, tebuconazole solution, or thiophanate-methyl solution, spraying about 50-70 kg per mu, once every one week, for a total of two or three treatments.

II. Southern corn leaf blight

1. Symptoms

Southern corn leaf blight occurs over a relatively wide time period. It can infect plants during both the seedling stage and the later stage of corn, and it generally also starts by infecting the lower leaves of corn, then slowly spreads upward. As time goes on, after the lesions expand, they become yellow-brown spindle-shaped. In the later stage, the leaves wither and die. If the ambient air is too humid, black fuzzy matter will be produced. Its pathogen generally overwinters in the form of mycelium parasitizing on the remnants of diseased plants, but its survival rate is not high. Places with more rainfall and poor soil fertility are prone to the disease.

2. Control methods

Select good varieties with strong disease resistance, strengthen field planting management, apply more organic fertilizer, strengthen field drainage, and improve the disease resistance of plants. Chemical agents can be used for control, such as carbendazim and thiophanate-methyl wettable powder or mancozeb solution, spraying 50-70 kg per mu, once a week, for 3 consecutive times to alleviate the symptoms.

III. Corn round spot disease

1. Symptoms

The part harmed by corn round spot disease is the ear, and it may also harm its husk leaves, leaves, and leaf sheath portions. This pathogen can cause the ear to rot, and the lesions slowly spread and multiply. The symptoms on the ear portion are the most severe, and sometimes cause the ear portion to wither and die. The mycelium of this pathogen is scattered on field straw and parasitizes there to overwinter, and by the next year it can attack again.

2. Control measures

Strengthen observation of corn and spray more drugs. Fenpropidin can be used for control. The main spraying area is on the ear. The ear is the part with the highest disease incidence.

The above are the main control methods for the main diseases of corn. The main diseases of corn are the three above. Others are seen relatively rarely, and their incidence rates are not that high. However, we should also pay attention and can usually spray some corresponding fungicides for control, which can play a preventive role.