What medicine does rice red blight (iron rust) hit? What are the symptoms? How to prevent and cure it?

Rice brown blight, also known as rust disease, commonly known as seedling boiling, stump, in rainy weather if the field water and fertilizer management is not appropriate, it is very likely to lead to the occurrence of red blight. Then what kind of medicine should be used for rice blight? What are the symptoms? How to prevent it?

rice blight

Rice brown blight, also known as rust disease. Once this disease occurs, it will cause slow leaf emergence of rice seedlings, slow tillering or no tillering, plant type clustering, poor root development, leaf function damage, resulting in early senescence of rice in late stage, seriously affecting the normal growth and development of rice, generally reducing yield by 10%-20%, serious up to more than 30%.

Disease usually occurs more frequently than at the early tillering stage and reaches the peak at the peak tillering stage.

Symptoms of rice blight

The typical external symptoms of the diseased plants are: the injured plants are short, the tillers are few and small, and the upper leaves are straight and the angle between the stems is small. When rice plants enter tillering stage, brown spots or short stripes appear on old leaves, the edges are not obvious, and scorched and withered appear from leaf tip down along leaf edge.

At the peak of tillering stage, brown spots appeared on the leaves, and then the spots increased and expanded. The leaves gradually turned brown and died from the base of the leaves. When the disease was serious, the leaves of the whole field looked like fire charred from afar.

Pulling up diseased plants can be seen root aging, reddish brown, soft spongy inelastic, some black, rotten, white root extremely small.

Occurrence Regularity of Rice Brown Blight

1. Soil potassium deficiency type

Because the available potassium content of soil itself is low, it can not meet the needs of rice growth for potassium and disease.

This type occurs mostly in shallow sandy soil fields, leaky fields and red and yellow soil paddy fields. The disease often begins more than ten days after rice planting. The leaf color of early rice plants is slightly dark green, the leaves are narrow and soft, the basal leaves gradually turn yellow or brown from the leaf tip along both sides of the leaf edge, and the root hairs are few and easy to fall off.

2. Plant poisoning type

Because the soil contains a large number of reducing chemicals such as iron, hydrogen sulfide and other toxic rice roots, reduce its vitality and disease.

This type mostly occurs in deep mud fields, long-term irrigation in deep water, poor ventilation and excessive application of undecomposed organic fertilizer fields. This kind of field rice seedling is difficult to turn green after planting, or after turning green, the rice seedling stands upright, almost no tiller, the leaf tip first turns green downward, the leaf midvein periphery yellows, and grows reddish brown black spots, even decays, has the smell similar to rotten eggs.

3. Low temperature induced type

Because of long-term low temperature and rainy weather affecting the development of rice roots, resulting in reduced ability to absorb fertilizer and disease.

This type occurs mostly in rainy weather or plum rain season in early rice growth, and occurs in large areas at the same time, but the degree is light and heavy. Because of the low temperature condition, the upper tender leaves of the plant become pale yellow, many brown needle-like dots also appear on the leaves, the lower old leaves are yellow-green or pale brown at first, and then the rice roots are soft, elastic, white and thin. In addition, rice seedling planting too deep, partial application of nitrogen fertilizer, long-term water accumulation in rice fields, etc., will aggravate the occurrence of rice brown blight.

Control method of rice brown blight

The disease must be comprehensively prevented and controlled, and prevention should be the priority. Corresponding measures should be taken according to different occurrence types to prevent and control the disease.

1. Intensive cultivation and soil improvement

Through deepening the tillage layer, promote soil maturation, avoid continuous no-tillage and interplanting; transform low-yield fields, improve soil and improve irrigation and drainage system for muddy fields with poor drainage; plough and sun-dry the soil in time after harvesting the previous crop, improve soil maturation degree and improve soil permeability.

2. Strengthen cultivation management and improve plant disease resistance

Timely sowing, strengthening water slurry management, shallow water to live trees, promote early growth; balanced fertilization, more decomposed organic fertilizer, increased phosphorus and potassium fertilizer, dry and wet alternately, timely shelving, cultivating strong seedlings; straw returned to the field, should appropriately increase the amount of base fertilizer, base fertilizer ratio adjusted to 6:4, nitrogen appropriate forward, in order to accelerate the decomposition of straw, strengthen water layer management, water to adjust gas, water to adjust fertilizer.

3. Strengthen classified guidance and control the disease as soon as possible

K-deficient fields

Potassium fertilizer should be applied and quick-acting nitrogen fertilizer should be applied appropriately; fermented fields with excessive organic matter should be drained immediately; during low temperature and rainy days, timely drainage and alternate dry and wet management should be carried out to prevent long-term deep irrigation.

To the diseased field

① Appropriate increase of potassium fertilizer (about 7.5kg/mu) to prevent partial application of nitrogen fertilizer;

(2) Expose the field properly, adhere to the "shallow-wet-dry" water slurry management mode, dehydrate the field, increase soil aeration, increase root activity, promote new roots, and improve the potassium absorption capacity of roots.

4. Chemical control

① Generally, one mu of rice field needs to use 90% crystal trichlorfon 100-150 g, perhaps 80% dichlorvos 150 ml, 50 kg of water, and need to spray when the rice field is shallow. To make it work better.

② Drain the rice field first, and then irrigate it with a small cloth bag containing trichlorfon after one day. After 12 hours, the larvae can be killed.