CN113558051A

CN113558051A - Acaricidal composition

Info

Publication number: CN113558051A
Application number: CN202111006524.8A
Authority: CN
Inventors: 吴泽伟
Original assignee: Guangdong Zhongxun Agri Science Corp
Current assignee: Guangdong Zhongxun Agri Science Corp
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2021-10-29

Abstract

The invention relates to an acaricidal composition which has good control effect on various mites, in particular to tetranychus cinnabarinus by compounding spirodiclofen and alkyl ethyl sulfonate. The alkyl ethyl sulfonate has strong contact activity on adult mites and nymph mites, can paralyze and dehydrate the mites, is matched with the spirodiclofen to further act on eggs and young mites of the tetranychus cinnabarinus, kills the eggs and the young mites of the tetranychus cinnabarinus, inhibits the egg hatching rate, and leads the adult mites, the nymph mites and the eggs of the mites to be inhibited from growing and dying.

Description

Acaricidal composition

Technical Field

The invention relates to the technical field of acaricides, and particularly relates to an acaricide composition.

Background

In the cotton planting process, tetranychus cinnabarinus is a main insect pest harmful to cotton, nutrient juice is mainly absorbed on the back of cotton leaves, more white spots appear on the front of the leaves in the early stage of the damage, leaf stalks turn red after several days, leaves fall and stalk collapse if the leaves fall and the stalk collapse are like burning, tree vigor and yield are influenced, and large-area yield reduction or top harvest is caused.

However, the difficulty of mite control is getting higher and higher at present, because the resistance of mites is increased year by year under the continuous medicament selection pressure, the control effect of acaricide is greatly reduced, the environment is affected by increasing the dosage of acaricide, the acaricide is not beneficial to environmental protection, the control of cotton diseases and insect pests faces a great challenge, and higher requirements are provided for the control of cotton diseases and insect pests, so that a high-efficiency acaricide is necessary to be researched.

Disclosure of Invention

Based on the above, the acaricidal composition needs to be provided.

The technical scheme for solving the technical problems is as follows: an acaricidal composition comprising: the composition comprises spirodiclofen, alkyl ethyl sulfonate and an auxiliary agent, wherein the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.1-10: 1.

in one embodiment, the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.2-5: 1.

in one embodiment, the composition comprises the following components in parts by mass:

1-30 parts of spirodiclofen;

1-30 parts of alkyl ethyl sulfonate;

20-70 parts of an auxiliary agent.

In one embodiment, the adjuvant comprises: at least one of dispersing agent, antifreezing agent, thickening agent, defoaming agent, penetration enhancer, disintegrating agent, solvent and filler.

In one embodiment, the method further comprises the following steps of: 10 to 30 portions of composite synergist.

In one embodiment, the composite synergist comprises: boric acid, monopotassium phosphate, animal amino acid, humic acid, methylene succinic acid, trace elements, a plant growth regulator and a plant extract.

In one embodiment, the plant extract comprises: scutellaria baicalensis extracting solution, perilla leaf extracting solution, rosemary extracting solution, honeysuckle extracting solution, coptis chinensis extracting solution, fructus cnidii extracting solution and seaweed extracting solution.

In one embodiment, the trace elements include: at least one of iron, zinc, manganese, chromium, and molybdenum.

The invention has the beneficial effects that: according to the acaricidal composition provided by the invention, the spirodiclofen and the alkyl ethyl sulfonate are compounded, so that the acaricidal composition has a good control effect on various mites, and particularly has a good control effect on tetranychus cinnabarinus. The alkyl ethyl sulfonate has strong contact activity on adult mites and nymph mites, can paralyze and dehydrate the mites, is matched with the spirodiclofen to further act on eggs and young mites of the tetranychus cinnabarinus, kills the eggs and the young mites of the tetranychus cinnabarinus, inhibits the egg hatching rate, and leads the adult mites, the nymph mites and the eggs of the mites to be inhibited from growing and dying.

Detailed Description

The present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It is to be noted that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In one embodiment, an acaricidal composition comprises: the composition comprises spirodiclofen, alkyl ethyl sulfonate and an auxiliary agent, wherein the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.2-5: 1. specifically, the alkyl ethyl sulfonate has strong contact activity, quickly paralyzes mites, dehydrates the mites to death, has no effect on drug effect, is matched with the spirodiclofen to inhibit fat synthesis of the mites, blocks energy metabolism of the mites, kills eggs and young mites of tetranychus cinnabarinus, and has the effect of inhibiting the hatching rate of eggs of female mites, so that grown mites, nymphs and mite eggs can be inhibited from growing, and tetranychus cinnabarinus at different stages can be killed comprehensively.

By compounding the spirodiclofen and the alkyl ethyl sulfonate, the composition has good control effect on various mites, particularly Tetranychus cinnabarinus. The mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.1-10: 1, the acaricide composition has excellent activity, has obvious synergistic effect, has the characteristics of small dosage and high acaricidal efficiency, can quickly exert the pesticide effect, overcomes and delays the pesticide resistance of mites, is favorable for reducing the dosage and reduces the influence on the environment. Furthermore, the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.2-5: 1, the composition has obvious synergistic effect on tetranychus cinnabarinus and obviously improved control effect.

In one embodiment, the adjuvant comprises: at least one of dispersing agent, antifreezing agent, thickening agent, defoaming agent, penetration enhancer, disintegrating agent, solvent and filler. Specifically, the dispersant comprises: at least one of polycarboxylate, lignosulfonate, naphthalene sulfonic acid formaldehyde condensate sodium salt, alkylphenol polyoxyethylene, fatty acid polyoxyethylene ester, fatty amine polyoxyethylene ether and glycerol polyoxyethylene ether fatty acid ester, wherein the antifreezing agent comprises: at least one of ethylene glycol, propylene glycol and glycerol, the thickener comprising: at least one of xanthan gum, carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose, magnesium aluminum silicate, and polyvinyl alcohol, the antifoaming agent comprising: at least one of silicone oil, a silicone defoaming agent and C8-10 fatty alcohol, wherein the penetration enhancer comprises: at least one of sodium dodecyl sulfate, calcium dodecyl benzene sulfonate, nekal BX, alkylbenzene sulfonate, polyoxyethylene triphenyl-ethylene phenyl phosphate, Chinese honeylocust fruit powder, silkworm excrement and soapberry powder, wherein the disintegrating agent comprises: at least one of sodium nitrophenolate, sodium bicarbonate, magnesium chloride, aluminum chloride, sodium chloride, urea, ammonium sulfate, and bentonite, the solvent comprising: solvent oil S-200, dimethylbenzene, trimethylbenzene, tetramethylbenzene, methylnaphthalene, methyl oleate, fatty acid methyl ester, pine-base oil, soybean oil, biodiesel, sec-butyl acetate, dimethyl carbonate, diesel oil, white oil, engine oil, N-methyl pyrrolidone and one or more of water, wherein the filler comprises: at least one of kaolin, diatomite, bentonite, white carbon black, light calcium carbonate, attapulgite, clay, talcum powder, quartz sand, starch, alkyl polyglycoside, urea, potassium chloride and ammonium chloride.

In one embodiment, the acaricidal composition comprises, in parts by mass: 1 to 30 parts of spirodiclofen, 1 to 30 parts of alkyl ethyl sulfonate, 3 to 8 parts of dispersant, 1 to 5 parts of antifreeze, 0.1 to 2 parts of thickener, 0.1 to 0.8 part of defoamer and 40 to 60 parts of solvent. Specifically, the acaricidal composition is a suspending agent, and is prepared by adding 3-8 parts by mass of a dispersing agent, 1-5 parts by mass of an antifreezing agent, 0.1-2 parts by mass of a thickening agent, 0.1-0.8 part by mass of an antifoaming agent and part of a solvent into a stirrer, and uniformly stirring and mixing to obtain a premix; then stirring and mixing the spirodiclofen, the alkyl ethyl sulfonate and the balance of solvent uniformly according to a proportion to obtain a mixture, mixing the mixture and the premix, adding the mixture and the premix into a ball mill, and performing ball milling operation for 2-5 h to obtain the acaricidal composition with the particle diameter of less than 5 mm.

In one embodiment, the acaricidal composition comprises, in parts by mass: 1 to 30 parts of spirodiclofen, 1 to 30 parts of alkyl ethyl sulfonate, 3 to 10 parts of dispersant, 1 to 10 parts of penetration enhancer, 1 to 5 parts of disintegrant and 0.9 to 5 parts of filler. Specifically, the dosage form of the acaricidal composition is water dispersible granules, and the acaricidal composition is prepared by adding 1-30 parts of spirodiclofen, 1-30 parts of alkyl ethyl sulfonate, 3-10 parts of dispersant, 1-10 parts of penetration enhancer, 1-5 parts of disintegrant and 1-10 parts of filler into a stirrer, mixing and stirring, adding into an ultramicro jet mill, crushing, adding into a kneader, kneading, adding into a fluidized bed granulation dryer, granulating and drying.

In order to improve the acaricidal effect of the acaricidal composition, in one embodiment, the acaricidal composition further comprises the following components in parts by mass: 3 to 7 parts of composite synergist. Specifically, the composite synergist is a composite system, which comprises: boric acid, monopotassium phosphate, animal amino acid, humic acid, methylene succinic acid, trace elements, a plant growth regulator and a plant extract. In this example, the mass parts of boric acid and potassium dihydrogen phosphate were 1 part, 0.5 part, and 3 parts, respectively, of the plant growth regulator and the plant extract.

Specifically, boric acid can provide boron for cotton and can also play a role in bacteriostasis, monopotassium phosphate is used for providing phosphorus and potassium for cotton, trace elements provide iron, zinc, manganese, chromium and molybdenum for cotton, plant growth regulators, animal amino acids, humic acid and methylene succinic acid contain a large amount of active organic ingredients, and mutual synergistic effect can be generated between the active organic ingredients, so that absorption is promoted, the utilization efficiency is improved, the cell activity of a crop spraying part can be obviously improved, the growth performance is further improved, the photosynthetic utilization rate is improved, and the crop development is obviously promoted.

Further, the plant extract comprises: scutellaria baicalensis extracting solution, perilla leaf extracting solution, rosemary extracting solution, honeysuckle extracting solution, coptis chinensis extracting solution, fructus cnidii extracting solution and seaweed extracting solution. The scutellaria baicalensis extracting solution contains baicalin, proline and benzoic acid, has an inhibiting effect on bacillus, staphylococcus aureus and the like, the perilla leaf extracting solution contains volatile oil and perillaldehyde, can have an inhibiting effect on candida albicans, trichophyton and gypsum-like microsporum, and can inhibit the generation of superoxide anion, the rosemary extracting solution contains volatile oil and phenolic acid components, has antioxidant, antibacterial and anti-inflammatory effects, the honeysuckle extracting solution contains chlorogenic acid and isochlorogenic acid, has a broad-spectrum antibacterial effect, has an inhibiting effect on pathogenic bacteria such as staphylococcus aureus, bacillus, pathogenic fungi and the like, and can promote plant cells to release lysin for sterilization, the coptis extracting solution contains berberine, phellodendron lactone and coptisine, has an inhibiting effect on staphylococcus, streptococcus, bacillus subtilis and the like, and the cnidium monnieri fructus extracting solution contains osthol and xanthotoxin, the seaweed extract has an inhibiting effect on pathogenic microorganisms, the seaweed extract has trehalose, the seaweed extract can have a nonspecific protection effect on various bioactive substances, the activity of organic active ingredients in the plant extract can be maintained, a large amount of active organic ingredients in the plant extract can further improve the pest resistance effect, mites, fungi, bacteria and spores thereof can be effectively killed, the seaweed extract not only can have a synergistic effect with spirodiclofen and alkyl ethyl sulfonate and has a good control effect on tetranychus cinnabarinus, but also can improve the overall stress resistance of cotton and promote the growth and development of cotton.

In one embodiment, the composite synergist further comprises: 0.01 to 0.1 part of nano-selenium, the nano-selenium has high biological activity and is safe and nontoxic, and the nano-selenium can rapidly enter plant cells under the photosynthesis of plants, thereby promoting the rejection function of the cells, improving the disease and insect resistance of the plants, accelerating the aging and the breaking of pesticide molecular chains in the plant cells, and greatly reducing the pesticide residue in crops.

In one embodiment, the composite synergist further comprises: 0.05 to 0.2 portion of sodium benzoate, which has small acute toxicity and mild epidermal cells on plant leaf surfaces, is easy to penetrate phosphate bilayers of bacteria and fungi into the cell bodies of the bacteria and the fungi due to the larger lipophilicity of the sodium benzoate, can interfere the permeability of cell membranes, inhibit the absorption of the cell membranes to amino acid, ionize and acidify alkali storage in cells after entering the cell bodies, inhibit the activity of respiratory enzyme systems of the cells, and prevent the condensation reaction of acetyl coenzyme A, wherein the acetyl coenzyme A is an important intermediate metabolite of energy substance metabolism and is a pivotal substance in the metabolism of the energy substances in vivo, three nutrient substances of sugar, fat and protein can generate acetyl coenzyme A in the metabolic process to enter tricarboxylic acid circulation, and are oxidized to generate carbon dioxide and water, and energy is released to synthesize ATP (Adenosine triphosphate), therefore, the bacteria and the fungi die due to the lack of energy in the life activities by inhibiting the synthesis of ATP, and further play a role in bacteriostasis and sterilization.

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto. All the raw materials and reagents used in the present invention are commercially available raw materials and reagents, unless otherwise specified. In the examples, the components are used in g and mL in parts by mass.

Examples 1 to 7 and comparative examples 1 to 7

The miticidal compositions of examples 1 to 7 and comparative examples 1 to 7, wherein the miticidal composition comprises the components shown in table 1 in parts by mass.

TABLE 1 acaricidal composition of examples 1-7

TABLE 2 acaricidal compositions of comparative examples 1-7

The formulations of examples 1 to 4 in Table 1 and comparative examples 1 to 7 in Table 2 were prepared according to the following procedure:

(1) adding the spirodiclofen, the alkyl ethyl sulfonate and a part of water into a stirrer in proportion, and uniformly stirring and mixing to obtain a premix;

(2) adding polycarboxylate, ethylene glycol, xanthan gum, silicone oil and the balance of water into a stirrer according to a ratio, adding the composite synergist in comparative examples 3-7, uniformly stirring and mixing to obtain a mixture, adding the mixture and the premix into a ball grinding machine, and performing ball grinding operation, wherein the ball grinding time is controlled to be 2.5 hours, so as to obtain the acaricidal composition of examples 1-4 and comparative examples 1-7, wherein the acaricidal composition is in a suspending agent shape.

The formulations of examples 5-7 in table 1 were prepared according to the following procedure:

(1) adding the spirodiclofen, the alkyl ethyl sulfonate, the polycarboxylate, the glycol, the lauryl sodium sulfate, the urea, the kaolin and the composite synergist into a stirrer according to a proportion, and uniformly stirring and mixing to obtain a mixed material;

(2) adding the mixed material into an ultramicro jet mill, carrying out crushing operation, adding the mixed material into a kneader, carrying out kneading operation, then adding the kneaded material into a fluidized bed granulation dryer, and carrying out granulation and drying to obtain the acaricidal composition of examples 5-7, wherein the acaricidal composition is in the form of water dispersible granules.

Comprehensive toxicity determination:

the acaricidal compositions prepared in examples 1 to 7 and comparative examples 1 to 7 were used as examples to perform comprehensive toxicity measurement.

The determination method comprises the following steps: with reference to the method in NY/T1154.12-2008 standard, the slide dipping method was employed.

The Panonychus ulmi Luck is used as a test target. Cutting the double-sided adhesive tape into 2cm long, sticking the double-sided adhesive tape to one end of a glass slide, selecting healthy nymphs with consistent physiological state, sticking the backs of the nymphs to the double-sided adhesive tape, wherein 30 heads of each piece are placed in a container filled with wet sponge by paying attention to avoid sticking of mite feet, tentacles and mouthpieces, covering the container with a cover, and placing the container at the temperature of 25 +/-1 ℃. After 2 hours microscopic examination, dead and injured individuals were removed and 30 heads of each piece were replenished. Immersing a glass slide stuck with a plurality of mites in a test liquid medicine, slightly shaking the glass slide, taking out after immersing for 5s, absorbing redundant liquid medicine by using absorbent paper, putting the glass slide into a white porcelain plate padded with wet sponge, covering the glass slide with a plastic film with good light transmittance, and finally placing the glass slide in a temperature condition of 25 +/-1 ℃ with a light period of L: and D ═ 16: 8) h. Each treatment was set up in 4 replicates and the set-up immersion in clear water was used as a blank. Wherein, the test data are counted after 3 days, and the mortality and the corrected mortality are calculated. If the control mortality is lower than 5%, no correction is needed; if the control mortality rate is between 5% and 20%, correction is needed; if the control mortality is greater than 20%, the test needs to be redone.

Respectively establishing a toxicity regression equation by taking the logarithmic value of the medicament concentration (mg/L) as an independent variable x and the probability value of correcting the death rate as a dependent variable y, and calculating LC50 and the co-toxicity coefficient of the mixed medicament thereof by adopting DPS software.

Calculating the formula:

the Theoretical Toxicity Index (TTI) of mixed preparation is toxicity index of A medicine and the percentage content of A medicine in 100 mixed preparation

+ virulence index of the drug B x 100 percent of the drug in the mixture

TABLE 3 comprehensive virulence measurement results of examples 1 to 7 and comparative examples 1 to 7

LC50 is (Lethal Concentration 50, Lethal Concentration) which means the Concentration of a toxic substance that causes half of the tested animals to die in an animal acute toxicity test, wherein a co-toxicity coefficient (CTC) is an index for measuring whether an insecticide mixture has a synergistic effect, and the co-toxicity coefficient is an actually measured toxicity index/theoretical toxicity index x 100, specifically, the synergistic effect evaluation method refers to a biological standard method NY/T1154.7-2006, and the synergistic effect of the mixture of the insecticide is evaluated according to a co-toxicity coefficient method (CTC), that is, the co-toxicity coefficient (CTC) is greater than or equal to 120 and shows a synergistic effect; the co-toxicity coefficient (CTC) is less than or equal to 80, and the antagonism is shown; 80 < co-toxicity coefficient (CTC) < 120 showed additive effects.

As can be seen from the data in table 3, when the spirodiclofen and the alkyl ethyl sulfonate are compounded to be used as the active ingredients of the acaricidal composition in the examples 1 to 7 of the present invention and the comparative examples 1 to 2, the acaricidal composition with low lethal medium concentration, high safety and a co-toxicity coefficient of more than 120 can be obtained, and the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.1 to 10: 1, when the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 3: 1, the synergistic effect is most obvious, and the co-toxicity coefficient is highest.

Further, by comparing the example 3 with the comparative examples 3 to 7, the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 3: 1, the composite synergist with different parts by weight can achieve obvious gain effect and can improve the control effect on tetranychus cinnabarinus.

And (3) field test:

the test method comprises the following steps: taking the acaricidal compositions prepared in examples 1-7 and comparative examples 1-7 as examples to perform a field pesticide application test, setting a blank control group, carrying out no pesticide application treatment, wherein the test site is located in a grass lake farm in Changji, Xinjiang, diluting the acaricidal composition with water to spray cotton, the liquid spraying amount per mu is 30L, then counting the population base of Tetranychus cinnabarinus before pesticide application, 3 days after pesticide application and 15 days after pesticide application, and calculating the control effect.

The drug effect calculation method comprises the following steps:

TABLE 4 field test results for prevention and treatment of Tetranychus cinnabarinus

Group of	Dilution factor	Control effect 3 days after drug (%)	Control effect (%) 15 days after administration
				Example 1	1000 times of	55.17	82.11
Example 2	1000 times of	61.22	82.74
				Example 3	1000 times of	89.10	95.21
Example 4	1000 times of	74.11	84.05
				Example 5	1000 times of	83.33	80.17
Example 6	1000 times of	87.36	84.11
				Example 7	1000 times of	91.77	75.21
Comparative example 1	1000 times of	21.21	63.14
				Comparative example 2	1000 times of	76.33	42.11
Comparative example 3	1000 times of	89.39	95.33
				Comparative example 4	1000 times of	90.52	95.47
Comparative example 5	1000 times of	91.10	96.62
				Comparative example 6	1000 times of	90.85	95.86
Comparative example 7	1000 times of	89.97	95.54

As can be seen from table 4, when examples 1 to 7 and comparative examples 1 to 2 are compared, the effect of the combination of spirodiclofen and alkyl ethyl sulfonate on tetranychus cinnabarinus control is better than that of each control single agent treatment, the control effect of single spirodiclofen or alkyl ethyl sulfonate is lower, but the drug effect after combination is remarkably improved, and the control effect is remarkably improved, wherein the control effect of example 3 is the best, that is, when the mass ratio of spirodiclofen to alkyl ethyl sulfonate is 3: 1, the spirodiclofen and the alkyl ethyl sulfonate are compounded to obviously reduce the population base of tetranychus cinnabarinus, the control effect reaches 95.21% 15 days after the tetranychus cinnabarinus is taken, the control effect is obviously improved, the use dosage of pesticide can be reduced, the influence of the pesticide on the environment is reduced, and the use cost is reduced.

Further, by comparing the example 3 with the comparative examples 3 to 7, the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 3: 1, the composite synergist with different parts by weight can achieve an obvious gain effect, not only can provide necessary nutrient substances for the growth of cotton, but also can achieve a synergistic effect with spirodiclofen and alkyl ethyl sulfonate, and improve the control effect on tetranychus cinnabarinus.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above embodiments only express a few embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An acaricidal composition comprising: the composition comprises spirodiclofen, alkyl ethyl sulfonate and an auxiliary agent, wherein the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.1-10: 1.

2. an acaricidal composition according to claim 1, wherein the mass ratio of the spirodiclofen to the alkyl ethyl sulfonate is 0.2-5: 1.

3. the acaricidal composition according to claim 1, which comprises the following components in parts by weight:

1-30 parts of spirodiclofen;

1-30 parts of alkyl ethyl sulfonate;

20-70 parts of an auxiliary agent.

4. An acaricidal composition according to claim 3, characterized in that said adjuvant comprises: at least one of dispersing agent, antifreezing agent, thickening agent, defoaming agent, penetration enhancer, disintegrating agent, solvent and filler.

5. The acaricidal composition according to claim 3, further comprising, in parts by mass: 10 to 30 portions of composite synergist.

6. An acaricidal composition according to claim 5, characterized in that said composite synergist comprises: boric acid, monopotassium phosphate, animal amino acid, humic acid, methylene succinic acid, trace elements, a plant growth regulator and a plant extract.

7. An acaricidal composition according to claim 6, characterized in that said plant extract comprises: scutellaria baicalensis extracting solution, perilla leaf extracting solution, rosemary extracting solution, honeysuckle extracting solution, coptis chinensis extracting solution, fructus cnidii extracting solution and seaweed extracting solution.

8. An acaricidal composition according to claim 6, characterized in that said trace elements comprise: at least one of iron, zinc, manganese, chromium, and molybdenum.