JP2006262845A - Seed treatment method - Google Patents

Abstract

The present invention provides a seed treatment method that is easy to handle, does not use agrochemicals, has no possibility of residual chemicals, does not adversely affect seeds, and can effectively prevent mold generation and spoilage. .
The seed is contacted with an aqueous solution having sodium hypochlorite adjusted to a neutral range.
[Selection figure] None

Description

  The present invention relates to a seed treatment method for preventing mold generation and spoilage even when stored or coated seeds are used.

  Plant seeds such as flower buds and vegetables have problems such as mold generation or rot during storage. In order to solve such problems, the use of pesticides for seed disinfection such as benomyl and thiuram has been known by the Agricultural Chemicals Control Law (Non-patent Document 1) and the like.

  However, when such a pesticide is used, the pesticide itself has persistence, and when such a pesticide is used for disinfection, it often has an adverse effect on the subsequent germination and growth of the seed.

Furthermore, since there is concern about the effects of pesticides on the human body, careful handling of pesticides and actual disinfection work are required, and problems with the remaining pesticide disposal methods are likely to occur. Here, agricultural chemicals themselves have an adverse effect on the environment, and therefore measures such as discontinuation of use or reduction of the amount of use have been required.
Agricultural Chemicals Control Law (Act No. 83 of July 1, 1948)

  The present invention improves the conventional problems described above, that is, does not use agrochemicals, is easy to handle, has no adverse effects on the possibility of residual chemicals and seeds, and effectively generates and decays mold. It aims at providing the processing method of the seed which can prevent.

  In order to solve the above problems, the seed treatment method of the present invention is characterized in that, as described in claim 1, the seed is contacted with an aqueous solution having sodium hypochlorite adjusted to a neutral range.

  The seed treatment method according to claim 2 is characterized in that, in the seed treatment method according to claim 1, the neutral region is in a range of pH 5 to 7.5.

  The seed treatment method according to claim 3 is the seed treatment method according to claim 1 or 2, wherein the seed is a seed for gel-coated seed processing.

  According to the seed treatment method of the present invention, organic pesticides such as benomyl and thiuram are not used, handling and implementation are easy, and there is no adverse effect on the possibility of residual chemicals and plant seeds. In addition, the occurrence of mold and decay can be prevented.

  The seed treatment method of the present invention is applied to plant seeds, and is then used for drying and storing as necessary, but it is applied to gel-coated seed technology for forming a coated gel layer made of an aqueous gel around seeds. Can also be applied. When applied to gel-coated seed technology, it is possible to prevent bacteria and fungi from being brought into the coated gel layer. It is possible to prevent the occurrence of damage such as rot and mold of the layer, so that it is possible not only to prevent the occurrence of the disease of the coated gel seed, but also the mechanical seeding caused by the defective shape of the coated gel layer due to these obstacles. Problems such as disappearance can be solved at the same time.

  In the present invention, it is necessary to use an aqueous sodium hypochlorite solution adjusted to a neutral range. Here, effective chlorine is highly effective against bacteria and fungi and is rapid. Furthermore, since sodium hypochlorite decomposes spontaneously, there is no risk of long-term residual, and it has been used as a material that easily decomposes when it comes into contact with organic matter.

  Among them, neutral calcium hypochlorite was commercially available as an agricultural material and agricultural water purification agent, and this neutral calcium hypochlorite has been used by applying it to seed disinfection. However, when this neutral calcium hypochlorite was used, the effect was not sufficient, especially in the case of gel-coated seeds in which a coated gel layer made of an aqueous gel was arranged around the seeds, the incidence of mold was high. Have been used because they are easy to obtain and handle (tablets with a diameter of about 2 mm).

  In the present invention, by using a sodium hypochlorite aqueous solution adjusted to a neutral range, a high treatment effect can be obtained in a very short time without adversely affecting the subsequent seed growth.

  The sodium hypochlorite aqueous solution adjusted to the neutral range is, for example, a commercially available sodium hypochlorite aqueous solution (usually effective chlorine concentration is 5%), and the required magnification assuming the final effective chlorine concentration. And then adjusted to neutral range by adding acid or the like. In this case, an inorganic acid such as hydrochloric acid is usually used, but an acidic liquid such as acetic acid or pyroligneous acid may be used alone or in combination.

  Here, it is desirable to carry out in a neutral range, particularly in a range of pH 5 to 7.5. When the pH is higher than 7.5, the effective chlorine concentration cannot be sufficiently increased, or depending on the effective chlorine concentration, a sufficient effect may not be obtained by a short immersion treatment. On the other hand, if the pH is lower than 5, the effective chlorine component is decomposed and cannot be used.

  Since the effective chlorine component decomposes if left as described above, the sodium hypochlorite aqueous solution adjusted to the neutral range is usually prepared immediately before use, particularly when the effective chlorine concentration is low. However, in the case of a sodium hypochlorite aqueous solution whose effective chlorine concentration is adjusted to a neutral range of about 200 ppm, it can be stored for about three months without causing a significant decrease in concentration.

  Note that the effective chlorine concentration is determined by the DPD method (diethyl-p-phenylenediamine method), the o-toluidine method (this method is not used in general due to problems with the human body and environment), the current method, or It can be measured using a general method such as absorptiometry, and can be conveniently measured using a commercially available measurement kit.

  The effective chlorine concentration in the sodium hypochlorite aqueous solution in the neutral range used in the present invention is preferably 7 ppm to 14000 ppm. If it is less than 7 ppm, the effect of treatment may not be obtained, and if it exceeds 14000 ppm, it may affect the germination rate and growth of the seed after treatment. A more preferable range is 100 ppm or more and 3000 ppm.

  In this way, the seed is brought into contact with an aqueous sodium hypochlorite solution adjusted to a neutral range at an appropriate concentration. At this time, it is preferable to immerse in a sodium hypochlorite aqueous solution adjusted to a neutral range in order to ensure the effect of the present invention, but it is performed by other means such as spraying the aqueous solution on seeds. May be.

  The immersion time is usually from 10 seconds to 30 minutes. If it is too long, the effect is not improved, and the germination rate and growth of the seeds after treatment may be affected. Moreover, a process is normally performed at room temperature (15-30 degreeC).

  The amount of seed treatment with respect to the sodium hypochlorite aqueous solution adjusted to the neutral range is not particularly limited as long as all the seeds can uniformly contact the sodium hypochlorite aqueous solution adjusted to the neutral range. In addition, since the effective chlorine concentration in this aqueous solution is drastically reduced during the treatment, the wastewater treatment of the aqueous solution after use is extremely easy and can be appropriately diluted or mixed with wastewater having COD components. The waste water treatment is practically unnecessary because it can be completely harmless by the above-mentioned treatment, or it is harmless even in the state as it is.

  The seed after the treatment using the sodium hypochlorite aqueous solution in the neutral range is dried as necessary. Air drying may be used, and methods such as heat drying at a temperature suitable for seeds or hot air drying may be employed.

  Seeds treated in this way can be sown as they are, stored under appropriate conditions, or processed into pellet seeds or gel-coated seeds and then stored under appropriate conditions such as sowing or refrigeration. It can be sown later.

  Here, a method for producing a gel-coated seed will be described. In gel-coated seeds, one or more seeds are encapsulated in a coated gel layer made of an aqueous gel that is larger than seeds, so that precise mechanical sowing is possible and germination and growth are ensured. It has an excellent feature that it can be used.

  The aqueous gel that forms such a gel-coated seed coating gel layer is selected from sodium alginate, gellan gum, xanthan gum, locust bean gum, carboxymethylcellulose, pectin, gelatin, carrageenan, sodium polyacrylate, and agar. -What is formed with at least 1 sort (s) of synthetic gel forming polymer and water is mentioned. Of these, there are those that require the presence of metal ions for gelation, and salts, alkalis, and the like that supply these metal ions are appropriately added. Furthermore, various preservatives, fertilizer components, growth promoters and the like can be added as appropriate as the third component.

  For example, the gel coating layer forms a droplet of an aqueous solution having an aqueous gel-forming polymer at the tip of a thin tube, and one or more seeds treated as described above using a thin tube are added to the droplet. Then, it can be produced by dropping the solution into a solution (coagulating solution) containing metal ions having a function of solidifying the droplet. At this time, if necessary, a gas such as air or oxygen can be sealed in the droplet.

  Examples of the aqueous solution that forms an aqueous gel together with metal ions include aqueous solutions of sodium alginate, sodium polyacrylate, and the like. In addition, divalent metals such as calcium and barium and aluminum are used as metal ions for curing them as an aqueous gel, and these are usually used as an aqueous chloride solution in order to prevent adverse effects on plant objects.

  Moreover, a carboxymethylcellulose aqueous solution can be used as the aqueous gel-forming aqueous solution, and a potassium aluminum sulfate (potassium alum) aqueous solution can be used as the coagulating liquid.

  Here, the water content of the aqueous gel capsule is desirably 90% or more. If the moisture content is less than 90%, the gel capsule becomes hard and may prevent plant protrusions (buds and roots coming out of the gel capsule).

  Since such gel-coated seeds have moisture around the seeds, the seeds are usually stored under environmental conditions such as temperature and light that do not normally germinate or are difficult to germinate. However, even after germination, until the roots and buds emerge (protrude) from the coated gel layer, they can be stored without adversely affecting the seed plants.

  Examples of the seed treatment method of the present invention will be described below. As seeds, delphinium (two types, called “delphinium 1” and “delphinium 2”, respectively), Eustoma grandiflorum, and lily of the sun are used, and the final grade of reagent grade 5 is set so that the effective chlorine concentration becomes a predetermined concentration. % Aqueous solution containing effective chlorine in neutral range diluted with sodium hypochlorite solution and adjusted to pH 7 ± 0.3 with dilute hydrochloric acid (effective chlorine concentration is measured by DPD method) In addition, about the high concentration area | region which cannot be measured, it diluted and measured to the measurable range using distilled water, and converted from the measured value and the dilution rate.

<Treatment According to the Present Invention: Examination with Bare Seeds>
The seeds shown in Table 1 were immersed for 5 minutes in an aqueous solution of sodium hypochlorite (room temperature) containing 200 ppm of effective chlorine as described above (hereinafter abbreviated as “A200 treatment”).

  Then, after drying each child by ventilation, place 20 particles in a petri dish with a diameter of 12 cm with wet filter paper at intervals, and put a total of 100 particles under conditions (temperature, light) suitable for germination. It was allowed to stand until the number of germination did not increase. (Example 1).

  For comparison, as in the above, but not an aqueous sodium hypochlorite solution, Chemomicron G (neutral calcium hypochlorite (effective chlorine 70%) manufactured by Nippon Soda Co., Ltd.) was dissolved 200 times (weight). Ratio), an aqueous solution (effective chlorine concentration 3000 ppm (actual measurement value) pH 10.8) soaked in seeds for 10 minutes (Comparative Example 1: “G treatment”), and immersion treatment and drying treatment were performed. No seeds, that is, seeds before dipping treatment (Comparative Example 2 “untreated”) were germinated in the same manner as described above.

  Then, the fungal incidence and germination rate were examined. Here, when the germination rate does not increase, the mold occurrence rate is counted by visually observing whether or not filamentous fungi are generated on the seed and the surrounding filter paper, and this is determined as the “mold occurrence rate”. did. Germination rate is the percentage of those that germinated normally. In many cases, the seeds with molds did not germinate or failed to germinate normally. These results are shown in Table 1.

<Treatment according to the present invention: examination with gel-coated seeds>
Using the two types of delphinium seeds, Eustoma seeds and Synppo lily, and untreated seeds treated with A200 or G as described above, gel-coated seeds (Example 1, Comparative Example 3 and Comparative Example 4 respectively) ) Was produced.

  Each seed is introduced into a droplet of a 1.5 wt% sodium alginate aqueous solution formed at the lower end of the glass tube using the tube portion of the glass tube, and then the droplet is added to a 10 wt% calcium chloride aqueous solution. It was dripped to form a gel-coated seed in which the seed was enclosed in an aqueous gel capsule. At this time, the size of the gel capsule was 5 mm in diameter, and the moisture content of the coated gel layer was 98.5% by weight.

  Thereafter, each gel-coated seed is placed in a petri dish having a diameter of 12 cm with an interval of 20 grains, and the germination rate does not increase under conditions (temperature, light) suitable for germination of the seeds of a total of 100 grains. The mold generation rate and germination rate at that time were examined. The results are shown in Table 2.

  From Table 2, in the gel-coated seed which performed the A200 process which concerns on this invention with respect to the naked seed, the high mold prevention effect is acquired and the germination rate is also high. Moreover, it can be seen that the effect of the A200 treatment is higher than that of the G treatment by Chemmicron G under a condition where the effective chlorine concentration is higher. In addition, as for the part where mold occurs in the gel-coated seed, there are a lot between the gel coating layer and the seed surface, and then the surface of the gel layer. It becomes impossible and mechanical sowing which is one of the characteristics of gel-coated seeds becomes difficult.

<Treatment according to the present invention: Effect of effective chlorine concentration>
When adjusting the sodium hypochlorite aqueous solution adjusted to the neutral range, the amount of sodium hypochlorite was changed, and the effective chlorine concentration was 7 to 140000 ppm, and 9 types of hypochlorous acid were adjusted to the neutral range. The same eustoma seeds as described above were treated in the same manner as in the above A200 treatment using an aqueous sodium solution, and the germination rate and mold generation rate of them (bare seeds) were examined in the same manner as in Example 1. In addition, gel-coated seeds were prepared for seeds treated with a treatment solution in the range of 7 to 3500 ppm in the same manner as in Example 2 above, and their germination rate and mold generation rate were also examined. Table 3 shows the results.

  From Table 3, the reduction in germination rate is practically not seen when the effective chlorine concentration of the used treatment solution is in the range of 7 ppm to 140,000 ppm, and the mold incidence is within this range (compared to 3% in G treatment in Table 2). It is clear that it can be kept very low.

<Treatment according to the present invention: Effect of pH>
The germination rate and mold occurrence rate were examined in the same manner as in Example 1 using an aqueous solution of sodium hypochlorite adjusted to a neutral range with a pH of 5 and an effective chlorine concentration of 200 ppm. The value was the same level as in Example 1, and no significant difference was observed.

<Comparison with conventional pesticide disinfection>
A commercially available benomyl thiuram (manufactured by Hokuko Chemical Co., Ltd.), an organic pesticide generally used for seed disinfection of vegetables and flower buds, is treated with B20 soaking seeds in a 20-fold dilution with water, 200 with water B200 treatment for immersing seeds in double dilution, B1000 treatment for immersing in 1000-fold dilution with water, G treatment with Chemmicron G used above, A200 treatment according to the present invention, and water containing no drug The blank process to immerse was performed with respect to each primula seed. The subsequent germination rate and mold occurrence rate were evaluated in the same manner as described above. The results are shown in Table 4.

  Table 4 shows that compared to the A200 treatment according to the present invention, the B20 treatment does not germinate at all, the B200 treatment has a high germination rate despite the low germination rate, and the B1000 treatment does not have a very low germination rate. It turns out that the occurrence rate is very high, and when these results, G treatment, and blank treatment are comprehensively judged, the A200 treatment according to the present invention has a high germination rate and a low mold occurrence rate, which is extremely excellent. It can be understood that this is a processing method.

  According to the seed treatment method of the present invention, it is easy to handle without using agricultural chemicals, there is no adverse effect on the possibility of residual chemicals and seeds, and it is possible to effectively prevent the occurrence of mold and decay. Therefore, it can be suitably used as a treatment method before sowing seeds.

Claims (3)

  A seed treatment method comprising contacting a seed with a sodium hypochlorite aqueous solution adjusted to a neutral range.   The seed treatment method according to claim 1, wherein the neutral range is a range of pH 5 to 7.5.   The seed treatment method according to claim 1 or 2, wherein the seed is a seed for processing a gel-coated seed.