JPS5918366B2 - herbicide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a herbicide having an excellent killing effect on various weeds.

Herbicides whose main ingredients are chlorates such as sodium chlorate and calcium chlorate have traditionally been used as non-selective weed control agents on forest land and open land.

However, such chlorate herbicides generally have short-lasting effects and tend to decompose within a short period of time after application.

Therefore, the present inventor conducted experiments with the aim of providing a non-selective herbicide that has a slower decomposition rate than conventional chlorate-based herbicides and maintains its herbicidal effect over a long period of time. As a result of repeated research, the present invention has been completed.

That is, the herbicide of the present invention contains a reaction product of sodium chlorite and peroxide pyrophosphate as an active ingredient.

The herbicide of the present invention, like conventional chlorate herbicides, is non-selective and can kill most weeds. It can be applied by etc.

However, it is most effective to spray directly onto the foliage during the prime growing season when the plant height is approximately 5 to 10 crfL.

The amount of herbicide to be sprayed can be determined as appropriate depending on the type of weed, application period, etc.

In short, it is sufficient to use an effective amount for killing the plants, and there is no need for strictness in the amount of spraying.

For example, -year-old grass weeds such as Japanese grass weed,
Relatively small amounts, e.g., 1 to 1 per area, are applied to sagebrush, sagebrush, and the annual broad-leaved weeds sagebrush, wormwood, American chiliflower, and staghorn.
By spraying around 2 kg, it can be killed in a few days.
Since subsequent re-occurrence can be prevented for 2 to 3 months, the trouble of re-spraying during this period can be saved.

For perennial weeds such as mugwort, sagebrush, sorrel, red lily, thicket, and dandelion, use a medium amount, e.g.
By spraying about 3 to 5 kg per area, the plants can be killed in a few days.

Among perennial weeds, such as pampas grass, raspberry, kudzu, Japanese knotweed, and goldenrod are sprayed in a larger amount than annual weeds, for example, about 8 to 10 kg per are.

The herbicide of the present invention can be applied to non-agricultural land such as forest land, open land, mulberry orchards, orchards, fallow fields, etc. when a relatively large amount is to be sprayed; ,
Suitable for weeding common fields and paddy fields, such as pine weeds and cypresses.

To obtain the herbicide of the present invention, it is sufficient to simply react sodium chlorite and peroxide pyrophosphate.

The peroxide pyrophosphate to be reacted with sodium chlorite in the present invention can be obtained, for example, by the following method.

That is, hydrogen peroxide is gradually added to an approximately 20% aqueous solution of phosphoric acid while cooling to generate peroxide of phosphoric acid, which is then neutralized with an alkali such as sodium hydroxide or potassium hydroxide while continuing to cool. Alternatively, while cooling sodium pyrophosphate, hydrogen peroxide is gradually added dropwise to react with it.

Peroxide pyrophosphate can be used as a soda salt, potassium salt, ammonium salt, etc., but soda salt is most preferred in terms of stability.

When reacting sodium chlorite and peroxide pyrophosphate, for example, 40-6% of a 25% solution of sodium chlorite
0wt, % sodium peroxide pyrophosphate 60-40wt,
A simple operation can be adopted in which % is gradually added while stirring to cause the reaction to occur.

Since this reaction is exothermic, the temperature of the reaction solution is 40°C.
Raise the temperature to ~50°C.

Since excessive temperature rise may cause decomposition of the reaction product, the temperature of the reaction solution is preferably kept at about 30° C. by cooling.

When stirring is continued for 60 to 90 minutes, the reaction solution gradually becomes paste-like.

By air-drying the paste-like reaction product thus obtained, a mostly odorless white powder is obtained.

In addition, no harmful gas such as chlorine dioxide gas was observed to be generated in any of the steps described above.

The thus obtained reaction product, which is a white powder, is used as a herbicide in the present invention.

This white powder is stable at room temperature without absorbing moisture, and is easily soluble in water.

It also has extremely low toxicity to the human body.

For the herbicide of the present invention, the white powder obtained above can be used directly as a powder, but an appropriate dosage form such as a wettable powder or a granule can be selected depending on the conditions of use.

When preparing a herbicide, it can be prepared by using an inert carrier or the like according to the intended dosage form, and by a general formulation method for herbicides.

The most notable property of the herbicide of the present invention is the slow rate of decomposition of the agent compared to conventional chlorate herbicides.

In other words, since the chemical gradually decomposes after being sprayed, the herbicide effect lasts for 2 to 3 months after being sprayed, making it possible to maintain stable efficacy over a long period of time.

In addition, it can be expected to have a fertilizer effect on the pyrophosphate that remains after decomposition.

The present invention will be further explained below with reference to Examples.

Example 1 50 wt.% of a 25% solution of sodium chlorite was placed in a reaction tank, and 50 wt.% of sodium peroxide pyrophosphate was gradually added thereto with stirring.

At this time, the reaction solution in the reaction tank is 40-50% due to exothermic reaction.
Since the temperature rose to .degree. C., the reaction tank was water-cooled to maintain the reaction solution temperature at about 30.degree. C. in order to prevent excessive heat generation.

By continuing to stir gently in this state for 90 minutes, a paste-like reaction product was obtained.

This paste-like material was air-dried to obtain a white powder herbicide product of the present invention.

This herbicide can be used on grasshoppers, foxtail grass, Japanese dustweed,
1 per area in a fallow field where gramineous weeds such as grass weeds and broad-leaved weeds such as grasshoppers, wormwood, American chiliflower, and grasshoppers grow year-round.
kg and 2 kg were sprayed at an average rate so as to sufficiently contact the weed stems and leaves.

The results of observing the dead state of weeds after spraying were as follows.

Example 2 The herbicide powder of the present invention obtained in Example 1 was applied to mugwort,
The solution was sprayed at an average rate of 3 and 5 ky per area in an open area where perennial weeds such as succulent sorrel, sorrel, Japanese sorrel, Japanese sorrel, Japanese radish, dandelion, etc. were growing, so as to sufficiently contact the foliage of the weeds.

The results of observing the dead state of weeds after spraying were as follows.

Example 3 60 wt.% of a 25% solution of sodium chlorite was placed in a reaction tank, and 40 wt.% of potassium peroxide pyrophosphate was gradually added thereto with stirring.

In the same manner as in Example 1, the reaction solution temperature was maintained at approximately 30°C by water cooling to prevent excessive heat generation due to reaction heat, and stirring was continued gently for 90 minutes to obtain a paste-like reaction product, which was air-dried. The mixture was dried to obtain a white powder herbicide product of the present invention.

Apply this herbicide at the base of perennial weeds such as strawberry and kudzu at 10% per plant. And sprayed to 30r.

The results of observing the dead state of weeds after spraying were as follows.

As can be seen from the above-mentioned examples, various weeds can be reliably killed by using the herbicide of the present invention,
Furthermore, the herbicidal effect remains even 90 days after application.

Claims (1)

[Claims] 1. A herbicide whose active ingredient is a reaction product of sodium chlorite and peroxide pyrophosphate.