JPS5919081B2 - Herbicide composition for paddy fields - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to α-(β-naphthoxy)propionanilide (hereinafter abbreviated as N0PA).

) and the general formula (wherein, R is -OCH3, -0CH2CH2
X or -COOCH3, where X is a chlorine atom,
Or it represents a fluorine atom.

The present invention relates to a herbicide composition for paddy fields containing a diphenyl ether compound represented by the following as an active ingredient.

More specifically, by mixing the compound represented by the general formula (1), including a new compound in which R is -CH2CH2F, with the known compound N0PA, the range of suitable use period and the killing of the herbicide are improved compared to conventional paddy field herbicides. An excellent herbicide composition that has a significantly expanded grass spectrum, that is, can be used at any time from the germination period to the growth period of paddy weeds, and can also control perennial weeds that are difficult to control with conventional herbicides. It provides:

Herbicides for paddy fields in Japan are roughly divided into three categories based on the timing of use: early-season herbicides, mid-season herbicides, and late-season herbicides, and the first two account for the majority of the amount used.

Initial herbicides include GNP (2,4,6-dolychlorophenyl-4-nitrophenyl ether) and NL.
P (2,4-dichlorophenyl-4-nitrophenyl ether), and as a medium-term herbicide, SWEP M [methyl-N-(3,4-dichlorophenyl) carbamate 2=methyl-4- Mixture with chlorophenoxyacetic acid ethyl ester], Mixture with Saturn 5C8-(4-chlorobenzyl)-N-N-diethylthiol carbamate and 2-methylthio-4,6-pisethylamino-s-h riazine] etc.

Early stage herbicides are extremely effective when used at the beginning of the outbreak, but their effectiveness decreases significantly when used during the peak bloom stage.

Mid-season herbicides are effective from the weed germination stage to the growth stage, but if used during the germination stage, they cause significant chemical damage to paddy rice.
Its use is limited to the period when the growth of paddy rice is considerably advanced.

Furthermore, depending on the temperature and soil conditions, phytotoxicity may occur or the effectiveness may decrease.

Furthermore, these herbicides are not sufficiently effective against perennial weeds, and instead encourage the growth of perennial weeds.

Recently, there has been a desire for herbicides that can control all weeds in a single treatment and can be used over a wide range of periods to save labor in agricultural work. There is no herbicide that does not cause any phytotoxicity to paddy rice during its entire growing period and that satisfies this requirement.

The present inventors have conducted extensive research with the goal of developing a herbicide that can be used at any time from the beginning of weed germination to the growing season immediately after rice transplantation, exhibiting an appropriate control effect, and is harmless to paddy rice. As a result, a mixture of the compound represented by the general formula (1) and N0PA in an appropriate ratio had an extremely significant herbicidal effect that far exceeded expectations, and a small amount that could not be controlled by each component alone. It was discovered that at a dosage of 1, it has a remarkable control effect not only on annual weeds, but also on the perennial weeds that have recently become more prevalent, such as porcupine, firefly, and snail, and that it has no phytotoxic effects on paddy rice. The invention has been completed.

The following compounds are exemplified as active ingredients of the composition of the present invention represented by the general formula (1).

2,4-dichlorophenyl-3-,,! ) xy-4-nitrophenyl ether (hereinafter referred to as compound A) 2,4-
Dichlorophenyl-3-(β-chloroethoxy)-4-
Nitrophenyl ether (hereinafter referred to as compound B5),'
2,4-dichlorophenyl-3-(β-fluoroethoxy)-4-40 phenyl ether (hereinafter referred to as compound C), 2,4-dichlorophenyl-3-carpoxime f
#-4-=trophenyl ether (hereinafter referred to as the compound).

Among the above compounds, compound C is
This is a new compound related to No. 89.

All of these compounds are herbicides that exhibit contact herbicidal action and have a strong suppressive power against grass weeds at the beginning of germination, so they can be used before and after weed germination, for example in paddy fields, from about 3 days before rice planting to 6 days after rice planting. It must be used by the end of the day.

The herbicidal power of these compounds decreases as the weeds grow, and in particular, their herbicidal effects against broad-leaved weeds such as the grasshopper and perennial weeds such as the weeds and fireflies decrease.

Therefore, these compounds have practical drawbacks in that the types of weeds to which they can be applied and the timing of application are limited.

On the other hand, N0PA suppresses weeds at the beginning of their emergence, and its effect is particularly strong under stagnant conditions.It also has an extremely strong herbicidal effect on contact with growing weeds; Although it is highly effective against broad-leaved weeds, it has the disadvantage of low suppressive power against grass weeds, such as Japanese millet.

However, the conventional phenoxy herbicides 24-D and MCPA
It has the superior feature of not causing any malformed leaves or other chemical damage to paddy rice.

The present invention (by appropriately mixing N0PA, which has the above-mentioned drawbacks, and the compound represented by the general formula (1) above, not only compensates for the drawbacks of applying each alone, but also suppresses weeds due to the synergistic effect) This makes it possible to significantly increase the application and usage period for

That is, by applying a mixture of parts by weight of NoPA1 and 0.5 to 2 parts by weight of the compound represented by the general formula (1) of the present invention, it is possible to not only weeds at the time of germination but also gramineous weeds and broad-leaved weeds that have grown to some extent. It exhibits a strong suppressive power against weeds and perennial weeds such as weeds and fireflies, and this indicates that the compound of general formula (1) and N0P
This is an epoch-making herbicidal effect that was first achieved by mixing A.

The herbicidal composition of the present invention can be formulated into various forms and used as a herbicide for paddy fields, but its practical value is particularly enhanced when it is applied as granules to stagnant paddy fields.

Next, the effects when applied to stagnant rice fields will be explained using test examples.

Test example 1 Soil 3,3k where seeds of common weeds in paddy fields are naturally mixed
Fill a 1/5000th area Wagner pot with 0.8 g of each of KN, P2O5, and K20 and fertilize the entire layer with chemical fertilizers, add an appropriate amount of water, and stir thoroughly to create a water-filled state.

Next, two paddy rice seedlings (leaf age 3.0) grown in a greenhouse were used as one plant, and the two plants were planted per pot at a depth of 3 crrL. The seeds were mixed and grown in a greenhouse.

3 or 8 days after transplantation, a predetermined amount of the test compound was used to treat the soil with stamina.

One month after the chemical treatment, the amount of remaining grass and the chemical damage to paddy rice were investigated, and the results shown in Table 1 were obtained.

As can be seen from the results in Table 1, N0PA has a small herbicidal effect on Japanese grasshopper when treated 3 days and 8 days after transplantation, and is effective against broad-leaved weeds such as Japanese grasshopper, Japanese grasshopper, and grasshopper, as well as on Japanese cypress and firefly. is high.

On the other hand, Compounds A, B, C, and D were generally highly effective when treated 3 days after transplantation, except for perennials such as Prunus japonicum, Helaomodaca, and Firefly, but when treated 8 days after transplantation, the effects decreased overall, and It is relatively effective against family weeds, but it is slightly less effective against broad-leaved weeds, and it is hardly effective against perennial fireweeds and weeds.

In contrast, N0PA and compounds A, B, C or D
The drug mixed with
In addition to showing sufficient growth suppressing power against Japanese millet,
It was also shown to be effective against the common weeds, Japanese cypress, and perennial weeds such as porcupine weeds, staghorn weeds, and firefly.

Moreover, it showed excellent practicality with no phytotoxicity to paddy rice.

Test Example 2 A paddy field where common weed seeds are naturally mixed was tilled and fertilized using the usual method (1 kg per a of N, P205, K20), roughage and land leveling, 1 area Iom2
(2.5 m x 4 m), and two paddy rice seedlings with leaf age of 5.0 were transplanted into this as one plant with a furrow spacing of 30 and a plant spacing of 15 cr.

After transplanting, the water depth was maintained at 3 to 5 crrL, and 300 g of the test compound per granule area was sprayed on the water surface 3 days after transplantation and 8 days after transplantation.

One month after spraying, the amount of remaining grass was measured, and the chemical damage to paddy rice was also observed and the results shown in Table 2 were obtained.

According to the results of Test Example 2, each single drug group was highly effective after 3 days of treatment, but the overall effect decreased after 8 days of treatment.
It has little effect on firefly etc.

However, in the mixed area, it is highly effective regardless of the treatment time or grass type, and it is clear that there is no chemical damage to paddy rice at all.

Although the blending ratio of the active ingredients in the herbicidal composition of the present invention can be applied over a wide range, it is desirable to blend 0.5 to 2 parts by weight of the compound represented by general formula (1) to parts by weight of NoPAI.

The herbicidal composition of the present invention is used by mixing with a solid carrier such as a diluent or a filler depending on the purpose of use. At that time, if necessary, auxiliary agents such as stabilizers, dispersants, suspending agents, etc. By adding a spreading agent, penetrating agent, wetting agent, etc., it can be used as a wettable powder, granule, or powder.

Further, the herbicidal composition of the present invention can be mixed with pesticides such as fungicides, insecticides, and other herbicides, fertilizing substances such as urea, ammonium sulfate, ammonium phosphorus, and potassium salts, and/or soil conditioners. Not only can they be used, but also mixed preparations with these are possible.

The total amount of active ingredients in the herbicide composition of the present invention is 1 to 1 in granules.
20%, and 30-60% for irrigation agents is desirable.

Next, examples of the composition of the present invention will be shown.

Example 1 Parts of NoPAI granules, 7 parts of compound A, 60 parts of bentonite, 23 parts of talc, 2 parts of polyoxyethylene glycol monolaurylate, and 1 part of naphthalene sulfonic acid condensate were mixed and processed using a granulator in a conventional manner. Granulate according to the method to obtain 100 parts of granules.

Example 2 Parts of granules NoPAI, 5 parts of compound B, 2 parts of sodium dodecylbenzenesulfonate, 1 part of sodium ligninsulfonate, 35 parts of talc, and 50 parts of bentonite were mixed, and granulated by a normal method using a granulator. Granulate to obtain 100 parts of granules.

Example 3 25 parts of wettable powder N0PA, 20 parts of compound C, 50 parts of bentonite, and 5 parts of sodium dodecylbenzenesulfonate are mixed to obtain 100 parts of wettable powder.

As mentioned above, the composition of the present invention can be used at any time from the beginning of weed germination to the peak of weed germination immediately after rice transplantation.
It is harmless to paddy rice and can control all weeds with a single application, making it significantly superior to conventionally used herbicides.

Conventionally, herbicides differ from fungicides and insecticides in that the rice planting period is
Because there are differences in the growth of weeds even after ~4 days, the timing of spraying has to be staggered.The reality is that mechanized spraying over a wide area is not possible and labor-saving in agricultural work is hindered. It is.

Since the composition of the present invention has a significantly long suitable period of use, it can be applied at the same time as rice planting even if the rice planting period is around 10 to 20 days. Therefore, joint application over a wide range is possible, contributing to labor savings. There's a lot to do.

Claims (1)

[Scope of Claims] 1 α-(β-naphthoxy)propionanilide and the general formula (wherein R is -0CH3, 0CH2CH2X or -
COOCH3, where X represents a chlorine atom or a fluorine atom. ) as an active ingredient.