JPS5852965B2 - Sterilizing composition for agriculture and horticulture - Google Patents

Description

Detailed Description of the Invention The present invention provides 4,5,6,7-titrachlorophthalide (hereinafter simply referred to as rTcFJ) and 1,2-dimethyl N-C
The present invention relates to an agricultural and horticultural fungicidal composition containing a mixture of 3',5'-dichlorophenyl)cyclopropanecarboxylic acid monoamide (hereinafter referred to as "compound (1)") as an active ingredient.

In recent years, as rice cultivation methods have become more labor-saving and mechanical transplantation of young seedlings has become widespread throughout the country, major changes have appeared in the appearance of rice diseases.

In particular, the period during which rice is exposed to high temperatures during the ripening stage has become longer than ever, causing rice blast disease and rice ear blight diseases caused by invasion by rice sesame leaf blight fungi, rice brown leaf blight fungi, rice row blight fungi, etc. is occurring frequently.

However, there are few fungicides that are effective against these diseases.

Therefore, there is an urgent need to develop new simultaneous control agents and control techniques for these diseases.

TCP, which is one of the active ingredients of the present invention, has already been used in the
The agricultural fungicide disclosed in Specification No. 4-32594 is known as having a specific preventive effect against rice blast, has extremely low toxicity to humans, livestock, fish and shellfish, and is phytotoxic to various crops. Due to its high safety, it is currently in widespread practical use as a special agent for controlling rice blast disease.

However, TCP is not effective against rice blast because it is ambivalent and has a poor therapeutic effect when sprayed after infection, so it is commercially available in combination with kasugamycin or organophosphorus-based rice blast control agents, or it has not been put into practical use. The current situation is that it is progressing.

Moreover, TCP cannot be expected to have any effect on rice panicle blight caused by invasion by various rice pathogenic bacteria as described above.

In view of these circumstances, the present inventors took advantage of TCP's extremely high chemical safety and the rare effect of preventing rice blast disease shown by pre-infection spraying, as well as its sustainability, and developed the above-mentioned method. A variety of compounds were tested and investigated in order to compensate for the shortcomings and develop a practical simultaneous control agent for rice blast and rice panicle blight that would lead to labor-saving control.

As a result, by using a new fungicide consisting of a mixture of TCP and Compound (1) (Japanese Patent Publication No. 47-43813), which is known as a disease control agent for vegetable gardening, the above purpose was fully achieved. They have discovered that this is the case and have completed the present invention.

The agricultural and horticultural fungicidal composition of the present invention exhibits an extremely high synergistic control effect and rain resistance effect on rice blast and rice panicle blight, which is difficult to estimate from the use of each agent alone.

In carrying out the present invention, the appropriate blending ratio of the above-mentioned active ingredients is 1 to 5 parts by weight of compound (1) to TCFL, but it may be changed as appropriate depending on the conditions at the time of application and the disease occurrence situation. It is possible to change the blending ratio and use it.

When formulating the agricultural and horticultural fungicidal composition of the present invention, various carriers and adjuvants used in conventional methods are added to form powders (including DL type), irrigation agents, liquids, flowable agents, etc. It can be made into any desired form such as microgranules, granules, and tablets.

Furthermore, in actual use of the agricultural and horticultural fungicidal composition of the present invention, it is also possible to use it in combination with various fungicides and insecticides.

Next, Examples of the agricultural and horticultural fungicidal composition of the present invention will be shown.

Example 1 (Irrigation agent) 5 parts (weight parts) of TCFL (same below), compound (1) 20
15 parts of white carbon, 2 parts of polyoxyethylene nonylphenol ether, 4 parts of sodium lignin sulfonate, and 44 parts of clay were placed in a ribbon mixer and mixed.
After sufficiently pulverizing with an atomizer, the mixture is mixed again with a ribbon mixer to obtain an irrigation agent.

This irrigation agent can be diluted 500 to 1,000 times with water and applied to fences before or immediately after the onset of rice blast disease, rice ear blight disease, and rice blight disease using an appropriate spraying device. By spraying at a rate of 100 to 180 parts per 10 are, these various diseases can be controlled singly or simultaneously.

Example 2 (Powder) 2.0 parts of TCP, 2.0 parts of compound (1), 2.0 parts of white carbon, 0.3 parts of PAP (physical property improver), and 93.7 parts of clay were placed in a ribbon mixer. After mixing and sufficiently pulverizing with an atomizer, the mixture is mixed again with a ribbon mixer to obtain a powder.

This powder can be used to prevent rice blast and rice ear blight diseases by scattering them on the rice body before or immediately after the onset of the disease at a rate of 3 to 4 kg per 10 ares using an appropriate spraying device. Can be controlled individually or simultaneously.

Next, the disease control effect of the agricultural and horticultural fungicidal composition of the present invention will be explained using test examples.

Test example 1 Rice blast disease control effect test (field seedling) Dried rice (cultivar Sasanishiki) was immersed in a 200-fold diluted solution of Benlate T hydrating agent 20 (commercially available seed disinfectant) for 48 hours and sterilized, followed by conventional methods. The rice seeds soaked and germinated were sown in rows (July 13B).

The spraying of the chemicals was adjusted by diluting the wettable powder containing the active ingredient for each vehicle with water to twice the final spraying concentration, and adding equal amounts of the solution.

Then, this mixed solution was sprayed twice with a small hand-held sprayer to 100m1 of each area (the first spraying was carried out at 7 days after the pathogen inoculation).
on July 23rd, and the second spraying was on July 30th).

The disease onset was investigated by investigating the percent percentage of rice blast lesion dead area 21 days after the second chemical spraying, and the control value percent of each test chemical was determined using the following formula.

In addition, in the present invention, the expected value (PE:
%) was determined, and the presence or absence of a synergistic effect was determined from the relationship with the actual measured value (PC: %).

PE (%) = P a + P b (100-P a )
/100 In this formula, Pa indicates the actually measured pesticidal value (5) by using TCP, and pb indicates the actually measured pesticidal value (yes) by using compound (1).

Judgment is based on the following criteria. P C>P E two-synergistic effect PC=PE: Additive effect PC<PE: antagonistic effect The results are shown in Table 1.

Test Example 2 Rice panicle blight control effect test (field) As in Test Example 1, rice seeds were sterilized with Benlate T wettable powder 20, and 2.5-leaf stage seedlings of the varieties Nipponbare and Reihou, which were grown in boxes according to the general practice method, were machined. Transplanted (May 15th).

Honda fertilizer application amount (base fertilizer) is 20 kg of Rinkaan No. 204 (12-20-14) per 10 ares, PK Kakai 2 with magnesium.
0 kg, and additional fertilizer was applied in August 1st with 15 ky of Takko NK Kasei.

The test area was 15m' in two consecutive sections.

Each test drug prepared according to Test Example 1 was applied at the earing stage (August 22nd).
Using a backpack-type fully automatic sprayer, the seeds were sprayed at an even rate of 1,501 ml per 10 ares twice: once (August 31st) and during the milk ripening period (August 31st).

The disease onset investigation was carried out on September 30th, and the disease severity of ears was determined for 30 rice plants in each district according to the following disease severity criteria.

In addition, panicle blight due to rice sesame leaf blight was investigated using Nipponbare, and panicle blight due to rice row blight was investigated using Reihou, and according to Test Example 1, the control value (%) of each chemical sprayed plot was evaluated in comparison with the non-sprayed plot. I asked for it.

In addition, chemical damage was investigated 10 days after spraying.

Ear.

Disease severity -4A+2B+C×100 N N: Total number of panicles surveyed A: The head of the panicle is affected and the whole panicle strength S is dead B:
Test in which the head, cob, or ramus is damaged and one-half or more of the panicle is withered.C: The cob or rachis is infested and less than one-half of the panicle is dead. The results are shown in Table 2.

Test Example 3 Rice Blast Control Effect Test (Pot) As the test rice, 3-leaf stage seedlings of Asahi variety cultivated in clay pots with a diameter of 9 crrL were used.

The chemicals were adjusted to a predetermined concentration by mixing equal amounts of the irrigation agents containing the active ingredients of each vehicle at twice the final spray concentration.

This mixed solution was sprayed onto 5 pots of 50 ml using a spray gun on a turntable.

The spores of the blast fungus (Pyricularia oryzae) were inoculated to form spores on the diseased leaves, and 50 pI of Tween 20 (trade name of polyoxyethylene sorbicun monolaurate manufactured by Kao Atlas ■) was added. The number of spores was adjusted to about 100 per field of view under a 150x microscope, and the spores were inoculated by spraying one day after spraying.

After inoculation, the seeds were stored in a greenhouse with 100% humidity and a temperature of 24°C for 24 hours, and then transferred to a greenhouse at 24°C to induce disease onset.

To investigate the onset of disease, the number of lesions per leaf on the third leaf was investigated 6 days after inoculation, and the control value was calculated using the following formula.

In addition, chemical damage to rice was investigated using the following indicators.

Drug damage index 5: Severe 4: Severe 3: Much 2: Little 1: Slight O: None

Claims (1)

[Claims] 1 4.5.6.7-titrachlorphthalide and 1,2-
A fungicidal composition for agriculture and horticulture, characterized in that it contains a mixture with dimethyl-N-(3,'5'-dichlorophenyl)cyclopropanecarboxylic acid amide as an active ingredient.