What should be done when the grain crop rice develops white head disease? When does it occur? What causes it? How can it be prevented? What medicine can cure it?

Rice white head disease is a common disease after rice heading, occurring in all planting areas, and this disease can seriously affect yield and reduce benefits, so during the planting period, management techniques must be strengthened. So what should be done when rice develops white head disease? When does it occur? What causes it? How can it be prevented? What medicine can cure it?

Occurrence time:

During the heading process of rice or for a period after heading, due to pests and diseases (rice neck blast, stem borers, etc.) and mechanical damage, the development of the rice panicle is terminated, the stem tissue can no longer transport water and nutrients to the panicle, and the rice panicle produces a phenomenon in which the glumes turn white due to water loss.

Causes:

1. Pests

Before and after rice heading, there are still many pests, generally mainly the striped stem borer, yellow stem borer, rice planthopper, pink stem borer, etc. They can all cause rice white heads. Let us briefly discuss each:

Striped stem borer: mainly damages rice plants; many small holes can be seen on the stems, which are left by the striped stem borer.

Yellow stem borer: first damages inside the panicle bud, then gradually feeds downward, and can bite off the panicle stem; it generally appears in groups.

Rice planthopper: there are many species, and the specific species will not be discussed here. When rice is at the heading stage, if the temperature is suitable, there will be a major outbreak, sucking the sap of rice plants or panicle necks, causing great damage.

Pink stem borer: the damage is similar to that of the striped stem borer, but the holes left after damage are somewhat larger than those of the striped stem borer.

2. Diseases

There are also many diseases that cause rice white heads. Common ones include rice blast, sheath blight, bakanae disease, etc. Their symptoms and damage are also discussed separately below:

Rice blast: due to differences in the damage period and location, rice blast can be divided into seedling blast, leaf blast, node blast, neck blast, and grain blast. At the heading stage, if node blast and neck blast occur severely, they easily lead to white heads; generally, with more continuous rainy weather, the disease incidence is relatively more severe.

Sheath blight: if the rice field is irrigated with sewage for a long time or the field is planted too densely, sheath blight will be severe. In addition, high temperature and high humidity weather is also an important factor in the occurrence of sheath blight. Generally, the leaf sheath is infected, showing gray-green or gray-brown irregular lesions.

Bakanae disease: also called leggy disease. The plants grow taller than normal rice, but the leaves are narrow and long, yellow in color, and root growth is also inhibited. Some do not head, and some do not set grain after heading, forming white heads.

3. Other causes

Other causes are mainly caused by climate, and there are 3 common ones:

Drought: before and after heading, when the field is too dry and the relative humidity is below 50%.

Excessive rain: before and after the rice heading stage, continuous rain affects normal heading or results in no grain setting after heading.

High temperature: when rice is at the heading stage, it is relatively sensitive to temperature. If the temperature is higher than 35 degrees, it will cause poor pollen development, prevent normal fertilization, and affect heading.

Control measures:

1. Choose varieties with relatively strong disease and pest resistance, and seed dressing treatment can be carried out before sowing.

2. Water and fertilizer management must keep up. Measures such as base fertilizer, topdressing, drainage, and re-watering will not be introduced in detail here. Friends who are interested can follow and check.

3. Pest control. This article directly discusses chemical agents. The striped stem borer, yellow stem borer, and pink stem borer all belong to Lepidoptera pests. Available agents include emamectin benzoate · chlorpyrifos, Kangkuan, Bacillus thuringiensis, flubendiamide, etc. For rice planthopper, agents such as nitenpyram, fenvalerate, deltamethrin, buprofezin, pymetrozine, etc. can be selected.

4. Disease control: also directly discussing chemical agents. For rice blast, agents such as isoprothiolane, triadimefon, prochloraz, etc. can be selected; for sheath blight, agents such as propiconazole, diniconazole, hexaconazole, hymexazol, etc. can be selected; for bakanae disease, agents such as bakanae fungicide, prochloraz, etc. can be selected.