CA1227656A - Plant growth regulator composition - Google Patents

Abstract

Abstract of the Disclosure A plant growth regulator composition and a method of promoting root formation and root anchorage of paddy rice. The plant growth regulator composition of the present invention comprises phosphorylcholine or a salt thereof and an agriculturally acceptable carrier. Root formation and root anchorage of paddy rice is promoted by applying the paddy rice a choline salt, phosphorylcholine or a salt of phosphorylcholine.

Description

~7~i~6 Background of the Invention I. Field of the Invention The present invention relates to a plant growth regulator composition, a method for improving crop yields, and a method of promoting root formation and root anchorage of paddy rice.
II. Description of the Prior Art The immersion treatment of the seedlings of sweet potato (I'm _ batatas)/ with choline salts solution has been observed to improve crop yields (Special Bulletin of the Chiba-Ken Agricultural Experiment Station, No. 3, 1973). Phosphorylcholine is used as a drug for treating diseases of the liver/ but its use as a plant growth regulator is not previously known.
Agricultural production can be characterized biologically as the collection of solar energy on the surface of the earth using the photosynthetic properties ox green plants, and the supply of oxygen to the atmosphere. However, this is not always an efficient way to utilize solar energy. Taking a look at the world food situation, it is predicted that the world's population will approximately double by the end of the century, and that it will be extremely difficult to ensure the production of enough food to feed this population increase.
A great deal of research has been devoted to coping with this anticipated population increase. jet, most Lo R&D conducted with the aim of raising agricultural productivity has consisted of little more than improve-mints in production technology; very little effort has been directed toward gaining a detailed understanding of the functions inherent to plants and how these can be enhanced. Plants generally make use of solar energy through photosynthesis to synthesize carbohydrates from water and carbon dioxide, and supply oxygen to the atmosphere. They also carry out respiration, which lo involves the absorption of atmospheric oxygen and the release of carbon dioxide. There are two types of plant respiration: photo respiration, which occurs during exposure to light, and dark respiration, which occurs in dark places. Photo respiration has been observed only in C3 plants. Large amounts of carbon compounds are consumed by photo respiration. In fact, it has been reported that, in some types of plants, 50% of the assimilated carbon compounds are broken down by photo respiration. However, were it be possible to selectively inhibit photo respiration without adversely affecting other metabolic processes within the plant, this would allow one to raise the productivity of crops.
Improvements in rice cultivation techniques have made it possible to grow rice in cold regions. However, the low temperatures sometimes prevent rice seedlings from taking root.
In the course of research on stimulating the solar 6~;6 energy-fixing function of green plants, -the inventors discovered that phosphorylcholine and its salts are able to increase the efficiency of plant photosynthesis -to promote crop yields. The present inventors further discovered that the phosphoric choline, its salts, and choline salt stimulate root formation and anchoring of rice seedlings. The present invention is based on the discoveries.
Siam__ of the_Inventio_ One object of the present invention is to provide a plant growth regulator composition by which crop yields, the root formation and root anchoring in rice seedlings can be promoted.
Another object of the present invention is to provide a method of increasing crop yields and a method for regulating the growth of plants, such as promoting root formation and anchoring in rice seedlings.
The present invention provides a plant growth regulator composition comprising an effective amount of phosphorylcholine or a salt thereof in an agriculturally acceptable carrier.
The present invention further provides a method of promoting crop yields by applying the above plant growth regulator composition to plants.
The present invention still further provides a method of forming and anchoring roots of rice seedlings by applying the rice seedlings an effective amount of ISSUES

a plant growth-regulating compound selected from the group consisting of phosphorylcholine, a salt -thereof, or a salt of choline.
According to the present invention, the effective ingredient reduces the photo respiration of -the plants to promote the crop yields, to promote the formation and anchorage of the rice seedling roots.
Detailed Description of the Preferred Embodiment The choline salts used in the method of the present invention may be inorganic salts such as hydrochloride, phosphate, polyphosphate, sulfate, nitrate, and carbonate salts. Organic salts such as acetate, citrate (choline dihydrogen citrate), lactate, and l tart rate (choline bitartrate~ salts can also be suitably used.
Phosphorylcholine salts that may be used include phosphorylcholine chloride sodium salt and phosphorylcholine chloride calcium salt.
The most desirable of these choline salts are the hydrochloride, the phosphate, and the choline bitartrate. Of these, the hydrochloride is especially desirable. Phosphorylcholine chloride sodium salt is desirable as a phosphorylcholine salt.
Choline and phosphorylcholine or so are well-known and commercially available, and salts thereof can be easily produced by a conventional process.
Phosphorylcholine can also be obtained by reacting choline with ortho phosphoric acid or its salt as 7~;5~

disclosed in Japanese Patent Disclosure (Cook) No.
52-113924.
The plant growth regulator composition of the present invention may be formulated for application in any known and conventional form, such as a powder, aqueous solution, or emulsion, or as a suspension in water or oil. Among the formulations just mentioned above, aqueous solution is most preferred. In the formulations, phosphorylcholine or its salt may be contained in the amount of 1 wit% to 75 wit%. Further, the plant growth regulator composition of the present invention can contain another conventional agriculturally active ingredient such as fertilizer, insecticide, bactericide, and the like. In addition, a surfactant may preferably contained in the amount of 1 wit% to 20 wit% to promote the adsorption and penetration of the active ingredient. Preferred surfactants may include non ionic surfactant such as polyoxyethylene alkyd ether and anionic surfactant such I as laurel sulfonic acid triethanolamine salt.
The amount of the effective ingredient to be applied varies with the type of plant, the stage of plant growth, the manner of application, the time of application, and molecular weight of -the choline salt but normally ranges from 100 to 10,000 grams, and preferably from 500 to 4,000 grams of active ingredient per Hector. The effective ingredient of the present 3L2;27~

invention is generally sprayed onto the stalks and leaves of the plant in the form of an aqueous solution.
An aqueous solution containing lo to 20,000 ppm, and preferably 300 to Lowe ppm of -the growth regulating compound is sprayed.
When phosphorylcholine or a salt thereof is used to promote root formation, -the seedlings are immersed in its aqueous solution of l to 500 ppm, and preferably lo to lo ppm.
lo When choline salts are used to promote root formation or anchoring in rice seedlings, the roots of the rice seedlings are generally irrigated with an aqueous solution before being transplanted, and preferably at least lo days before transplantation. The concentration of choline salts used in this case is 10 to l,000 ppm, and preferably 25 to 200 ppm.
Generally a good time to apply the plant growth regulating compound is when photo respiration by the plant is at its peak. For instance, use at some point from the period of reproductive growth to the harvesting period for the plant is desirable. However, depending on the plant, use during the period of vegetative growth may provide more desirable effects. In other words, there are no specific limits on the period of administration.
The plant growth regulator composition of the present invention can be used for C3 plants such as ~L2~7~

rice, wheat, beans, sugar beet, sweet potato, potato, onion and spring onion i.e., plants -that represent major food sources. When the plant growth regulator composition of the present invention is employed, it is capable of regulating the growth and also increasing the yields of C3 plants.
Example 1 Preparation of choline salt_ A mixture of 242 grams of 50% choline and 50 my of pure water was cooled to 5C in a nitrogen atmosphere and 110 g of 89% phosphoric acid was added thereto drops while stirring.
This gave 402 grams of a 50% choline phosphate (choline salt of phosphoric acid) solution having a pi of 4.9. This aqueous solution was concentrated to give the phosphate salt.
Aqueous solutions of various other choline salts shown in Table 1 below were prepared in the same way by using different acids. Each of these solutions was concentrated and crystals of the respective salts obtained. In cases where the salt was difficult to obtain as crystals, it was used in the form of an aqueous solution.
Table 1 gives the chemical names, formulas, and properties of several choline salts and phosphorylcholine salts thus obtained. The compound No.
will be used through the specification.

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2~6S6 Experiment 1 _ _ __ __ _, _ Rice leaf blades were mounted in moist cotton within a chamber (acrylic resin box 10 x 10 x 0.6 cm).
The light intensity, room temperature, and relative humidity were held at 40 Clucks, 25C, and 80~1 respect lively. The rate of photo respiration was determined by measuring the rate of carbon dioxide discharge from the difference in carbon dioxide concentration at the chamber inlet and outlet while passing carbon dioxide-free air through the chamber at a flow rate of one liter per hour.
The carbon dioxide concentration was measured with an infrared carbon dioxide analyzer.
The prepared compounds were dissolved to various concentrations in distilled water, and adjusted to a pi of 7. One milliliter of solution was injected with a syringe through a silicone rubber plug into the moist portion of the cotton within the leaf chamber. The normal rate of photo respiration of rice leaf blades was about 2.7 my of COY per square decimeter per hour.
Table 2 shows the percent inhibition of photo respiration by the prepared compounds. The ratio of inhibition shown in Table 2 is defined by the following equation:
/ amount of generated COY per Inhibition (I am-O-ut-nt-iom-fe agen--erateed- cooper x 100 \ unit time before treatment I

Table 2 Compound Concentration Inhibition No. (my) (~) 2 8.8 - - 17.5 Experiment 2 One hundred liters per ten ares of various strength solutions of invented plant growth-regulating compound to which surfactant (polyoxyethylene alkyd ether) had been added to a concentration of 200 ppm were sprayed onto potato plants (variety: Danshaku) at the peak of the flowering stage two months after planting in experimental plots.
The potatoes were harvested one month later and the weight of the harvested potatoes was measured. The results are shown in Table 3.

ISLES

Table 3 Compound Concentration kg/10 ares Yield*
No. ppm) _ Jo _ _ _ __ _ _ Untreated _ 2,900 100 500 3,630 125 1,000 3,770 130 2,000 3,190 110 * Ratio to untreated plot (=100) Experiment 3 _ _ __ ___ _ _ One hundred liters per ten ares of various strength solutions of plan-t growth-regulating compound to which surfac-tant (polyoxyethylene alkyd ether) had been added to a concentration of 200 ppm were sprayed onto the stalks and leaves of sweet potatoes (variety: Kogane Sanguine) 1.5 months after planting in experimental plots.
The sweet potatoes were harvested two months later and the weight of the harvested sweet potatoes was measured. The results are shown in Table 4.
Table 4 Compound Concentration.¦kg/10 ares Yield*
No. (ppm) Untreated _ 1,990 100 500 2,180 110 1,000 2,380 120 2,000 1,950 __ 9 _ *Ratio to untreated plot (=100) 3L7~76~

Experiment 4 __ _ _ _ _ _ The basal 2 - 3 centimeters of sweet potato seedlings (variety: Cook No. 14) were immersed for 24 hours in an aqueous solution of the plan-t growth-regulating compound at various concentrations.
The immersed seedlings were then multi cultivated in plots. On the seventh day after planting, some of the seedlings were dug up and the lengths of the new roots were measured.
Table 5 gives the results.
Table 5 Compound Concentration Total root No. (ppm) length (mm) per plant _ ____ Untreated _ 22 I;` 100 85 The weight of the sweet potatoes was measured 110 days after planting the seedlings, and the results in Table 6 obtained.

Table 6 Compound Concentration kg/10 ares Yield*
No. (ppm) Untreated _ 1,890 100 6 20 2,360 125 2,270 120 100 1,850 98 ___ __ __ _ ______ _ * Ratio to untreated plot (=100) US

Experiment 5 Paddy rice seeds (variety: Yukihikari) disinfected with a 200-fold solution of a disinfectant (manufactured by Du Pont under the trade name of Banality) were planted in seedling boxes treated with 6 grams of 4% disk infect ant (manufactured by SANYO Co., Japan, under the trade name of Tachigalen~ per box (30 x 60 x 3 cm) for soil sterilization. Twenty-four days after planting, the boxes were irrigated with 500 my of choline chloride solution at varying strengths. Twenty-five days after planting/ three clumps of five plants each were transplanted into l/5000-are Wagner pots and the growth after 10 days was checked. The average temperature during this period was low at 14.8C. The results 15 obtained are given in Table 7.
Table 7 Fresh weight*
leaves and stem roots ..
Untreated 100 100 Tao g/plant) (0.28 g/plant) Choline chloride (20 ppm) 96 130 " " (50 ppm) 98 160 " " (100 ppm) I 165 * Ratio to untreated plot Experiment 6 Paddy rice seeds (100 g per box) (variety:

Ishihikari) disinfected with a 200-fold solution of :

Banality were germinated in a incubator at 32C. Two days later, germinated paddy seeds were planted in seedling boxes filled with artificial soil and left in a seedling incubator at 32C for two days. Five hundred my of a 1000-fold solution of a disinfectant (manufactured by SHEA DIAMOND ALKALI, Japan, under the trade name of Deacon) was applied and the seedlings grown under controlled conditions in a polyvinyl house.
Five days before transplantation, the seedling boxes were irrigated with 12.5 my, 25 my, or 50 my of choline phosphate diluted in 500 my of water. Thirty-five days after planting the seeds, the seedlings were transplanted into a paddy field, and growth was examined one month after transplantation. the results are given in Table 8.
Table 8 plant height number of mg/box (cm) stems Untreated - 22.3 4.9 Choline phosphate, 12.5 21.1 5.3 ,, I 25 21.2 5.8 " " 50 19.0 5.0 The mean temperatures following transplantation were as follows.

ISSUES

. . ... .... . . .. ..
Number of days after trays- 0--4 5-910-1415-19 20-24 25-29 plantation _ _ Mean tempera- 12.0 18.5 15.8 19.1 17.1 17.1 -lure I

The roots of the seedlings treated with choline phosphate were cut at the time of transplantation, placed in a 100 cc beaker containing water, and the degree of root formation examined after 14 days of growth at 15C. The results are presented in Table 9.
Table 9 (A) (B) I
mg/box root number rooting emergence length of roots strength of root per plant hairs Untreated - 0.7 cm 3.3 squint Choline salt 12.5 1.1 cm 2.5 2.8 abundant " 25 1.3 cm 4.0 abundant ., 50 1.0 cm 3.2 abundant

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A plant growth regulator composition comprising an effective amount of phosphorylcholine or a salt thereof in an agriculturally acceptable carrier.

2. The composition as defined in claim l, wherein the salt of phosphorylcholine is phosphorylcholine chloride sodium salt or phosphorylcholine calcium salt.

3. The composition as defined in claim l or 2, wherein the carrier is water.

4. A method of promoting root formation of paddy rice comprising applying the seedling of the paddy rice an effective amount of a plant growth-regulating compound selected from the group consisting of phosphorylcholine, a salt thereof, and a salt of choline.

5. The method as defined in claim 4, wherein the plant growth-regulating compound is in the form of an aqueous solution and the solution is applied to the seedling by irrigating the seedling with the solution.

6. The method as defined in claim 5, wherein the plant growth-regulating compound is a salt of choline, and the concentration thereof in the solution is 10 to 1,000 ppm.

7. The method as defined in claim 5, wherein the plant growth-regulating compound is phosphorylcholine or a salt -thereof, and the concentration thereof in the solution is 1 to 500 ppm.