CN102239866A - Composite bactericide containing dithianon and pyraclostrobin and application thereof - Google Patents

Abstract

The invention relates to a composite bactericide composition belonging to the technical field of composite bactericide pesticides and application thereof. The composite bactericide containing dithianon and pyraclostrobin is characterized by comprising active components, i.e., dithianon and pyraclostrobin, wherein the weigh mixing ratio of the dithianon to the pyraclostrobin is (40:1)-(1:4). The composite bactericide has the following advantages: 1. the synergistic effect is obvious; 2. compared with the single dose, after compounding, the usage amounts of the dithianon and the pyraclostrobin are reduced obviously; and 3. the generation of resistance to drugs is avoided or postponed, and by compounding, the two bactericides can mutually make up disadvantages when being used alone.

Description

Contain the composite bactericide and the application thereof of dithianon and pyraclostrobin

Technical field

The present invention relates to two kinds of a kind of combination sterilization composition, particularly dithianon and the pyraclostrobins composite bactericide after bactericide compounded, belong to composite bactericide agricultural chemicals and applied technical field thereof.

Background technology

For a long time, because aborning in order to guarantee that agricultural output and presentation quality use chemical pesticide in a large number, ecotope is produced immense pressure, and cause pathogen under high agricultural chemicals selection pressure, to develop immunity to drugs rapidly, further strengthened the bactericide consumption, thereby cause agricultural product persticide residue severe overweight, people and animals, environment are caused significant damage.The development and utilization Environmental compatibility, reduce the agricultural chemicals dosage, the agricultural chemicals resource of avoiding pesticide resistance to produce favored day by day.

Dithianon (dithianon) is a Merck KGaA company in the bactericide of the exploitation sixties in 20th century, has the multiple mechanism of action, can by with the normal growth metabolism of reaction of sulfur-bearing group and interference cell respiration inhibition germ.This bactericide has advantages such as wide spectrum, resistance are low, low toxicity, can be used for preventing and treating the control of drupe, a kind of fruit, such as apple, pear, etc. multiple diseases.Obtained development and utilization (number of patent application: 200910021485.1,200910021811.9,200910021676.8,201010003068.7,200910219585.5 etc.) at home.Pyraclostrobin is a kind of novel methoxy acrylic bactericide (strobilurins), and by the mitochondrial breathing of electronics transfer inhibition between cytochrome b and c1 in the blocking-up respiratory chain, the supply of interference cell energy causes the pathogen cell death.But because of this bactericide mechanism of action is single, if long-term single use causes pathogen to develop immunity to drugs; The independent use cost of this bactericide is higher in addition.By carrying out effectively compositely, advantages such as the pesticide resistance of delaying produces, reduces production costs, increases the service life are arranged all with other bactericide.Also obtained exploitation (number of patent application: 200810014754.7,200810014753.2,200910136088.9,200910023008.9,201010170358.0 etc.) at home.Be used to prevent and treat ring rot of apple after dithianon and pyraclostrobin are composite and yet there are no report.

Ring rot of apple is the thorny problem on the present apple production, and the harm fruit can cause a large amount of decayed fruits, and harm limb can cause the weak and branch death of tree vigo(u)r, causes output to reduce and quality decline, and annual economic loss is inestimable.At present, chemical control is still the main means of ring rot of apple integrated control.At present, the bactericide pyraclostrobin has begun to be applied to prevent and treat ring rot of apple.But there is great pesticide resistance risk in methoxy acrylic bactericides such as long-term single a large amount of use pyraclostrobins.Avoiding pesticide resistance to produce is the problem that current PCO must be considered.

Summary of the invention

The object of the present invention is to provide a kind of composite bactericide that contains dithianon and pyraclostrobin of preventing and treating ring rot of apple, the present invention is on the basis of above-mentioned existing patented technology, the application in agriculture field by further research dithianon and complex composition thereof is especially finished at the ring rot of apple study on prevention.

The present invention is by studying independent use of protective fungicide dithianon and systemic fungicide pyraclostrobin and composite back Toxicity Determination and the field trial to ring rot of apple; estimate the reasonability of the microbicide compositions of different compound proportions; inquire into dithianon and the composite control efficiency of pyraclostrobin, reduce dosage to reach, reduce production costs, avoid or delay purpose such as pesticide resistance generation.

The technical solution adopted in the present invention is as follows:

Composite bactericide contains active component dithianon and pyraclostrobin, and the weight proportion of the two is 40: 1～1: 4; The optimum weight proportioning is 4: 1;

The composite bactericide that contains dithianon and pyraclostrobin of the present invention is had outstanding performance aspect the ring rot of apple preventing and treating.

Single agent dithianon has certain control efficiency to ring rot of apple, but therapeutic action is poor.Single agent pyraclostrobin is applied to prevent and treat ring spot and has good control efficiency, but has huge potential pesticide resistance risk.The composite application of dithianon and pyraclostrobin prevents and treats ring rot of apple and has following advantage:

1, synergistic effect is obvious.Dithianon and pyraclostrobin two components are 40: 1～1: 4 to the weight ratio that the ring rot of apple bacterium has synergistic effect in the complex composition, and coefficient of synergism is all greater than 1.5, and especially with 4: 1 synergistic effect maximum, coefficient of synergism was 5.09.The sub-district, 20% dithianon pyraclostrobin suspending agent field of making according to the field actual conditions prevents and treats ring rot of apple and has all obtained remarkable prevention effect.

2, all obviously minimizings of usage amount of dithianon and pyraclostrobin are compared in composite back with single agent.Two kinds bactericide compounded after, considering active constituent content and using under the situation of multiple that the actual field usage amount of dithianon has reduced by 64.76%; The pyraclostrobin consumption only is 32% of single agent usage amount in the combination sterilization composition.

3, avoid or delay pesticide resistance and produce.The protective fungicide dithianon has many, the advantage such as be difficult for developing immunity to drugs of action site, but interior suction therapeutic action is poor; Pyraclostrobin is a systemic fungicide, and action site is single, very easily develops immunity to drugs.Two kinds of bactericide are by composite inferior position can remedy two kinds of bactericide mutually and use separately the time.

Embodiment

The present invention is elaborated with following specific embodiment, but limitation of the present invention absolutely not, percentage all is weight percentage in all proportionings.

Embodiment 1 Toxicity Determination and compound proportion screening

1.1 reagent agent

22.7% dithianon suspending agent, Jiangsu Heyi Chemical Industry Co., Ltd.'s product.It is standby to be made into the 5000mg/L mother liquor with distilled water.

250g/L pyraclostrobin missible oil, BASF European Co.,Ltd's product.It is standby to be made into the 10000mg/L mother liquor with distilled water.

1.2 strains tested

Ring rot of apple bacterium (Botryosphaeriadothidea) separates acquisition on the sick sample of field typical case, the first generation bacterial strain that the single cell culture purifying obtains is preserved standby in 4 ℃ of refrigerators.

1.3 experimental technique

The biomass growth rate method (mycelium growth rate test) that adopts FAO to recommend.

1.3.1 the preparation of pastille flat board

1.3.1.1 composite reagent scheme

Table 1 dithianon and pyraclostrobin compound proportion

1.3.1.2 the preparation of pastille flat board

Drug concentration gradient according to 1.3.1.1 sets adds medicament in the PDA medium that quantitatively dissolves, and makes the pastille flat board, is blank with pastille flat board not, and every concentration repeats 3 times.

1.3.2 connecing bacterium cultivates

Beat along cultured colony edge with diameter 0.6cm card punch and to get bacterium dish, with the sterilization transfer needle bacterium dish is reversed and be transplanted on the flat board, placed under 25 ℃ of conditions constant temperature culture 7 days.

1.3.3 inspection as a result

Measure bacterium colony expansion diameter with ruler intersection mensuration, expand diameter with not dispenser contrast bacterium dish and compare, obtain medicament and suppress growth rate.

1.3.4 statistical analysis

Do regression analysis according to each drug concentration logarithm value and corresponding mycelial growth inhibition rate probability value, calculate each medicament virulence regression equation, correlation coefficient (r) and EC ₅₀

When carrying out the medicament joint toxicity measuring,, estimate the synergy type of complex composition according to the coefficient of synergism (SR) of Wadley method calculating complex composition.Estimate the synergistic effect of composite reagent according to coefficient of synergism (SR), promptly SR＜0.5 is an antagonism, and 0.5≤SR≤1.5 are summation action, and SR＞1.5 are synergistic effect.Coefficient of synergism (SR) calculates by formula (1), (2):

$X_1=\frac{P_A+P_B}{P_A/A+P_B/B}\×100---\left(1\right)$

In the formula:

X ₁----complex composition EC ₅₀Theoretical value, unit is mg/L;

P _A----percentage composition of A in the complex composition, unit is percentage (%);

P _B----percentage composition of B in the complex composition, unit is percentage (%);

A----complex composition EC ₅₀Theoretical value, unit is mg/L;

B----complex composition EC ₅₀Theoretical value, unit is mg/L.

$\mathrm{SR}=\frac{X_1}{X_2}\×100---\left(2\right)$

In the formula:

The coefficient of synergism of SR----complex composition;

X ₁----complex composition EC ₅₀Theoretical value, unit is mg/L;

X ₂----complex composition EC ₅₀Measured value, unit are mg/L.

1.4 experimental result

Dithianon and pyraclostrobin proportioning all show synergistic effect to the ring rot of apple bacterium in 40: 1～1: 4 scope, especially 4: 1 proportioning synergy is especially remarkable, and coefficient of synergism is 5.09 (tables 3).

Table 3 dithianon and pyraclostrobin are to the best proportioning The selection result of ring rot of apple bacterium

The field plot trial of 2 pairs of rings rot of apple of embodiment

Filter out dithianon and pyraclostrobin proportioning 40: 1～1: 4 according to indoor compound proportion screening experiment, all show synergistic effect.On indoor proportioning screening experiment basis, consider single agent in the field practical situations, we have made 20% dithianon pyraclostrobin suspending agent, wherein contain 16% dithianon composition, contain 4% pyraclostrobin composition.

2.1 arrange test medicine and sub-district

" " pesticide field efficacy medicine test criterion (two) " the 118th part: bactericidal agent for preventing and treating ring rot of apple " according to the chief editor of The Institute for the Control of Agrochemicals of the Ministry of Agriculture,PRC designs the field control effectiveness test of 20% dithianon pyraclostrobin suspending agent to ring rot of apple.Experimental cultivar is a red Fuji apple tree.

2.1.1 reagent agent

22.7% dithianon suspending agent, 800 times.(Jiangsu Heyi Chemical Industry Co., Ltd.'s product)

250 grams per liter pyraclostrobin missible oil, 3000 times.(BASF European Co.,Ltd's product)

20% dithianon pyraclostrobin suspending agent, 1500 times.(academy of agricultural sciences, Yantai City makes)

2.1.2 contrast medicament

800 times of 80% mancozeb M-45 wetting powders.(The Dow Agrosciences, LLC.'s product)

2.1.3 sub-district design

6 processing are established in test altogether, and 24 sub-districts are established in 4 repetitions of every processing altogether, and 4 of every sub-districts become the strain tree.Each sub-district randomized arrangement.Spraying equipment adopts workers and peasants' 26 type high pressure power driven sprayers, with in the tree crown all the branch blades even medicine, till dripping.

2.2 control time and drug effect computational methods

2.2.1 control time and method

Picking time, centre 2 strains were chosen in every sub-district, investigated whole fruits, and the total fruit of record number, sick fruit number calculate preventive effect with diseased fruit rate; Storage period, after respectively handling fruit after will gathering and rejecting disease, worm, wound fruit, the same day, the dress basket was put under the natural room temperature, store back 10 days, 20 days, the 30 days once sick fruit numbers of investigation respectively, with accumulation diseased fruit rate calculating preventive effect.

2.2.2 drug effect computational methods

2.3 result of the test

Have outstanding performance in the test of field control ring rot of apple at the 20% dithianon pyraclostrobin suspending agent of making on the basis of lab screening, 1500 times of preventive effects in picking time are more than 90%, the preventive effect of storage period is 85.71%, is significantly higher than the preventive effect (table 4) of 800 times of 800 times of 22.7% dithianon suspending agents and contrast medicament 80% mancozeb M-45 wetting powders.Newly develop the preventive effect indifference of 3000 times of the preventive effect of 1500 times of suspending agents and 250 grams per liter pyraclostrobin missible oil.

Table 420% dithianon pyraclostrobin suspending agent field control ring rot of apple result of the test

Annotate: data are and pat equal data everywhere in the table.

Claims (3)

1. the composite bactericide that contains dithianon and pyraclostrobin is characterized in that containing active component dithianon and pyraclostrobin, and the weight proportion of the two is 40: 1～1: 4.

2. according to the described composite bactericide that contains dithianon and pyraclostrobin of claim 1, the optimum weight proportioning that it is characterized in that described dithianon and pyraclostrobin is 4: 1.

3. the composite bactericide that contains dithianon and pyraclostrobin as claimed in claim 1 or 2 is used to prevent and treat ring rot of apple.