NZ232626A - Pellitised seed coated with urea-aldehyde condensate type fertiliser - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £32626 2326 26 • * NO DRAWINGS Priority Date(s): Complete Specification FiJed2j.*.?:\7fe' Class* ^ ^ IQ .[<=&*: Publication Date: , P.O. Journal, No: .

NEW ZEALAND PATENTS ACT. 1953 No.: Date: COMPLETE SPECIFICATION PKT.T.BTX2ED SEED t/We. NITTO CHEMICAL INDUSTRY CO., LTD-, a corporation organized under the laws of Japan, of 5-1, Manmouchi-l-chome, Chiyoda-ku, Tokyo, Japan hereby declare the invention for which &/ we pray that a patent may be granted to V3BSJus, and the method by which it is to be performed, to be particularly described in and by the following statement: - (followed by page - la -) 232626 1 BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a pelletized seed. More particularly, the present invention relates 5 to a pelletized seed which simplifies the sowing work, has a high germination percentage and can improve the environment at the early stage of the growth of plant body.

Prior Art Pelletization of seed has hitherto been attempted with the aim of facilitating the handling and uniform sowing work of seed, enhancing its germination percentage, making the growth uniform and protecting seed against drifting from the soil and hazards by wild birds 15 and insects.

Pelletized seed is advantageous in that a grassland can be produced by merely sowing it without cultivating the land and it can be utilized for cropping a rapidly sloping land where a mechanical cultivation is 20 difficult to practise.

A pelletized seed is usually produced by mixing seeds with various pelletizing materials such, as a granulating material, a binder material and the like, a water-absorbing material, etc., granulating the mixture - la- 232626 1 by a compression molding method, a wet-coating method using a rotary granulating machine, a method of extruding a kneaded mixture with water, etc., and then drying the granulated product (for example, Japanese Patent 5 Application Kokai (Laid-Open) 51-145710, 57-79802, 59-192006, etc.).

A plant body grows while consuming the endosperm for a while after the germination. After it has reached a certain stage of growth, however, it must take up 10 nutrients from outside such as soil, for the sake of growth. In order to promote the early growth of plant body, it is desirable to incorporate fertilizer components into the pellet previously, and many studies have hitherto been conducted on this problem. 15 When a pellet contains fertilizer components, however, the so-called "fertilizer injury" (salt damage) can take place. Thus, unlike the usual case of carrying out a seeding and fertilizer application separately, all the seeds present in a pelletized seed come into a 20 direct contact with fertilzier components contained in the pellet, which greatly enhances the danger of making troubles on germination and growth.

Further, since the conventional chemical fertilizers generally have a high water-solubility, the 25 fertilizer components in the pellet can be flowed out and lost by rain water and thereby their previous addition can become meaningless.

In order to meet the requirement of this field 232626 1 to obtain fertilizer components of a pelletized seed causing less fertilizer injury, the present invention provides a pelletized seed excellent in germination and growth and small in the loss of nutrients by rain water 5 and the like.

SUMMARY OF THE INVENTION The present inventors have eagerly studied to solve the above-mentioned problems and found that the above—mentioned requirement can be met by incorporating 10 a condensate formed between urea and an aldehyde compound into a pelletized seed. Based on the finding, the present invention has been accomplished.

Thus, the present invention relates to a pelletized seed comprising a plant seed and a condensate 15 formed between urea and an aldehyde compound.

An object of the present invention is to provide a pelletized seed which can simplify the sowing work, has a high germination percentage and can improve the environment for early growth of plant body. 20 Other objects and advantages of the present invention will become apparent from the following descriptions.

PREFERRED EMBODIMENTS OF THE INVENTION The aldehyde compounds which can be used for 25 producing the condensate formed between urea and an aldehyde compound (hereinafter referred to as condensate) 232 © © 1 to be incorporated into the pelletized seed of the present invention include formaldehyde, acetaldehyde, propionaldehyde, crotonaldehyde, isobutyraldehyde, glyoxal and the like.

The condensates include urea-formaldehyde condensate, 2-oxo-4-methyl-6-ureidohexahydropyrimidine (crotonylidene diurea), propylidene diurea, isobutylidene diurea, glycol-uril, and the like.

Although the condensates are only slightly 10 soluble in cold water, they are partially soluble in hot water. That is, they are such condensates that, when 1 part by weight of the condensate in anhydrous state is immersed in 20 parts by weight of hot water at 80°C for 30 minutes, the percentage of eluted portion based on 15 the weight (hereinafter referred to as hot water elution percentage) is 0.1 to 30% by weight, preferably 0.1 to 20% by weight, and more preferably 0.5 to 10% by weight.

G A percentage of eluted portion is expressed by (100 - A)% by weight, wherein A is a percentage by weight of 20 undissolved portion.

Hereinunder, a case that the condensate is that formed between urea (hereinafter sometimes referred to as U) and formaldehyde (hereinafter sometimes referred to as F) is explained as an example. This condensate is 25 hereinafter referred to as D-F condensate.

This condensate has methylol group(s) in its molecular structure.

As the U-F condensate, those having a total 232626 1 methylol content of 0.05 to 1.5% by weight, preferably 0.15 to 1.0% by weight, only slightly soluble in cold water, and having a hot water elution percentage of 0.5 to 10% by weight, all based on the weight in anhydrous 5 state, are used- Since such a condensate is appropriate in degree of condensation and gradually decomposed in the soil, it promotes germination of seed and growth of plant body without exercising a serious inhibition on the 10 germination of seed and growth of plant body. Such an effect cannot be obtainable from a completely condensed urea resin having only a slight quantity of methylol group or from a U-F condensate having a larger quantity of remaining methylol group and containing a large 15 quantity of water-soluble components.

The D-F condensate can be produced by condensing a preliminary D-F condensate prepared so that a molar ratio U:F ultimately comes to from 1:0.9 to 1:1.2, further in the presence of an acidic substance. 20 Next, embodiments of the method of obtaining a D-F condensate are mentioned.

As the method of obtaining the preliminary D-F condensate, the following method (a) or (b) can be referred to: Method (a) A mixture prepared by mixing urea and 37% formalin at such a. quantitative ratio as to give a molar ratio U:F of from 1:0.9 to 1:1.2 is adjusted to pH in a range of 7-8 with an alkaline substance such as 232 6 y » ' m « 1 sodium hydroxide or the like, and then it is heated at 95°C. When a white turbidity appears in the reaction mixture, the reaction is stopped and the reaction mixture is again adjusted to pH 7-8. Thus, a preliminary D-F condensate 5 is obtained.

Method (b) A mixture prepared by mixing urea and the formalin at such a quantitative ratio as to give a molar ratio U:F of from 1:2.0 to 1:2.5 is adjusted to pH 7-8 with an alkaline substance such as sodium hydroxide 10 or the like and reacted at a temperature of from 20 to 95°C for from 1 to 30 hours. After the mixture is again adjusted to pH 4-7, it is further reacted at 80-98°C. The time at which a liquid taken out from the reaction mixture becomes slightly cloudy when it is cooled to 20°C, 15 is taken as the end point of the reaction. Then, an additional quantity of urea is added so that total molar ratio U:F comes to from 1:0.9 to 1:1.2, and the reaction is further made to progress. When a white turbidity appears in the reaction mixture, the reaction is stopped 20 to obtain a preliminary D-F condensate.

The D-F condensate can be produced by adjusting the preliminary D-F condensate prepared according to the above-mentioned method (a) or (b) to pH 3-5 with an acidic substance such as sulfuric acid, phosphoric acid or the 25 like, and reacting it at a temperature of 60-80°C while evaporating water in an apparatus for agitating and mixing the reaction mixture such as kneader, ribbon mixer or the like, until water content of the reaction mixture reaches 232626 c 1 45% by weight or less. The D-F condensate thus prepared has a form of powder or granule. Any forms of product may be used in the present invention.

When a molar ratio D:F is out of the above-5 mentioned range and an amount of urea is smaller than specified above in producing of the D-F condensate, the total methylol content in the resulting D-F condensate G is high. On the other hand, when a molar ratio D:F is out of the above-mentioned range and an amount of urea 10 is larger than specified above. The resulting D-F condensate decomposes in the soil too rapidly. In both these cases, such a condensate has a tendency to inhibit the germination of seed.

The condensation reaction of the preliminary 15 D-F condensate in the presence of acidic substance progresses more rapidly when a pH of the reaction system is lower and a reaction temperature is higher, and a degree of condensation becomes higher when a reaction time is longer. With progress of the reaction, total 20 methylol content in the condensate decreases, and its hot water elution percentage decreases.

When a D-F condensate of which total methylol content and hot water elution percentage are out of the ranges specified above is incorporated into a pelletized 25 seed, the germination of seed is inhibited.

The plants of which seed can be used as a pelletized seed of the present invention include pasture plants such as orchard grass, Italian rye grass, timothy, 232626 1 alfalfa, Kentucky bluegrass and the like; vegetables such as carrot, tomato, eggplant, celery, lettuce, cucurbitaceous plants (such as watermelon, netted melon, cucumber, etc.) and the like; flowering plants such as 5 petunia, garden portulaca, begonia, poppy, gloxinia, baby's-breath, snapdragon, sage, sweet pea and the like; lawn grasses such as bent grass, perennial rye grass, Korai turf, wild turf and the like; and woody plants such as bush clover, white birch, mountain alder, Japanese 10 red pine, mountain birch, and the like.

The pelletized seed of the present invention can be produced by pelletizing a plant seed and a condensate using pelletizing materials such as a granulating material, binder material and the like.

In producing the pelletized seed of the present invention, water-absorbing material and various adjuvants may be appropriately selected and used in addition to the above-mentioned pelletizing materials, if necessary.

The granulating materials which can be used in 20 the present invention include soil, heavy clay, calcium carbonate, slaked lime, ash from plants, diatomaceous earch, vermiculite, bentonite, zeolite, chaff, peat moss, pulp, compost, sawdust and the like.

The binder materials usable in the present 25 invention include carboxymethyl cellulose, polyvinyl alcohol, sodium alginate, synthetic resin pastes, gum arabic, gelatine and the like. The binder material may be used in an appropriate amount. For example, it is used o O 232626 O" . .., 1 in an amount of 2 to 3 parts by weight per 100 parts by weight of a granualting material, in case of gum arabic.

An amount of the pelletizing material and a 5 size of pellet may be appropriately selected so that every one pelletized seed comes to contain from 1 to 5 seed(s) .

In the pelletized seed of the present invention, the condensate is an indispensable component, and its 10 amount is from 0.1 to 10 parts by weight, preferably from 0.5 to 5 parts by weight based on 100 parts by weight of the pelletizing material.

As a water-absorbing material, a starch-acrylic acid graft copolymer, a crosslinked product of acrylic 15 acid, chitosan, pullulan gel or the like are appropriately used.

An adjuvant may be appropriately selected from germination promoter, plant growth promoter, fungicide, insecticide and the like and added for the purpose of 20 additionally promoting germination and growth of the plant.

Preferably, the pelletized seed of the present invention is produced by compounding a seed with a pelletizing material and a condensate, and optionally 25 with a water-absorbing material and adjuvant, adding an appropriate quantity of water, kneading the mixture, pelletizing the kneaded mixture by a method of extrusion or the like, and then drying the pellet. A drying 232 6 2 j • ■ 1 temperature should be in a range where the enzymes in the seed keep their activity. That is, it is preferably 40°C or less.

The pelletized seed of the present invention 5 has the following advantages: 1) Since the condensate used in the present invention gradually decomposes in the soil, it promotes the germination of seed and growth of plant body without exercising serious inhibition on its germination and growth. 2) Since the condensate used in the present invention is only slightly soluble in water, its loss by rain water and the like is slight, so that it brings about a growth-promoting effect with certainty.

Next, the present invention is illustrated more specifically referring to the following Referential Example, Examples and Comparative Examples.

However, the present invention should not be construed to be restricted by the examples.

REFERENTIAL EXAMPLE 1 (Preparation of U-F condensate) Urea and 37% formalin were mixed together so that a molar ratio U:F came to 1:1, and the mixture was adjusted to pH 8.0 with sodium hydroxide. An amount, equal to the amount of the used urea, of water was added thereto, and a temperature was elevated up to 95 °C in one hour at a constant speed of temperature elevation. Subsequently, the mixture was kept at 95°C for 30 minutes, and then 232626 1 was again adjusted to pH 8.0, and the mixture was rapidly cooled to room temperature to obtain a preliminary U-F condensate.

The preliminary condensate thus obtained was 5 heated to 75°C in a kneader while agitating it, after which 3.0% by volume of 40% phosphoric acid was added.

While keeping the content at 75°C and dehydrating it with stirring, it was reacted for 3 hours to obtain a U-F condensate.

Based on the weight in anhydrous state, the U-F condensate thus obtained had a total methylol content of 0.75% by weight and a hot water elution percentage of 7.5% by weight.

EXAMPLES 1 and 2, and COMPARATIVE EXAMPLES 1-8 15 1) Preparation of pelletized seed 800 Grams of heavy clay, 200 g of peat moss, 20 g of gum arabic, 5 g of orchard grass seeds and the U-F condensate obtained in Referential Example 1 or various fertilizer components shown in Table 1 used for comparison 20 were compounded and kneaded together with pure water. The kneaded mixture was strained through a sieve having an opening size of 7 mm and dried at 40°C to obtain pelletized seeds. One pellet thus obtained contained 3 to 4 seeds. 2) Growth test of the pelletized seed Table 1 illustrates the results of growth tests of the pelletized seeds obtained above. •■-rr. ... > 232 6 1 Place of test: A field in vinyl house 2 * Scale of test: 0.25 m /one test plot, 60 pellets/one test plot, one-plot three series test plot Period of test: 41 days (daily mean atmospheric temperature: 18°C) A germination percentage of a pellet was calculated based on one piece of pellet. The plant was dug up 41 days after the seeding, and its fresh weight 10 and dry weight were measured. The results are summarized in Table 1.

As shown in Comparative Examples 1-4 in Table 1, conventional chemical fertilizers had a tendency to inhibit the growth. Particularly, when amounts used 15 thereof were increased, they caused severe inhibitions on the germination of seed and growth of plant body (Comparative Examples 5-8) .

On the other hand, condensates according to the present invention had a tendency to help the 20 germination and growth even at the concentration at which the conventional chemical fertilizers caused the severe inhibitions. o o 00, 0 »• Table 1 Fertilizer component Germination percentage of pellet (%) Crop weight per 0.25 m2 (g) its amount (g) Fresh weight Dry weight Example 1 U-F condensate 87.2 .64 4.23 Comparative Example 1 Ammonium sulfate 72.2 13.97 1.94 " 2 Urea 84.4 .20 3.16 » 3 Ammonium nitrate 85.6 17.18 2.38 " 4 Ammonium chloride 80.0 9.78 1.57 Example 2 U-F condensate 40 85.6 19.87 2.65 Comparative Example 5 Ammonium sulfate 40 66.1 4.46 0.69 6 Urea 40 73.3 .65 0.89 11 7 Ammonium nitrate 40 76.1 .84 0.77 8 Ammonium chloride 40 60.0 3.42 0.52 Control 0 82.2 18.98 2.54 IV) CM ro o> ro o> 232626 • ' j > EXAMPLES 3-8 and COMPARATIVE EXAMPLES 9 and 10 1) Preparation of pelletized seed 700 Grams of heavy clay, 200 g of peat moss, 20 g of calcium carboante, 20 g of superphosphate of lime, 20 g of potassium sulfate, 1 g of Snow Growace (plant growth promoter), 15 g of gum arabic, 15 g of perennial rye grass seeds and a U-aldehyde condensate (the above-mentioned U-F condensate, isobutylidene diurea or crotonylidene diurea) or ammonium chloride as a comparative fertilizer component were compounded at the compounding ratio shown in Table 2. After adding water, the mixture was kneaded. The kneaded mixture was molded by means of a sieve plate type granulating machine (pelleter) having an opening size of 6 mm and dried at 40°C to obtain pelletized seeds. One pellet thus prepared contained 3 to 4 seeds. 2) Growth test of the pelletized seed Table 2 illustrates the results of growth tests of the pelletized seeds obtained above.

Place of test: A field in vinyl house Scale of test: 0.22 m /one test plot, 60 pellets/one test plot, one-plot three-series test plot Period of test: 39 days (daily mean atmospheric temperature: 17°C) The germination percentage was calculated based on one piece of pellet. Fresh weight and dry weight of 232626 1 \the plant were measured 39 days after the seeding. The results are summarized in Table 2. 0 0 O (> Table 2 Fertilizer component and its amount (g) Germination percentage of pellet (%) Crop weight per 0.22 m2 (g) Fresh weight Dry weight Example 3 U-F condensate 10 85.0 60.97 6.93 " 4 Isobutylidene 10 diurea 87.2 78.90 8.70 " 5 Crotonylidene 10 diurea 85.0 81.17 9.23 Comparative Example 9 Ammonium chloride 10 76.8 31.93 2.29 Example 6 U-F condensate 20 80.0 53.43 6.13 " 7 Isobutylidene 20 diurea 81.1 58.07 6.40 " 8 Crotonylidene 20 diurea 80.0 54.47 .90 Comparative Example 10 Ammonium chloride 20 77.8 13.20 1.17 Control 0 78.9 53.23 .93 232B2G

Claims (13)

WHAT WE CLAIM IS:

1. A pelletized seed comprising a plant seed and a condensate formed between urea and an aldehyde compound.

2. A pelletized seed according to Claim 1, wherein the aldehyde compound is at least one member selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, crotonaldehyde, isobutyraldehyde and glyoxal-

3. A pelletized seed according to Claim 1, wherein the condensate has a hot water elution percentage (percentage of eluted portion, based on the weight in anhydrous state which a condensate shows when one part by weight is immersed in 20 parts by weight of hot water at 80°C for 30 minutes) of; 0.1 to 30% by weight.

4. A pelletized seed according to Claim 1, wherein the condensate has a hot water elution percentage of 0.1 to 20% by weight.

5. A pelletized seed according to Claim 1, wherein the condensate has a hot water elution percentage of 0.5 to 10% by weight.

6. A pelletized seed according to Claim 1, wherein the aldehyde compound is formaldehyde, "and the condensate has a hot water elution percentage in a range from 0.5% to 10% by weight and a total methylol content in a range from 0.05% to 1.5% by .weight.

7. A pelletized seed according to Claim 6, wherein 232626 the total methylol content is in a range of 0.15% to I.0% by weight.

8. A pelletized seed according to Claim 1, wherein the plant seed is at least one member selected from the group consisting of seeds of orchard grass, Italian rye grass, timothy and alfalfa.

9. A pelletized seed according to Claim 1, wherein the plant seed is at least one member selected from the group consisting of seeds of carrot, tomato, eggplant, celery/ lettuce and cucurbitaceous plants.

10. A pelletized seed according to Claim 1, wherein the plant seed is at least one member selected from the group consisting of seeds of petunia, garden portulaca, begonia, poppy and gloxinia.

II. A pelletized seed according to Claim 1, wherein the plant seed is at least one member selected from the group consisting of seeds of bent grass, Korai turf and wild turf.

12. A pelletized seed according to Claim 1, wherein plant seed is at least one member selected from the group consisting of seeds of Kentucky bluegrass, watermelon, netted melon, cucumber, baby's-breath, snapdragon, sage, sweet pea, perennial rye grass, bush clover, white birch, mountain alder, Japanese red pine and mountain birch.

13. A pellet as claimed in any one of the preceding claims snh<;t.ant.i*nvrifscrihpri with reference to any example thereof. DATED THIS IWOFMcu-j igPlj PARK & SON PER AGENTS FOR THE APPLK