JP3197177B2 - Control method of rice seedling rot and rice seedling blight bacterial disease - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

A ) Object of the Invention Field of the Invention The present invention relates to kasugamycin or a salt thereof (hereinafter referred to as "KS").
M "), and a new method for controlling rice seedling rot and rice seedling bacterial wilt.

2. Description of the Related Art KSM, which is an active ingredient of the present invention, is effective against rice blast, brown leaf spot, and leaf sheath browning of rice. It is also known that a rice seedling box treatment agent is effective in controlling rice seedling rot and rice blast by mixing with seedling cultivation soil before and after sowing [Japanese Patent Publication No.
No. 56202, Japanese Patent Publication No. 2-6726, Japanese Patent Publication No. 2-6727, and "Agrochemical Handbook 1992"
Year Edition (Japan Plant Protection Association, July 3, 1992
Page 228 to page 231]. In addition, for bacterial seed disease of rice, cupric hydroxide or oxolinic acid is used alone or as a mixed or mixed agent with ergosterol biosynthesis inhibitors such as triflumizole, pefurazoate, prochloraz, ipconazole, etc. It is used as a seed disinfectant for rice brown streak, rice seedling rot and rice seedling blight.

[0003] until 0005 This, in nursery box, KSM granules the simultaneous control of rice seedling rot diseases and rice blast disease as a purpose (which refers to a granulate comprising the KSM. Same. Below) is used ing. This KSM granule shows a high control effect on rice seedling rot by sowing rice seed paddy and then mixing it into soil for soil covering to cover the soil. However, in order to stably maintain a high control effect, a treatment with a high dose is required, and the treatment must be carried out so as to prevent uneven application. In addition, the same tendency is shown for controlling rice seedling rot. Further, according to this control method, a practical control effect on leaf blast after transplanting rice seedlings to Honda cannot be obtained if a dose effective for rice seedling rot is applied.

[0004] On the other hand, a method of diluting KSM wettable powder with water and sowing it in a nursery box or irrigating the seedling culture immediately after emergence of rice has been attempted. However, according to this method, if the KSM granules are effective when applied, irrigation of the same dose (for example, 2000 mg / kg of the active ingredient of KSM)
Box) does not show a practical control effect on rot of rice seedlings, and it is also the same against bacterial wilt of rice seedling and leaf blast after rice transplantation to Honda. The technology is not practical (JP-B-63-56202, JP-B-2-6726, JP-B-2-6727).
Reference). Under such circumstances, in the nursery box, it is possible to reliably control rice seedling rot, which is a major bacterial disease, and bacterial wilt of rice seedling, and in addition to rice blast after transplanting Honda. The development of a new control technology that shows a great effect is desired. An object of the present invention is to provide a method for controlling a disease in a nursery box that meets such a demand.

[0005]B) Configuration of the invention Means for solving the problem  The present inventors have conducted intensive studies to solve the above problems.
Was. As a result, kasugamycin or a salt thereof (eg,
Diluting the solution containing hydrochloride) with water,
One rice seedling box (length x width x
Height: 30cm x 60cm x 3cm) and effective spray density
1000-80000 ppm, preferably rice seedling rot
In the case of sepsis control, the ratio of 4000ppm to 40000ppm
In the case of rice seedling blight control, 8000 ppm
10 ml to 100 m each at a ratio of 80000 ppm
l, preferably for both diseases, 25 ml to 50 ml
That is, by spraying a small amount of high concentration KSM,
Excellent control effect on both diseases was found
did. In addition, after the transplantation of Honda, it is necessary to control leaf blast.
Even so, it turned out to be effective.

As a result of further study, the following new findings were obtained. That is, a solution containing kasugamycin or a salt thereof is diluted with water, and rice seedlings that have already developed rice seedling rot and rice seedling blight in the first to second leaf stages are placed in one box (30 cm) of a rice seedling box. × 60cm × 3cm: same as above)
The effective spraying concentration is 100 ppm to 8000 ppm at a rate of 100 ml to 1000 ml, preferably 250 ml to 5 ml.
Spraying to 00 ml can prevent the spread of these bacterial diseases and find that an excellent control effect on both diseases can be obtained, thereby completing the present invention.

[0007] In acting present invention, KSM or a salt thereof, in the control method of the present invention, it acts as a control active ingredient against bacterial diseases. Although the mechanism by which KSM exerts its control effect on these bacterial diseases is unclear, high concentrations of KS are observed in the early stage of rice germination, that is, in the single sheath stage or the first and second leaf stages.
It is considered that when the M solution is treated, KSM is rapidly absorbed from the root through the germ and the soil, and a high and stable control effect can be obtained. No phytotoxicity was observed for rice. Next, preparation examples of the present invention are shown. In addition, "parts" in the preparation examples indicates parts by weight.

Formulation Example (Liquid) KSM (hydrochloride) 2 parts Polyoxyethylene nonylphenyl ether 5 parts Water 93 parts Total 100 parts These were uniformly mixed to obtain a liquid. These KSM solutions may be prepared according to a generally widely used method for preparing agrochemical solutions. In addition, commercially available K
SM solution can also be used as it is.

[0009]

EXAMPLES Next, the disease control effect of the present invention will be described with reference to examples. Example 1 Pest Control Effect on Rice Seedling Rot (Part 1) As a test paddy, a naturally infected paddy (variety: Nipponbare) collected from a field where rice paddy bacterial disease frequently occurred was 1000 times as large as a pefurazoate emulsion (pefurazoate 15%). Seed disinfection was performed at 15 ° C. for 24 hours at a ratio of 1: 1 to the ratio of seed rice to liquid (V / V) in the diluent. After the disinfection, the seeds were soaked in tap water twice the seeding capacity at 15 ° C. for 5 days. After that, the treated paddy is 30 ° C
For 15 hours, and seeded in a standard nursery box (1800 cm ² ) on a commercial granular soil (Kumiai granular soil No. 3) in an amount of 150 g in terms of dry paddy per section. Then, after a germination treatment at 32 ° C. for 2 days, a predetermined amount of a KSM solution prepared according to the formulation example was sprayed on the germinated rice seedlings using a spray gun, and then controlled in a greenhouse. At 20 days after seeding, the rice seedlings in 1/10 of the nursery box were examined for rice seedling rot and the number of healthy seedlings based on the following investigation criteria. Then, the diseased seedling degree is obtained by the following equation,
The control value (%) was calculated from the comparison with the untreated plot. Table 1 shows the results.

Investigation criteria for rice seedling rot 0: disease-free seedling 1: mild seedling: the base of the first leaf or the second leaf is bleached, but the growth is almost the same as that of the disease-free seedling. 2: Neutral seedling: The base of the first leaf or the second leaf is decolorized and accompanied by abnormal leaf emergence. Growth is about 1/3 of disease-free seedlings. 4: Severe seedlings: with abnormal leaf emergence, with extremely poor growth. Includes bud leaf sheath death.

[0011]

(Equation 1)

[0012]

[Table 1]

[0013] The controlling effect (Part 1) subjected試籾for Example 2 Rice bacterial seedling blight, 10 ⁷ to rice flowering stage of 1993 / m
l Inoculated paddy and healthy paddy obtained by spraying rice seedling blight bacterium (scientific name: Pseudomonas plantarii) were mixed at a ratio of 1: 9, and paddy was used. This is the same as Example 1 except that it is as shown in FIG.

Criteria for Investigation of Bacterial Disease of Rice Seedling 0: Disease-free seedling 1: Mild seedling: Whitening is observed at the base of the second leaf, but growth is almost the same as that of disease-free seedling. 3: Neutralized seedling: Whitening was observed at the base of the second leaf, and the growth was about 1/2 of the disease-free seedling. 5: Severe seedlings: seedlings that die after budding.

[0015]

(Equation 2) The results are shown in Table 2.

[0016]

[Table 2]

Example 3 Control Effect on Rice Seedling Rot (Part 2) As the test paddy, pefurazoate solution was prepared separately from healthy paddy and naturally infected paddy (cultivar: Nipponbare) collected from a field where rice paddy bacterial disease frequently occurred. (Rice-to-liquid ratio (V / V)) in a 1000-fold dilution of (perfurazoate 15%) at a ratio of 1: 1 to 15
It was soaked and disinfected at 24 ° C. for 24 hours. After the disinfection, the seeds were soaked in tap water twice the seeding capacity at 15 ° C. for 5 days. Thereafter, the treated paddy was germinated at 30 ° C. for 15 hours. Then, a box that is 1/10 the size of the standard nursery box (length x width: 12 x 15 = 18)
0 cm ² , height 3 cm) is filled with a commercially available granular soil (Kumiai granular soil No. 3), and as shown in the figure below, a central 3 × 4 cm (length × width) portion (hereinafter “section A”) 1 g) of the above-mentioned naturally infected paddy, and 14 g of healthy paddy were uniformly sowed on the cultivated soil around the section A. Then, after germination treatment at 32 ° C. for 2 days, the plants were managed in an acrylic greenhouse. Sowing 12
When the development of mild symptoms of rice seedling rot was observed in the "A zone" of rice seedlings that reached the 1.5 leaf stage on the day, a commercially available water-diluted KSM solution prepared according to the formulation example was commercialized. Of the spreading agent is increased to 10,000 times, and a predetermined amount thereof is sprayed on the whole rice seedling and the nursery box using a spray gun for painting (pressure 1.0 cm ² ), and then again. Controlled in an acrylic greenhouse.

Disease investigation was carried out 20 days after sowing in three places of 1/10 seedling raising boxes, namely, section A (central 3 cm × 4 cm section), section B (central 6 cm × 9 cm section), section C (A, B
Of the rice seedlings except for the two plots) were examined for rice seedling rot and the number of healthy seedlings based on the following survey criteria.
Then, the diseased seedling degree was determined by the following formula, and the control value (%) was calculated from the comparison with the untreated plot. Table 3 shows the results. In addition, the test was performed in three sections per section, and the spraying amount and the active ingredient amount in the table were converted and displayed in the standard nursery box application.

Investigation criteria for rice seedling rot 0: disease-free seedling 1: mild seedling: The base of the first leaf or the second leaf is bleached, but the growth is almost the same as that of the disease-free seedling. 2: Neutral seedling: The base of the first leaf or the second leaf is decolorized and accompanied by abnormal leaf emergence. Growth is about 1/3 of disease-free seedlings. 4: Severe seedlings: with abnormal leaf emergence, with extremely poor growth. Includes bud leaf sheath death.

[0020]

(Equation 3)

[0021]

[Table 3]

[0022] The controlling effect (Part 2) subjected試籾for Example 4 Rice bacterial seedling blight, 10 ⁷ to rice flowering stage of 1993 / m
1) Inoculated paddy obtained by spraying rice seedling blight bacterial germs (Pseudomonas plantarii, Pseudomonas plantarii) and healthy paddy were uniformly mixed at a ratio of 1: 1. Since it was recognized on the day, it is the same as Example 3 except that spraying was performed on that day and the investigation criteria were as follows. Table 4 shows the results.
Shown in

Criteria for Investigation of Bacterial Wilt Disease of Rice Seedling 0: Disease-free seedling 1: Mild seedling: Whitening is observed at the base of the second leaf, but growth is almost the same as that of disease-free seedling. 3: Neutralized seedling: Whitening was observed at the base of the second leaf, and the growth was about 1/2 of the disease-free seedling. 5: Severe seedlings: seedlings that die after budding.

[0024]

(Equation 4)

[0025]

[Table 4]

[0026]

According to the control method of the present invention, a high control effect is obtained against rice seedling rot and rice seedling bacterial wilt. Further, the control effect can be surely exerted by spraying a small amount of a high-concentration solution containing KSM at the time when rice seedlings germinate and pods emerge. In addition, KSM was added to the seedlings that reached the first and second leaf stages and developed rice seedling rot and bacterial seedling blight disease.
Is surely exerted against these bacterial diseases when a liquid preparation containing is spread. Therefore, it is useful as a method for controlling these bacterial diseases of rice seedlings. In addition, any of the control methods described above exerts an extremely high control effect on the control of leaf blast after transplantation to Honda. Therefore, it is useful as a method for controlling rice seedling boxes.

──────────────────────────────────────────────────続 き Continued on the front page Examiner Shohide Hoshino (56) References JP-A-8-133922 (JP, A) JP-A-57-42612 (JP, A) JP-A-57-42611 (JP, A) JP-A-57-42610 (JP, A) JP-A-56-75420 (JP, A) JP-A-56-75419 (JP, A) JP-A-56-75418 (JP, A) JP-A-56-75417 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A01N 63/02

Claims (2)

(57) [Claims] 1. A solution containing kasugamycin or a salt thereof is diluted with water, and the rice seedlings at the time when they have already emerged and pods have emerged per box (30 cm × 60 cm × 3 cm) per rice seedling box 1000 ppm to 80 as effective spray concentration
A method for controlling rice seedling rot and rice seedling blight disease, which is sprayed at a rate of 000 ppm to 10 ml to 100 ml. 2. A solution containing kasugamycin or a salt thereof is diluted with water, and the rice seedlings that have already developed rice seedling rot and rice seedling blight in the first to second leaf stages are placed in a rice nursery box. The effective spray concentration is 100 ppm to 8000 ppm per box (30 cm x 60 cm x 3 cm), and 1
A method for controlling rice seedling rot and rice seedling bacterial wilt, which is sprayed in an amount of 00 ml to 1000 ml.