PESTICIDAL COMPOSITION

Abstract: The invention relates to pesticidal composition against bacterial plant diseases comprising as active ingredient a nitrofurane derivative of the general Formula I - wherein X represents a group of the Formula a/ and optionally one or more known fungicidal active ingre­ dient/s/ in a total amount of 1-99 % by weight, whereby the ratio of the active ingredient of the general Formula I to the known fungicidal active ingredient/s/ amounts to 1:99 - 99:1, preferably 1:9 - 9:1 if the composition comprises two active ingredients and 1:9:0.5 - 1:1:5, preferably 1:4:1 - 1:1:4 if the composition comprises three active ingredients, respective­ ly, in admixture with suitable inert solid or liquid carrier/s/ or diluents/s/ and usual auxiliary agents such as wetting agents, dispersing agents, adhesives, anti-foaming agents and/or antifreezers.

Description: This invention relates to pesticidal compositions for controlling bacterial plant diseases, a process for the preparation thereof and their use in agriculture for the control of bacterial plant diseases. According to an aspect of the present invention there are provided pesticidal compositions against bacterial plant diseases comprising as active ingredients furazolidone (1) and carbendazim (or MBC) (2-methoxycarbonylamino-benzimidazole) in a weight ratio of 1:1·5-9 in admixture with suitable inert solid or liquid carrier(s) or diluent(s) or auxiliary agents such as wetting agents, dispersing agents, adhesives, antifoaming agents and/or antifreezers. The compositions of the present invention are useful in the control of the following bacterial diseases or bacterial and fungal diseases of plants, respectively: Agrobacterium tumefaciens O Agrobacterium tumefaciens C-58 Agrobacterium tumefaciens B-6 Agrobacterium radiobacter K-84 Erwinia uredowora Erwinia carotovora var, atroseptica Erwinia carotovora Corynebacterium michiganense Corynebacterium nebraskense Xanthomona spp. Fusarium spp., Rhizoctonia spp., Botrytis spp., Sclerotinia spp., Alternaria spp., Penicillium spp., Aspergillus spp., Rhizopus spp. The compositions of the present invention are particularly suitable for the protection of propagating materials - e.g. seeds, tubers, bulbs, cuttings, before sowing or during storage. In addition to the large number of fungal diseases, plants are also subject to damage caused by various phytopatlogenic bacteria. The most important characteristics of the diseases induced by plant patlogenic bacteria are summarized by Klement [Plant Protection /1982/ No. 3]. Pesticidal active ingredients used against simultaneously occuring fungal and bacterial diseases are summarized in Table 1, where the prior art citations are disclosed as well. Chemical Abstracts, no 141709n discloses studies on the sensibilizing and stabilizing effect of macromolecules, such as of the nitrofurane derivative 1b on plant-protecting suspensions. However, none of the above compositions is suitable for complete protection and therefore antibiotics are used for the control of bacterial infection. In most countries however, the use of antibiotics in agriculture is prohibited. It is the object of the present invention to overcome the deficiencies of known methods in the control of bacterial plant diseases. More particularly the object of the present invention is to provide efficient protection against bacterial plant diseases and a plant protecting agent suitable for the simultaneous control of bacterial and fungal diseases. It is known from veterinary practice that nitrofuran derivatives are active against certain gram-negative bacterium strains. However, prior art is completely silent in teaching any antibacterial use of nitrofuran derivatives in plant protection. According to pre-tests and in vitro tests carried out in connection with the present invention the following nitrofuran test-compounds are used: CH-819, Furazolidone = 5-nitro-furfurylidene-3-amino-2-oxazolidone; CH-1237, Nitrofurantoin: N-/5-nitro-furfurylidene-2/-1-amino-hydantoin; CH-1552 = 3-/5-nitro-furfuryldene-amino/-imidazole-2-thiol; CH-2007 = 2-/5-nitro-furfurylidene-amino/-4-chloromethyl-5-/2-chloroethyl/-thiazole; CH-2011 = 2-/5-nitro-furfurylidene-amino/-4-methyl-5-/2-chloroethyl/-thiazole; CH-2103 = 2-/5-nitro-furfurylidene-amino/-4-methyl-5-/2-hydroxyethyl/-thiazole. The results are summarized in Table 2. It is noteworthy that Erwinia carotovora and Agrobacterium tumefaciens strains are highly sensitive towards compound No. 819 but moderately sensitive towards compound No. 1552. On the basis of the pre-tests further in vitro tests are carried out in order to determine the biological activity of certain nitrofurane derivatives and combinations of nitrofurane derivatives with fungicidal active ingredients. Further details of the present invention are to be found in the following Examples without limiting the scope of protection to the said Examples. Example 1 Activity data of the test compounds against Erwinia carotovora var. atroseptica in Petri-dish test The test is carried out with five replicates for each dose by using a nutrient medium suitable for the isolation of Erwinia carotovora. The bacterium is propagated in a nutrient medium on slant agar and with the bacterium suspension isolated from a pure culture the nutrient medium cooled to 40-50 o C is inoculated by the following method. Into Petri-dishes having a diameter of 10 cm a nutrient medium /20 ml/ is poured and after solidification 4 holes are bored into each Petri-dish. Into each hole 0.1 ml of the suspension is applied. Incubation is carried out at 25 o C. The results are disclosed in Table 4. It appears from the above data that on the basis of the size of the inhibition zone nitrofurane derivatives CH-819 proved to be active against Erwinia carotovora var. atroseptica in a concentration of 1.0-1.5 mg/ml at a dose of 0.1 ml/hole. Benomyl and MBC do not increase the bactericidal activity. Example 2 Potato tubers /Desire species/ are cut into two pieces; holes /depth 15 mm, diameter 10 mm/ are bored at an approximately same distance from each other /twice 5 holes/. 0.1 ml of an aqueous suspension comprising Erwinia carotovora var. atroseptica bacterium is added dropwise into the holes /0.1 ml into each hole/. The test compound is poured into the holes pre-treated with the bacterium with the aid of a micropipette after half an hour. The treated and infected tubers are kept in a humid chamber for three days /72 hours/ whereupon the evaluation is carried out. The holes are cut in two parts perpendicular to the original cutting plane, the soft rot pieces are stratched out and weighed. The efficiency of the treatment is evaluated by comparing with the untreated control on the basis of the following scale: Infection category 0 = 0 - 5 % 1 = 6-10 % 2 = 11-25 % 3 = 25-50 % 4 = above 50 %. The above percental values represent the weight of the stratched material pectolized by E. carotovora stroseptica related to the weight of the control. "0" indicates the most favourable and "4" indicates the least effective treatment. The results are summarized in Table 5. The plant protecting agents may be formulated in various forms and the composition is selected by taking into consideration the conditions of application, the plant cultivating technology and the available machinery. In order to protect tubers, bulbs, root-stocks and rhizomes during storage it is necessary to subject the said propagating materials to treatment before storage. The said technology is substantially identical with or similar to the so-called "dressing process" generally used for the pre-sowing treatment of the above parts of the plants and seedlings. The said dressing methods can be carried out at different points of time. The pesticidal compositions of the present invention may be formulated in usual and conventional forms e.g. powders, water dispersible powders, suspension concentrates, granules etc. The preparation of the compositions of the present invention comprises two fundamental steps which may be often combined with each other: The first step comprises the preparation of an active ingredient having a suitable particle. It has been found that in order to achieve the desired result 70 % of the particles must have a particle size below 10 µm. This may be carried out by two methods. According to the said methods the active ingredient is ground to the desired particle size by a dry process /e.g. in an air current mill/ or a wet method /e.g. in a pearl or sand mill/. According to a preferred form of realization of the process the chemical reaction used for the preparation of the active ingredient is carried out in such a manner that an active ingredient having the desired particle size should be obtained; thus the use of the expensive grinding apparatus having a high energy demand can be rendered superfluous. The second step is the preparation of the desired formulation whereby the particles of the active ingredient are contacted with the auxiliary agents, carriers, diluents, adhesives, activity increasing compounds, colouring agents etc. Example 3 The following composition is prepared: Example 4 After digging up potato tubers of a propagation degree of UT-1 /Desire species/ are treated on the 23rd October with certain doses of the test compounds in the form of wet dressing /15 l of treating liquid/to/. The potato collected with a machine is purified before treatment, sorted, the lumps, residual stems and ill tubers are removed. 200 tubers are used for each treatment and 3 replicates are carried out for each dose. The treated tubers are put into cloth sacks and placed into aerated large pile storage equipments. During storage the temperature is adjusted below 15 o C and the relative moisture content amounts to 80-90 %. The changing environmental parameters of the prismatic storing equipment /temperature, moisture content/ provide suitable conditions for the pathogenic pests. Evaluations are carried out on the 31st April of the next year. The weight and ratio of the healthy and infected tubers, the rate of abating and the infection degree of the pests is determined. The results are summarized in Table 6. The results of the above industrial scale test prove the effectiveness of the combination of the present invention against plant diseases. On untreated control Fusarium dry rot cause the largest losses but the damages induced by Erwinia car. var. atrospetica are high as well. Example 5 Potato /Desire species/ is treated before planting with certain doses of the test compounds by using a dressing machine type GUMOTOX at a dose of 6.5 l of treating liquid/to. Planting is carried out with the aid of a 4-Sa BP-75 planting machine. The size of the plots is 0.5 ha, the number of replicates amounts to 3 and the weight of seed tubers is 2.8 to/ha. 15 days after sowing the plants not sprouted as a result of Rhizoctonia germ infection are counted, on an area of 4 x 50 running metres the Thizoctonia shoot-infection is determined /200 shoots each/ the infection of the tubers is counted by inspecting 200 tubers each and the ratio of the tubers having a seed size of 4-6 cm is determined. The results are summarized in Table 7. As a result of dressing carried out before sowing the crops yield and the weight of potato crops /%/ increased to a significant extent. Example 6 Sensitivity of plant pathogens and bacteria towards mixtures of carbendazim and furazolidone of various ratios In vitro bactericidal tests are carried out. The minimal inhibitory concentration of various mixtures of the said two xenobiotics is determined as follows: Various ratio mixtures of the two antibiotics are formulated and amixed with the nutrient medium having the composition disclosed below. The final concentration of furazolidone amounts to 1000, 100, 10, 1 and 0.1 mg/l, respectively. The concentration of carbendazim in the medium varies depending on the mixing ratio. The relative efficiency related to furazolidone is calculated on each tested species for each mixing ratio /25 species/. The results are calculated by using the formula of McKiney /Sváb 1981: Biometrical methods in research, Mez gazdasági Kiadó Budapest/. The results are graphically plotted on Figure 1, in which the % effectiveness for the mixtures tested and other substances for comparison is given on the y-axis. It has been found in a surprising manner that if carbendazim dominates in the mixture the bactericidal activity of furazolidone is significantly increased, namely in certain cases by 100 times /see Table 3/. This synergism may be observed particularly in the Xanthomonas genus. Nutrient medium Agar powder nutrient medium /Human OEV/ 26 g; Bacto agar 2.5 g; glucose 3 g; yeast extract 1 g; Bacto peptone 2 g; potassium dihydrogen phosphate 0.55 g; potassium chloride 0.1 g; sodium chloride 0.1 g; magnesium sulfate 0.125 g; calcium chloride 0.125 g; iron citrate 0.02 g; micro element solution according to Hoagland and Arnon 1 ml /related to 1 litre of the nutrient medium/. The pH value of the nutrient medium is adjusted to 6.5 by adding a 2 N ammonium hydroxide solution. Inoculation The test compounds are added to the nutrient medium having a temperature of 50 o C before plate moulding. Inoculation is carried out after solidifaction according to usual methods of bacteriology. Example 7 Elimination of Xanthomonas oryze infection in rice by seed-dressing The pathogen is isolated from seeds originating from the Far-East and showing unidentified infectedness. These seeds are used in the treatment. 250 seeds are treated in each treatment before germination with mixtures of Kolfugo 25 FW and Furazolidine 30 FW used in suitable doses /Example 7/. Since Kolfugo 25 FW was completely inactive against pure cultures it was not used for the treatment of seeds. The seeds are subjected to pre-germination in wet filter paper for 48 hours /this is a model of the so-called "dopog" method/ whereupon 200 seeds having a germ-fundament are selected for each treatment. These seeds are punctured with a needle at the stem of the radicle. The thus treated seeds are sown in a sterile soil and grown in a phytotrone /12 hours' illumination, at 28 o C during the day and at 25 o C during the night/ for 15 days whereupon the results are evaluated.

Claims: A pesticidal composition for controlling bacterial plant diseases comprising as active ingredients furazolidone and carbendazim in a weight ratio of 1:1.5-9, in admixture with suitable inert solid or liquid carrier(s) or diluent(s) and auxiliary agents such as wetting agents, dispersing agents, adhesives, anti-foaming agents and/or antifreezers. A process for the preparation of a composition according to claim 1, which comprises admixing the active ingredients with the carriers, diluents and auxiliary agents. A method for combatting bacterial plant diseases which comprises applying onto the plants, the soil or the environment thereof an effective amount of a composition according to claim 1.

Inventors: ANGYAN, SANDOR, DETRE, TAMAS, MARMAROSI, KATALIN, OROS, GYULA, RACZ, ISTVAN, SOS, JOZSEF, SZEGO, ANDRAS
Applicants: CHINOIN GYOGYSZER ES VEGYESZETI TERMEKEK GYARA RT.
Application year: 1985
Main classification: A01N43
IPC codes: A01P1, A01N47, A01N43, A01N37, A01P3, A01N1