JP3058745B2 - Labor saving control method of rice disease - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to sowing seeds without performing seed disinfection operations such as dipping, dressing and spraying, which are indispensable for box nursery of rice, and spraying chemicals on the seeds immediately after sowing. ,
Alternatively, the present invention relates to a labor-saving method for controlling a disease in which a seed-borne disease and a seedling-killing soil disease are simultaneously controlled by irrigation.

[0002]

2. Description of the Related Art Various seed disinfectants have been developed and used so far. Seed disinfection methods using these chemicals are generally performed by immersing rice seeds in a diluent of the chemicals or by coating powdery chemicals such as wettable powder on the seeds, as shown in the test examples below. It is. On the other hand, N-propyl-N- [2- (2,4,6-trichlorophenoxy) ethyl] imidazole-1-carboxamide (hereinafter referred to as “compound A”), (E) -4- Chloro-α, α, α-trifluoro-N- (1-imidazol-1-yl-2-propoxyethylidene) -o-toluidine (hereinafter referred to as “compound B”) is used as a rice seed disinfectant. The thing is, "Kumiai Pesticide Directory 19
No. 91 "(All Agriculture, September 1, 1990) No. 666-
667, pages 722 to 725, and the like.

[0003] As a method for controlling seedling-killing soil disease in rice cultivation and seedling cultivation, an agent containing 3-hydroxy-5-methylisoxazole or tetrachloroisophthalonitrile as an active ingredient is treated with soil before seeding. Or irrigation treatment immediately after sowing or after emergence, is also known as S- (4-methylsulfonyloxyphenyl) -N
A method of mixing methylthiocarbamate with a seedling culture soil has been performed (“Agrochemical Handbook 1989 Edition”, page 214, page 216 to page 217, page 164 to page 1).
65 pages, Japan Plant Protection Association 11/1989
Issued on March 20).

However, seeds are seeded without disinfecting the seeds in advance, and Compound A and Compound B are sprayed on the seeds immediately after seeding.
Alternatively, a method of irrigating and covering the soil, and a technique of controlling seed-borne diseases and dead soil diseases by this method have not been known so far.

[0005]

Conventionally, in order to control the seed-borne disease of rice, seed disinfection such as immersing the seed in a chemical solution or dressing the seed with a drug has been widely performed. In general, seed disinfection is complicated and time-consuming, for example, it is necessary to immerse seeds in a chemical solution for a certain period of time or to air-dry after coating a chemical and then soak in stagnant water. For this reason, joint seedlings are widely used as part of labor saving in rice cultivation.However, the amount of chemical used for disinfection of seeds is large, and lime etc. can be added to the waste liquid to prevent environmental pollution. is necessary. Therefore, establishment of a more labor-saving seed disinfection method instead of the conventional seed disinfection method is desired.

The present invention has been made in view of the above circumstances, and provides a method for controlling rice diseases by labor-saving seed disinfection.

[0007]

Configuration of the Invention

Means for Solving the Problems The present inventors have studied diligently to solve the above-mentioned problems. As a result, the seed rice is not immersed, dressed, sprayed, etc.
Seedling box by standard method (length x width x height = 60cm x 30cm x
3 cm), and immediately thereafter, compound A or compound B
By spraying the agent containing the active ingredient on the surface of the seed rice, or by irrigating the seedling cultivation medium and sowing it,
It has been found that seed-borne diseases and wilt diseases can be effectively controlled. That is, in the case of a drug containing the compound A as an active ingredient in terms of the amount per one seedling raising box from the top of the seed rice in a pigeon breast state immediately after sowing, the compound A has a concentration of 1.25 mg to 125
Solution containing 0 mg, 5 mg to 5
000 mg of the solution, each 20 ml to 200
or 200ml to 2000ml
By irrigating and cultivating the seedling cultivation soil that has been sown, the seed disinfection effect is equal to or greater than that obtained by the conventional seed disinfection method for seed-borne disease and seedling-killing soil disease. It was found that it could be obtained. Also,
According to the spraying method or the irrigation method of the present invention,
It does not cause harm to rice and does not require chemical dipping or air drying compared to conventional seed disinfection, and waste liquid treatment does not remain as there is no residual disinfectant liquid like conventional seed disinfection. It was found that the work was labor-saving because it was unnecessary.

[0008]

[Examples] (Control method) As the agent containing compound A or compound B as an active ingredient used in the method for labor-saving control of rice disease of the present invention, a newly formulated drug may be used, but a commercially available drug may be used as it is. Can also be used. Such examples include wettable powders, emulsions, flowables and the like containing compound A or compound B as an active ingredient.

The content of compound A and compound B in these preparations is not limited, but is usually 1
It is in the range of 50% to 50%, and can be formulated and used by a conventional method. When these drugs are used, these drugs are diluted 10 to 1000 times with water, and one box of a nursery box (length × width × height = 60 cm × 30 cm) is used using an appropriate spraying device.
The amount of the chemical solution of 20 to 200 ml per 3 cm) is preferably diluted 50 to 200 times, and the amount of the chemical solution of 50 to 100 ml may be sprayed on the seed rice in a pigeon breast state. In the case of irrigation, dilute 100 to 10,000 times and add 20 per box.
A solution volume of 0 to 2000 ml, preferably 500 to 20
It may be diluted by a factor of 00 and irrigation with 400-1000 ml of the drug solution may be performed.

In the control method of the present invention, a drug containing Compound A or Compound B as an active ingredient may be used alone, but depending on the purpose of use, these may be mixed, or other fungicides, plant growth regulators may be used. It can be sprayed by mixing with agents, fertilizers and the like.

Next, examples of pharmaceutical preparations used in the labor-saving control method of the present invention will be described. In the examples, all parts are parts by weight.

Example 1 (Wettable powder) Compound A 5 parts Sodium ligninsulfonate 3 parts Polyoxyethylene nonyl phenyl ether 2 parts White carbon 5 parts Clay 85 parts

Example 2 (Wetting agent) Compound B 20 parts Sodium ligninsulfonate 3 parts Polyoxyethylene nonyl phenyl ether 2 parts Clay 75 parts

Example 3 (emulsion) Compound A 5 parts Xylol 85 parts Polyoxyethylene nonylphenyl ether 10 parts

Example 4 (Emulsion) Compound B 20 parts Xylol 70 parts Polyoxyethylene nonylphenyl ether 10 parts

Example 5 (Floable agent) Compound A 5 parts Polyoxyethylene nonylphenyl ether 1 part Lignin sodium sulfonate 4 parts Xanthan gum 2% aqueous solution 10 parts Water 80 parts

Example 6 (Floable agent) Compound B 20 parts Polyoxyethylene nonylphenyl ether 1 part Sodium ligninsulfonate 4 parts 2% aqueous solution of quisanta gum 10 parts Water 65 parts

The method for labor-saving control of rice diseases may be carried out by using wettable powders, emulsions, flowables, and commercially available wettable powders, emulsions, flowables, etc. prepared by uniformly mixing the above-mentioned compositions. That is, when the above drug is diluted with water and the drug solution concentration is Compound A, the solution is sprayed at a concentration of 50 ppm to 6250 ppm, preferably 250 ppm to 2500 ppm, or 5 ppm to 625 ppm, preferably 25 ppm.
Irrigation may be performed at a concentration of ~ 250 ppm. Compound B
200 ppm to 2500 ppm, preferably 100 ppm
Spray at a concentration of 0 ppm to 10000 ppm, or 2
0 ppm to 2500 ppm, preferably 100 ppm to
Irrigation may be performed at a concentration of 1000 ppm.

In this case, the amount of the sprayed drug solution depends on the drug solution concentration, but is 20 ml to 200 ml, preferably 40 ml to 100 ml per box of the seedling raising box.
200 ml to 2000 ml, preferably 400 ml to 1
000 ml.

[0020]

When the method for controlling labor-saving control of the present invention is carried out, the following effects are obtained. That is, according to the control method of the present invention, seed-borne diseases such as rice scab, rice sesame leaf blight, rice blast, etc., and wilt diseases such as Fusarium spp., Rhizopus spp., And Trichoderma spp. Seedling blight can be effectively controlled.

Further, when the control method according to the present invention is carried out, a high control effect can be obtained even on a rice scab disease caused by a benzimidazole-resistant rice scab, which is insufficient in the control effect by the conventional seed disinfection method. Can be In addition, the control method of the present invention requires only spraying or irrigating a chemical solution on the seed rice after sowing, so that the control operation is simpler than the conventional seed disinfection method. Also, unlike the case where seeds are immersed, there is no need to dispose of a chemical solution, so that it is not necessary to dispose of the chemicals and there is no concern about environmental pollution.

Next, test examples will be shown to demonstrate the usefulness of the method for controlling labor-saving rice diseases according to the present invention.

[0023]

[Test example]

Test Example 1 Effect on Inaba Deer Seed Disease Inaba Deer Seed Disease Paddy [Seed paddy of variety "Hatsusei"; Affected paddy rate 48
%, 63% of benzimidazole drug-resistant bacteria in diseased paddy] was immersed in water at 20 ° C. for 4 days, and drained.
Germination treatment at 2 ° C overnight is performed, and seedlings exhibiting pigeon chest shape are placed in one nursery box (length x width x height = 60cm x 30cm x 3cm).
The seeds were sown per 150 g in terms of dry rice. After sowing, automatic spraying device (Nozzle used: Flat fan nozzle SS 880
The wettable powder prepared according to the example using 6) was diluted to a predetermined concentration, and sprayed onto a seedling raising box at a rate of 50 ml per box. Also,
In the irrigated area, 500 ml per box was irrigated with a commercially available watering can. After spraying, the soil was covered, and germination treatment was performed at 32 ° C. for 2 days. After germination, the seeds were placed in a half-shade area, shielded from light with a cold gauze in a greenhouse.

The seedling cultivation medium used was commercially available Kumiai granular cultivation K (manufactured by Kureha Chemical Industry Co., Ltd.).

Thirty days after sowing, one third of the nursery box was examined for the number of diseased seedlings showing symptoms such as stunting and death, and the number of disease-free seedlings, and the diseased seedling rate (%) was calculated by the following formula. And the control value (%) was determined. In addition, phytotoxicity was observed for the germination rate, growth degree, and the like, and indicated by the following phytotoxicity.

[0025]

(Equation 1)

[0026]

(Equation 2) Degree of phytotoxicity-: None ±: Minor +: Small ++: Medium ++: Large

This test was carried out in three sections per section, and the average control value (%) was determined. Table 1 shows the results.

[0028]

[Table 1]

Note 1) Seed disinfection method in control plot Seed paddy was immersed in a chemical solution of a predetermined concentration for 24 hours, and then immersed in water at 20 ° C. for 3 days. After immersion, drain the water at 32 ° C for 15
Seed seeds that had undergone germination for a period of time and were in a pigeon breast state were sown at 150 g per dry seed conversion box per nursery box. After the soil was covered, the seedlings were managed in the same manner as the nursery box of the present invention.

Note 2) The values in parentheses in the untreated plots indicate the rate of seedlings (%) of the disease caused by rice and scab.

Test Example 2 Effect on rice sesame leaf blight Rice sesame leaf blight-infected paddy (variety “Nipponbare”) was immersed in water at 20 ° C. for 4 days, drained, germinated at 32 ° C. overnight, and pigeon breast. Seedlings in a seedling box (length x width x height = 60)
(cm × 30 cm × 3 cm) and 150 g in terms of dry paddy. After sowing, the wettable powder prepared according to the example was diluted to a predetermined concentration in the same manner as in Test Example 1, and the drug was treated in the same manner as in Test Example 1. Thereafter, the nursery box was managed in the same manner as in Test Example 1. went.

Twenty-one days after sowing, the number of diseased seedlings and the number of disease-free seedlings in which a spot of rice sesame leaf blight was observed on the stems and leaves of one-third of the nursery box was examined. (%) Was determined. Also, as for the phytotoxicity, the germination rate, the degree of growth, and the like were observed in the same manner as in Test Example 1, and the phytotoxicity was evaluated.

This test was carried out in three sections per section, and the average control value was determined. Table 2 shows the results.

[0034]

[Table 2]

Note 1) Seed disinfection method of the control group is Test Example 1.
Was performed in the same manner as described above. Note 2) The value in parentheses in the untreated plot indicates the rate of seedlings of rice sesame leaf blight (%).

Test Example 3 Effect on rice damping-off caused by Trichoderma fungus Seed paddy of rice (variety "Hatsusei") lodged by wind and rain at 20.degree.
Seeds in water for 4 days, drain the water, germinate overnight at 32 ° C, and convert the seed paddy showing pigeon breast into dry paddy per box (length x width x height = 60cm x 30cm x 3cm) At 15
0 g was seeded. After sowing, the wettable powder prepared according to the examples was diluted to a predetermined concentration, and the seedlings were treated with 50 ml for spraying and 500 ml for irrigation per box. Subsequently, Trichoderma oryzae (Trichode) cultivated in advance on a potato and glucose agar medium at 24 ° C. for 5 days.
rm oryzae), water was added to adjust the spore concentration of the bacterium to about 10 ⁵ per ml, and 50 ml of the spores was added per liter of seedling culture soil, and mixed well. After the spraying, the soil was covered with the seedling cultivation soil, and the nursery box after the spraying was managed in the same manner as in Test Example 1.

Twenty-one days after sowing, one-third of the nursery box was examined for the number of diseased seedlings and the number of disease-free seedlings showing the symptoms of damping-off, and the control value (%) was determined in the same manner as in Test Example 1. Was. In addition, the germination rate and the degree of growth were observed in the same manner as in Test Example 1 for the phytotoxicity, and the phytotoxicity was evaluated.

This test was carried out in three groups per section, and the average control value (%) was determined. Table 3 shows the results.

[0039]

[Table 3]

Note 1) The seed disinfection method of the control group is Test Example 1.
Was performed in the same manner as described above. Note 2) The number in parentheses in the untreated plot indicates the rate of seedling emergence of seedling damping (%).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A01N 47/38 A01N 43/50

Claims (1)

(57) [Claims] (1) N-propyl-N- [2- (2,4,6
-Trichlorophenoxy) ethyl] imidazole-1-
Carboxamide or (E) -4-chloro-α, α, α
-Trifluoro-N- (1-imidazol-1-yl-
Immediately after sowing the 2-propoxyethylidene-o-toluidine in a seedling raising box, the seedlings are sprayed on seeds before soil covering, or the seeds are irrigated and cultivated in the seedling cultivation soil.
Labor saving control method for rice disease. [0001]