DEVICE FOR CONTROLLING PESTS IN PLANT CULTIVATION ROOM

Abstract

Provided is a pest control device with which it is possible to reliably exterminate pests in a cultivation room. This invention is provided with a spraying means equipped with nozzles for spraying a chemical solution containing a pest control agent into a plant cultivation room. Liquid droplets being sprayed from the nozzles measure 100 m or smaller, and have an average particle diameter of 10-30 m. The nozzles are disposed so that the spray from the nozzles fills the entirety of the plant cultivation room interior in a uniform manner. The invention is provided with a control device for causing the nozzles to spray so that the humidity in the plant cultivation room is 90-100%.

Claims

1. A device for controlling pests in a plant cultivation room, comprising a sprayer having nozzles for spraying a liquid chemical containing a pest control agent inside a plant cultivation room; wherein diameters of droplets sprayed from said nozzles are not more than 100 m, and an average particle diameter of said droplets is not less than 10 m nor more than 30 m; and said nozzles are so disposed that sprays injected from said nozzles uniformly fill an entire region inside said plant cultivation room; and said device for controlling pests further comprising a control device for spraying said liquid chemical from said nozzles so that a humidity inside said plant cultivation room becomes not less than 90% nor more than 100%.

2. The device for controlling pests according to claim 1, wherein piping headers are installed in an upper space inside said plant cultivation room; and said nozzles are attached to each of said piping headers at certain intervals or air blowers are arranged inside said plant cultivation room with said air blowers being mounted on elevating machines respectively; and said nozzles are attached to a ring header provided on an outer periphery of a fan of each of said air blowers at predetermined intervals.

3. The device for controlling pests according to claim 2, wherein said nozzles each having a spray amount of 0.37 ml/second to 5.61 ml/second, a spray pressure of 2 MPa to 6 MPa, and a spray angle of 50 to 80 degrees are attached to said piping headers at intervals of 100 cm to 300 cm or said nozzles are attached to said ring header provided on said fan at intervals of 10 cm to 20 cm.

4. The device for controlling pests according to claim 2, wherein through a change-over valve, a liquid chemical-side branch pipe and a water-side branch pipe are coupled to a liquid flow pipe connected to said nozzle-attached piping headers or to said ring header of said fan to supply water to said nozzles as cleaning water after said liquid chemical is supplied to said nozzles and selectively use said nozzles as fine mist spraying nozzles for cooling the air inside said plant cultivation room and as nozzles for humidifying said air inside said plant cultivation room.

5. The device for controlling pests according to claim 1, wherein a hygrometer is installed inside said plant cultivation room, and a control device for receiving a detected value from said hygrometer is provided to turn on and off said spray of said liquid chemical from said nozzles so that said detected value falls within a set range.

6. The device for controlling pests according to claim 1, comprising a control device which sets a condition of starting said spray of said liquid chemical and a condition of stopping said spray of said liquid chemical in advance and which has a program for spraying cleaning water for a predetermined period of time after said spray of said liquid chemical is stopped; and start of said spray of said liquid chemical from said nozzles, stop of said spray thereof, and subsequent cleaning are executed unattendedly at regular intervals based on said program registered in said control device.

7. The device for controlling pests according to claim 1, wherein said nozzles are attached to said piping headers extended in a longitudinal direction of said plant cultivation room by adjacently disposing said nozzles at certain intervals in a longitudinal direction of said piping headers in such a way that spray ranges of said nozzles contact each other or are spaced at gaps not more than 300 cm, and said nozzles are attached to both side surfaces of said piping headers in a width direction thereof orthogonal to said longitudinal direction thereof by disposing said nozzles oppositely to each other or arranging said nozzles in a staggered manner.

8. The device for controlling pests according to claim 2, wherein said air blower installed on said elevating machine is so constructed that at a low position, said liquid chemical is blown upward from said nozzles toward lower surfaces of leaves and at a high position, said liquid chemical is blown downward toward upper surfaces of leaves of short plants or sideways toward upper surfaces of leaves of high plants.

9. The device for controlling pests according to claim 2, wherein said air blower to be mounted on said elevating machine is located at a high position when water is sprayed for fine mist cooling and for humidification.

10. The device for controlling pests according to claim 1, wherein said nozzle has a nozzle tip having an injection orifice formed at a liquid flow-out side of a check valve whose stop valve is urged toward a valve closing direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 shows a plant cultivation room of a first embodiment of the present invention. FIG. 1(A) is a perspective view. FIG. 1(B) is a sectional view in a vertical direction. FIG. 1(C) is a sectional view in a horizontal direction.

[0050] FIG. 2 is an explanatory view for explaining piping headers, having nozzles attached thereto, which are installed inside the plant cultivation room shown in FIG. 1 and a liquid supply flow path through which a liquid is supplied to the piping headers.

[0051] FIG. 3(A) is a plan view showing a nozzle to be attached to the piping header. FIG. 3(B) is a sectional view of the nozzle. FIG. 3(C) is a perspective view showing main parts of FIG. 3(A).

[0052] FIG. 4 is a schematic plan view showing a modification of arrangement positions of the nozzles to be attached to the piping headers.

[0053] FIGS. 5(A) and 5(B) show a modification of the arrangement of the piping headers inside the cultivation room.

[0054] FIGS. 6(A) and 6(B) show a modification of the nozzle to be attached to the piping header.

[0055] FIG. 7 shows arrangement of parts installed inside a plant cultivation room of a second embodiment of the present invention, wherein (A) is a schematic plan view and (B) is a side view of (A).

[0056] FIG. 8(A) is a side view showing a state in which an air blower having a nozzle-attached fan is set at a high position with the air blower being mounted on an elevating machine. FIG. 8(B) is a side view showing a state in which the air blower is set at a low position by lowering the elevating machine.

[0057] FIG. 9 is a front view of a ring header to which nozzles of the fan are attached.

[0058] FIG. 10 is an explanatory view showing a state in which a liquid chemical is sprayed to front and lower surfaces of leaves of a plant being cultivated.

[0059] FIGS. 11(A) and 11(B) show a modification of the second embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0060] The embodiments of the present invention are described below with reference to the drawings.

[0061] FIGS. 1 through 3 show a device for controlling pests in plant cultivation room of a first embodiment installed inside a plant cultivation house.

[0062] In the first embodiment, piping headers 3 each having nozzles 5 attached thereto are installed in an upper part inside a cultivation room 2 surrounded with a plant cultivation house 1 consisting of a vinyl house. The nozzles 5 are used for many purposes of spraying a liquid chemical, fine mist cooling, and humidification. Ridges 9 or cultivation beds for comparatively short plants P such as tomato, strawberry, lettuce are installed inside the cultivation room 2.

[0063] As shown in FIG. 1, the cultivation room is rectangular in its horizontal section and surrounded with peripheral walls 2a through 2d and a ceiling. Opening/closing doors and windows with meshes are provided at appropriate positions of the peripheral walls 2a through 2d.

[0064] Each of the piping headers 3 to be provided inside the cultivation room 2 consists of a liquid supply round pipe. The piping headers 3 are disposed over almost the entire length of the cultivation room 2 in a longitudinal direction thereof by arranging the piping headers at upper positions interposed between adjacent ridges 9. Thus, the piping headers 3 are arranged in a width direction of the cultivation room orthogonal to the longitudinal direction of the cultivation room. In the first embodiment, the number of the piping headers 3 is four. The vertical position of each piping header is set higher than an expected height of the plant P at the time of growth.

[0065] The nozzles 5 are attached to each piping header 3 at both sides in the width direction thereof. As shown in FIG. 4, the nozzles 5 to be attached to both sides of each piping header 3 may be arranged in a staggered manner by attaching the nozzles thereto alternately in the longitudinal direction of the piping header. The positions of the adjacent nozzles 5 to be attached to each piping header 3 are spaced at a dimension of L1. The dimension L1 is differentiated according to a spray range of the nozzle 5 to be attached to the piping header. The nozzles 5 to be used in the first embodiment are spaced at intervals of 100 to 300 cm (200 cm in the first embodiment) so that the spray ranges (fs) of the adjacent nozzles 5 contact each other. Thereby sprays injected from the nozzles 5 spread over the entire plant cultivation region of the cultivation room 2.

[0066] As shown in FIG. 2, one end of each of the four piping headers 3 installed inside the cultivation room 2 is connected to one of four pipes 6a branched from one common liquid supply pipe 6, whereas the other end of each piping header 3 is closed. After the pump 7 is installed on the common liquid supply pipe 6, the common liquid supply pipe is branched to a liquid chemical-side branch pipe connected to a liquid chemical tank 10 and to a water-side branch pipe connected to a water tank 11. A three-way electromagnetic valve 12 is mounted at a branched position of the common liquid supply pipe to selectively supply the liquid chemical and water to the nozzles 5.

[0067] A control device 15 controls the drive of the pump 7 and that of the three-way electromagnetic valve 12. The control device 15 sends operation signals to the pump 7 and the three-way electromagnetic valve 12, based on a program registered therein in advance. Humidity and temperature inside the cultivation room 2 detected by a temperature-humidity sensor 16 installed inside the cultivation room 2 are sent to the control device 15.

[0068] The nozzles 5 mounted on the piping headers 3 generate semi-dry fog, droplets of which have diameters not more than 100 m and an average diameter not less than 10 m nor more than 30 m. Because the nozzles 5 spray the semi-dry fog, the droplets thereof do not drop, but can be floated in the air inside the cultivation room.

[0069] As the nozzle 5, a one-fluid nozzle, shown in FIG. 3, consisting of a spray nozzle having a check valve is used. The spray nozzle is disclosed in the publication of Japanese Patent No. 5118410 obtained by the present applicant. The spray nozzle having the check valve has a feature of allowing a fluid to circulate through the check valve in one go at a required pressure and a required flow rate when the check valve is opened and shutting off a flow path in one go when the supply of the fluid is stopped to shorten a period of time in which the fluid is sprayed at a low pressure and make it difficult for water stop failure to occur so that the dripping of the fluid from the spray nozzle is prevented.

[0070] The nozzle 5 accommodates a check valve 20 inside a housing 30 and a nozzle tip 21 with a closer 28 being disposed at a liquid flow-out side of the check valve 20. Inside the check valve 20, a spring 23 is mounted in a compressed state between the closer 28 and a stop valve 24 made of rubber to urge the stop valve 24 in a valve closing direction. The nozzle 5 is so constructed that by the pressure of a liquid which flows into the check valve 20 from a throttle flow path 25 disposed at a liquid inflow side, the stop valve 24 is moved against the urging force of the spring 23 to open a first sealing part 24A of a valve seat and a second sealing part 24B thereof to thereby inject the liquid from an injection hole 27 provided on the nozzle tip 21. A strainer 29 is mounted at the liquid inflow side to flow the liquid, having a required pressure, which has flowed from the piping header 3 into the check valve 20 after the liquid passes through the strainer 29.

[0071] As shown in FIG. 3(C), the nozzle 5 is so constructed that four flow paths 21b communicating with a central injection hole 21a from an outer peripheral side of the nozzle tip 21 are provided on an inflow-side end surface of the nozzle tip 21 at intervals of 90 degrees to introduce the liquid into outer peripheral portions of the flow paths 21b from a gap formed on an outer peripheral surface of the closer 28 so that water which has flowed into the nozzle tip 21 is swirled to flow the water into the central injection hole 21a to inject the water from the injection hole 27 disposed at the front end of the nozzle tip.

[0072] When a liquid chemical or water is supplied to the one-fluid nozzles 5 from the piping headers 3 at a required water pressure set by a discharge pressure of the pump 7, the liquid chemical or the water passes through the throttle flow path 25 disposed at the inflow side of the check valve 20 to open the check valve. In detail, in a valve-opening operation of the check valve 20, after the first sealing part 24A of the valve seat opens against the urging force of the spring 23, the second sealing part 24B opens instantly to allow the liquid having a predetermined water pressure to pass therethrough in one go. When the second sealing part 24B opens and the stop valve 24 moves to the side of the closer 28, the liquid which has passed the second sealing part 24B flows into the flow path 21b of the nozzle tip 21 through the gap and is injected from the injection hole 27 disposed at the front end of the nozzle through the central injection hole 21a. When the supply of the liquid is cut off, the first sealing part 24A of the check valve 20 and the second sealing part 24B thereof close.

[0073] As apparent from the foregoing description, the nozzle 5 is so constructed that when the check valve 20 opens, it does not occur that a small amount of water flows into the injection hole 27 little by little, but the water can be sprayed at a required water pressure in one go. Thus, the spray pattern does not become turbulent. In addition, at the outflow path side of the check valve 20, because the water is flowed to the nozzle tip 21 through the gap, the gap acts as a throttle flow path of the water. Thus, it is possible to allow the water to have a high pressure from a start time of injection and atomize droplets. Thereby it is possible to spray the liquid as fine droplets having an average diameter of 10 to 30 m. When the supply of the water is stopped, the water hardly accumulates in a range from a closing position of the check valve 20 to the injection hole 27. Thus, it is possible to prevent the droplets from dripping from the injection hole 27.

[0074] As described above, the nozzle 5 sprays droplets each having a particle diameter of not more than 100 m and an average particle diameter of 10 m to 30 m. The amount of the spray injected from the nozzle is 0.37 ml/second to 5.61 ml/second. The pressure of the spray is 2 MPa to 6 MPa. The angle of the spray is 50 to 80 degrees.

[0075] The control device 15 automatically executes the start of the spray of the liquid chemical, the stop of the spray thereof, the subsequent supply of cleaning water to the nozzle for a predetermined period of time, the start of the spray for fine mist cooling, the stop of the spray for fine mist cooling, the start of spray for humidification, and the stop of the spray for humidification.

[0076] In the first embodiment, during the season in which pests breed, the liquid chemical is automatically sprayed once every three days. When the temperature-humidity sensor 16 installed inside the cultivation room 2 detects that the humidity is 90% to 100%, the spray of the liquid chemical is stopped, and water is supplied to the nozzles 5 for 10 minutes to clean the nozzles 5 after the supply of the water thereto is stopped. In this manner, the spray of the liquid chemical and the cleaning of the nozzles are carried out unattendedly at regular intervals.

[0077] A worker may start the spray by operating an operation button when the worker finds pests. The worker leaves the cultivation room 2 after the spray starts. The spray is automatically stopped.

[0078] It is possible to install cameras inside the cultivation room 2 to send images photographed by the camera to the control device 15. In a case where pests or worm-eaten states are detected from the images, the liquid chemical may be sprayed.

[0079] When the liquid chemical is sprayed from the nozzles 5, it is possible to float the liquid chemical in the air because the average particle diameter of the sprayed liquid chemical is not less than 10 m nor more than 30 m. Because the nozzles 5 are so disposed that the spray ranges of the adjacent nozzles are adjacent to each other, it is possible to spread the liquid chemical over the whole region of the cultivation room 2 where the plant P is cultivated. In addition, because the liquid chemical is sprayed until the humidity of the liquid chemical reaches the set target humidity 90%, it is possible to fill the cultivation room 2 entirely in the height direction thereof with the liquid chemical. Consequently, the droplets of the sprayed liquid chemical float in the air. Thus, it is possible to attach the liquid chemical to the upper surface (surface) of the plant P by the spray which falls from the nozzles 5 located above the plant and also attach the liquid chemical to the lower surfaces (lower surfaces) of leaves, although it is difficult to attach the liquid chemical thereto. Consequently, it is possible to expel pests which attach to the lower surfaces of the leaves by the liquid chemical. Further, droplets which attach to the leaves evaporate because they are small. Thus, unlike coarse fog, it is possible to prevent the droplets from becoming large and thus prevent the leaves from becoming wet. Therefore, it is possible to prevent a vicious circle from occurring because the liquid chemical is not excessively supplied to the plant.

[0080] The liquid chemical is successively sprayed from the nozzles until the humidity inside the cultivation room reaches a predetermined humidity of 85% lower than a set target humidity of 90% and thereafter intermittently sprayed until the humidity inside the cultivation room reaches the set target humidity of 90%. The liquid chemical may be successively sprayed from the nozzles until the humidity inside the cultivation room reaches the set target humidity of 90%.

[0081] Because the spray of the liquid chemical is automatically stopped, the worker can leave the cultivation room 2 while the liquid chemical is being sprayed and is thus not adversely affected by the liquid chemical.

[0082] The above-described system for spraying the liquid chemical is utilized for fine mist cooling and humidification.

[0083] That is, the control device 15 receives a detected value sent from the temperature-humidity sensor 16. When a detected temperature (for example, 30 degrees) reaches a value set in the program, water is sprayed from the nozzle to perform fine mist cooling. When the detected temperature inside the cultivation room 2 drops to a predetermined temperature (26 degrees), the spray of water is stopped.

[0084] When the humidity inside the cultivation room 2 decreases, water is sprayed from the nozzles 5 to humidify the air inside the cultivation room 2.

[0085] When water is sprayed over the entire region inside the cultivation room 2 from nozzles 5, fine mist flows inside the cultivation room. While the fine mist is flowing, droplets vaporize by depriving the ambience of heat of vaporization, thereby allowing the internal temperature of the cultivation room 2 to be rapidly lowered. Water is sprayed from the nozzles 5 from the upper part of the cultivation room toward locations below the root of the plant P.

[0086] When the temperature inside the cultivation room 2 reaches the set temperature by the spray of the water or when the humidity reaches the predetermined value (for example, 80%), the spray of water from the nozzle 5 is stopped.

[0087] It is possible to automatically cool the air inside the cultivation room according to the rise of the temperature inside the cultivation room and automatically stop the cooling when the temperature inside the cultivation room lowers to the set temperature. Thereby it is possible to prevent the air inside the cultivation room from being overheated and hold the temperature inside the cultivation room in a temperature condition suitable for growing the plant. In addition, it is possible to hold the humidity inside the cultivation room in a humidity condition suitable for growing the plant.

[0088] As shown in FIG. 4, the nozzles 5 may be attached to the piping header 3 in a staggered arrangement in the longitudinal direction of the cultivation room.

[0089] Because other constructions are identical to those of the above-described embodiment, the description thereof is omitted herein by denoting like parts by like reference numerals.

[0090] As shown in FIG. 5, it is possible to arrange cultivation rooms 2-1 and 2-2 each having a length of 5700 cm and a width of 900 cm in parallel with each other, mount piping headers 3-1 and 3-2 at the center of the cultivation rooms 2-1 and 2-2 respectively, and plumb the nozzles 5 on the piping headers with the nozzles facing each other.

[0091] A nozzle shown in FIGS. 6(A) and 6(B) may be used as the nozzle 5.

[0092] The nozzle 5 consists of the nozzle disclosed in the publication No. 5037897 of Patent obtained by the present applicant. That is, the nozzle 5 is composed of the tubular body 62 and the nozzle tip 63 fixed to the inner surface of the spray-side wall 62b of the body 62. One end of the cylindrical peripheral wall 62a of the body 62 is closed with the spray-side wall 62b. The injection orifice 62c is formed at the center of the spray-side wall 62b. The other end of the peripheral wall 62a is formed as the opening 62d communicating with the supply pipe. Liquid flows into the hollow portion 62e of the body 62.

[0093] The nozzle tip 63 is substantially disk-shaped. The nozzle tip 63 is formed when the body 62 is formed by molding a material and is fixed to the inner surface of the spray-side wall 62b of the body 62. The nozzle tip 63 has the injection hole 63a at its central portion. The injection hole 63a communicates with the injection orifice 62c disposed at the center of the spray-side wall 62b of the body 62. A nutrient solution and water are sprayed as a swirling flow through the injection hole 63a and the injection orifice 62c. The injection hole 63a is composed of a tapered hole portion 63a-1 whose diameter decreases in a direction from the inflow side and a small-diameter hole portion 63a-2 continuous with the tapered hole portion 63a-1 and communicating with the injection orifice 62c. Swirling grooves 63b each curved in the shape of an arc are formed on the inner surface of the nozzle tip 63 at intervals of 90 degrees. The inner peripheral edge of each swirling groove 63b communicates with the periphery of the tapered hole portion 63a-1 to flow the liquid into the small-diameter hole portion 63a-2 through the swirling groove 63b with the liquid swirling.

[0094] At the injection side of the nozzle 5, water flowing into the body 62 from the ring header 53 flows into the tapered hole portion 63a-1 of the injection hole 63a as a swirling flow through the swirling groove 63b of the nozzle tip 63. Because inside the tapered hole portion 63a-1, the water collides with the inner circumferential surface of the tapered hole portion 63a-1 with the water swirling. As a result, droplets are atomized and flow from the tapered hole portion 63a-1 into the small-diameter hole portion 63a-2 disposed at the injection side. Thereafter the atomized droplets are injected as semi-dry fog consisting of fine droplets whose diameters are not more than 100 m and whose average particle diameter is not less than 10 m nor more than 30 m from the injection orifice 62c of the body 62 communicating with the small-diameter hole portion 63a-2.

[0095] FIGS. 7 through 10 show a second embodiment.

[0096] As shown in FIG. 7, in the second embodiment, blowers 70 are installed inside the cultivation rooms 2 (2-1, 2-2) of the plant cultivation house 1. More specifically, two air blowers 70A are disposed at both sides of one end of each cultivation room having a length of 57000 mm and a width of 9000 mm in the longitudinal direction of the cultivation room. Two air blowers 70B are disposed at both sides of the center of each cultivation room in the longitudinal direction of the cultivation room. Two air blowers 70C are disposed at both sides of the other end of each cultivation room in the longitudinal direction thereof. Thus, a total of six air blowers 70 are installed inside each cultivation room.

[0097] As shown in FIG. 8, each air blower 70 is installed on an elevating machine 80. A lower platform 81 and an upper platform 82 of the elevating machine 80 are coupled to each other with an X-type coupling member 83 which can be placed in rise and fall states. As shown in FIG. 8(A), when the X-type coupling member 83 is placed in the rise state, the air blower 70 installed on the upper platform 82 is placed at a high position. When the X-type coupling member 83 is placed in the fall state by folding it, the air blower 70 installed on the upper platform 82 is placed at a low position. The air blower 70 can be selectively located at the low position and the high position. A running wheel is mounted on a lower surface of the lower platform 81 to transport the air blower to arbitrary positions.

[0098] At required intervals, the nozzles 5 are attached to a ring header 53 provided on a wind blow-out side outer periphery of a case 52 incorporating a fan of each air blower 70. The nozzles 5 are attached to an inner peripheral side of the ring header 53 by tilting the nozzles 20 to 50 degrees (45 degrees in this embodiment) to speed up a spray speed by mixing the spray injected from the nozzles 5 with air blown out from the fan.

[0099] The diameter of the air blower is set to 40 cm to 55 cm. The nozzles 5 are attached to the ring header 53 at intervals of 10 cm to 20 cm. A high-pressure hose 85 for supplying the liquid chemical and water to the ring header 53 is connected thereto to spray the mixture of the liquid chemical and the water from the nozzles 5. The supply path for supplying the liquid chemical from the liquid chemical tank to the ring header 53 and the supply path for supplying the water to the ring header 53 are similar to those of the first embodiment. Thus, the description thereof is omitted herein. The control device automatically executes the start and stop of the spray of the liquid chemical, the subsequent supply of cleaning water, the start and stop of the spray for fine mist cooling and the spray for humidification as in the case of the first embodiment.

[0100] The air blower 70 is attached to a bracket mounted on the upper platform 82 in such a way that the air blower is capable of tilting downward and upward.

[0101] In the second embodiment, the air blower 70 having the nozzle 5 can be selectively disposed at the low position and the high position, as shown in FIG. 10. When the liquid chemical is sprayed, the air blower 70 is set at the low position to spray the liquid chemical upward toward the lower surfaces of leaves of the plant P. The air blower 70 is sometimes set at the high position to spray the liquid chemical downward toward the upper sides of the leaves of the plant P. By spraying the liquid chemical toward both surfaces of the leaves, it is possible to efficiently exterminate pests by the liquid chemical.

[0102] On the other hand, when water is sprayed for fine mist cooling and humidification, the air blower 70 is set at the high position to spray the water downward for efficient cooling and humidification.

[0103] Because the other constructions and action of the second embodiment are similar to those of the above-described embodiment, the description thereof is omitted herein.

[0104] FIGS. 11(A) and 11(B) show a modification of the second embodiment.

[0105] In the modification, a mounting ring 94 projectingly mounted on an upper plate 91 of an elevating machine 90 is hooked on a supporting beam 88 mounted at an upper part inside the cultivation room to hang the elevating machine 90 toward the plant in an upper space. A multi-stage telescopic rod 93 is interposed between the upper plate 91 and the lower plate 92 thereof to hang the air blower 70 from a lower surface of the lower plate 92.

[0106] The multi-stage telescopic rod 93 has telescopic rods 93a through 93d consisting of large and small cylinders. As shown in FIG. 11(A), by accommodating the cylinders 93b through 93d in the upper-stage largest cylinder 93, the air blower 70 is located at a high position. As shown in FIG. 11(B), by stretching all of the cylinders 93a through 93d, the air blower 70 is located at a low position.

[0107] At cooling and humidifying times, the air blower 70 is set at the high position to spray water downward from the nozzles 5 attached to the ring header 53, whereas at a pest controlling time when the liquid chemical is sprayed, the air blower 70 is set at the low position, and the nozzles 5 are turned upward to spray the liquid chemical toward the lower surfaces of leaves of the plant.

[0108] Because the other constructions of the modification are similar to those of the second embodiment, the description thereof is omitted herein.

EXPLANATION OF REFERENCE SYMBOLS AND NUMERALS

[0109] 1: plant cultivation house [0110] 2: cultivation room [0111] 3: piping header [0112] 5: nozzle [0113] 10: liquid chemical tank [0114] 11: water tank [0115] 53: ring header [0116] 70: air blower [0117] 80, 90: elevating machine