AU688717B2 - Method for exterminating pests injurious to plants - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: e* Name of Applicant: Kabushiki Kaisha Seibutu Kino Kogaku Kenkyusho Actual Inventor(s): Yoshitami Yanohara Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: METHOD FOR EXTERMINATING PESTS INJURIOUS TO PLANTS Our Ref: 495238 POF Code: 147137/312859 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- Title of the invention: Method for exterminating pests injurious to plants Background of the invention: The present invention relates to the method for exterminating pests provided with organs for tracheal .respiration, such as plant lice, green caterpillars, army worms, etc. gathering on the various kinds of plants, such as edible herbs or green vegetables, root vegetables, etc.

The conventional water culture involves the use of a hydroponic vessel arranged within the spacious cultivation building. The culture solution is put into the said hydroponic vessel. The roots of plants are directly caused to immerse in the same culture solution and thereby absorb 15 nitrients in it. Thus, it becomes unnecessary to use herbicides, soil conditioners, etc. which were used for soil culture. However, many buildings used for water cultivation are open and, therefore, such pests as plant lice, green caterpillars, army worms and the like tend to be parasitic 20 on plants. Further, even when the building for cultivation is closed, pests are carried into the building together with seedlings from without.

Thus, there has been heretofore used an insecticide or repellent for exterminating such pests. As a result, 25 agricultural chemicals employed remain in the form of residue even in the crop produced by the water culture. Thus, there has been arisen a problem to be solved.

•*-Objects and 'summary of the invtonef----,, The object of the present invention is to prov for the method for thoroughly exterminating e gathering on plants without using agricultural icals.

The other object of the ent invention is to provide for the method for th efghly exterminating pests without having an evil e e upon plants.

evarious objects mentioned above may be realized through ,,hc mcthcdo of the procont invention for oxtorminating poests.

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t^ l lq -1B- Objects and summary of the invention: In one aspect the present invention provides for the method for thoroughly exterminating pests gathering on plants without using agricultural chemicals.

In a further aspect the present invention provides for the method for thoroughly exterminating pests without having an evil effect upon plants.

The various aspects mentioned above may be realized through the methods of the present invention for exterminating pests.

In one aspect the present invention provides a method for exterminating plant pests including adjusting the concentration of an aqueous solution for exterminating pests to cause the said solution to have an osmotic pressure approximately equal to that of the cell sap of the plants to be treated, then, dipping and keeping the said plants inhabited by pests in the said solution for a period of time required for exterminating said pests, and then, taking the said plants out of the said solution.

In a further aspect the present invention provides a method for exterminating plant pests including adjusting the concentration of the culture solution used for water culture of the plants to cause the said culture solution to have an osmotic pressure approximately equal to that of the cell sap of the said plants under culture, then, dipping and keeping the said plants inhabited by pests in the said culture solution for a period of time required for exterminating said pests, 9 wtrand then, returning the said plants to their original position relative to the *,ater culture solution.

0* 9°O#l* 0 o 07,06 0) 0- 0 0a n inc -saxa jmnccoa ror oxtorminating-- posp c-mpri-c B concentration of the solution treated for rminating pests by causing the said treate ution to have an osmotic pressure approximat equal to that of the cell' sap of plants from epests should be removed and causing the said fto dip and stay at the said treated soluti'on for period of tcftopminntingtho rpe-.

Referring to such insects as plant lice, green caterpillars, army worms etc., there are openings called spiracles on their body surface. From these spiracles, finely branched tracheas extend into their body tissue. Oxygen is introduced into the tissue from without by way of these tracheas through spiracles. Then, carbon dioxide is discharged outside through spiracles. This is the so-called tracheal 15 respiration. Therefore, when insects are kept within the solution for the fixed period of time required, the insects would come to die, because their gaseous exchange through their spiracles becomes impossible. For example, the time required for causing plant lice to die is three to four 20 hours; army worms, 30 minutes to two hours. This fact teaches that, if it is the only the purpose to cause pests to die, plants inhabited by pests have only to be dipped for a long time. However, there is a risk that plants themselves may likewise suffer a serious damage if they are carelessly kept in the solution for a long time.

Searches and experiments have been conducted in the various ways as to the risk involved when plants are placed in the said treated solution. Then, the following fact has been found. When plants are dipped in the treated solution, it becomes impossible for plants to carry out a gaseous exchange through stomata on their leaves. Thus, they suspend their photosynthesis. However, if the cells of plants retain their cell sap in the same state as before, they would continue to live. As long as they continue to be alive, even if they are taken out of the solution after the prolonged immersion, plants would resume their photosynthesis and continue to grow in a normal way. Further, plants are able ^4i' -i2- I Ito retain their cell sap within the solution, if the osmotic pressure of the said treated solution is made equal to that of the plant cell sap.

According to the method of the present invention for exterminating pests, as mentioned above, the osmotic pressure of the treated solution is made approximately equal to that of the plant cell sap. When plants are dipped into the treated solution, there is kept under control the diffusion between the said treated solution and the plant cell sap. Thus, plants are caused to retain their cell sap.

Thereby, the plants do not suffer from any adverse effect, and are capable of exterminating pests collecting on plants.

For example, there are two solutions contacting with each other with the cell membranes as the border. In this 15 instance, the solution having a higher concentration has a bigger osmotic pressure than the solution having a lower concentration. When their concentrations are equal, their osmotic pressures are likewise equal. Therefore, by making an adjustment for making the concentration of the treated 20 solution approximately equal to that of the plant cell sap, the osmotic pressures of both solutions can be made equal.

C. *"Experiments were conducted. Spinaches, salads and lettuces under water culture were dipped into culture solutions the concentrations of which are approximately equal to those of 25 their cell saps for three hours, six hours and twelve hours respectively, Thereafter, they were taken out of the culture solutions and returned to their normal water culture media.

The result is that no abnormality is observed at all in the appearances of each of the plants. Furthermore, they continued to grow in a normal way.

Reference is made to the plants which are particularly suitable to the employment of the method of the present invention for exterminating pests. They are plants under cultivation according to the water culture method, pebble culture method, slag wool culture method, etc. But the suitable plants are not limited to those subject to the above culture methods.

-3- Further, "the treated solution for exterminating pests" used for the present invention includes the use of the culture solution, as the treated solution, in use for water culture, etc. and the use of salt solution, etc. separately prepared.

Brief description of the drawings: Figure 1 is a view shown in cross section of the plants under water culture.

Figure 2 is a view in cross section of the plants under the treatment for exterminating pests.

Figure 3 is a view shown in perspective of the push frame.

Detailed description of the preferred embodiments: 15 As shown in Figure 1, the culture solution 2 comprising water and various nitrients is put into the box-shape water culture tank 1 with its top open. The rectangular floatable planting plate 3 made of foamed styrol is caused to float on the surface of the said culture solution 2. The root parts 20 of plants P (for example, spinaches) are held within penetrating pores made in the said planting panel 3. Their roots are caused to dip in the culture solution 2 under the panel 3.

The concentration of said culture solution 2 is adjusted to 26 be made equal to that of the cell sap of the said spinaches.

*a In process of their cultivation within the said water culture tank 1, plant lice and green caterpillars collecting on plants P are exterminated in the manner mentioned below.

As shown in Figure 2, the whole planting panel 3 is pushed down by the use of push frame 4 and all plants P are dipped into the culture solution 2.

Reference is made to the said push frame 4. As shown in Figure 3, the rectangular frame 5 is made slightly smaller than the said planting panel 3. Arms 6 are projected respectively, at a right angle to the rectangular frame from the four corners of the said frame 5. Simultaneously, the terminal parts of the arms 6 are formed into stoppers -4bent in a hook shape. The setscrew 8 is screwed on each of stoppers. The net 9 made of metal wire, thread or the like is supported by each of arms 6 in its intermediate part.

In operation, 'he frame 5 is placed on the four sides of the planting panel 3. Thereafter, each of arms 6 is pushed down, and the plants P are caused to dip into the culture solution 2 together with the planting panel 3. Then, the net 9 prevents the plants from rising to the surface of the solution. While the plants P arc allowed to be immersed in the culture solution 2, the setscrews 8 of the stoppers 7 engaged with the side walls of the culture tank 1 are screwed on the said side walls. Thus, the push frame 4 is fixedly placed.

*The aforementioned plant immersion was carried out for four 15 hours and ten minutes under the solution temperature of in the culture solution 2. During this time, the plants P suspended their photosynthesis. No diffusion was caused between the cell sap and the culture solution. Thus, the plant cells continue to live.

20 With the start of the said immersion, a part of pests collecting on plants come up, still alive, to the surface of the solution. After they float on the solution for a while, they are suffocated to death and sink in the solution. On the other hand, the remaining pests are, almost out of their 25 tracheal respiration, clinging to the plants in the culture solution. After approximately two hours, green caterpillars are suffocated to death, and separated from plants and sink.

After about four hours, plant lice are suffocated to death and follow the same course.

After the extermination treatment, the push frame 4 is lifted and plants P are caused to come up to the surface of the culture solution 2 together with the setting panel 3.

Then, the plants are returned to the original water culture status as shown in Figure 1. Plants P start the absorption of carbon dioxide and exhaust of oxygen through their stomata and resume their photosynthesis.

The aforementioned treatment for exterminating pests would 4- -6be conducted at any time, when necessary, till the harvest time of plants.

In addition to the above immersion method, the following method may be employed. As shown in Figure 1, a part of the culture solution 2 is transferred to another tank. Thereby, the solution level of the culture tank 1 is lowered about 50%. In consequence, the setting panel 3 is likewise lowered.

Thereafter, the push frame 4 is hung over the setting panel 3. At the same time, the setscrew 8 is screwed on the side wall of the culture tank 1. Then, the culture solution is put into the culture tank 1. Thus, its solution level is caused to go up high enough to submerge plants P. Then, they are immersed for the required time in the same manner as mentioned above. According to this example, there may be omitted the work for pushing down the setting panel 3 into the solution.

Throughout the description and claims of the specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps.

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Claims (2)

1. A method for exterminating plant pests including adjusting the concentration of an aqueous solution for exterminating pests to cause the said solution to have an osmotic pressure approximately equal to that of the cell sap of the plants to be treated, then, dipping and keeping the said plants inhabited by pests in the said solution for a period of time required for exterminating said pests, and then, taking the said plants out of the said solution.

2. A method for exterminating plant pests including adjusting the concentration of the culture solution used for water culture of the plants to cause the said culture solution to have an osmotic pressure approximately equal to that of the cell sap of the said plants under culture, then, dipping and keeping the said plants inhabited by pests in the said culture solution for a period of time required for exterminating said pests, and then, returning the said plants to their original position relative to the water culture solution. DATED: 30 October 1997 PHILLIPS ORMONDE FITZPATRICK Attorneys for: KABUSHIKI KAISHA SEIBUTU KINO KOGAKU KENKYUSHO .o 0# S S *.So Abstract of the disclosure: The method for exterminating plant pests comprises preparing the treated solution having an osmotic pressure equal to that of the cell sap of plants from which pests are to be exterminated, and dipping the said plants in the said treated solution for a period of time required for exterminating pests. When the said plants are dipped the said treated solution, the diffusion between the said treated solution and the said plant cell sap is kept under control, by keeping the osmotic pressure of the said treated solution equal to that of the said plant cell sap. g -8-