Rice koji disease is a common rice disease, how to prevent rice koji disease?

Rice whitefly disease, also known as whitefly disease, is one of the three major diseases of rice, caused by green rice nuclear mold infection. The disease is an important disease that often occurs in the panicle stage of rice. After the onset of rice blast, it not only affects the yield of rice, but also seriously affects the quality of rice and human health.

At present, the incidence of rice blast is increasing year by year in many rice-growing areas of China. So, how does rice koji disease come about?

<> causes of rice koji disease. The pathogenic bacteria that cause moyamoya disease of rice overwinter in the soil or on diseased grains in the form of chlamyspores or hard cores, and the conidia and ascospores produced in the 7th and 8th summer and autumn of the following year begin to invade the flowers and young seedlings of rice through airborne transmission. Bacteria can develop at temperatures from 24 to 32 degrees Celsius, with temperatures from 26 to 28 degrees being the most suitable for development.

Bacteria cannot grow when the temperature is below 12 degrees Celsius or above 36 degrees Celsius.

The pathogen is mainly infected at the heading and flowering stages of rice, and the disease begins to appear after the grain filling stage, mainly harming the grains in the rice cone. At the beginning of rice infection, a yellow-green lump is exposed at the junction of the slices, which gradually expands and covers the entire slices. Generally, diseased grains are 3-4 times larger than normal grains, dark green, smooth surface, and then cracked, emitting dark green powder.

In the first 10-15 days of the rice breakage stage, spray control with insecticides. 40g of 20% penxime-tebuconazole powder per mu, or 40g of 30% benz-alaconazole suspension, or 80g of fluconazole suspension, one of the above agents can be selected, add 20g of deltamethrin water, add 80g of potassium dihydrogen phosphate, and add 30kg of water for spray control, in order to avoid drug resistance, the above formula can be used alternately.

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In this case, you can use drugs with better efficacy**, to choose disease-resistant varieties, you must choose the right agent according to the growth of crops, usually do a good job of prevention, the temperature of planting should be controlled between 12 degrees and 36 degrees, you must water and fertilize in time, and you should also do a good job of bacterial transmission and infection, prune branches and leaves in time, and do a good job of ventilation.

You can choose good, disease-resistant rice seeds, transplant rice seedlings to carry out pesticide control, often observe the growth of rice, and carry out timely topdressing on rice.

To select disease-resistant and high-yield varieties, before sowing to select and eliminate disease, the application of chemical fertilizers needs to be appropriate, can be prevented and controlled with drugs.

After harvesting, the field should be sunburned, and it should be deeply turned, disease-resistant varieties should be selected, pesticides should be sprayed, and companion planting should be carried out.

Reason: Rice is too tender and green in the later stage of growth, and it encounters rainfall and high temperature during the flowering period, which is conducive to the development of pathogens, so it is easy to induce this disease. Growers want to **:

Avoid leaving seeds in diseased fields, and burn the grains in diseased fields as soon as possible to avoid the spread of pathogens. Choose disease-resistant varieties of abundant products. Strengthen cultivation management, pay attention to increasing the application of phosphorus and potassium fertilizers, and prevent late application and partial application of nitrogen fertilizers.

Because of fungal infection, it is related to the land, and may also be caused by the problem of variety, when encountering this problem, we must spray pesticides in time, we must pay attention to the use of fertilizers, we must pay attention to scientific management, and clean up the diseased plants in time.

Rice koji disease is a disease that affects the panicle of rice. There are usually one to a few grains on a panicle, and in severe cases, as many as a dozen or even dozens of grains are diseased. The diseased grains in the affected panicle were first cracked to reveal light yellow lumps, and then the damaged parts gradually expanded, turning black-green and cracked, and emitting dark green powder.

With the increase of diseased grains, the empty grain rate increases significantly, and the 1000-grain weight decreases, resulting in a serious decline in rice quality. The toxins produced by rice koji bacteria contaminate rice, and after humans and animals eat it, it can cause poisoning and seriously endanger the health of humans and animals.

There were obvious differences in the resistance of different varieties to rice koji disease, and rice koji disease could occur from heading to maturity stage, and the booting stage was the most susceptible. Climatic conditions are an important factor affecting the development and infection of rice koji disease, especially the most closely related to rainfall and temperature, in the rice booting to heading stage, due to high temperature and humidity, the pathogen is the most suitable for development, long-term low temperature and low sunshine, rainfall can weaken the disease resistance of rice. In addition, the amount of chemical fertilizer (especially nitrogen fertilizer) increases, and the growth of rice after heading is too lush and green, and rice koji disease is easy to aggravate. The comprehensive prevention measures for rice koji disease are as follows:

1) Choose high-yield and disease-resistant varieties.

Generally speaking, the disease of loose spike type and early maturing varieties is mild; The disease was more severe in dense-spike and late-maturing varieties.

2) Select disease-free seeds and do a good job of seed treatment.

Before sowing, the seeds were selected in salt water, the diseased grains were eliminated, and the seeds were soaked in warm soup with 57 warm water for 10 minutes, and then washed and germinated and sown. Or add 50 kg of water with kilograms of quicklime, soak 30 35 kg of rice seeds (can be combined with the prevention and control of evil seedling disease), the soaking time is generally 15 20 conditions 4 5 days, lime water should be higher than rice seeds, so that rice seeds are always submerged under the water layer.

3) The diseased grains should be removed in time when the diseased grains are found in the early stage, and the severely diseased plots should be deeply turned after harvest so that the sclerotium and curved balls can rot in the soil, and the field debris should be cleaned up before spring sowing to reduce the source of bacteria.

4) Appropriate application of chemical fertilizer, to prevent too much late application of nitrogen fertilizer, nitrogen, phosphorus, potassium with the use of nitrogen fertilizer, nitrogen fertilizer to take base, tiller, ear fertilizer 1 3, do not apply too much ear fertilizer.

5) Pharmaceutical prevention and control.

It is advisable to take about 10 days before rice heading. If ** rice koji disease is an epidemic year, about 10 days before the breach, 120 150 ml of 10% Zhenling (Jing Laya) suspension can be used every 667 m2; or 400 500 ml of 5% Jinggangmycin aqueous solution, spray on kilograms of water, and spray again 7 days before heading.

Rice koji disease: (fungal disease) 1, the key is early prevention, 5-7 days before the rice breakage, optional: 43% Haolik, 30% Ai Miao, 18% polyvenitone powder, 30% copper succinate fertilizer, 20% copper thiomycetes, 50% Luxiang No. 6, well.

Wax buds. 75% oxime. Tebuconazole, 300 g benzo.

Propiconazole, hexaconazole, thioframide, nitrilebenzole, fluconazole. etc., (spray control).

2. When the disease is severe, it can be used: prochloraz, copper hydroxide, basic copper sulfate, etc. (spray, can knock off the gray buds.) ）

Rice koji disease, a fungal disease, is more common in the process of rice planting, is a kind of disease that farmers have a "headache", once the rice is infected, endanger the panicle and rice grains, from the quality and yield will be affected, therefore, the correct understanding of rice koji disease, timely prevention and control work, to ensure the normal growth of rice and the final high yield.

Rice koji disease is mainly harmful to the rice panicle, once infected with rice koji disease, a kind of mycelium will be formed in the rice grain, this mycelium gradually becomes larger, resulting in the cracking of rice grains, carefully observe the cracked rice grains, you will find that there are light yellow lumps of things (some people say it is spores), these lumps of things will be scattered on both sides, after a certain period of time, become dark green, and then continue to harm, these spores will break open, become dark green powder, when encountering wind and rain weather, will fall off with wind and rain.

The rice ears or rice grains that have been harmed by rice koji disease can not continue to grow normally, and some cases where the harm is not serious will also cause unfavorable factors for the quality of rice grains, which shows that the harm of rice koji disease is very great.

There are two main factors in the transmission of rice koji disease, one is the pathogen carried by the seed itself, and the other is the infection of the remaining fungus in the soil.

In the first case, a certain paddy field is infected with rice koji disease or the surrounding rice fields are infected with rice koji disease, when the rice is mature and harvested, the probability of carrying rice koji disease on the seeds is greatly increased, and we may not find it in normal times, but in the second year, if these seeds are used as self-reserved seeds for sowing or raising seedlings, when the rice panicle stage, rice koji disease will slowly emerge, and then begin to multiply and spread in a large area.

In the second case, the soil carries rice koji pathogens, these pathogens have strong adaptability, even in the cold weather of winter, they can safely overwinter, and wait until the temperature rises in the second year, after the rice is sown, it begins to reproduce slowly, and when it reaches the panicle stage, it spreads with the flow of wind and rain.

Under certain characteristic conditions, the incidence of rice koji disease increases greatly, or the incidence is more serious, mainly in four points:

When the rice is in the heading and flowering period, it encounters even rainy weather, and the probability of rice koji disease will be greatly increased at this time, and whether it is early rice or a season of rice, in the heading and flowering period, it is just when there are more rainy days, I believe everyone has a deep experience.

Due to the excessive density, when the rice is in the middle and late stages, the field ventilation is not good, coupled with mutual shading, affecting the normal photosynthesis of leaves, the resistance of rice plants is weakened, and the occurrence of rice koji disease will increase.

According to the planting experience, between 25 degrees and 30 degrees is suitable for the growth of rice koji disease, but when the temperature is higher than 35 degrees or lower than about 10 degrees, rice koji disease will not be harmful.

When nitrogen fertilizer is applied too much or too late, it will lead to the occurrence of vigorous growth and the occurrence of rice koji disease will become serious.

It may be due to rice koji disease in the rice field or from a nearby field. It is also possible that individual seeds carry the disease. Because the bacteria in the soil can infect the rice, when the rice is harvested, the seeds may carry the bacteria of rice koji disease.

In the second year, the rice grows and becomes infected with the disease.

Rice koji disease is also known as pseudosmut, green smut, cereal flower disease and powdery mildew, and China and Japan also call it"Harvest disease", caused by a fungus. In 1878 Cook first obtained specimens from India and named them us-tilago virens.

1. Rainy rice is an important reason for the epidemic of rice koji disease. 2. The lower temperature of rice at the heading stage is the main reason for the epidemic of the disease. 3. Excessive application of nitrogen fertilizer, partial application of nitrogen fertilizer aggravates the condition.

4. No drug prevention and control is used at the breaking heading stage, so that the pathogen can drive straight in. 5. There are also certain differences in resistance between varieties (combinations).

Rice koji disease is one of the common diseases that endanger rice, and it is of great significance to fully understand the causes of this disease and effectively prevent, improve yield, reduce costs and reduce costs in production. In recent years, rice koji disease has become one of the main diseases and common diseases that harm rice in China's Yangtze River areas, and it generally occurred in the rice areas of our city last year, among which the disease of some dry fields in Sanshan and Liangjiang is more serious, and the loss of yield and output value is larger, and the loss rate is generally 5-10%. A few serious losses can reach 30%.

So, what is the cause of rice koji disease?

The rainy season helps the spores of the fungus to germinate, and even the rain can cause epidemics until the panicle bursts. The results of the survey showed that the severity of the illness was positively correlated with the number of rainy days, and the severity of the illness was mild when it was less than two days.

The invasion of rice koji fungus causes harm, low temperature or low temperature is beneficial, high temperature is unfavorable. The average daily temperature is less than 25, the extremely low temperature is less than 23, the duration is more than 2 days, and the lowest extreme temperature is less than 20. On the contrary, as the temperature increases, the condition decreases.

Low temperature will not only lead to the reduction of the resistance of rice itself, leading to favorable disease, but also prolong the time of organs at the angle of attack, which is conducive to the invasion of pathogens.

The large-scale popularization of cultivation and identification of diseased varieties is closely related to the aggravation of rice koji disease in Yigushan year by year. It has been observed that there are very few varieties that are absolutely resistant to rice koji disease. The more we advocate high-quality, high-yielding, disease-resistant varieties (rice koji disease), the more serious rice koji disease will be in this variety. For example, AFG series, etc.

Excessive application of nitrogen fertilizer and forced application of nitrogen fertilizer aggravated the disease.

Excessive application of nitrogen fertilizer, no application of phosphorus and potassium fertilizer, and coveting green grain fields, the disease is the most serious. Nitrogen fertilizer was suitable, and the disease was minor in the fields without phosphorus and potassium fertilizer, but it was still very severe. Nitrogen, phosphorus and potassium are suitable, and the seedlings are normal growth fields, and the disease is mild.

Excessive application of nitrogen fertilizer and excessive application of nitrogen fertilizer aggravated the disease, and the simultaneous application of nitrogen, phosphorus and potassium had a significant control effect on the epidemic of the disease.

The results of the investigation showed that the two adjacent Qiuhonglianyou No. 6 were sown, fertilized and the seedlings grew similarly on the same April 24, and a small hill was applied with fungicide once at the rupture stage and at the full heading stage. Another case of prevention without medication and **, the disease is. Administration at the panicle breaking stage has a significant control effect on the disease, while no administration leads to the direct influx of pathogens and accelerates the epidemic.

According to the survey, most of the growers did not carry out targeted prevention before the disease cracked Zhaotong, and the farmers did not pay attention to it when it first occurred, and did not take effective measures against the symptoms in time, although it came in. Although the prevention ** has been accepted, the disease has developed rapidly due to the misguided drug, and the poor prevention and control is an important factor in the prevention of rice koji disease**.

To sum up, we must pay attention to the above factors in the rice heading period to prevent the occurrence of rice koji disease.