JPH1146520A - Gel-coated seed and method for producing the same - Google Patents

Abstract

(57) [Problem] To provide a gel-coated seed that can be stored for a long period of time without using a special agent or performing a special treatment. The coating gel layer has a water content of 10% by weight or more and 9% or more.
Gel-coated seeds that are 0% by weight or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a gel-coated seed. In particular, it relates to a gel-coated seed technology capable of long-term storage.

[0002]

2. Description of the Related Art The technique of encapsulating plant seeds in microcapsules of an aqueous organic gel, that is, the technique of gel coating of seeds, has improved the germination rate due to the water contained in the gel coating, and has not been suitable for mechanical sowing. Such small seeds or non-spherical seeds can be mechanically sowed, or the addition of various chemicals and fertilizers to the gel layer has a remarkable effect of improving the growth or yield of crops. It has become. Among these, coating with an aqueous organic gel capsule gel cured by metal ions has become particularly widely used because it is easy to produce, inexpensive, and has little adverse effect on seed germination. I have.

However, the gel-coated seed has a very high moisture content gel layer around the seed and easily germinates, so that it cannot be stored at room temperature. Here, refrigerated storage has been performed. However, for long-term storage of about 30 days, -2
C. must be maintained, and 5 C. cannot be accommodated by a general ordinary refrigerator, and the equipment is costly. As another preservation method, a solution has been attempted by drying the coated gel layer and absorbing water immediately before sowing. That is,
When the water content in the gel-coated seed is set to 5% by weight or less, the germination rate decreases, and long-term storage becomes possible. However, when water is absorbed thereafter, the surface layer of the coated gel layer falls off in the process of swelling with water and loses its smoothness. Strength increases. As described above, the handleability of the gel capsule from which the surface layer has fallen is extremely low, and there has been a problem that clogging occurs during transfer or in a hopper such as a seeder. The present applicant has made technical proposals for solving these problems in the past, such as Japanese Patent Application Laid-Open No. 5-56707. It was not a definitive solution.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gel-coated seed which can be stored for a long period of time without using a special agent or performing a special treatment.

[0005]

In order to solve the above-mentioned problems, the gel-coated seed of the present invention has a coated gel layer having a moisture content of 10% by weight or more and 90% by weight or less as described in claim 1.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The gel-coated seed of the present invention has a water content of a coating gel layer of a gel-coated seed prepared by a known method (hereinafter referred to as "moisture content of a coating gel layer of gel-coated seed"). )). For example, a droplet of an aqueous gel-forming aqueous solution for seed coating is formed at the tip of a thin tube, seeds are added to the droplet using a thin tube, and then the gel droplet has an effect of insolubilizing the gel with water. A gel-coated seed prepared by dropping a solution containing a metal ion can be used. In the case of gel-coated seeds having a water content of 85% by weight or less, decay and mold generation of the coated gel layer are suppressed even at room temperature storage. However, in the case of gel-coated seeds having a high water content of around 90%, storage at room temperature is considered. It is also possible to add an antibacterial component harmless to plants in advance in the coating gel layer. The plant seed contained in the gel-coated seed of the present invention may be a normal seed or a plant tissue culture such as an adventitious embryo or a multi-bud.

The adjustment of the moisture content may be carried out, for example, with ventilation using a hot-air dryer or the like, or may be achieved by leaving the container in a container such as a desiccator containing a desiccant. However, since it is necessary to quickly adjust the seeds before germination, the adjustment is desirably performed using a hot-air dryer. When adjusting the moisture content in a ventilation state using a hot-air dryer or the like, it is preferable to place the gel-coated seeds uniformly and without overlapping on a wire mesh, for example, since the occurrence of variation can be suppressed, which is preferable. . Here, if the degree of drying of the gel-coated seeds is different, the storable period is different, which makes management difficult. When using a wire mesh,
The use of a coarse mesh will speed up the drying of the seeds and the use of a fine mesh will slow the drying. Zircon or paper can be used instead of wire mesh. When paper is used, the use of thin paper results in faster drying, and the use of thick paper results in slower drying.

The temperature for adjusting the moisture content is desirably 35 ° C. or more and 60 ° C. or less. If the temperature is too high, it will damage the seeds, while if it is too low, the time to complete the adjustment will be longer,
The seeds germinate and grow, resulting in so-called protrusions of buds and roots from the coated gel layer. When dried at a temperature of 50 ° C. or higher, mold generation is suppressed in the coated gel layer even after storage at room temperature, and as a result, there is no disease caused by these molds. When protrusion occurs in the gel-coated seed,
It is very likely that these prominent shoots and roots will be catastrophically damaged during mechanical sowing. For this reason, the gel-coated seeds having the protrusions are selected and sown manually, or sown with anticipated loss. However, the former requires a great deal of time for sorting and sowing, while the latter creates waste and makes it difficult to control the number of effective seeds, and in some cases, involves extra work such as thinning after emergence. Is required.

In the present invention, the moisture content of the coated gel layer (hereinafter, also simply referred to as "moisture content") must be 90% by weight or less. By keeping the water content, growth and protrusion of the seed can be suppressed. Here, the protrusion means that the seeds germinate and the buds or roots reach out of the gel coating layer. In the gel-coated seed of the present invention,
The moisture content of the coating gel layer must be 10% by weight or more. The coated gel layer having a water content of less than 10% by weight is not completely restored when immersed in water, and peels off on the surface layer, and many troubles such as hopper clogging occur, so that mechanical seeding cannot be practically performed.

[0010] Some of the seeds contained in the gel-coated seeds and those having bubbles therein for supplying oxygen to the germinated buds and roots, however, if the drying is excessive, these bubbles are broken, and the seeds are broken. Oxygen is supplied abundantly, so that the growth may be rather accelerated. In this case, it is necessary to keep the moisture content at a level at which the bubbles are maintained. Here, a preferable range of the water content of the coating gel layer is 70% by weight or more and 90% by weight or less. Within this range, the germination / growth inhibitory effect and the thickness of the coated gel layer are sufficient, so that projection is less likely to occur, the storage period is extended, and gel-coated seeds having air bubbles can be handled. The optimum range of the water content is 70% by weight or more and 85% by weight or less.

In the present invention, the moisture content of the coated gel layer of the gel-coated seed is measured as follows. That is, the seeds are taken out from the gel-coated seeds using a knife or the like, the coated gel layer is collected, and measured by an infrared moisture meter. The storage period of the gel-coated seed of the present invention can be further extended by refrigeration, that is, by keeping it at a normal refrigerator temperature of about 5 ° C.

The gel-coated seeds according to the present invention can be soaked in water by immersion in water after storage and before sowing to restore the coated gel layer, and can be mechanically seeded in the same manner as ordinary gel-coated seeds. At this time, the moisture content of the coating gel layer was 10
% Or more, the surface layer does not fall off and is restored smoothly. In the case of a moisture content of 70% by weight or more and 90% by weight, the size immediately before drying is quickly returned by immersion for 10 minutes. Also,
When the water content is less than 70% by weight, the time until restoration is slightly longer.

[0013]

Embodiments of the present invention will be described below. [Preparation of Gel-Coated Seeds] First, gel-coated seeds before drying were designated and prepared as follows. Outside diameter of tomato seeds 8
A 3% by weight aqueous sodium alginate solution was introduced into a 3% by weight aqueous solution of sodium alginate using a glass tube having a diameter of 6 mm and an inner diameter of 6 mm, and the resulting solution was dropped into a 10% by weight aqueous solution of calcium chloride. Gel-coated seed A (coated gel layer (average value of 100 pieces), diameter: 0.73 cm, weight: 0.2 g, moisture content:
94.3% by weight). It has air bubbles inside, and the tomato after germination grows by breathing the oxygen of the air inside.

[Study of moisture content adjusting method: drying with hot air dryer] Gel-coated seeds A200 were applied to a petri dish having a diameter of 12 cm.
Put the pieces. At this time, they overlapped about two steps. These seeds are dried with a hot air drier at 50 ° C. so that the average moisture content of the coated gel layer is 85% by weight, and the dispersion of the diameter and weight of the gel-coated seeds thereafter (difference between maximum value and minimum value, and
(Average value) and variations in the water content of the coated gel layer were examined (test section α). On the other hand, similarly using a petri dish,
However, a thin paper was spread in a petri dish, and 50 gel-coated seeds A were put thereon, and dried in the same manner as in the test section α. At this time, the gel-coated seeds A were in one stage without overlapping each other (test section β). In addition, a test piece γ in which a thin paper is spread and gel-coated seeds A are placed thereon in one layer, and a test piece in which thinner paper is laid on the gel-coated seed in the same manner as the test piece γ δ was dried in the same manner as in the test section α, and the evaluation was performed. Tables 1 and 2 show the variation in diameter and weight of these gel-coated seeds, respectively, and Table 3 shows the variation in moisture content of the coated gel layer of these gel-coated seeds.

[0015]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━ Test area difference (mm) Average value (mm) ───────── ───────────────── (Gel-coated seed A) 0.73 10.46 α 4.87 7.32 β 2.36 6.43 γ 3.51 5.50 δ 1.38 6.18 ━━━━━━━━━━━━━━━━━━━━━━━━━━

[0016]

[Table 2] ━━━━━━━━━━━━━━━━━━━━━━━━━━ Test area difference (g) Average value (g) ───────── ───────────────── (Gel-coated seed A) 0.015 0.635 α 0.418 0.314 β 0.058 0.216 γ 0.201 0.126 δ 0.112 0.199 ━━━━━━━━━━━━━━━━━━━━━━━━━━

[0017]

[Table 3] Test area difference (%) Average value (%) ───────── ───────────────── (Gel-coated seed A) 295.2 α2 94.3 β1 94.9 γ1 94.5 δ1 95.0 ━━━ ━━━━━━━━━━━━━━━━━━━━━━━

[Study of moisture content adjusting means] A thin paper is laid, and gel-coated seeds A are arranged on the thin paper so that they do not overlap.
Further, a thin paper was placed thereon and dried in a hot air dryer set at 50 ° C. The time-dependent change in the water content of the coated gel layer of the gel-coated seed at that time was examined. Further, a thin paper was laid in a silica gel desiccator, and the gel-coated seed A was further placed thereon so as not to overlap and sealed. Then, in a thermostat at 25 ° C, the moisture content of the coating gel layer of the subsequent gel-coated seed was changed. Was examined over time. These results are shown in FIG.

FIG. 1 shows that the gel-coated seed of the present invention can be obtained by using a hot air dryer or a desiccator. In addition, when using a hot air dryer,
It can be seen that the time required for adjusting the moisture content can be shorter than in the case of using a desiccator, and thus the germination of seeds can be suppressed.

[Examination of storage stability at room temperature] In the examination of the moisture content adjusting means, the gel-coated seeds having different moisture ratios produced by using a hot air drier were kept at 25 ° C. in a thermostat, respectively, and then the germination rate and the protrusion were determined. The change in rate was examined. Figure 2 shows the change in budding rate
FIG. 3 shows the change in the protrusion ratio. According to FIGS. 2 and 3,
Germination is suppressed by the gel-coated seed having a water content of 90% by weight or less, and the protrusion that cannot be mechanically sowed is reduced. In particular, when the water content is 85% or less, normal temperature storage for one week is possible, and when the water content is in the range of 70% by weight or more and 85% by weight, long-term normal temperature storage of the gel-coated seeds for two weeks is possible. .

[Study by Storage at Normal Temperature] In the same manner as in the study of the means for adjusting the moisture content, 25 gel-coated seeds (hereinafter, referred to as "gel-coated seeds B") whose moisture content was adjusted to 84.9% by weight were used. C. for 7 days, then immersed in water for 10 minutes, and after confirming that the coating gel layer was completely restored, further immersed in 0.5% by weight of hydrogen peroxide for 10 minutes to carry out an oxygen enrichment treatment. Then, a germination test was performed in a thermostat at 20 ° C. under dark conditions. The progress of the germination rate and the protrusion rate at this time are shown as “84.9%” in FIGS. 4 and 5, respectively. Similarly, the gel-coated seed A having a water content of 94.3% by weight was stored at 25 ° C. for 7 days without adjusting the water content, and then subjected to an oxygen-enrichment treatment, and a germination test was similarly performed. The data obtained in this case is also described as “94.3%”. 4 and 5 that when the coated seed B according to the present invention is used, although the germination is small at the time of sowing, the subsequent germination is early and so-called simultaneous germination is possible. . It can also be seen that there is no protrusion at the time of sowing. However, the protrusion after sowing was quick, suggesting that the simultaneous germination effect could be obtained. Such simultaneous germination makes the management and harvesting of the seedlings easy and efficient.

On the other hand, when the gel-coated seed A whose moisture content is not adjusted is used as it is, molds are often generated in the coated gel layer by the ordinary temperature storage treatment for 7 days. There was something that the mold had reached. In the case of the gel-coated seed B, regardless of storage at room temperature for 7 days,
There was no mold. When the gel-coated seed A was used as it was, it was stored at room temperature for 7 days.
% Were prominent. Also, the germination rate and protrusion rate after seeding were low in elongation, which is considered to be due to the loss of germination ability due to mold.

[Examination by refrigerated storage] Next, refrigerated storage was examined using the same gel-coated seed B as that prepared above. The gel-coated seed B is stored at 6 ° C. for 7 days,
Then, after immersion in water for 10 minutes, restoration of the coated gel layer was confirmed, oxygen enrichment treatment was performed, and a germination test was performed in a thermostat at 20 ° C. under dark conditions. The progress of the germination rate and the projection rate at this time is shown as “84.9%” in FIGS. 6 and 7, respectively. In the same manner, the gel-coated seed A having a water content of 94.3% by weight was stored at 6 ° C. for 7 days without adjusting the water content, and then subjected to an oxygen-enrichment treatment, and a germination test was similarly performed. "94.3%" for the data obtained
It is described as.

6 and 7 that the gel-coated seed without water content adjustment causes a loss of 5% even when stored at a low temperature, but the gel-coated seed B according to the present invention causes a loss. Since there is no protrusion, no loss occurs. In addition,
The rate of buds and protrusion at 4 sunrises after sowing were exactly the same level as when gel-coated seed A was used.

[Effect investigation by moisture content adjustment by hot air]
Next, the presence or absence of the influence of the moisture content adjustment by hot air was examined. Immediately after preparing the gel-coated seed A, after immersing in water for 10 minutes, the restoration of the coated gel layer was confirmed, and oxygen enrichment treatment was performed.
A germination test was performed in a dark place at 20 ° C. in a thermostat. 8 and 9 show the progress of the germination rate and the protrusion rate at this time, respectively.
As “84.9%”. Similarly, immediately after the gel-coated seed A having a water content of 94.3% by weight was prepared without adjusting the water content, oxygen enrichment treatment was performed, and data obtained when a germination test was similarly performed. Also "94.3%"
Also described as It was confirmed from FIGS. 8 and 9 that the moisture content adjustment treatment at 50 ° C. had no effect on the germination rate and projection rate of the seed.

[0026]

The gel-coated seed of the present invention is excellent in that it can be stored at room temperature, and can be easily and completely restored.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a moisture content adjustment time and a moisture content.

FIG. 2 is a view showing the effect of a difference in water content on the storage stability (germination rate).

FIG. 3 is a diagram showing the effect of a difference in moisture content on storage stability (projection rate).

FIG. 4 is a diagram showing a change in germination rate after sowing of a gel-coated seed according to the present invention stored at room temperature.

FIG. 5 is a diagram showing the change in the protrusion rate after sowing of the gel-coated seed according to the present invention stored at room temperature.

FIG. 6 is a graph showing changes in the germination rate after sowing of the gel-coated seed of the present invention according to the present invention stored in a refrigerator.

FIG. 7 is a view showing the change in the protrusion rate after sowing of the gel-coated seed of the present invention according to the present invention stored in a refrigerator.

FIG. 8 is a diagram showing that the adjustment of the moisture content by hot air does not affect the germination rate.

FIG. 9 is a diagram showing that adjustment of the moisture content by hot air does not affect the protrusion ratio.

Claims (6)

[Claims] 1. The coating gel layer has a water content of 10% by weight or more and 9% or more.
A gel-coated seed having a content of 0% by weight or less. 2. The gel-coated seed according to claim 1, wherein the water content is 70% by weight or more and 90% by weight or less. 3. The gel-coated seed according to claim 1, wherein the water content is 70% by weight or more and 85% by weight or less. 4. The water content of the coated gel layer of the gel-coated seeds is 1
A method for producing a gel-coated seed, comprising adjusting the amount to 0% by weight or more and 90% by weight or less. 5. The method for producing a gel-coated seed according to claim 4, wherein the adjustment of the moisture content is performed in a ventilation state. 6. The method for producing a gel-coated seed according to claim 4, wherein the adjustment of the moisture content is performed at 35 ° C. or higher and 60 ° C. or lower.