JPS5852206A - Labor-saving controlling method for blight of rice plant and growth promoting method of rice plant - Google Patents

Abstract

PURPOSE:To control the blights of rice plants efficiently with saved labor and promote the growth of the rice plants after transplanting to the fields, by applying a small amount of a drug containing kasugamycin or its salt and probenazole to seedling raising boxes in planting rice seeds of the rice plants in the seedling raising boxes. CONSTITUTION:In sowing rice seeds of rice plants in raising boxes, a granular or powdery agent containing kasugamycin or its salt and a 3-allyloxy-1,2-benzoisothiazole-1,1-dioxide (probenazole) is applied to the seedling raising boxes at a weight ratio between the former and latter of (50-200):(100-1,000)mg to control the blights of the rice plants and promote the growth thereof. The agent is used to treat the soil by the mixing method of mixing the earthing up soil for covering soil, applying the agent after the sowing and before the soil covering or mixing the whole layers. Blast and the seedling rot of rice plants can be controlled at the same time.

Description

[Detailed Description of the Invention] A labor-saving and effective method for controlling diseases that occur in Tomogo rice seedlings transplanted to the seedling box and Honda by simply applying a small amount of chemicals to the seedling box, and a method for effectively controlling rice seedlings after transplanting to the Honda. It relates to a method of promoting growth.

Specifically, the active ingredients are kasugamycin or its salts (hereinafter referred to as KBM) and 3-allyloxy-1,2-
Add a granular or powdered agent containing a mixture of penzoisothiazole-1,1-dioxide (hereinafter referred to as propenazole) to a rice seedling box (length x width x height:
3 0 cMIX 6 051 The present invention provides a method and a method for promoting growth of rice.

The drug granules or guarding agent may be applied to the seedling nursery box by any suitable method. From a practical standpoint, the following three methods can be cited.

1) A method of mixing soil for covering soil in advance and covering it with soil after sowing (method of mixing soil for covering soil).

2) A method of mixing with the seedling box ± (cultivating soil for bed soil and cultivating soil for covering soil) before sowing, and covering with soil after sowing (full-layer mixing method).

3) Method of spraying after sowing and then covering with soil (pre-treatment method of covering soil after sowing) The method of the present invention does not cause chemical damage to rice (rice seedling rot and rice seedling blast that occur during the seedling raising period). ,
In addition, it can also control rice fungal blast, which does not occur within 30 days after transplanting rice seedlings to Honda, and promote rooting of rice seedlings after transplanting to Honda (promoting the elongation of the main machine length, increasing the number of plates). It has been recognized that the growth of rice seedlings can be significantly promoted by promoting growth (increase in plant height) and growth elongation (increase in plant height). Conventionally, granules containing KPM were treated in seedling boxes to prevent rice blast and rice blast disease. Methods for controlling rice seedling rot at the same time are known (Japanese Patent Application Laid-open Nos. 5.6-75417 to 56
There is also a method of controlling rice B blast that occurs in Honda by applying granules containing propenazole to seedling boxes from 3 days before transplanting to Honda and on the day of transplanting. It is publicly known. Furthermore, it is also known that a method for controlling rice blast disease is spraying on Honda rice fields with a mixture of KK8M and propenazole, such as imperial preparations or irrigation agents (Bulletin No. 11846-18155).
.

In the present invention, the known KPM and propenasolt are mixed in a specific manner as described above, and the granular or powdered agent containing the same is processed in a specific usage method, as described above. In addition to being able to control diseases during seedling raising and rice blast disease that occurs after transplanting to Honda over a long period of time, this technology has not been found with any of the techniques of K8M, propenazole, or a mixture of 8M and propenazole. This provides completely new knowledge that significantly promotes the growth of rice.

In recent years, seeds and seedlings for machine transplantation have become popular nationwide.
28-550 to ensure uniform germination in addition to being densely sown.
It is often kept under a constant temperature of C for 2 to 3 days, and then cultivated under high temperature and humidity.

Therefore, along with rice blast and rice bacterial blight disease (P),
seudomonaa glumas: Rice seedling rot disease caused by Pseudomonas gourmet) occurs frequently,
This has become a problem.

Until now, in order to control rice blast among these diseases in seedling box cultivation, methods containing isozolothiolane (chemical name: diisopropyl-1,3-dithiolan-2-ylibumalonate) as an active ingredient have been used. A few days after sowing or just before transplanting, add granules to the seedling box at 111i per 50~
75F (12 capsules: 6.ooo q to 9 active ingredients)
,000 q) How to apply,! Add granules containing lopenazole to a seedling box from 3 days before transplanting to just before transplanting. CB4 granules: Active ingredient 15O0
11f to 2.400 q) Application methods have been put into practical use. - According to this method, kernels that can practically control rice blast can be obtained with the usual application amount of each granule, but rice seedling rot It is completely effective against diseases. In addition, if the chemical agent of Nire et al. is applied in a larger amount than the normal usage amount, or if the usual usage amount is mixed with the seedling growing soil before and after sowing, or if the soil is pre-treated after sowing, However, it is either impossible to increase the control effect against rice seedling rot, or it only gives the undesirable result of stunting or suppressing the growth of rice.Therefore, in seedling box cultivation.

There is a need to establish a chemical and control technology that can practically control not only rice A blast disease but also rice seedling rot.The present inventors have developed a new seedling box application control agent that meets these needs. and conducted extensive research to develop its control technology. As a result, we first applied 8M in the form of granules to 1 fl of a rice seedling box (*X width x height = 30 dX < 5OcFllX
An average of 16 to 18 boxes of young seedlings are used per 10 acres of 3crn), and the active ingredient is 50 to 2.00.
Treating 0 cape with either the method of mixing soil for covering soil, mixing the whole layer, or spraying after sowing before covering soil (it is a trap), does not cause any phytotoxicity to rice Ktl &<, rice blast disease and conventional We found that rice seedling rot, which was difficult to control with chemicals, could be controlled at the same time. In particular, for rice blast, treatment with less than 1.0019 dW is effective against rice blast, but when it becomes more than 1.000 kg, it is even more effective against rice blast when it is transplanted to Honda and produces 9 ilK. and established a technology for the simultaneous control of rice seedling rot and rice blast.
17027S No. 55-117027).

However, with these methods, the duration of the control effect after transplantation is said to be 10 days after transplantation, at the 3rd to 4g stage of rice, even if 8M is applied to more than 1,000 capes. It has its drawbacks.

In order to strengthen the shortcomings of 8M, the present inventors have conducted extensive research on the effectiveness of combining KPM and various II agents to prevent rice rot and rice blast, and have developed the present invention. That is, according to the present invention, by applying the above-described method to a seedling growing box, rice seedling rot and rice seedling blast that occur during the seedling growing period,
In addition, it can also control rice blast disease that occurs up to 30 days after rice seedlings are transplanted to Honda.
A pot that can significantly promote the growth of rice seedlings after transplantation.In contrast to the present invention, the conventional method of using propenazole granules as described above has been shown to cause rice seedling rot, which occurs in the early stage of seedling raising. and is not effective against rice seedling blast.

In addition, the usual dosage of 1,600sr to 2
．． Since the same method of use as in the present invention was applied in the range of 400 aycD, it showed KH control activity for rice seedling rot, but it was not practical.
This method cannot be used, and the drug dose i 1,000~
Even if the dosage is reduced to below 500 to 1.00 (1 w), rice growth can still be suppressed, and the dosage can be reduced to 5.
0jIf or less, the growth of rice is suppressed (but it is completely ineffective against rice seedling rot (KH), and the control effect against rice seedling blast disease is also poor, so this method is not practical. However, surprisingly, in 100,119 to 1,000 q of such desebenazole, 8
When used in combination with 50IIF to 2.000 all of M, rather than suppressing the growth of I1,
It was found that it has the effect of significantly promoting the growth of rice.

In this case, the use of propenazole 1ttt100 to 5
The growth promoting effect is remarkable in the 00v range. In addition, as a disease control effect, it synergistically exerts a control effect against rice seedling rot and rice seedling blast in seedling boxes, and the purpose of control can be fully achieved with a low dose of treatment. . Also.

For leaf blast disease after transplanting to Honda, even if KSM and probenazole are mixed at dosages that do not show any residual effect when used as single agents, they have sufficient practical control effect until 30 days after transplantation. can get.

The findings of the present invention are based on conventional rice blast control technology that involves spraying KPM-containing powders, irrigation agents, emulsions, and liquids on Honda's rice stems and leaves, or applying granules alone to rice seedling boxes; f Rice blast disease control technology by applying a powder containing lopenazole, isogusethiolane, etc. to seedling boxes, or spraying powders, irrigation agents, emulsions, etc. containing a mixture of ijKsM and propenazole to Honda's rice stems and leaves. This was discovered for the first time by the present inventors (no one could have predicted this based on the rice blast control technology based on KSM, f-lopenazole). Not only does it provide applied technology, but it also provides a completely new technology as a treatment agent for seedling boxes.

In order to efficiently utilize the excellent effects of the present invention, K can be obtained by simply treating a granular or powdered agent containing KSM and propenazole in the above-mentioned ratio using the specific processing method described above. In this case, the word granular or powdery means geometric granular or powdery, so it is not used in the field of agricultural chemical formulation technology. It means granular or powdery. Therefore, as the granules, granules, fine granules, fine granules F, and powders can be used, and as the powders, Fi, powders, Driftless (DLL & agents, irrigation agents, and coarse powders) can be used.

Examples of the production of granules and powders used in the present invention and examples of the method of the present invention are listed below, but the present invention is not limited to these examples. Parts indicate parts by weight. Also, KPM used hydrochloride.

Production Example 1 Granules 15 parts of KSMl, 0.15 parts of propenazole, 3 parts of calcium ligninsulfonate, and 95.7 parts of Merck clay mixture were thoroughly kneaded and granulated, dried and sized to form granules. Production Example 2 5.75 parts of powder KSM, 0.75 parts of propenazole, 0.5 parts of silicic anhydride fine powder, 0.5 parts of calcium stearate and 92.5 parts of clay were uniformly mixed. A powder was obtained.

Example 1 (Efficacy test for controlling rice seedling rot and seedling blast caused by bacterial rice blight) 1) Chemical treatment method (a) Mixing of soil for covering soil Commercially available granular soil (Kureha granular soil) was placed in a seedling box. 1 box contains 8kI of soil for use as bed soil, and holds 2t of water.
The rice seeds were irrigated using the rice seedlings, and the rice seeds, which had germinated and became dove-breast-shaped, were sown at an amount of 200 tons (calculated as dry weight) per seedling-raising box. Next, a certain amount of the granules prepared according to Production Example 1 and 4/4 of culture soil for rear soil were thoroughly mixed, and the seedling raising box of the sowing wave was covered with soil. Fill each seedling box with 1.8 kj of granular culture soil as bed soil, irrigate with 2 tons of water, and germinate the seed rice, which has become dove-breast shaped, into one wheel of the seedling box. A certain amount of granules prepared according to Production Example 1 was sprinkled on one of the 200 tons of seeds sown in terms of weight, and the soil was covered with 0.6 k# of culture soil for covering soil prepared in advance. (c) Seedling raising culture soil mixing treatment ( Full layer mixing treatment) Production example 1
Thoroughly mix a certain amount of granules prepared in accordance with
8 o'clock was used as bed soil and packed into a seedling box (3 tons, 1 part, 0.6 kl)
(was used for soil covering), then one ring of the seedling box (F) was irrigated with water from step 21 using dew, and the rice seeds that germinated and became pigeon-breasted were added to one box of the seedling box (dry weight). The seeds were sown at a rate of 20° each and were then kept in a thermostat at 32°C for 2 days to treat germination. After germination, the seeds were cultivated in a vinyl container.

2) Method for measuring the control effect (a) To investigate the onset of rice seedling rot, 10 days after sowing, one-fifth of the seedling boxes were examined for the number of rot-killing bacteria and the number of leaf sheath browning bacteria, and the disease severity was calculated using the following formula. The rice seedling rot control value was calculated from the comparison with the disease severity in the untreated area.

(b) Regarding the seedling blast control effect, see 5-1
After 5 days, a rice blast fungus spore suspension (150 spores per field of view under a 150x optical microscope) was added to each seedling box.
It was spray inoculated at 5 parts/g and kept in a greenhouse at 24°C for 20 hours. After inoculation, the seedlings were transferred again to a plastic container, and 6 days after inoculation, 300 seedlings per box were placed in a second nursery box.
The number of expanding lesions of rice blast II was investigated, and the blast control value (2)) was calculated using the following formula.

The control value is (1+)
), and B indicates the total number of blast lesions on the 300 leaves surveyed (second leaf) in the untreated area. (c) Control of blast disease after transplantation The effects were examined as follows. Air-dried paddy soil 3.2 was fertilized with 3 tons of ba, 3.6 tons of peracid lime, and 1 ton of potassium chloride per 1 liter of paddy soil, water was added, and the soil was stirred well to restore the condition of the paddy fields. Then, 15 to 7 rice plants at the 2.3 to 2.5 leaf stage 20 days after sowing were hand-planted as one plant with the seedling medium still on. 5 days after transplanting, After 10 days, 20 days, and 30 days, the spore suspension of the rice blast fungus was treated once (approximately 150 spores per field of view under an optical microscope at 150x magnification).
Spray inoculation was carried out for 3 days per day at t-1. After inoculation, the temperature is 24'C and the relative humidity is 85-95°C. The rice blast disease prevention value (a) was calculated.

Control value - (1--) Shows the average number of rice blast disease expansion lesions of (Top developed Jim at the time of inoculation) ・In addition, the diseased paddy used in the rice seedling rot control effect test in this example died at the time of opening in the previous year, and in the early stage of heading and when the ears were set. During the period, bacterial rice blight disease MS suspension (I
This is seed rice of the variety "Sasanishiki" obtained by seeding S* seeds (108/-).

In addition, the seed rice used in the rice blast control effect test in this example was Okayama Yamano product sI "Asahi".

The test was conducted in three consecutive sessions in each area, and the average control value was calculated.
The results are shown in Tables 1 to 6.

Note 1 Control agent (11 tlj Irrigation agent containing 2 doses of streptomycin + 21 d-inzolothiolane)
Note 2: The numbers in parentheses are the average severity of rice seedling rot in the untreated plot, and the average value of the total number of blast hook-spreading lesions on the second leaves of 300 rice seedlings. and the average number of blast-spreading lesions per leaf of the uppermost developed leaf at the time of inoculation.

Example 2 (Rice growth promotion effect test 1iit>Production example 1
As in Example 1, a certain amount of granules prepared according to the above were mixed with soil for covering soil, sprinkled before sowing, and mixed with soil for raising seedlings (full-thickness mixing treatment [1)], and packed into seedling boxes. $32
Germination was carried out by keeping it in a constant temperature chamber at 'C for 2 days. After germination, greening was carried out in a greenhouse at 28 to 306 C during the day and -118 to 20 C at night. From 7 days before transplanting, normal cultivation management was carried out in a plastic greenhouse. The seeds were hardened and transplanted to paddy fields.

On the day of transplantation and 14 days after transplantation, the growth status of the rice plants was investigated, and leaf blight, which is a leaf blight caused by propenazole, was investigated.

In this example, the seed rice used in the rice growth promotion effect test was the Miyagi Itoya variety "Sasanishiki". This test was conducted in three consecutive plots, and the average value was calculated. t
In addition, the degree of leaf blight in rice plants was examined using the following criteria. Leaf withering occurs on 601 or more to less than 60- of the second leaf or 311 &) Small: Leaf withering occurs on 1 or more and less than 301 of the relevant leaf area (second or third leaf) The results are as shown in Tables 7 to 12.3Note 1v
I4 test i1 shows the average value of 300 rice seedlings.

Claims (1)

[Scope of Claims] 1. Kasugamycin t contains its salts and 3-allyloxy-1,2-benziisothiazole-1,1-dioxide as active ingredients when sowing rice seeds in seedling boxes. Place one box of granular or powdered agent in a seedling box (Length x Width x Height: 50 is x 60 es
5 am) Allr effect g is 11 and the former is 5 (lat
&ishi 2.000 at, the latter 100 da to 1.0
A labor-saving method for controlling rice diseases and promoting the growth of rice by applying at a rate of 11 at the time of sowing, which is characterized by applying at a rate of 0.00 If. A method according to claim 1, in which the mosquito granular agent or ring agent is applied by covering with soil after sowing, and a patent claim in which the mosquito granular agent or ring agent is applied by mixing in advance with the bed soil of the seedling box and the culturing soil for covering soil. 4. The method according to claim 1, wherein the method according to claim 1 is applied by applying a grain granule or powder agent after sowing rice seeds in a seedling nursery box and before covering with soil.