JPH07126111A - Herbicide - Google Patents

Abstract

(57) [Summary] [Structure] A herbicide containing a tropolone salt and / or a hinokitiol salt and ethylenediaminetetraacetic acid salt as an active ingredient, and a herbicidal method using the herbicide. [Effect] To provide a herbicide and a herbicidal method which have a sufficient herbicidal activity and are safe for the human body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a herbicide and a herbicidal method which are highly safe for the human body.

[0002]

BACKGROUND OF THE INVENTION Since the use of 2,4-D as a chemical weeding means, a huge number of herbicides have been developed and the time required for weeding has been dramatically reduced. In recent years, due to the increasing environmental problems, the need for highly safe herbicides that do not pollute the environment has increased, and therefore has herbicidal activity and does not have harmful side effects on the human body. There was a strong demand for a drug that can be used with peace of mind.

The inventors of the present invention searched for a compound that is likely to be used as a herbicide from among natural substances that are easily decomposed in nature and are known as plant growth inhibitory active substances,
As a result, we focused on tropolone and hinokitiol as compounds satisfying such conditions. Tropolone and hinokitiol are known substances, and especially hinokitiol is known as a food additive, and is used as a fungicide and insect repellent (JP-A-4
9-85230), pest repellent (JP-A-50-4072)
5), anticaries agent (JP-A-59-29618, 59-2)
9619), an antiseptic method for foods (JP-A-59-29467)
7), plant growth, activator and bactericidal agent (JP-A-51-
22819). On the other hand, tropolone was also known as a termite control agent (JP-A-49-55829), a container for keeping plant freshness (JP-A-49-102862), and an external preparation (JP-A-63-33313). Furthermore, tropolone and hinokitiol have plant growth inhibitory activities (Chem. Pharm. Bull. 39 (9), p.
p2378-2381) was also known.

[0004]

However, both tropolone and hinokitiol have low solubility in water. Especially, in the case of hinokitiol, it does not dissolve even if a surfactant is used, and it does not dissolve to some extent even if heated. It will crystallize over time. Therefore, it has been difficult to use both compounds as they are as herbicides. As a means for solving such a problem, there has been known a method of neutralizing hinokitiol in the form of a salt or the like with acetic acid or the like (Japanese Patent Laid-Open No. 51-29469), but this method uses sodium hinokitiol. This is applicable when producing a salt, but not when producing a potassium salt of hinokitiol. Furthermore, this method involves the operation of adding an excessive amount of alkali and then neutralizing it, which is a problem in that it takes time and labor.

Both tropolone and hinokitiol show no herbicidal activity unless they are at a considerably high concentration (1% to 0.5%), and they show herbicidal activity only when they come into contact with plants. In order to obtain a good herbicidal effect, a considerable amount of spraying is required. An object of the present invention is to solve such a problem, specifically, to improve the solubility of tropolone and hinokitiol in water, and herbicidal activity, and to provide a herbicide that is safe for the human body. Especially.

[0006]

Means for Solving the Problems As a result of intensive studies on the method for improving the herbicidal activity of tropolone and hinokitiol, the present inventors have made tropolone and hinokitiol into a salt form, and added ethylenediaminetetraacetic acid salt to them. Then, they found that the herbicidal activity increased synergistically, and completed the present invention.

That is, the first aspect of the present invention is a herbicide containing tropolone salt and / or hinokitiol salt and ethylenediaminetetraacetic acid salt as active ingredients. Here, the metal salt used for the tropolone salt may be potassium or sodium, and the metal salt used for the hinokitiol salt may be potassium or sodium. Examples of the metal salt used for ethylenediaminetetraacetate include potassium, sodium, magnesium, calcium, copper, iron,
Mention may be made of manganese, lithium or zinc.

The second aspect of the present invention is a method of weeding, which comprises applying the above herbicide to weeds. Hereinafter, the present invention will be described in detail. As the tropolone salt, sodium salt, potassium salt and the like can be used, but the tropolone salt is not limited to these salts, and other salts can also be used. It is also possible to use only a single salt,
It is also possible to use a mixture of a plurality of salts.

As the salt of hinokitiol, sodium salt, potassium salt and the like can be used, but not limited to these salts, other salts can be used. Further, as with tropolone, not only a single salt but also a plurality of salts can be mixed and used. As ethylenediaminetetraacetic acid salt (hereinafter referred to as "EDTA salt"), it is preferable to use disodium salt, dipotassium salt, tetrasodium salt, tetrapotassium salt, but not limited to these salts, calcium salt, Copper salts, dilithium salts, iron salts, magnesium salts, trilithium salts, tripotassium salts, trisodium salts, zinc salts, manganese salts, tetralithium salts and the like can be used. Further, similar to tropolone and the like, not only a single salt but also a plurality of metal salts can be mixed and used.

The herbicide of the present invention can be produced by adding an EDTA salt to a tropolone salt and / or a hinokitiol salt and, if necessary, adding a surfactant and the like. At this time, the content of each component in the herbicide is
For tropolone salt 0.05% to 0.5%, preferably 0.125% to 0.25%, for hinokitiol salt 0.05 to 0.5%, preferably 0.125.
~ 0.25%, for EDTA salt 0.25-2
%, Preferably 0.5 to 1%.
The mixing ratio of tropolone salt and EDTA salt is 1:10.
It is preferable that the mixing ratio of the hinokitiol salt to the EDTA salt is in the same range as the mixing ratio of the tropolone salt to the EDTA salt.

The plants to be weeded are, for example,
Mallow family plants such as velvetleaf, Amaranthus plants such as blue millet, Acalyptaceae plants such as white azalea, Asteraceae plants such as Kosendangsa,
Examples thereof include leguminous plants such as Beggerweed and Kusanem, but are not limited thereto. When the herbicide of the present invention is used in an actual field, etc.,
Since it is effective against a wide range of weeds, it is preferably used as a non-selective foliar treatment agent. In order for the herbicide of the present invention to act effectively, the amount of EDTA salt per field 10a is 500 g to 4000 g, preferably 1000 to 20 g.
00g, the amount of hinokitiol salt and tropolone salt is 12
It is used in an amount of 5 g to 1000 g, preferably 250 g to 500 g.

[0012]

[Test Example] Various substances were added to hinokitiol to examine its effect on herbicidal activity. Abutilon was sown in four 6 cm × 6 cm pots and grown in a greenhouse for 10 days. The maximum concentration of the potassium salt of hinokitiol was set to 1%, and 1% tripotassium salt of EDTA or 1% soybean oil was added to each of the 6 concentrations at 1/2 dilution to prepare a preparation solution.
Spray each plant with 0.5 ml of the solution,
I investigated after a day. As a control, 1% EDTA tripotassium salt only solution, soybean oil 1% only solution and 1
A solution of% hinokitiol alone was prepared. Silwet L-77 was used as a surfactant to prepare a 0.05% solution. Evaluation criteria for herbicidal activity 5: Complete death (100% inhibition), 4: Great harm (80% inhibition) 3: Medium harm (60% inhibition), 2: Minor harm (40% inhibition) 1: Minor harm (20 % Inhibition), 0: Harmless (0% inhibition)

[0013]

[Table 1]

As is clear from the table, when 1% soybean oil was added to hinokitiol, there was no change compared with the herbicidal effect of hinokitiol alone, but when 1% EDTA tripotassium salt was added to hinokitiol. , The herbicidal effect was increased as compared with the case of hinokitiol alone.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the technical scope of the present invention is not limited thereto. (Example 1) Abutilon was sown in four 6 cm x 6 cm pots and grown in a greenhouse for 10 days. Set the maximum concentration of hinokitiol potassium salt to 0.25% and dilute 5 to 5
Concentration and maximum concentration of EDTA tripotassium salt 1%
As a result, the herbicide of the present invention prepared by diluting 5 times with 1/2 dilution, and multiplying the respective concentrations, was added to each plant in an amount of 0.5 ml per pot.
Each was sprayed and investigated 7 days later. As a control, a solution of hinokitiol potassium salt alone and EDTA
5 solutions of only tripotassium tetraacetic acid salt were prepared. Silwet L-77 was used as a surfactant to prepare a 0.05% solution.

The evaluation criteria for herbicidal activity are as follows. 5 Complete death (100% inhibition) 4 Major harm (80% inhibition) 3 Moderate harm (60% inhibition) 2 Minor harm (40% inhibition) 1 Minor harm (20% inhibition) 0 No harm (0% inhibition)

[0017]

[Table 2]

As shown in the table, the herbicidal activity was increased by adding the tripotassium salt of EDTA to the potassium salt of hinokitiol. When 1% of tripotassium salt of EDTA is added, 0.0625% of potassium salt of hinokitiol
It showed herbicidal activity up to the concentration. When 0.5% of EDTA tripotassium salt was added, the activity was up to 0.125% concentration of hinokitiol potassium salt.

Next, regarding the synergistic effect of the herbicidal activity of hinokitiol and EDTA, SR Colby ("Calculating Syner
gistic and Antagonistic Response of Herbicide Comb
inations "Weeds, 15/1, 1967 pp20-22). That is, the expected control rate of the mixture of hinokitiol and EDTA was calculated from the following formula, and the control rate of this was compared with the actual control rate of the mixture. The control rate is 5 of the evaluation criteria.
(Complete death) 100%, 4 80%, 3 60%, 2
Was calculated as 40%, 1 as 20%, and 0 as 0%. E (expected control rate) = X + Y−X * Y / 100 (X = control rate of potassium salt of hinokitiol and sodium salt of tropolone Y = control rate of tripotassium salt of EDTA) Below, potassium salt of hinokitiol and EDTA The expected control rate and the actual control rate of the mixture of tripotassium salts are shown.

[0020]

[Table 3]

As shown in the table, at almost all concentrations, the actually confirmed control rate was higher than the expected control rate E calculated by the Colby's formula. Therefore, it is considered that the herbicidal effect obtained by mixing the potassium salt of hinokitiol and the tripotassium salt of EDTA is synergistically improved. (Example 2) Four pots of 6 cm x 6 cm were seeded with velvet roots and grown in a greenhouse for 10 days. The maximum concentration of tropolone sodium salt is 0.25%, and the concentration is 1/2, and the concentration is 5%, and the maximum concentration of trisodium salt of EDTA is 1%.
As a result, the herbicide of the present invention prepared by diluting 5 times with 1/2 dilution, and multiplying the respective concentrations, was added to each plant in an amount of 0.5 ml per pot.
Each was sprayed and investigated 7 days later. As a control, a solution of tropolone sodium salt alone and a solution of EDTA tetrasodium trisodium salt alone were prepared at 5 concentrations. Silwet L-77 was used as a surfactant to prepare a 0.05% solution.

The evaluation criteria for herbicidal activity are as follows. 5 Complete death (100% inhibition) 4 Major harm (80% inhibition) 3 Moderate harm (60% inhibition) 2 Minor harm (40% inhibition) 1 Minor harm (20% inhibition) 0 No harm (0% inhibition)

[0023]

[Table 4]

As shown in the table, the herbicidal activity was increased by adding the trisodium salt of EDTA to the sodium salt of tropolone. When 1% of trisodium salt of EDTA was added, it showed herbicidal activity up to a concentration of 0.125% of sodium salt of tropolone. When 0.5% trisodium salt of EDTA is added, the sodium salt of tropolone is 0.1%.
It showed activity up to 25% concentration.

Next, the expected control rate (E) and the actual control rate were compared by the same method as in Example 1.

[0026]

[Table 5]

As shown in the table, at almost all the concentrations, the actually confirmed control rate was larger than the expected control rate E calculated by the Colby equation. Therefore, it is considered that the herbicidal effect by mixing the sodium salt of tropolone and the trisodium salt of EDTA was synergistically improved.

[0028]

[Examples of use] Liquid-type herbicides containing hinokitiol potassium salt and EDTA tripotassium salt as shown in Table 6 were prepared. When this solution was applied to a field as a 40 to 80-fold diluted solution, it showed a herbicidal effect on a wide range of weeds.

[0029]

[Table 6]

[0030]

EFFECTS OF THE INVENTION The herbicide of the present invention is highly safe because it has a sufficient herbicidal activity and a compound with few side effects harmful to the human body as an active ingredient. Therefore, the present invention is extremely useful in various industrial fields such as agriculture.

Front page continued (72) Inventor Masayasu Tanaka 6-2 Umegaoka, Midori-ku, Yokohama-shi, Kanagawa Japan Tobacco Inc. Plant Development Laboratory Yokohama Center

Claims (6)

[Claims] 1. A herbicide containing tropolone salt and / or hinokitiol salt and ethylenediaminetetraacetic acid salt as active ingredients. 2. The metal salt of tropolone salt is potassium salt,
Alternatively, it is a sodium salt.
The herbicide described. 3. The herbicide according to claim 1 or 2, wherein the metal salt of the hinokitiol salt is a potassium salt or a sodium salt. 4. A metal salt of ethylenediaminetetraacetic acid salt,
Potassium salt, sodium salt, magnesium salt, calcium salt, copper salt, iron salt, manganese salt, lithium salt, or
The herbicide according to claim 1, which is a zinc salt. 5. A metal salt of ethylenediaminetetraacetic acid salt,
The herbicide according to claim 1, which is a potassium salt or a sodium salt. 6. A herbicidal method comprising applying the herbicide according to any one of claims 1 to 5 to weeds.