JPH03133304A - Seed treating agent - Google Patents

Abstract

PURPOSE:To promote the germination of seed by using an agent containing a water-soluble chitin as a main component. CONSTITUTION:Natural chitin powder is dispersed in an alkaline aqueous solution (e.g. NaOH solution) having a concentration of 5-50% and aged under stirring at 25-40 deg.C for 30-110hr to obtain an alkaline aqueous solution of a partially deacetylated chitin having a deacetylation degree of 35-75%. The pH of the solution is adjusted to 5-9 with an acid to obtain a water-soluble partially acetylated chitin. The objective seed-treating agent is prepared by dissolving 0.001-2% of the partially acetylated chitin and, as necessary, an osmotic pressure controlling agent (e.g. mannitol), a plant hormone, a plant nutrient, etc., in water. Seeds are immersed in the seed-treating agent for 1min to 24hr and dried and the immersion and drying procedures are repeated 2-10 times.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a seed treatment agent for plant seeds comprising water-soluble chitin that has been partially deacetylated and has increased solubility in water.

Mechanization of sowing work and labor saving of thinning work are cited as specific goals of agricultural modernization. In order to achieve this goal, we need to shape and granulate the seed side of the crop into a shape that allows mechanical sowing, and to increase the germination rate and seedling development to ensure that one seedling is produced from one seed. There is a need to improve the performance of seeds, such as improved performance.

[Prior Art] Seed treatment technology is a technology that has been put into practical use to meet such demands for improved performance of seeds. Seed treatment technology, in terms of -C, means seed soaking treatment, wet-drying treatment, osmotic pressure treatment, coating treatment, and granulation treatment.

Among these, granulation processing is a technology for granulating and shaping fine seeds and irregularly shaped seeds, and is a technology to facilitate mechanical sowing, and there are many patents.

Treatments aimed at improving the germination rate of seeds include seed soaking treatment, wet-drying treatment, osmotic pressure treatment, and coating treatment.

The purpose of seed soaking treatment is to soak seeds in various chemical solutions and sow and cultivate the seeds. The main purpose is often to sterilize the seeds, but there are also cases where the seeds are soaked in solutions such as plant hormones in hopes of promoting growth.

Wet-dry treatment involves making seeds absorb water, drying them before germination and rooting, and then using the seeds for cultivation. This treatment may improve the germination rate.

Osmotic pressure treatment involves soaking seeds in a solution of salts, PEG, mannitol, etc., drying them before germination and rooting, and using the seeds for cultivation. Even with this treatment, an improvement in germination rate, an increase in germination vigor, and uniform growth of seedlings may be observed.

Coating treatment is a technology that uses a binder to cover the surface of seeds with fungicides, germination-promoting substances, etc. in a film to disinfect the seeds, improve the germination rate, and promote early growth.

(Problems to be Solved by the Invention) Up to now, such treatments are often treatments for advancing the age of the normal germination process of seeds. It is not an active treatment that imparts an additional effect, but rather a seed treatment technology that is expected to have a passive effect that simply speeds up the natural growth process of plants.

Attempts have also been made to treat plants with plant hormones to promote early growth, but the effects vary depending on the type of plant, and this technique has not yet been established. As a technology for actively promoting plant growth by treating seeds with a substance that has biological activity on plants, a patent application has been filed for chitosan and colloidal chitosan, which is a low-molecular version of chitosan (Japanese Patent Laid-Open Publication No. 139102/1982). ).

However, this technology is limited to seed coating treatments.

Furthermore, chitosan and colloidal chitosan are insoluble in water, and it is essential to use a dilute acid solution to dissolve them. Therefore, the solution is acidic and has a negative effect on plants, so it is necessary to neutralize it with an alkali. These problems make operations complicated and increase costs.

(Means for Solving the Problem) The present inventor has decided to treat seeds with chitin for the purpose of developing a seed treatment technology that actively promotes seed germination and contributes to improving the performance of seeds. We then discovered that by making chitin water-soluble and performing seed treatments such as seed soaking, osmotic pressure treatment, and coating treatment using the water solution, it had excellent effects on various plant species. ,
Based on this knowledge, we have completed the present invention.

That is, the present invention relates to a seed treatment agent for plant seeds made of water-soluble chitin and a seed treatment method using the same.

Chitin is a linear polymer of acetylglucosamine, and exists naturally in large amounts as a supporting tissue in crustaceans, fungi, and the like. This chitin is known to have physiological activity toward plants, such as eligitor activity that induces defense responses in plants. Chitin is originally a water-insoluble substance, and in the present invention, it is used after being made water-soluble. Water solubilization of chitin can be achieved by partial deacetylation. Partial deacetylation may be carried out according to a known method (Japanese Unexamined Patent Publication No. 53-47479, etc.). For example, first, naturally produced chitin powder is
By dispersing it in a 0% concentration alkaline aqueous solution, adding water and stirring, or directly freezing the dispersion and then repeating the process of thawing, viscous alkaline chitin water can be obtained.
Make it 8 liquids. Alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, supra-alkali metal hydroxides such as barium hydroxide and calcium hydroxide, and alkali metal carbonates such as sodium carbonate and potassium carbonate as alkaline hydrolyzing agents. Salt etc. are used. Although deacetylation of about 20% has already progressed at the stage of preparing the alkaline chitin aqueous solution, the product of this is insoluble in water. Therefore, the alkali chitin aqueous solution prepared until the desired 40 to 50% deacetylation is achieved is further aged for a predetermined period of time. In this case, if the temperature exceeds 50°C, the chitin compound will precipitate, resulting in a heterogeneous system, so it is necessary to ripen the product at a temperature below 50°C while maintaining a homogeneous state. . The degree of progress of deacetylation is closely related to the polymer concentration, alkali concentration, aging temperature, and aging time.
There is a certain relationship with the y11 liquid.

[-1 The conditions for achieving a deacetylation rate of 35 to 75% are aging temperature of 25°C for 30 to 110 hours;
At 30°C, it is 20 to 50 hours, and at 40°C, it is 10 to 30 hours.

After partial deacetylation by homogeneous alkaline hydrolysis to achieve a deacetylation rate of 35 to 75%,
This alkaline aqueous solution of partially deacetylated chitin was mixed with hydrochloric acid,
Accurately adjust ρ11 to pH 5 to 9, which is the isoelectric point of the partially deacetylated chitin, using an acid such as sulfuric acid while measuring with a pH meter, or use alcohols such as methanol, isopropanol, L-butanol, or ions. Dealkalize with exchange resin, etc.

After the dealkalization treatment, if dropped into an organic solvent such as acetone or methanol, water-soluble partially deacetylated chitin will precipitate. A purified product can be obtained.It is also possible to obtain a purified product by desalting by electrodialysis or osmotic membrane methods.

It is also possible to make chitosan water-soluble by chemically modifying it, and for example, chitosan obtained by sulfation can also be used.

In the present invention, the deacetylation rate thus obtained is 35 to 75%, and the average molecular weight is 1.5 million to 2.
700,000 water-soluble chitin is used as a seed treatment agent. The seed treatment agent may also contain other ingredients. Examples of other components include osmotic pressure regulators such as polyethylene glycol, mannitol, and polyvinylpyrrolidone, various plant hormones, plant nutrients, and fungicides.

Seed treatment is performed using water-soluble chitin in an aqueous solution.

The concentration of the aqueous solution is about 0.001 to 2%, preferably 0,
Approximately 1 to 0.2% O is appropriate. The seeds may be soaked at room temperature for a period of about 1 minute to 24 hours. When performing osmotic pressure treatment, the material is immersed in an aqueous solution to which mannitol, salts, PEG, etc. are added to increase the osmotic pressure. In the case of mannitol, the appropriate concentration is about 0.2 to 0.7 mol/l. The concentration of water-soluble chitin may be the same as above, and the appropriate soaking time is about 1 minute to 24 hours. After immersion, dry if necessary. - The coating treatment can be carried out by repeating dipping and drying. The number of repetitions is 2~
About 10 times is good.

In this way, seeds treated with water-soluble chitin can be sown and cultivated in the same way as regular untreated seeds.

Seeds that can be treated with the seed treatment agent of the present invention are not particularly limited as long as they are plants, but the seed treatment agent can be applied to seeds of various vegetables, grains, and the like.

〔Example〕

Example 1 Example of immersion treatment Method for preparing aqueous solution A water-soluble chitin aqueous solution can be easily prepared by adding a predetermined amount of chitin to water and stirring.

Lettuce (Red Wave) and carrot (Shunmai Jinggang Wusun) seeds were mixed with the above water-soluble chitin 0.07% solution (pH 5).
, 8) for 3 hours at 22°C, and then dried in a dryer for 30'
C11.5 hours followed by drying at 35°C for 1.5 hours. Akadama soil 7: The above seeds were sown in a plant bed containing beet moss 3 soil, and the seedling generation rate was investigated. The investigation is
Lettuce was tested 10 days after sowing, and carrots were tested 25 days after sowing. There were two plots with 100 seeds per plot, and the average value of the two plots was used for the seedling emergence rate. As a control,
Seeds that had been soaked in water and then dried were used. Table 1 shows the results.

Table 1 Number Seed treatment Lettuce Carrot
Water 82.5% 70.0
%2 Water-soluble chitin 95.5% 82.0
% As a result, it was found that the seedling emergence rate was improved for lettuce and carrots.

Example 2 Example of soaking treatment Lettuce (Red Wave), a variety that is difficult to germinate at high temperatures
After the seeds were treated with water-soluble chitin in the same manner as in Example 1, the germination rate at high temperatures was investigated. Lettuce is a seed with poor germination rate at high temperatures. Seeds were placed in a petri dish and germinated in a thermostatic incubator maintained at 30°C or 35°C, and the germination rate was examined after 10 bites.

The number of grains placed on the bed was 100 grains. Seeds soaked in water were used as a control. Seeds that had been soaked were used. Table 3 shows the results, and Table 2 shows the results.
show.

Table 2 Number Seed treatment 30°C35°C1 water
42.0% 1.0%2 Water-soluble chitin 83.0% 30.0%2 As shown in 2, it has become clear that treatment with water-soluble chitin overcomes the difficulty in germination at high temperatures.

Example 3 Soaking treatment example Spinach (late bolted bulk) seeds were soaked in 0.01% water-soluble chitin (pH 5,8) at room temperature for 5 minutes, and left to dry at room temperature. These seeds were sown in a raised bed with a bed width of 100 cm, with a row spacing of 15 cm, and 30 seeds per row, and the seedling emergence rate was investigated. Each section contained 300 grains (10 rows), and three repeated sections were set up. Sowing was done on June 27th and 15 days later on July 1st.
On the 2nd, the seedling incidence was investigated. The average value of the three plots was used for the seedling incidence. Controls included water-treated seeds and 0.005
Similar seed immersion table with % chitosan 3 No. Seed treatment Seedling emergence rate 1 Water treatment 64.9% 2 Chitosan 67.3% 3 Water-soluble chitin 72.6% Thus, water-soluble chitin treatment is effective for spinach at high temperatures. It was found to improve seedling emergence rate and was more effective than chitosan.

Example 4 Coated cucumber (Sweet Franch) seeds were dipped in a 0.05 water-soluble chitin aqueous solution for a short time (1 to 2 minutes), and after drying, dipping and drying were repeated 5 times. This operation coated the seed surface with chitin in the form of a film. These seeds were sown in strawberry packs containing soil in the usual way, 50 seeds per bag, and the germination rate and the incidence of large seedlings were investigated. Three plots were set up repeatedly, and the average values of the three plots were used for both the germination rate and the incidence of large seedlings.

Seeds treated with water were used as a control.

Table 4 shows the results.

Table 4 Number Seed treatment Germination rate Number of large seedlings after 8 days
After 12 days Water treatment 60.7% 69.3% 98 (
100)2 Water-soluble chitin 70.7% 76.7%
115 (117) Thus, it has been revealed that water-soluble chitin treatment promotes the early growth of cucumber.

Example 5 Soaking treatment example Melon (Rs Tokai R220) seeds were soaked in a 0.07% aqueous chitin solution for 12 hours and dried in the same manner as in Example 1. The seeds were sown on vermiculite, allowed to root, and then potted in 9 cm pots. After 30 days, the length of the hypocotyl and the weight of the above-ground part were measured. Seeds treated with water were used as a control, and significant differences with respect to the control were tested using a p1 test.The results are shown in Tables 5 and 6. Y4 raw chitin mating fl chrysanthemum average (cI[1) tffi<1 glance (cm) t(c
al) t(0,05) 10 3.68
0.346 10 3.79 0.375 0.6466 2
．． 101 None Table 6? fi"4・fIY Missing Village (44 votes Average (g)
ff? Heikan difference (g) t(c, al) t(0,0
5) 1 , + Question 1 io
1.1866 0.281612 #6?
l:t chin ta! Jl 10 1.5
496 0.13494 3.4Fn4
It was revealed that water-soluble chitin treatment had no effect on the length of the hypocotyl, but had a significant effect on increasing the weight of the above-ground part, as in the cases with 2.101 and σ1.

In other words, it was confirmed that water-soluble chitin treatment produced large, voluminous seedlings.

Example 6 Osmotic pressure treatment example Difficult to germinate seedless watermelon (63W-90) seeds were immersed in a 0.5M mannitol solution or a 0.5M mannitol solution containing 0.1% water-soluble chitin for 12 hours. Osmotic pressure treatment was performed. The seeds were washed with water, dried, and sown on vermiculite. This was returned to the greenhouse and germination rate was investigated 5 days later. Seeds treated with water or mannitol alone were used as controls. Table 7 shows the results.

Table 7 Seed treatment Untreated 0.5M mannitol 0.5M mannitol 0.1% Water-soluble chitin Germination rate 3% 5% 25% In this way, high osmotic pressure treatment with water-soluble chitin coexists can reduce the germination rate. It became clear that there was a breakthrough.

〔Effect of the invention〕

By using water-soluble chitin, seed treatments such as immersion treatment, coating treatment, and osmotic pressure treatment can be performed, and beneficial effects such as improved germination rate and seedling generation rate have been recognized in many plant species. It will be done. In addition, the effects of water-soluble chitin are
It was more effective than chitosan.

Claims (3)

[Claims] (1) Plant seed treatment agent made of water-soluble chitin (2) Seed treatment method characterized by using water-soluble chitin (3) The method for treating seeds according to claim (2), wherein the concentration of water-soluble chitin is 0.001 to 2%.