DE2204455A1 - Process for the preservation of storable harvested cereal grains and fruits - Google Patents

Description

Rohm and Haas Company, Independence Mall West, Philadelphia,

PA. 19105 / USA

Our file: S / R 14-68

Process for the preservation of storable harvested cereal grains and fruits

The invention relates to a method for preserving cereal grains and oil fruits at high humidity during storage or transport. It also deals with the control of fungi in such stored products. Finally, protective agents for stored cereal grains and oil fruits, which are used as active ingredients, fall within the scope of the invention Metal salts of N-lower alkyl substituted dithiocarbamic acid contain.

The Food and Agriculture Organization (FAO) of the United Nations has estimated that in India, Africa and South America up to 30% of the harvested grain destroyed during storage r> ro year will. In temperate zones, this loss is estimated at 5%. A good part of these losses occurs through Fungi, which in humid conditions reduce the Grain quality result, so that the grain for the production of food or by carrying out fermenting of various kinds becomes unsuitable.

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Three special conditions create storage loss:

a) Grain, for example corn or sorghum, which is harvested in the Midwest of the USA, for example, is often stored in a too moist condition due to the harvesting conditions.

b) There may be a need to quickly harvest and transport moist corn or other moist grain and to feed in order to achieve the maximum weight gain per ton of feed (fresh and non-dried grain is an excellent animal feed).

c) Will be grain with a marginal quality in terms of moisture content transported through humid tropical areas or shipped through humid temperate zones, then the moisture content can rise to such an extent that heating and decomposition occur. With certain moisture contents, an increase in the moisture content can occur by only 1% cause a significant amount of corn or wheat to heat up and decompose during storage.

Other sensitive fruits are peanuts, flax and soybeans. For example, soybeans are sold by the United States Department of Agriculture using one of rated on a scale ranging from 4, with moisture contents of 13%, 14%, 16% and 18% represented by each degree of storage will. Soybeans with the rating Mr.2 (14% moisture) are classified as poorly storable, and as a result of the risk of infestation by fungi that occur in this moisture content can grow.

There is a need for an agent that can contain soybeans, wet wheat, or wet corn with a rating of 2.3

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or 4 prior to processing or use as a Makes feed storable.

In US Pat. No. 1,972,961 it is described that some salts and esters of N-alkyldithiocarbamic acid are biological Have activity, but it is not stated that these compounds are used as fungicides and microbicides can be. Because of the in vitro values given there, there are hundreds of potential uses in question. Of these compounds, the iron (III), sodium and zinc salts are mentioned. In connection with the Zinc salt is not reported to have any biological effectiveness. Of the iron (III) and the sodium salt it is stated that that they are effective in vitro against various types of fungi. Furthermore, in connection with these compounds, a suitable synthesis method indicated.

Ferbam (iron III dimethyldithiocarbamate) and Ziram (its Zinc analog) have already been sold as foliar fungicides. It was found that the sodium salt of N-methyldithiocarbamic acid (Metham Sodium) particularly effective against Root knot nematode (see U.S. Patent 2,766,554). Methame sodium and its zinc analogue (see US Pat. No. 3,113,908) were mainly marketed as soil nematocides, although these compounds appear to have some activity as soil fungicides.

In US Pat. No. 2,792,327, only metham sodium is used for the control of fungi on living plants and for the treatment of seeds. Regarding the However, no efficacy values are given for plant seed treatment.

The fourth contained in this last-mentioned US-PS show that the salt in question is a relatively poor foliar fungicide. Example 1 shows that metham

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Sodium in vitro is able to control two fungi on agar for a period of three days. This connection enables when spraying on young tomato plants a 75% Control of fungi causing late blight compared to untreated control plants. at a study using very young bean plants shows about 50% control of rust causing Fungi found in comparison to the control plants. Since control rates in this order of magnitude are economical are not interesting, so far the usability of these alkali salts in addition to an application on the floor is not suggested. The mentioned patent does not suggest the possibility of the connection in question to be used effectively to improve the shelf life of grains and fruits.

In addition, the use of methane sodium was considered Fungicide for application to leaves has not been considered on an industrial scale. It was therefore due The prior art does not expect this selected group of fungicides to be effective with edible plants can be contacted without risk. Rather, metham sodium has so far only been used as a soil fungicide viewed.

Albeit hence the metal salts of N-alkyldithiocarbamic acid have been known as biological active ingredients for at least UO years, it has not yet been recognized that these compounds, in particular the alkali salts, such as the sodium and zinc salts of this acid, are now unique Have effectiveness.

In connection with highly effective fungicides, such as

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wise nabam, mercury chloride, mercury phosphates, Phenols and ethylene dibromide have so far only been negative Results relating to the control of organisms which impair the storage of grain are given. this very much confirm the unpredictable results obtained when using known soil microbicides on this special field of treatment of grains achieved. Also, are Zineb and Mancozeb, as shown in more detail below will be similarly ineffective in this particular field of application.

It was therefore believed that the only viable method was to control the moisture content as well as the Temperature of the stored grains to prevent the growth of mold.

The potential uses for an effective grain and oil crop protectant are as follows:

a) Application as a spray on damp maize, which comes from a harvesting machine and is loaded onto a truck.

b) Application in the form of a spray, which is applied to rice, flax, sorghum, wheat, barley, oats or the like Sprayed at the time of harvest.

c) application in the form of a spray that is sprayed onto grain loaded onto ships from railway wagons, especially when parts with high humidity are mixed with parts with low humidity.

d) Application in the form of a dust. or a spray on a silage to prevent mycotoxin formation.

e) Spread on sugar cane and raw cotton before making bales to avoid decomposition processing.

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f) Sprinkle on harvested soybeans and peanuts before grinding to prevent aflatoxin formation and fungus degeneration of the feed meal and oil obtained during and after processing.

The invention is based on the unexpected finding that the zinc and sodium salts of N-methyldithiocarbamic acid particularly effective at combating fungi that are common grow on stored moist grain and oil crops, such as wheat, corn, oats, Feis, flax, Sorghum, barley and soybeans. These salts are particularly effective in combating fungi, which are known in the art Form mycotoxins in stored, very moist wheat grains. Furthermore, after volatilization, these compounds leave behind which occurs when combined with "cooked" animal feeds, with minimal residue.

The object of the invention is to create a new fungicide for stored, very moist cereal grains. Through the invention fungus control is made possible which differs from that which is carried out using the known Grain protectant is carried out, and as a result a wider range of fungicidal activity as well as the minimal residue left. Further falls within the scope of the invention to provide a feed made from a grain treated in this way has been. No further fungus growth or aflatoxin production occurs with this feed. The invention allows the treatment of cut silage to eliminate the potentially harmful fungi while the beneficial bacteria are not influenced. Furthermore, a cereal fungicide for Provided that is more effective and economical

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than the more recently developed treatments such as using propionic acid and thiabentazole.

Combating the decomposition of grain during storage caused by mycotoxin-forming fugi, such as Aspergillus flavus, Gibberella zeae, and Penicillium spp. is possible through selected metal salts of N-methyldithiocarbamate. The sodium and zinc salts are particularly effective on stored corn and wheat with a moisture content of 20-26%.

The main putrefactive fungi are made from the grain with dosages of 57-454 g per ton (1/8 to 1 Ib per ton) eliminated. In this way, the grain treated in this way is not only preserved but also does not act as a Source of vaccination for various food and feed formulations, which are made from it. In general, quantities are used in practically all areas of application of the active ingredient between about 113 and about 907 grams (0.25 to 2 lbs. per ton) of depositable or stored and grain to be preserved gives satisfactory results.

Grain and fruit preservatives are according to the invention made available in which the active ingredient of the general formula

R NHC SM

corresponds to where R is a straight chain lower alkyl group of up to 3 carbon atoms, and M is zinc or Sodium, with an inert auxiliary material also being provided as a carrier.

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Attempt I.

400 g of a non-sterile wheat are mixed with water and a vaccine from Aspergillus flavus and Candida albicans treated to increase the moisture content to 26%. The wheat treated in this way becomes 16 hours long stored in 1 liter vessels. At the end of this period 15 ml of the potential toxin are added in a 30% acetone solution, whereupon the Vessels are rotated. The grain is then kept under high humidity for a period of 5 weeks. Then the grain is examined with regard to its decomposition and the settlement of fungi.

Three dosages are used based on the well-known mode of action of the fungicide thiabentazole (TBZ) against Penicillium species. The dosages are 2 84, 22 7 and 5 7 g / t of the moist grain.

Series:

1. The experiment is started on day 1.

2. Seedlings are removed from the mass and placed on damp filter paper to prevent the formation of traces without noticing the effect of the constriction in the vessel (on day 24). The total colonization is also determined,

3. On day 3 7, the decay is determined.

Table I Determination of the total colonization on day 24

284g 227g 57g

l.TBZ + ++ ++

2. zinc N-methyl-

dithiocarbamate - +

3. Comparative attempt +++ not tested not tested

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Mycelia grow together in such a way that a determination a single species distribution] is difficult. It will, however no Penicillium detected in the TBZ treated proportions. The portions treated with compound 2 are completely exempt from all fungi at quantities of 227 and 284g / t.

On day 20, small samples of 25 seedlings are removed from the respective vessels. These seedlings are placed on damp filter paper to facilitate the development of internal fungi. The fungus colonization is determined after h days (cf. Table III).

Fungus growth on
on a damp Table II 57g TBZ ^b 2 84 g Yes
very easy I. Yes
Zinc N-methyl-.
dithiocarbamate Day 24 ^a on seedlings that
Filter paper have been brought II. 227g. Yes
s none

^a Predominantly Rhizopus / Phoma spp. Thiabentazole

Table III

Determination of the volume percentage of decomposed

■ Grain on day 37

284g 227g 57g

^{In the TBZ} 100 ^a 100 ^a 100

II. Zinc N-methyl

dithiocarbamate 0 0 70

The growth of aerial mycelia is between the seedlings limited.

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The use of salts of N-methyldithiocarbamate allows a fight against fungi that occur when storing grain. The dosage unit can in the case of the zinc salt of N-methyldithiocarbamate are only 57g / t of the grain or fruit in certain treatments,

Fungus control is different from using TBZ or another fungistatic protectant carried out control in the following points:

1. the fungi are killed and not just inhibited;

2. Most of the fungicide evaporates;

3. The steam distribution in the grain allows less elaborate measures to reach every grain.

Experiment II

The following study is carried out using moist wheat by a method similar to that of method described in experiment I. Comparative tests are carried out, with each test three times is repeated, the basis being the weight of the active ingredient. Inoculation with Candida is omitted. The results are summarized in Table IV.

Table IV ^a

% Fight against destruction of wheat

after 14 days

281 g / t active ingredient 227g / t active ingredient 57g / t active ingredient

Treatment wheat wheat wheat

1. Zinc N-methyldithiocarbamate 100 100

2. Iron N-methyldithiocarbamate 100

3. Dithane AHO ^C 56

4. Vaoam 90

5. Comparison

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100 100 16 3 90 17th

26% moisture, fungi are fought ^b not applicable N ab am

Comparison of the tested compounds

The wheat is examined after 11 days (see Table IV), it is found that the N-methyldithiocarbamates are very are effective as a protective agent. Sodium ethylene bisdithiocarbamate (Dithane A40) is bad. The zinc N-methyldithiocarbamate is visibly superior to the sodium salt after 14 days.

Most Fungi Made From Metham Sodium Treated Wheat isolated 21 days after storage are those that have come from the open field and not pose a storage hazard. Aspergillus flavus is made from the zinc, iron and sodium salts of M-methyldithiocarbamic acid eliminated.

Experiment III

1. Corn

A similar experiment is carried out using moist corn. The grains are before the treatment inoculated with Gibberella zeae. On the 7th day the corn controls are strong due to a significant natural Penicillium infection rotted. On day 14, 15 corn seedlings are made each with the same dosage three batches on water agar after surface sterilization in a 2% hypochlorite solution in order to determine the extent of the internal infestation in the seedlings. The percentage of infestation comes from the Table V.

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Table V

% of the internal infestation of wheat and maize that occurs at 26% humidity at one temperature has been stored at 21 ° C for a period of 21 or IU days, determined by surface disinfection and application to water agar

Wheat 21 days after storage

Corn 14 days after storage % total fungi

to link

** I. Sodium N-Methyl- *** dithiocarbamate ^ as Vapam blue

% total fungus 284g / t 227g / t 57g / t

2. Zinc N-methyldithiocarbamate

£> 3.iron N-methyl- ζ dithiocarbamate

■ z ω ■ α

U.Dithane A40 5th comparison ⁰

13th

11

10

heavily rotten 75% colonization

% Aspergillus / Penicillium ""

227g / t 57g / t 284g / t 227g / t 57g / t

50% - by Aspergillus
and Penicillium

20th
12th

10

38

24

14th

62% colonization

ro ro ο j ^ -ο cn

badly rotten at this dosage; mainly Alternaria from the interior of the seedlings, the ° The probability of survival in storage is not great; Alternaria, Aspergillus, Penicioium;

Penicillium, Aspergillus, Fusarium (strong); ^e The activity is clear, however, the 'chemical instability causes poor storage stability and handling raises problems.

The test using corn shows excellent prevention of destruction by zinc and sodium N-methyl dithiocarbamate, while the activity of the iron salt is measurably lower.

Based on the values given in Table V, a panel of experts will determine the storage risk in the case of Wheat and corn examined, each with reference to the five protective agents examined. The results are summarized in Table VI below:

Table VI

estimated storage risk . _{Wheat Maig}

1. no risk above no risk at 227 g 57 g 'or above

2. no risk above no risk at 227g • 57g

3. no risk above moderate risk at 57g 2 84g as a result of

Fusarium

4. high risk moderate as a result of

Penicillium spp.

A significant percentage of internal infestation is caused by the treatments with both the sodium and the Removed zinc salt.

Experiment IV

Method;

Three corn sprout samples (100 g each) are hydrated by adding 10 ml of water for a period of time 24 hours prior to treatment to increase the moisture content from 10 to 20%.

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Another 4% moisture (24% total) is generated as the slurry is applied, with its help the respective treatment is carried out on the moist seedlings. The dosage concentrations are 454g, 227g and 113g of the active ingredient per ton of seedlings, with the exception of propionic acid, which is in an amount of up to 1810g / t was examined,.

After a storage period of 2 weeks, to give the fungi the opportunity to settle on the embryos and inner parts of the seedlings to settle, 40 seedlings are removed from each vessel and placed on 5% NaCl agar, namely after surface disinfection in a dilute hypochlorite solution. After 5 days on the agar, the fungus will grow inside of the seedlings are examined and the percentage of colonization is determined.

The results are summarized in Table VII.

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Table VII

Percent colonization and percent control of fungi naturally growing in stored corn

Corn with a moisture content of 24%

treatment Quantity g / t Zineb ^a 454th
227 ' 113 Mancoζeb 454 227 113 spray dry
netes Nabam ^c HSH 227 113 Zinc N-methyl
dithiocarbamate 454
227 113 Sodium N-Methy!
dithiocarbamate - HSH
227 * 113 Propionic acid 1810 907 454 227

estimated amount g / t% colonized% control storage risk

45 69

79

42 57 57

24 17 64

48

0 0 0

0 1

35 86

23
0 bad
bad 0 bad 28 bad 0 bad 0 bad 59
72 bad
bad 0 bad 99 good to excellent 92 Well 18th bad 100 excellent 100 excellent 100 excellent 100 excellent 98 good to excellent 40 bad 0 bad

Zxnkäthylenbxsdithxocarbamat

Manganethylene bisdxthiocarbamate, coordination product with zinc ion Disodium ethylene bisdithiocarbamate

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This investigation shows that the sodium N-methyldithiocarbamate is somewhat superior to zinc salt (which, however, also has a good effectiveness at relatively low concentrations owns). The others derived from dithiocarbamate Fungicides are noticeably worse. Propionic acid is the standard substance commonly used and provides at 907 to 1810g / t satisfactory results, but not effective at lower doses.

The activity of the sodium and zinc compounds suggests that the fungi are within the seedlings themselves be killed. The fungi controlled, which cause putrefaction when stored, are species of Penicillium, Fusarium, Aspergillus, Rhizopus. The predominantly occurring organism is a species of Penicillium that 80% of the infected seedlings of the untreated control sample grows.

A significant percentage of internal infestation will both by treatment with the sodium as well as the zinc salt eliminated.

Experiment V

Silage treatment

An attempt is made to establish the protective effect

of zinc and sodium N-methyldithiocarbamate in a silage

to investigate.

green
A / silage is used that is composed as follows: 50% red clover, 20% alfalfa and 30% broad beans. This silage is dusted with a spore concentrate from A. flavus on sebum and packed in airtight plastic bags. After 6 days, the bags are opened and the mean percentage of colonization by A. Flavus is determined (Table VII). 3 sachets of 100g foliage are used for each dosage unit. "

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Table VIII

Mean percentage of colonization by Aspergillus flavus on legume silage after treatment with 22 7g / t of the examined Protective agent

Jl remarks

considerable rhizopus contamination, but mainly A. flavus

Bacterial growth is evident

Rhizopus / Botrytis from broad beans

Rhizopus

Strong bacterial ferment, some rhizoüus

1. Zinc N-methyldithiocarbama V.

2. Sodium N-methyldithiocarbamate ^b

3. Compare,

a. no treatment, natural flora

b. inoculated with A. flavus

c. No. 1, not inoculated

d. No. 2, not inoculated

sprinkled on the silage sprayed on the silage

The above-mentioned sodium salt when used in an amount of 227g / t an excellent control of the growth of A. flavus in the silage. The zinc salt is less effective, possibly as a result of poorer distribution as dust.

The use of N-methyldithiocarbamate salts enables one good control of fungi occurring during storage. The dosage unit of zinc N-methyldithiocarbamate can be in certain Cases only 113-g / t of the grain to be treated or of the fruits to be treated.

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received

- Vf * -

λ *

The use of the invention can be restricted by statutory provisions, in particular by the food law.

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Claims (5)

·: Claims 1. Method of combating fungi that occur during storage of cereal grains and oil fruits that undergo hydration are accessible, cause rotting, characterized in that said products in suitable Condition, essentially at the time of storage, a fungicidally effective amount of a metal salt of an N-alkyl substituted Dithiocarbamic acid of the formula R-NHC-S-M where R is lower alkyl having up to 3 carbon atoms and M is zinc or sodium, is added. 2. The method according to claim 1, characterized in that the salt used of sodium N-methyldithiocarbamate consists. 3. Method according to claim 1, characterized in that the salt used consists of zinc N-methyldithiocarbamate. 4. The method according to claim 1, characterized in that the combated, causing decay during storage Fungi from Aspergillus flavus, Fusarium, Penicillium spp. or combinations thereof. -19- 209842/1015 5. The method according to claim 1, characterized in that the fungicidally effective amount employed is between about 113 and 154 grams (0.25 to 1 pound) per tonne of that to be protected storable material is " 209842/1015