Why soaked rice and mite disease

Miao Miao disease is also known as a long-term illness, and occurs in all rice regions of the country. The symptoms are that the diseased grain does not usually germinate or can not be unearthed after sowing. The diseased seedlings in the seedling stage were finer than the healthy seedlings, the leaf sheaths were slender, the leaves were pale yellow, the roots were poorly developed, and some of the diseased plants died before transplanting.

Soaking seeds is one of the effective ways to prevent the disease. However, some farmers have reported that their rice seeds have been soaked this year, but why is there a disease in the field? The author analyzes the reasons as follows:

First, the operation is not standardized, there is no special soaking pool, the concentration of soaking seeds is arbitrary, and even some farmers soak seeds in flowing streams, or even soak together with the bags, resulting in insufficient contact between the seeds and the liquid. The effect is naturally poor.

Second, the soaking time is insufficient. Generally, it needs to be soaked for at least 4 hours, preferably 12 hours to 24 hours. Some farmers only soaked for two or three hours or even less than half an hour.

Third, it is possible to use unqualified pesticides, such as the quality of the drug is not up to standard, or even fake drugs, or mistake the seed dressing agent as a soaking agent.

Fourth, there are more cases of germination. Some farmers have high temperature during germination, especially when the machine is transplanted, which causes the temperature of the germination stage to be high, and the pathogen is easy to infect; some of the dry-covering field covers the film, resulting in higher seedbed temperature, which is also conducive to pathogen infection and disease. development of.

Fifth, it is possible to use the same soaking agent for a long time, resulting in resistance. For example, long-term use of prochloraz can be used alternately with 25% cymene suspension 2000-4000 times and 16% sterilized wet powder 500-700 times. Liquid, etc.

At present, a small number of farmers blame the occurrence of the disease on the rice grains in the seeds, commonly known as "rice", which is the seed without shells. This is a great misunderstanding of the disease. Without the seed of the shell, as long as the rice is intact and the germ is not damaged, it can germinate normally and develop into a normal and robust plant, which has nothing to do with the disease. The hybrid seed itself has the physiological characteristics of tight closure of the hull, and the mechanical action during the threshing process causes the hull to fall off and form a "rice valley". In general, there are some “rice grains” in the hybrid seeds, but they are not a seed quality problem, and have nothing to do with the disease.