JPH0967221A - Nematocide composition and prevention of pine wilt disease using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nematocide, esp. a pine wood nematode controlling agent, by using a specific extract from margosa, and to conduct a more effective prevention of pine wilt disease without virtually affecting the environment. SOLUTION: This nematocide composition contains, as active ingredient, pref. 0.1-95wt.% of an azadirachtin obtained by grinding a margosa and then subjecting the ground margosa to extraction by a known method. The resultant azadirachtin-contg. extract is usable directly as the nematocide however, in general, can also be subjected to agrochemical preparation manufacturing process. In this case, the resultant agrochemical preparation is pref. liquid for the purpose of its injection into trunks (in the form of a solvent solution or emulsion). Combined use of a surfactant with this nematocide can enhance its effect. For applying this composition to pine trees, e.g. ampule injection or spot injection method is taken, its amount being 0.1-1000ml per pine tree in terms of the preparation.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a nematicidal composition containing azadirachtin and a method for preventing pine wilt disease using the composition.

[0002]

2. Description of the Related Art In recent years, dead trees of pine trees, which are representative trees of Japan and are important as forest resources, have occurred over a wide area.
The so-called "pine withering phenomenon" has become a social problem. For this reason, research into the cause of pine wilting and methods of preventing pine wilting has been actively conducted. From the results of the studies so far, it was clarified that one of the causes of pine wilting is an acute wilt disease caused by pine wood nematode, which is a kind of pine scabworm, pine wood nematode. Methods for preventing pine wilt disease by selecting nematode resistant varieties, felling extermination, and searching for natural enemies are being studied. Among them, as a chemical control method, a method of spraying aerial insecticides against live trees in order to control pine wood beetle or pine wood nematode, a method of insecticidal treatment against dead trees, a drug for living trees Injecting tree trunks and treating soil.

However, these control methods have merits and demerits, and if they are not comprehensively taken into consideration, sufficient effects will be obtained, taking into consideration the damage situation of pine species, growing environment conditions, life history of the vector pine wood beetle, etc. I can't. Moreover, while spraying chemicals over the air enables wide-area control, it involves the risk of destroying natural ecosystems, and there are many problems such as the danger of environmental pollution and lack of appropriate control effect. Furthermore, organic phosphorus-based mesulfenphos, which has been frequently used, and drugs such as morantel tartrate and levamisole hydrochloride, do not always provide sufficient effects, and all of them have a problem in that they have large restrictions in handling. are doing. On the other hand, azadirachtin is an insecticidal component present in tree neem (neem), and tree extract has been used as an insecticide for a long time. This is a mixture of a plurality of compounds, and the chemical structures of the constituents have been studied, and some of the structurally determined components are known. Various tests have been conducted on the insecticidal activity of this product, and it has been put to practical use as an insecticide partly overseas. However, it has never been known that the compound has nematicidal activity.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a nematicidal composition, which is more effective using the composition, and
It is intended to provide a method for preventing pine wilt disease that has little impact on the environment.

[0005]

The present invention relates to a nematicidal composition containing azadirachtin. Also, the present invention
The present invention relates to a pine wood nematode control agent containing azadirachtin. Furthermore, the present invention relates to a method for preventing pine wilt disease, which comprises applying a nematicide containing azadirachtin to pine trees. In the present invention, it was found that a composition containing azadirachtin surprisingly has nematicidal activity, exhibits excellent effects in controlling pine wood nematodes, and exerts excellent effects in preventing pine wilt disease.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Azadirachtin, which is an active ingredient contained in the nematicidal composition of the present invention, is obtained by crushing neem tree (neem tree, origin India) and extracting it by a known method. To be In addition, Margosan-O and Neemix of Grace (Netherlands) are commercially available.
Azatin from Agri Dyne (USA) or the like may be used. The obtained azadirachtin-containing extract can be directly used as the nematicide of the present invention,
A common pesticide formulation can also be used. The formulation is preferably a liquid formulation for injection into the trunk, and can be dissolved in a solvent or used as an emulsion.

As the solvent used here, for example,
Aromatic hydrocarbons such as benzene, toluene and xylene,
Aliphatic hydrocarbons such as cyclohexane, hexane, heptane and pentane, ketones such as acetone, methyl ethyl ketone, butyl ketone and cyclohexanone, amides such as dimethylformamide and dimethylacetamide, halogenated hydrocarbons such as dichloroethane and trichlorobutane, methyl Examples thereof include alcohols such as alcohol, ethyl alcohol and butyl alcohol, esters such as ethyl acetate and ethyl propionate, ethers such as dibutyl ether and dioxane, and water.

The nematicide of the present invention can enhance the effect by using a surfactant together. Examples of the surfactant that can be used here include nonionic surfactants such as sorbitan fatty acid ester, monoglyceride, polypropylene glycol fatty acid ester, polyoxyethylene alkyl aryl ether, sodium lignin sulfonate, sodium alkylbenzene sulfonate, and sodium lauryl sulfate. And anionic surfactants such as Insecticides other than azadirachtin, nematicides and the like may be appropriately used in combination with the nematicidal composition of the present invention. When the composition of the present invention is prepared as a solution or an emulsion, a solvent and / or a surfactant is mixed, so that the content of the active ingredient becomes 0.1 to 95% by weight, preferably 1 to 80% by weight. It is better to adjust it.

When the nematicidal composition of the present invention is applied to pine, a method of injecting it into a tree trunk can be preferably applied. As a method of injecting the composition of the present invention into a tree trunk, an ampoule injection method, a spot injection method, a boring injection method, a conformal injector method, a drop injection method and the like can be arbitrarily selected.
It can be appropriately selected depending on the purpose, time, age of the tree, size of the tree and damage condition, but usually, the treatment amount per tree is 0.1 to 1000 ml, preferably 1 to 50 ml in the formulation amount.
The amount of the active ingredient is about 0 ml, and the amount of the active ingredient is about 0.0015 g to 45 g, preferably about 0.015 g to 22.5 g. By the composition of the present invention and the method of using the composition, it is possible to control pine wood nematodes that live in or are about to live in pine trees and prevent pine wilting.

[0010]

EXAMPLES The present invention will be described in more detail with reference to the following examples and test examples. Example 1 3.0 parts of azadirachtin, 1.0 part of polyoxyethylene nonyl ether and 96 parts of xylene were mixed well to obtain a 3% emulsion. Example 2 3.0 parts of azadirachtin was dissolved in 97 parts of methyl ethyl ketone to obtain a 3% solution.

Test Example 1 Each drug of each concentration shown in Table 1 below in a 10 ml vial 2
ml (diluted and adjusted with water) was put into each, and about 800 pine larvae of the 3rd instar larvae / 0.1 ml were released, and the mortality rate after 24 hours at room temperature was calculated. In addition, in the determination of the life and death of the pine wood nematode, the one that stiffened and did not move was regarded as dead. The results are shown in Table 1.

[0012]

[Table 1] Comparative substance: generic name mesulfenphos O, O-dimethyl-O-3-methyl-4- (methylsulfyl) phenylphosphorothioate

Test Example 2 Using the 15-year-old black pine of 10 strains in each test section, two holes were drilled in the trunk of each tree about 1.5 m above the ground, and the compositions prepared in Examples 1 and 2 were used. 50 ml / hole was injected by the ampoule injection method. Eight weeks after the injection, a hole was drilled at a height of about 2.5 m above the tree trunk, and a pine wood nematode was inoculated deep into the cortex of the tree trunk. The number of nematodes inoculated is about 20
000 heads / tree. In addition, the bark of the tree trunk about 50 cm above the pine wood nematode inoculation site was damaged,
The amount of resin exuded was measured. The comparative control substance was treated in the same manner, and a drug-free and nematode-free section was provided. Table 2 shows the results.

[0014]

[Table 2] Control area 1 Product name: Nemanone (generic name: mesulfenphos) Control area 2 Product name: Gringuard (generic name: Morantel tartrate)

In the table, the resin outflow amount was visually evaluated according to the following criteria. The amount of resin is an index of the medicinal effect against eucommia because the resin disappears as pine wilting causes pine wilting. Nematode non-inoculation section ++++ (reference amount) Slightly less than non-inoculation section ++ Significantly less than non-inoculation section + Almost no resin-

[0015]

INDUSTRIAL APPLICABILITY According to the present invention, a composition containing azadirachtin has excellent nematicidal activity, is excellent in controlling pine wood nematodes, and is excellent in preventing pine wilt disease. .

Claims (3)

[Claims] 1. A nematicidal composition containing azadirachtin. 2. A pinewood nematode control agent containing azadirachtin. 3. A method for preventing pine wilt disease, which comprises applying the composition of claim 1 to pine.