JPH05316817A - Method for controlling pathogenic bacterial diseage in raising seedling of paddy rice - Google Patents

Abstract

PURPOSE:To suppress and control the occurrence of bacterial damping-off of paddy rice which is a serious disease and injury to raised seedlings of paddy rice by bringing a powdered porous substance into contact with an unhulled rice seed. CONSTITUTION:An unhulled rice seed subjected to hastening of germination is dressed and brought into contact with a porous substance (e.g. charcoal, chaff smoked coal, vegetable active carbon and/or coal-based active carbon or activated alumina), having preferably <=30mm diameter and a microporous structure and powdered to <=75mum particle diameter in an amount of 0.1-10 pts.wt. (preferably 2-5 pts.wt.) based on 100 pts.wt. unhulled rice seed to perform the objective control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling bacterial diseases that occur in rice seedlings.

[0002]

2. Description of the Related Art First of all, aseptic seed pad is used for controlling various bacterial diseases in rice seedlings caused by infection of pathogenic bacteria to paddy rice seed, but in reality, it is difficult to secure aseptic seed paddy. is there. Therefore, heat treatment of seed paddy, salt water selection, and sterilization (disinfection) with pesticides are performed. However, it is difficult to treat a large amount of heat treatment uniformly and effectively from the viewpoint of difference in water content of seed paddy and equipment, and salt water selection is significant in that good seeds can be obtained, but sterilization is expected. Therefore, the use of pesticides has various problems such as safety for humans and animals, environmental pollution, and generation of resistant bacteria.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method which is free from the problems of the above-mentioned conventional techniques and which is effective in controlling bacterial diseases which occur in rice seedlings.

[0004]

The present invention is a method for controlling bacterial diseases in paddy rice raising seedlings, which comprises bringing a powdered porous substance into contact with seed paddy.

In the present invention, the porous material has a diameter of 30 nm.
Charcoal, chaffed charcoal, coconut charcoal, sawdust charcoal, bark charcoal, etc.
Porous inorganic substances such as activated alumina, silica gel, zeolite (calcined or synthetic), diatomaceous earth, activated clay, coal-based porous substances obtained by carbonization or semi-carbonization of lignite, brown coal, and bituminous coal, and plant-based activated carbon or coal-based activated carbon. And so on. Of these, activated carbon is preferred. The plant-based activated carbon refers to charcoal, sawdust, coconut shell, sugar waste (bagasse), waste molasses, and the like as raw materials.

The particle size of the pulverized porous material is not particularly limited, but the smaller the particle size, the better the adhesiveness and the higher control effect. A particle size of 75 μm or less is preferred.

The following method is practical for bringing the porous material into contact with the seed paddy. (1) 0.1 to 10 parts, preferably 2 to 5 parts, of a porous substance is coated on the germinated paddy per 100 parts of the germinated paddy. (2) 1 to 50 parts per 100 parts of dry paddy in soaking water at the time of soaking
Part of the porous material is mixed in and the seed water is stirred. (3) 1 per 100 parts of germinated paddy with a porous substance on the surface of the bed soil before sowing of seed paddy and / or on the seed paddy after seeding and before covering with soil
Spread 0 to 40 parts and bring them into contact.

The porous substance used in the present invention adsorbs pathogenic bacteria that survive on seed paddy and culture medium, and inhibits its activity to prevent entry into uninfected paddy or rice seedlings. It is also considered that it also adsorbs toxic substances produced by pathogenic bacteria and reduces the action on paddy rice seedlings to suppress the occurrence of bacterial disease of paddy rice seedlings.

In the control of bacterial diseases of rice seedlings according to the present invention, it is possible to use other agricultural chemicals for disinfecting seeds in combination.

The control method of the present invention remarkably suppresses the expression of rice bacterial blight bacterial rot and rice seedling wilting bacterial disease, and the growth inhibition of seedlings as seen in the conventional use of fungicides is not observed at all. I can't.

[0011]

EXAMPLES The present invention will now be described in more detail with reference to examples. Example 1 Seed paddy (cultivar Koshihikari) was inoculated with seedling killing bacteria by the following method.

[0012] Rice seedling bacterial killing bacteria cultivated in a test tube
Suspended in peptone water 10⁷ -10 ⁸ Rare in cfu / ml
About 1 kg of dry paddy is soaked in 1 liter of the diluted solution for 24 hours
After stirring (appropriately stirring), drain water and dry in the shade at 20-25 ° C.
It

Bacteria inoculated rice was soaked in water for 4 days, soaked, drained, allowed to stand overnight at about 30 ° C., and germinated in the shape of pigeon chest. The germinated seeds had various porous substances (particle size 75 μm) shown in Table 1. 2 parts of 100 parts of germinated paddy were coated.

Using a granular synthetic cultivation soil (trade name: Kumiai Synthetic cultivation soil No. 3) as a seedling-growing medium, seedlings were grown according to the seedlings in a rice seedling transplant box. In addition, germination is carried out at 31 ° C. for 48 hours using a germination device, and subsequent seedlings are grown in a greenhouse (day 20 ° C. to 25 ° C., night 1
The temperature was controlled at 5 ° C to 18 ° C. Powdered paddy is a nursery box (cultivation soil 3
150 g per kg) was used.

The morbidity during the seedling planting period (about 20 days after sowing) was investigated, and the results are shown in Table 1.

As a control group, 10 g of kasugamycin / metasulfocarb powder (trade name: phthalvalon, kasugamycin, and metasulfocarb, each containing 5%) was added and mixed per 3 kg of the above-mentioned synthetic soil, and the above inoculated paddy was used in the same manner. A section in which seedlings were raised (abbreviated as KM section) and a section in which seedlings were similarly raised using uncultivated soil (untreated section) were provided.

The investigated seedlings are 64 along the diagonal line of the nursery box.
About 1000 lines grown in a cm × 6 cm section were all measured.

The degree of disease is divided into five stages from A (no germination or incomplete extraction of the first leaf) to E (no symptoms) of the seedlings, and the number of individuals is a, b, c, respectively. It was calculated by the following equation as d and e. Disease severity = 100 × (4a + 3b + 2c + d) / 4 × (a
+ B + c + d + e) Disease incidence was calculated by the following formula. Incidence rate (%) = 100 × (a + b + c + d) / (a + b
+ C + d + e) The control value is 10% of the difference between the disease incidence in the untreated area and the disease incidence in each treated area and the disease incidence in the untreated area.
It is expressed as a percentage.

[0019]

[Table 1] In order to investigate the effect on paddy rice seedlings, we investigated the emergence and growth of healthy paddy of the same variety that was not inoculated with fungi, which was similarly coated with various porous substances and the same control section as in Table 1. , Shown in Table 2.

According to Table 2, in the treated area of the present invention, growth inhibition like that in the KM area was not observed, and it showed better growth than the untreated area.

[0021]

[Table 2] Example 2 The fungus inoculated paddy used in Example 1 was placed in water and immersed for 4 days,
On the 4th day, about 20% of the dry paddy weight was added with various porous substances shown in Table 2, stirred well and left for 1 day, drained off various porous substances and water, and left at about 30 ° C overnight. The seeds were allowed to stand and germinated in the shape of pigeon chest, and this germinated paddy was sown on the same granular synthetic soil as in Example 1. Subsequent operation and morbidity survey, the control section is Example 1
The results are shown in Table 3.

[0022]

[Table 3]

[0023]

INDUSTRIAL APPLICABILITY According to the present invention, the very easy operation of bringing a powdered porous substance into contact with paddy rice seeds effectively controls the paddy rice bacterial seedling blight, which is a serious disease of paddy rice seedlings. It is extremely useful for raising rice seedlings because it has no growth inhibition, no harm to humans and animals, and no environmental pollution.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toshiyuki Kawana, 1-729, 1-chome, Hondada-cho, Midori-ku, Chiba-shi, Chiba Prefecture (72) Inventor, Yoshikazu Hosoda 4169, 8169, Kamiiida-cho, Izumi-ku, Yokohama-shi, Kanagawa (72) Inventor Yoji Miyata 1692, Makuhari-cho, 3692, Hanamigawa-ku, Chiba-shi, Chiba

Claims (7)

[Claims] 1. A method for controlling bacterial diseases in paddy rice seedlings, which comprises bringing a powdered porous substance into contact with seed paddy. 2. The control method according to claim 1, wherein the porous substance is charcoal, chaff, charcoal, and / or various plant charcoal. 3. The control method according to claim 1, wherein the porous substance is plant-based activated carbon and / or coal-based activated carbon. 4. The control method according to claim 1, wherein the porous substance is one or more porous inorganic substances selected from activated alumina, silica gel, zeolite, diatomaceous earth and activated clay. 5. The method for controlling a pest according to claim 1, wherein the seed paddy is germinated, and the contact is by dressing with a porous material. 6. The control method according to claim 1, wherein the seed paddy is soaking in water, and the contacting is carried out by adding and stirring the porous substance to the soaking water. 7. The control method according to claim 1, wherein a porous material is sprayed and brought into contact with the surface of the bed soil before sowing of seed rice and / or the seed rice after sowing and before covering with soil.