JP2013106568A - Method for improving characteristic of coated seed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the germination rate or the like of coated seeds without causing cracks or collapse in coated layers.SOLUTION: The coated seed obtained by coating the outer peripheral surface of the seed with a powder material is preserved for a predetermined period in a humidity environment in which the water content of the internal seed is 10 dry wt.% or more. The preservation period preferably ranges from several hours to 10 days. The preservation temperature preferably ranges from 0°C to 40°C. It is further preferable to dry the coated seed until the water content of the internal seed is 7 dry wt.% or less after preserved for the predetermined period.

Description

  The present invention relates to a method for improving characteristics such as germination rate of coated seeds whose outer peripheral surface is coated with a powder material.

  For seeds such as vegetables, so-called granulated coated seeds (hereinafter sometimes referred to as “coated seeds”) whose seed surfaces are coated with an inorganic powder material have been widely used in recent years, for example, to save labor in sowing operations. It is popular. However, such coated seeds may have insufficient characteristics such as germination rate.

  Patent Document 1 proposes a method of extending the shelf life of seeds while maintaining the germination rate by performing water stress treatment or / and heat treatment on the priming seeds before dry-priming the priming seeds to a predetermined moisture content. ing. Patent Document 2 proposes a method for preventing the outflow of the active ingredient contained in the coat layer by giving an aqueous solution that can be absorbed by the seed to the coated seed before sowing.

JP 7-255218 A WO2011 / 28115

  However, the technique proposed in Patent Document 1 is not related to coated seeds. Further, with the proposed technique of Patent Document 2, it is difficult to avoid cracks and collapse of the coat layer.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method capable of improving the germination rate and the like of coated seeds without causing cracks or collapse in the coating layer. .

  In the method for improving characteristics according to the present invention, which achieves the above object, a coated seed in which the outer peripheral surface of the seed is coated with a powder material is stored for a predetermined period in a humidity environment in which the moisture content of the internal seed is 10% by dry weight or more. It is characterized by that. In the present specification, the moisture content of the internal seed is measured as follows.

[Method of measuring moisture content of internal seeds]
(1) A heat-resistant container having an arbitrary capacity is prepared, and its weight (referred to as weight a) is measured.
(2) A predetermined amount (for example, about 0.5 to 1.0 g) of the internal seed from which the coated layer of the coated seed of the present invention has been removed is placed in the heat-resistant container, and its weight (weight b) is set. taking measurement.
(3) Place the whole heat-resistant container in an oven and heat dry at 105 ° C. for about 16 to 24 hours.
(4) The dried heat-resistant container is placed in a desiccator containing silica gel, allowed to stand at room temperature, and then its weight (referred to as weight c) is measured.
(5) Obtain the water content from the following formula.
Moisture content (dry weight%) = (b−c) / (c−a) × 100

  Here, after storage for the predetermined period, it is preferable to dry until the moisture content of the internal seeds is 7% by dry weight or less.

  The storage period is preferably in the range of several hours to 10 days.

  Furthermore, the storage temperature is preferably in the range of 0 ° C to 40 ° C.

  In addition, according to the present invention, a coated seed whose characteristics are improved by any one of the methods described above is provided.

  In the method for improving the properties of coated seeds according to the present invention, water is not directly applied to the coated seeds, but water is applied to the internal seeds by the environmental humidity, so that germination of the coated seeds is caused without causing cracks or collapse in the coated layer. The rate can be improved.

  One of the major characteristics of the method for improving the properties of coated seeds according to the present invention is that the moisture content of the internal seeds is adjusted by the environmental humidity. This prevents the coating layer from cracking or collapsing. As will be described later, in the method for improving characteristics of the present invention, the moisture content of the internal seed is 10 dry weight% or more. The environmental humidity for keeping the moisture content of the internal seeds in such a range may be appropriately determined in consideration of the layer thickness and material of the coat layer, the seed type, the environmental temperature, etc., but it should be 70% RH or more. More preferably, it is 75% RH or more.

  And in this invention, it is another big characteristic to preserve | save for a predetermined period by making the moisture content of an internal seed into 10 dry weight% or more. If the moisture content of the internal seed is less than 10% by dry weight, characteristics such as seed germination cannot be improved. The moisture content of the inner seed is more preferably 13% by dry weight or more. Moreover, the suitable upper limit of the moisture content of an internal seed is 40 dry weight%.

  There is no particular limitation on the period of storage when the moisture content of the internal seeds is 10% by dry weight or more, and it may be appropriately determined from the seed type, the layer thickness of the coat layer, etc., but is generally in the range of several hours to 10 days. Is preferred.

  Further, the temperature during the storage period is not particularly limited, as in the storage period, and may be determined as appropriate based on the type of seed and the layer thickness of the coat layer. In general, the temperature is preferably in the range of 0 ° C to 40 ° C. . The storage temperature does not have to be a constant temperature and may be a variable temperature.

  As a preservation | save form, the form which puts a coat seed in the airtight container adjusted humidity so that the moisture content of an internal seed may become an equilibrium moisture content, and leave still for a predetermined period is mentioned, for example. Alternatively, in the production of coated seeds, when the powder material is gradually supplied while spraying water and / or a binder, the surface of the seed is coated with the powder material, and then the coated seeds are dried. When the moisture content of the seed is 10% by dry weight or more, the drying may be stopped and left for a predetermined period.

  The coated seed stored for a predetermined period is preferably dried until the moisture content of the internal seed is 7% by dry weight or less. It is because the transportability and storage stability of the coated seeds are improved by drying the moisture content to 7% by dry weight or less. More preferably, it is 6% by weight or less.

  The coated seed which is a target for property improvement in the present invention will be described. The seeds coated with the powder material are not particularly limited in shape and type. For example, (i) a length of 2.0 to 5.0 mm, a width of 0.5 to 2.0 mm, and a thickness of 0.3 -0.5 mm long granular seeds (for example, lettuce seeds), (ii) substantially spherical seeds (for example, cabbage seeds) having a diameter of 1.0-3.0 mm, and (iii) Examples include flat oval seeds having a diameter of 1.5 to 4.0 mm (eg, eggplant seeds), as well as seeds of any other shape. Specifically, for example, vegetable seeds, flower seeds, pasture seeds, wild grass seeds, cereal seeds and industrial crop seeds can be mentioned, and more specifically, the following can be mentioned.

  Examples of vegetable seeds include cucumber, melon, pumpkin and other cucurbitaceae vegetable seeds; eggplant, tomato and other solanaceous vegetable seeds; peas and kidney beans and other leguminous vegetable seeds; Seeds; Vegetable seeds of Brassicaceae such as turnips, Chinese cabbage, cabbage, Hanayasai, etc .; Brassicaceae vegetable seeds such as radish; Carrot, celery, etc .; Cryaceae vegetable seeds; Vegetable seeds of Lamiaceae; vegetable seeds of red crustaceae such as spinach.

  As the flower seeds, for example, flower seeds of Brassicaceae such as ha button, stock, alyssum, etc., flower seeds of the asteraceae such as Lobelia, for example, flower seeds of the asteraceae such as aster, zinnia, sunflower, etc. Flower seeds such as primroses such as snapdragons, flower seeds such as primulas such as primula, flower seeds such as rhododendrons such as begonia, and flower seeds such as Labiatae such as salvia, such as violets such as pansy and viola For example, plant seeds of solanaceae such as petunia, and plant seeds of gentian family such as eustoma.

  As pasture seeds, for example, pasture seeds of timothy (Owo wakaeri), Italian ryegrass (rat mulberry), verm douglas (gourd shiba), oat hay (soba), sudangrass, kraingrass, fescue, and orchardgrass (camogaya) .

  Examples of wild grass seeds include leguminous wild grass seeds such as alfalfa (Prunus serrata) and clover (white clover), for example, grass seeds such as grasses such as bark.

  Examples of cereal seeds include rice, barley, wheat, soybean, millet, millet and millet.

  Examples of the craft crop seed include red crustacean seeds such as sugar beet, solanaceous seeds such as tobacco, cruciferous seeds such as rapeseed, and gramineous seeds such as rush.

  The coated seeds of the present invention are powdered while spraying water and / or a binder on the seeds using a conventionally known granulator such as an inclined rotary pan granulator or a fluidized bed granulator. Manufactured by gradually supplying body material. If necessary, a water repellent, an agrochemical active ingredient, a pigment, and the like may be mixed in the inorganic powder material. Further, the granulation operation may be repeated to make the coat layer have a laminated structure. In addition, when long-term transportation and storage are considered, it is recommended to dry the coated seeds after granulation. The product temperature when drying the coated seeds is preferably 50 ° C. or lower, specifically 5 ° C. to 50 ° C., so as not to apply high temperature stress to the seeds. As the drying device, a conventionally known drying device can be used. For example, a fluidized bed dryer, a drum dryer, a stationary shelf dryer, or the like is preferably used. The moisture content of the internal seed in the coated seed after drying is preferably 7% by weight or less.

  There is no particular limitation on the shape and size of the coated seeds, and it is determined appropriately according to the size of the seeds and the plant species so as to be a size that does not hinder seed germination according to the workability of the seeding operation. Is done. The average particle size is usually in the range of 1 to 20 mm. Specifically, for vegetable seeds such as cabbage, lettuce, Chinese cabbage, carrots, etc., a spherical or nearly spherical shape with a diameter of 2.5 to 3.5 mm; for large seeds such as onions and leeks, tomatoes, eggplants, etc., the diameter Spherical or substantially spherical shape of 3.5 to 4.5 mm; For fine seeds such as eusuma, a spherical or substantially spherical shape and size of 1.0 to 1.7 mm in diameter can be mentioned.

  As a powder material for coating seeds, a powder material used in the field of normal coated seeds can be used. For example, kaolin minerals (kaolinite, dickite, nacrite, halosite, etc.), serpentine (chrysotile, lizardite, anticolite, amesite, etc.), montmorillonite minerals (sodium montmorillonite, calcium montmorillonite, magnesium montmorillonite, etc.), smectites (saponite) , Hectorite, soconite, hydelite, etc.), pyrophyllite, talc, wax, mica (muscovite, fengite, sericite, illite, etc.), silica (cristobalite, quartz, etc.), double-chain clay minerals (palygorskite, Sepiolite, etc.), sulfate minerals such as gypsum, dolomite, calcium carbonate, gypsum, zeolite, zeolite, tuff, vermiculite, laponite, pumice, diatomaceous earth, acidic clay, activated clay. Among these inorganic powder materials, one kind can be used alone, or two or more kinds can be mixed or used together. The content of the inorganic powder material in the entire coating layer is preferably in the range of 5 to 90% by weight, more preferably 10 to 70% by weight. The average particle diameter of the powder material used in the present invention is in the range of 1 to 100 μm, preferably 5 to 50 μm. The average particle size of the powder material was measured using a laser diffraction / confused particle size distribution analyzer (HORIBA LA-300, manufactured by HORIBA, Ltd.).

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these examples at all.

Example 1
150 g of onion seeds (number of grains: 40,000 grains) as the original seeds are put into a centrifugal flow type tumbling granulator having a diameter of 36 cm, and tap water is sprayed on the seeds while rotating and stirring. While spraying, the inorganic powder material was gradually added, and finally granulated until the weight of 100 grains became 3 g. And the granulated material was taken out from the granulator, and 35 degreeC warm air was sprayed for 15 minutes, and the coating layer was dried. Then, it was put in a shelf dryer set at a temperature of 35 ° C. overnight and dried until the moisture content of the internal seeds became 5% by weight or less.
Thereafter, the coated seeds were placed in a desiccator containing a saturated sodium chloride solution at a temperature of 15 ° C. and a humidity of 75.3% RH, and allowed to stand for 5 days, and the moisture content of the internal seeds was changed from 5 to 13.1 dry weight. %. Next, this coated seed was placed in an aluminum pack and stored at a temperature of 40 ° C. for 10 days. The coated seeds were dried after storage, and the moisture content of the internal seeds was adjusted to 5% by dry weight. The germination rate of the coated seeds obtained as described above was measured as follows. The results are shown in Table 1.

(Germination test)
Prepare two petri dishes with a diameter of 9 mm with two filter papers, drop 4.5 mL of water on it, place 50 seeds of the coated seeds on each floor, and store them under a light condition of 30 ° C. and about 900 lux. The germination rate (%) on the 4th and 8th days was measured.

(Comparative Example 1)
150 g of onion seeds (number of grains: 40,000 grains) as the original seeds are put into a centrifugal flow type tumbling granulator having a diameter of 36 cm, and tap water is sprayed on the seeds while rotating and stirring. While spraying, the inorganic powder material was gradually added, and finally granulated until the weight of 100 grains became 3 g. Then, the granulated product is taken out from the granulator, and after the coating layer is dried by blowing warm air of 35 ° C. for 15 minutes, it is immediately put in a shelf dryer set at a temperature of 35 ° C. overnight, and the moisture content of the internal seeds Was dried to 5% by weight or less.
The germination rate of this coated seed was measured as follows. The results are shown in Table 1.

  As is apparent from Table 1, in the coated seeds of Example 1 in which the characteristics of the present invention were improved, the germination rates on the 4th and 8th days were 65% and 88%, respectively. The germination rate was much higher than that. On the other hand, in the coated seeds of Comparative Example 1, the germination rates on the 4th and 8th days were as low as 14% and 34%.

  In the method for improving the properties of coated seeds according to the present invention, water is not directly applied to the coated seeds, but water is applied to the internal seeds by the environmental humidity. The germination rate can be improved, which is useful.

Claims (5)

  A method for improving the characteristics of a coated seed, wherein the coated seed whose outer peripheral surface is coated with a powder material is stored for a predetermined period in a humidity environment in which the moisture content of the internal seed is 10% by dry weight or more.   The method for improving the characteristics of coated seeds according to claim 1, wherein after the predetermined period of storage, the seeds are dried until the moisture content of the internal seeds is 7% by dry weight or less.   The method for improving the characteristics of coated seeds according to claim 1 or 2, wherein the storage period is in the range of several hours to 10 days.   The method for improving the properties of coated seeds according to any one of claims 1 to 3, wherein the storage temperature is in the range of 0C to 40C.   Coated seeds whose properties are improved by the method according to claim 1.