WO2017004744A1

WO2017004744A1 - Use of penflufen

Info

Publication number: WO2017004744A1
Application number: PCT/CN2015/083247
Authority: WO
Inventors: Jianjun Bai
Original assignee: Bayer Cropscience (China) Co., Ltd.
Priority date: 2015-07-03
Filing date: 2015-07-03
Publication date: 2017-01-12

Abstract

The present invention relates to use of Penflufen or a combination comprising Penflufen and further fungicides or insecticides for controlling rice bakanae, which is caused by Gibberella fujikurio.

Description

USE OF PENFLUFEN

The present invention relates to the use of Penflufen and of combinations comprising Penflufen and at least one further active ingredient for controlling rice bakanae. Furthermore the treatment of seed is mainly described to control rice bakanae.

Bakanae is a disease that infects the rice plant. This disease is caused by the fungus Gibberella fujikurio, the metabolism of which produces a surplus of gibberellic acid. In the rice plant, gibberellic acid acts as a growth hormone, causing hypertrophy. The afflicted plants, which are visibly etiolated and chlorotic, are at best infertile with empty panicles, producing no edible grains； at worst, they are incapable of supporting their own weight, topple over, and die. Gibberella fujikurio affects rice plants in Asia, Africa, and North America. In epidemic cases yield losses reach up to 20％or more.

Prochloraz， trichloroiso cyanuric acid and Tebuconazole are examples for compounds that are approved for controlling rice bakanae. It is desired to provide alternative fungicides which can be used for controlling rice bakanae, especially when the existing approved fungicides suffer from resistance issues.

Penflufen of formula (I) is known from WO2003/010149, and was generally disclosed as a fungicide. WO2003/010149 discloses a variety of diseases which can be treated by several compounds including penflufen, however, there is no mentioning of rice bakanae. The present application surprisingly found that penflufen can control rice bakanae through seed treatment for example, whose effect is comparable to some chemicals, such as prochloraz. As penflufen has a different mode of action from that of currently used chemicals, the present invention will be useful in helping to solve the resistance issue. Thus this invention now provides a new use of penflufen, and of combinations comprising penflufen and at least one further active ingredient for controlling rice bakanae.

In conjunction with the present invention “controlling” denotes a significant reduction of Gibberella fujikurio infection in comparison to the untreated group, more preferably the infection is essentially diminished (50-79％) , most preferably the infection is totally suppressed (80-100％) .

In an alternative embodiment of the present invention, penflufen as such or formulations thereof can be applied in combination with further known fungicides and insecticides for broadening the activity spectrum and in order to prevent the development of resistance. In many instances, synergistic effects are obtained, i.e. the activity of the mixture exceeds the additive activity of the individual components.

According to the invention the expression "combination" stands for a mixture of penflufen with at least one other compound, for example in a single "ready-mix" form, in a combined spray mixture composed from separate formulations of the single active compounds, such as a "tank-mix" , and in a combined use of the single active ingredients when applied in a sequential manner, i.e. one after the other with a reasonably short period, such as a few hours or days. Preferably the order of applying the compounds is not essential for working the present invention.

Formulations

The present invention further relates to a composition comprising Penflufen for controlling rice bakanae. The composition is preferably fungicidal composition which comprise agriculturally suitable auxiliaries, carriers, surfactants or extenders.

According to the invention, a carrier is a natural or synthetic, organic or inorganic substance with which the active ingredients are mixed or combined for better applicability, in particular for application to plants or plant parts or seed. The carrier, which may be solid or liquid, is generally inert and should be suitable for use in agriculture.

Useful solid carriers include: for example ammonium salts and natural rock flours, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and synthetic rock flours, such as finely divided silica, alumina and silicates； useful solid carriers for granules include: for example, crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite and dolomite, and also synthetic granules of inorganic and organic flours, and granules of organic material such as paper, sawdust, coconut shells, maize cobs and tobacco stalks； useful emulsifiers and/or foam-formers include: for example nonionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, for example alkylaryl polyglycol ethers, alkylsulphonates, alkyl sulphates, arylsulphonates and also protein hydrolysates； suitable dispersants are nonionic and/or ionic substances, for example from the classes of the alcohol-POE and/or -POP ethers, acid and/or POP POE esters, alkylaryl and/or POP POE ethers, fat and/or POP POE adducts, POE-and/or POP-polyol derivatives, POE-and/or POP-sorbitan or -sugar adducts, alkyl or aryl sulphates, alkyl-or arylsulphonates and alkyl or aryl phosphates or the corresponding PO-ether adducts. Additionally suitable are oligo-or polymers, for example those derived from vinylic monomers, from acrylic acid, from EO and/or PO alone or in combination with, for example, (poly) alcohols or (poly) amines. It is also possible to use lignin and its sulphonic acid derivatives, unmodified and modified celluloses, aromatic and/or aliphatic sulphonic acids and also their adducts with formaldehyde.

The active ingredients can be converted to the customary formulations, such as solutions, emulsions, wettable powders, water-and oil-based suspensions, powders, dusts, pastes, soluble powders, soluble granules, granules for broadcasting, suspoemulsion concentrates, natural products impregnated with active ingredient, synthetic substances impregnated with active ingredient, fertilizers and also microencapsulations in polymeric substances.

The active ingredients can be applied as such, in the form of their formulations or the use forms prepared therefrom, such as ready-to-use solutions, emulsions, water-or oil-based suspensions, powders, wettable powders, pastes, soluble powders, dusts, soluble granules, granules for broadcasting, suspoemulsion concentrates, natural products impregnated with active ingredient, synthetic substances impregnated with active ingredient, fertilizers and also microencapsulations in polymeric substances. Application is accomplished in a customary manner, for example by watering, spraying, atomizing, broadcasting, dusting, foaming, spreading-on and the like. It is also possible to deploy the active ingredients by the ultra-low volume method or to inject the active ingredient preparation/the active ingredient itself into the soil. It is also possible to treat the seed of the plants.

The formulations mentioned can be prepared in a manner known per se, for example by mixing the active ingredients with at least one customary extender, solvent or diluent, emulsifier, dispersant and/or binder or fixing agent, wetting agent, a water repellent, if appropriate siccatives and UV stabilizers and if appropriate dyes and pigments, antifoams, preservatives, secondary thickeners, stickers, gibberellins and also other processing auxiliaries.

The present invention includes not only formulations which are already ready for use and can be deployed with a suitable apparatus to the plant or the seed, but also commercial concentrates which have to be diluted with water prior to use.

Penflufen may be present as such or in their (commercial) formulations and in the use forms prepared from these formulations as a mixture with other (known) active ingredients, such as insecticides and fungicides.

The auxiliaries used may be those substances which are suitable for imparting particular properties to the composition itself or and/or to preparations derived therefrom (for example spray liquors, seed dressings) , such as certain technical properties and/or also particular biological properties. Typical auxiliaries include: extenders and solvents.

Suitable extenders are, for example, water, polar and nonpolar organic chemical liquids, for example from the classes of the aromatic and nonaromatic hydrocarbons (such as paraffins, alkylbenzenes, alkylnaphthalenes, chlorobenzenes) , the alcohols and polyols (which may optionally also be substituted, etherified and/or esterified) , the ketones (such as acetone, cyclohexanone) , esters (including fats and oils) and (poly) ethers, the unsubstituted and substituted amines, amides, lactams (such as N-alkylpyrrolidones) and lactones, the sulphones and sulphoxides (such as dimethyl sulphoxide) .

Liquefied gaseous extenders or carriers are understood to mean liquids which are gaseous at standard temperature and under standard pressure, for example aerosol propellants such as halohydrocarbons, or else butane, propane, nitrogen and carbon dioxide.

In the formulations it is possible to use thickeners such as carboxymethylcellulose, natural and synthetic polymers in the form of powders, granules or latices, such as gum arabic, polyvinyl alcohol and polyvinyl acetate, or else natural phospholipids such as cephalins and lecithins and synthetic phospholipids. Further additives may be mineral and vegetable oils.

If the extender used is water, it is also possible to use, for example, organic solvents as auxiliary solvents. Useful liquid solvents are essentially: aromatics such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons such as cyclohexane or paraffins, for example petroleum fractions, alcohols such as butanol or glycol and their ethers and esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents such as dimethylformamide and dimethyl sulphoxide, or else water.

Formulations comprising penflufen may additionally comprise further components, for example surfactants. Suitable surfactants are emulsifiers and/or foam formers, dispersants or wetting agents having ionic or nonionic properties, or mixtures of these surfactants. Examples thereof are salts of polyacrylic acid, salts of lignosulphonic acid, salts of phenolsulphonic acid or naphthalenesulphonic acid, polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, substituted phenols (preferably alkylphenols or arylphenols) , salts of sulphosuccinic esters, taurine derivatives (preferably alkyl taurates) , phosphoric esters of polyethoxylated alcohols or phenols, fatty esters of polyols, and derivatives of the compounds containing sulphates, sulphonates and phosphates, for example alkylaryl polyglycol ethers, alkylsulphonates, alkyl sulphates, arylsulphonates, protein hydrolysates, lignosulphite waste liquors and methylcellulose. The presence of a surfactant is necessary if one of the active ingredients and/or one of the inert carriers is insoluble in water and when application is effected in water. The proportion of surfactants is between 5 and 40 per cent by weight of the inventive composition.

It is possible to use dyes such as inorganic pigments, for example iron oxide, titanium oxide and Prussian Blue, and organic dyes such as alizarin dyes, azo dyes and metal phthalocyanine dyes, and trace nutrients such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc.

Further additives may be perfumes, mineral or vegetable, optionally modified oils, waxes and nutrients (including trace nutrients) , such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc.

Additional components may be stabilizers, such as cold stabilizers, preservatives, antioxidants, light stabilizers, or other agents which improve chemical and/or physical stability.

If appropriate, other additional components may also be present, for example protective colloids, binders, adhesives, thickeners, thixotropic substances, penetrants, stabilizers, sequestering agents, complex formers. In general, the active ingredients can be combined with any solid or liquid additive commonly used for formulation purposes.

The formulations contain generally between 0.05 and 99％by weight, 0.01 and 98％by weight, preferably between 0.1 and 95％by weight, more preferably between 0.5 and 90％of active ingredient, most preferably between 10 and 70 per cent by weight.

The formulations described above can be used for controlling rice bakanae, in which the formulations comprising penflufen are applied to the microorganisms and/or in their habitat.

Seed Treatment

The invention furthermore includes a method for treating seed.

Also disclosed is a method for controlling rice bakanae comprising applying penflufen or a combination comprising penflufen and at least one further active ingredient to seed or coating seed with penflufen or a combination comprising penflufen.

A further aspect of the present invention relates in particular to seeds (dormant, primed, pregerminated or even with emerged roots and leaves) treated with penflufen. The inventive seeds are used in methods for protection of seeds and emerged plants from the seeds from infection of Gibberella fujikurio. In these methods, seed treated with at least one inventive active ingredient is used.

It is also desirable to optimize the amount of the active ingredient used so as to provide the best possible protection for the seeds, the germinating plants and emerged seedlings from infection of Gibberella fujikurio, but without damaging the plants themselves. In particular, methods for the treatment of seed should also take into consideration the intrinsic phenotypes of transgenic plants in order to achieve optimum protection of the seed and the germinating plant with a minimum amount of compositions.

The present invention therefore also relates to a method for protecting seeds, germinating plants and emerged seedlings from infection of Gibberella fujikurio, including treating the seeds with the composition of the present invention. The invention also relates to the use of the compositions for treating seeds to protect the seeds, the germinating plants and emerged seedlings from infection of Gibberella fujikurio. The invention further relates to seeds which has been treated with the formulations of the present invention for protection from infection of Gibberella fujikurio.

One of the advantages of the present invention is that the treatment of the seeds with the formulations of the present invention not only protects the seed itself, but also the resulting plants after emergence, from infection of Gibberella fujikurio. In this way, the immediate treatment of the crop at the time of sowing or shortly thereafter protect plants as well as seed treatment in prior to sowing. It is likewise considered to be advantageous that the penflufen or combinations comprising penflufen can be used especially also for transgenic seed, in which case the plant which grows from this seed is capable of expressing a protein which acts against pests, herbicidal damage or abiotic stress. The treatment of such seeds with the penflufen or combinations comprising penflufen, for example an insecticidal protein, can result in control of certain pests. Surprisingly, a further synergistic effect can be observed in this case, which additionally increases the effectiveness for protection from infection of Gibberella fujikurio.

In the context of the present invention, penflufen is applied to seeds either alone or in a suitable combination. Preferably, the seed is treated in such a way to ensure no damage in the course of treatment. In general, seeds can be treated at any time between harvest and sowing. It is customary to use seed which has been separated from the plant and freed from the panicle of rice. For example, it is possible to use seed which has been harvested, cleaned and dried down to a moisture content of less than 13％by weight. Alternatively, it is also possible to use seed which, after drying, for example, has been treated with water and then dried again, or seeds just after priming, or seeds stored in primed conditions or pre-germinated seeds, or seeds sown on nursery trays, tapes or paper.

When treating the seeds, it generally has to be ensured that the amount of penflufen applied to the seed and/or the amount of further additives is selected such that the germination of the seed is not impaired, or that the resulting plant is not damaged.

Penflufen can be applied directly, i.e. without containing any other components and without having been diluted. In general, it is preferable to apply penflufen to the seed in the form of a suitable formulation. Suitable formulations and methods for seed treatment are known to those skilled in the art. Penflufen can be converted to the customary formulations relevant to on-seed applications, such as solutions, emulsions, suspensions, powders, foams, slurries or combined with other coating components for seed, such as film forming materials, pelleting materials, fine iron or other metal powders, granules, coating material for inactivated seeds, and also ULV formulations.

These formulations are prepared in a known manner, by mixing the penflufen or combinations comprising penflufen with customary additives, for example customary extenders and solvents or diluents, dyes, wetting agents, dispersants, emulsifiers, antifoams, preservatives, secondary thickeners, adhesives, gibberellins, and also water.

Useful dyes which may be present in the seed dressing formulations in accordance with the invention are all dyes which are customary for such purposes. It is possible to use either pigments, which are sparingly soluble in water, or dyes, which are soluble in water. Examples include the dyes known by the names Rhodamine B, C.I. Pigment Red 112 and C.I. Solvent Red 1.

Useful wetting agents which may be present in the seed dressing formulations in accordance with the invention are all substances which promote wetting and which are conventionally used for the formulation of active agrochemical ingredients. Preferred wetting agents are alkylnaphthalenesulphonates, such as diisopropyl-or diisobutylnaphthalenesulphonates.

Useful dispersants and/or emulsifiers which may be present in the seed dressing formulations in accordance with the invention are all nonionic, anionic and cationic dispersants conventionally used for the formulation of active agrochemical ingredients. Preferred dispersants are nonionic or anionic dispersants or mixtures of nonionic or anionic dispersants. Suitable nonionic dispersants include especially ethylene oxide/propylene oxide block polymers, alkylphenol polyglycol ethers and tristryrylphenol polyglycol ether, and the phosphated or sulphated derivatives thereof. Suitable anionic dispersants are especially lignosulphonates, polyacrylic acid salts and arylsulphonate/formaldehyde condensates.

Antifoams which may be present in the seed dressing formulations in accordance with the invention are all foam-inhibiting substances conventionally used for the formulation of active agrochemical ingredients. Silicone antifoams and magnesium stearate can be used with preference.

Preservatives which may be present in the seed dressing formulations in accordance with the invention are all substances usable for such purposes in agrochemical compositions. Examples include dichlorophene and benzyl alcohol hemiformal.

Thickeners which may be present in the seed dressing formulations in accordance with the invention are all substances usable for such purposes in agrochemical compositions. Preferred examples include cellulose derivatives, acrylic acid derivatives, xanthan, modified clays and finely divided silica.

Adhesives which may be present in the seed dressing formulations in accordance with the invention are all customary binders usable in seed dressing products. Preferred examples include polyvinylpyrrolidone, polyvinyl acetate, polyvinyl alcohol and tylose.

The formulations for on-seed applications in accordance with the invention can be used to treat rice seed either directly or after prior dilution with water. For instance, the concentrates or the preparations obtainable therefrom by dilution with water can be used to dress the rice seed. The formulations in accordance with the invention, or the dilute preparations thereof, can also be used for seeds of transgenic plants. In this case, additional synergistic effects may also occur in interaction with the substances formed by expression.

For treatment of seeds with the formulations in accordance with the invention, or the preparations prepared therefrom by adding water, all mixing units usable customarily for on-seed applications are useful. Specifically, the procedure in on-seed applications is to place the seeds into a mixer, to add the particular desired amount of the formulations, either as such or after prior dilution with water, and to mix everything until all applied formulations are distributed homogeneously on the seeds. If appropriate, this is followed by a drying operation.

GMO

As already mentioned above, it is possible to treat all rice plants and their parts in accordance with the invention. In a preferred embodiment, wild plant species and plant cultivars, or those obtained by conventional biological breeding methods, such as crossing or protoplast fusion, and also parts thereof, are treated. In a further preferred embodiment, transgenic plants and plant cultivars obtained by genetic engineering methods, if appropriate in combination with conventional methods (Genetically Modified Organisms) , and parts thereof are treated. The terms “parts” or “parts of plants” or “plant parts” have been explained above. More preferably, plants of the plant cultivars which are commercially available or are in use are treated in accordance with the invention. Plant cultivars are understood to mean plants which have new properties ("traits") and have been obtained by conventional breeding, by mutagenesis or by recombinant DNA techniques. They can be cultivars, varieties, bio-or genotypes.

The method of treatment according to the invention can be used in the treatment of genetically modified organisms (GMOs) , e.g. plants or seeds. Genetically modified plants (or transgenic plants) are plants of which a heterologous gene has been stably integrated into genome. The expression “heterologous gene” essentially means a gene which is provided or assembled outside the plant and when introduced in the nuclear, chloroplastic or mitochondrial genome gives the transformed plant new or improved agronomic or other properties by expressing a protein or polypeptide of interest or by downregulating or silencing other gene (s) which are present in the plant (using for example, antisense technology, cosuppression technology, RNA interference –RNAi –technology or microRNA –miRNA -technology) . A heterologous gene that is located in the genome is also called a transgene. A transgene that is defined by its particular location in the plant genome is called a transformation or transgenic event.

Plants and plant cultivars which are preferably to be treated according to the invention include all plants which have genetic material which impart particularly advantageous, useful traits to these plants (whether obtained by breeding and/or biotechnological means) .

Plants and plant cultivars which are also preferably to be treated according to the invention are resistant against one or more biotic stresses, i.e. said plants show a better defense against animal and microbial pests, such as against nematodes, insects, mites, phytopathogenic fungi, bacteria, viruses and/or viroids.

Plants and plant cultivars which may also be treated according to the invention are those plants which are resistant to one or more abiotic stresses. Abiotic stress conditions may include, for example, drought, cold temperature exposure, heat exposure, osmotic stress, flooding, increased soil salinity, increased mineral exposure, ozone exposure, high light exposure, limited availability of nitrogen nutrients, limited availability of phosphorus nutrients, shade avoidance.

Plants and plant cultivars which may also be treated according to the invention, are those plants characterized by enhanced yield characteristics. Increased yield in said plants can be the result of, for example, improved plant physiology, growth and development, such as water use efficiency, water retention efficiency, improved nitrogen use, enhanced carbon assimilation, improved photosynthesis, increased germination efficiency and accelerated maturation. Yield can furthermore be affected by improved plant architecture (under stress and non-stress conditions) , including but not limited to, early flowering, flowering control for hybrid seed production, seedling vigor, plant size, internode number and distance, root growth, seed size, fruit size, pod size, pod or ear number, seed number per pod or ear, seed mass, enhanced seed filling, reduced seed dispersal, reduced pod dehiscence and lodging resistance. Further yield traits include seed composition, such as carbohydrate content and composition for example starch, protein content, oil content and composition, nutritional value, reduction in anti-nutritional compounds, improved processability and better storage stability.

Plants that may be treated according to the invention are hybrid plants that already express the characteristic of heterosis or hybrid vigor which results in generally higher yield, vigor, health and resistance towards biotic and abiotic stresses.

Plants or plant cultivars (obtained by plant biotechnology methods such as genetic engineering) which may be treated according to the invention are herbicide-tolerant plants, i.e. plants made tolerant to one or more given herbicides. Such plants can be obtained either by genetic transformation, or by selection of plants containing a mutation imparting such herbicide tolerance.

Plants or plant cultivars (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are insect-resistant transgenic plants, i.e. plants made resistant to attack by certain target insects. Such plants can be obtained by genetic transformation, or by selection of plants containing a mutation imparting such insect resistance.

Plants or plant cultivars (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are tolerant to abiotic stresses. Such plants can be obtained by genetic transformation, or by selection of plants containing a mutation imparting such stress resistance.

Plants or plant cultivars (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention show altered quantity, quality and/or storage-stability of the harvested product and/or altered properties of specific ingredients of the harvested product.

Plants or plant cultivars (that can be obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are plants with altered seed shattering characteristics. Such plants can be obtained by genetic transformation, or by selection of plants contain a mutation imparting such altered seed shattering characteristics and include plants with delayed or reduced seed shattering.

Plants or plant cultivars (that can be obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are plants with altered post-translational protein modification patterns.

Application and Application Rates

Penflufen or combinations thereof can be applied directly, that is to say without comprising further components and without having been diluted. In general it is preferable to apply the compound or composition to the seed or the soil in the form of a suitable "formulation. Suitable formulations and methods for the treatment of seed are known to the skilled worker and are described, for example, in the following documents: US 4,272,417 A, US 4,245,432 A, US 4,808,430 A, US 5,876,739 A, US 2003/0176428Al, WO 2002/080675 A1, WO 2002/028186.

When treating the seed, care must generally be taken that the amount of the composition according to the invention applied to the seed and/or the amount of further additives is chosen in such a way that the germination of the seed is not adversely affected, or that the resulting plant is not damaged. This must be borne in mind in particular in the case of active compounds which may have phytotoxic effects at certain application rates.

When using the penflufen or combinations thereof according to the invention, the application rates can be varied within a relatively wide range, depending on the kind of application. In the treatment of parts of plants, the application rates of active compound combination are generally between 0.1 and 10 000 g/ha., preferably between 10 and 1000 g/ha. In the treatment of seeds, the application rates are generally between 0.001 and 50 g per kilogram of seed, preferably between 0.01 and 10 g per kilogram of seed, more preferably between 1 and 3 g per kilogram of seed. For the treatment of rice seed the same applies. For rice it is even more preferred that the application rate of penflufen varies between 2 and 3 g per kg of seed, such as about 2, about 2, 5 or about 3 g per kg of seed. In the treatment of the soil, the application rates of active compound combination are generally between 0.1 and 10 000 g/ha, preferably between l and 5000 g/ha.

Examples

The following examples illustrate particular embodiments of the invention in a non-limiting fashion..

Example 1: Inhibition of spore germination of Gibberella fujikurio by penflufen

Tested Subject

The tested subject is Penflufen. Particularly, 95.6％pure penflufen was provided by Bayer Crop Science, and was formulated into stock solution comprising an active concentration of 1.00×10⁴mg/L in DMSO, and then the obtained stock solution was placed at 4℃ in the refrigerator and was ready for use.

Carbendazim was used as a positive control. Particularly, 95％pure carbendazim (commercially available) was provided by the Second Pesticide Factory Co., Ltd in Jiangyin city of Jiangsu Province, and was formulated into stock solution comprising an active concentration of 5.00×10³mg/L in DMSO, and then the obtained stock solution was placed at 4 ℃ in the refrigerator and was ready for use.

In the experiment, the plate with water, agar, and tested subject has the following concentration. A plate with water and agar but without any tested subject was used as blank control.

Each treatment was repeated for four times.

Table 1. The specific concentration of tested subject

Experiment Gibberella fujikurio (provided by Department of Plant Pathology, College of Agriculture andBiotechnology of China Agricultural University) was inoculated onto Armstrong liquid medium (KH₂PO₄1.1g, MgSO₄·7H₂O 0.4g, glucose 20g, KCl 1.6g, Ca(NO₃)₂ 5.9g, ZnSO₄ 0.2mg, FeCl₃ 0.2mg,MnSO₄ 0.2mg, distilled water 1000mL), and was cultured for 72 h at 25±1 ℃ with shaking, from whichmany conidia were generated. Then, the resulting liquid was filtered and centrifuged, so that spores wereobtained. The obtained spores were used to form spore suspension with sterile water, in which theconcentration of the spores was 10⁶ spores/ml. Subsequently, the spore suspension was coated uniformlyon the plate with water, sugar, and tested subject, in an amount of 100 μl/well. Finally, the coated plate wascultured at 25±1 ℃ in the darkness. Each treatment was repeatedly determined for four times.

After 12 h, the status of spore germination was studied, and 300 spores were studied randomly perreplicate. In view of this, the mean value for four replicates was calculated and thus the mean sporegermination rate was obtained.

The inhibitory rate of the tested subject against spore germination was calculated. Then, the inhibitory ratewas converted to probability value (y), the concentration was converted to logarithm value (x). On thebasis of this, the regression curve equation y＝a+bx of toxicity of the respective drug against sporegermination of Gibberella fujikurio (Saw.) was obtained, and correspondingly the effective inhibitoryconcentration EC₅₀ and the correlation coefficient were obtained.

Results

The data shown in Tables 2, 3 and 4 demonstrate that Penflufen has excellent in vitro inhibitory effect onspore germination of Gibberella fujikurio, with its effective inhibitory concentration of 0.85mg/L.

Table 2. The inhibition of Penflufen against spore germination of Gibberella fujikurio

* the value was the mean value of values obtained from four repeated treatments.

Table 3. The inhibition of spore germination of Gibberella fujikurio by carbendazim

Table 4. Indoor toxicity of penflufen and cabendazim against Gibberella fujikurio

Based on the above-mentioned data, it can be concluded that Penflufen is useful for controlling sporegermination of Gibberella fujikurio.

Example 2: efficacy of seed treatment of penflufen for controlling rice bakanae in field experiment

Materials

In this experiment, the tested subjects were penflufen 240 g/L FS (commercially available under thetradename of

and penflufen 240 g/L FS (commercially available under the tradename of

+imidacloprid& tebuconazole 31.9％ FS (commercially available under the tradename of

The positive control drug was 25％ prochloraz (commercially available under the tradename ofShi Bai Ke from Jiangsu Huifeng Agrochemical Co., Ltd). Water was used as blank control.

The rice used in the experiment was EWAN 17, which was transplanted.

Experimental design and treatment

The experimental treatment groups were shown in Table 5. As for four treatments, each treatment groupwas repeated for three times, and thus a total of 12 plots (30 m² per plot) for all treatments.

Table 5. Experimental design and treatment

Method of seed treatment

1 kg of rice seeds were weighed for each treatment group. The tested subjects of groups 2 and 3 were diluted with water into 30 ml of slurries for application on the rice seeds. Diluted slurry was Poured onto seeds of each treatment group and fully mixed within 1 minute. The treated seeds were dried up at room temperature at least 24 hours before testing.

In treatment group 4, 2 ml 25％prochloraz EC was diluted into 2L of water. Soak the 1kg of seeds into prochloraz solution for 48 hrs in purpose of seed disinfection.

Results

1.The effect of controlling rice bakanae

The control effect of each treatment against rice bakanae was investigated during seedling stage and early heading stage, and the results was shown in Tables 6, in which the experimental data was statically analyzed using Duncan’s Multiple-Range test, and was calculated using the following equations:

Table 6. Control Effect rice bakanae by penflufen ----analysis of variance

The data shown in Tables 6 demonstrate that, during seedling stage, treatment groups 2and 3 have control effect of 76.25％and 82.06％respectively, whereas treatment group 4 using the positive control subject has control effect of 78.01％. The results of analysis of variance indicate that the difference between control effects of treatments groups 2, 3 and 4 is not significant (P＜0.05) .

During heading stage, treatments groups 2 and 3 have control effect of 81.96％and 87.51％, respectively, whereas treatment group 4 using the positive control drug has control effect of 84.09％. The results of analysis of variance indicate that the difference between control effects of other treatment groups 2, 3 and 4 is not significant (P＜0.05) .

In addition, the tested subjects in the range of experimental dose is safe for plants.

2. the quality of rice seedling

The emergence rate was investigated at 11 day after emergence, and the quality of rice seedling was investigated at 23 day after emergence. The corresponding results were as follows.

The emergence rate of the treatment groups is from 78％to 80.67％. The result of analysis of variance indicate that the difference between control effects of various treatment groups is not significant (P＜0.05) .

The plant heights of the treatment groups 1-4 are 30.6 cm, 27.9 cm, 24.5 cm, and 29.3 cm respectively.

The root numbers of the treatment groups 1-4 are 20.5, 21.9, 21.0, and 21.0 respectively. The stem weight of the treatment groups 1-4 are 0.70 g, 0.92 g, 0.66 g, and 0.72 g respectively. The root weight of the treatment groups 1-4 are 0.18 g, 0.24 g, 0.20 g, and 0.22 g respectively. The results of analysis of variance indicate that the difference between different treatment groups is present. The treatment group 2 significantly shows better growth than the other groups.

3.determination of yield

The seeds in the treatment groups 1-4 have a weight of about 26 g per one thousand seeds, a water content of 19.7％, with a yield of 519.20 kg, 538.75 kg, 544.29 kg, and 542.15 kg per 667 m² respectively. In particular, as compared with blank control, the yield of treatment groups 2, 3 and 4 is increased by 3.77％, 4.83％and 4.42 ％respectively. The results of analysis of variance indicate that there is no significant difference between treatments 2, 3 and 4 (P＜0.05)

Claims

Use of penflufen for controlling rice bakanae.
Use of a combination comprising penflufen and at least one further active ingredient for controlling rice bakanae.
Use of claim 2, wherein the at least one further active ingredient is an insecticide or a fungicide.
Use of claim 3, wherein the fungicide is a triazole fungicide or strobilurin fungicide.
Use of claim 4, wherein the triazole fungicide is tebuconazole.
Use of claim 4, wherein the strobilurin fungicide is trifloxytrobin.
Use according to any one of claims 1-4 for the treatment of rice seed.
Method for controlling rice bakanae comprising applying penflufen or a combination comprising penflufen and at least one further active ingredient to rice seed.