CA1309866C - Apparatus for use in plant growth promotion and flower development - Google Patents
Apparatus for use in plant growth promotion and flower developmentInfo
- Publication number
- CA1309866C CA1309866C CA000549288A CA549288A CA1309866C CA 1309866 C CA1309866 C CA 1309866C CA 000549288 A CA000549288 A CA 000549288A CA 549288 A CA549288 A CA 549288A CA 1309866 C CA1309866 C CA 1309866C
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- Canada
- Prior art keywords
- radiation
- screen
- range
- wavelengths
- green plants
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
- Y02A40/25—Greenhouse technology, e.g. cooling systems therefor
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- Cultivation Of Plants (AREA)
- Protection Of Plants (AREA)
- Greenhouses (AREA)
Abstract
ABSTRACT OF DISCLOSURE
Method and apparatus for encouraging maximal plant growth which method and apparatus comprise a light filter which prevents the natural decay of plant growth stimulating materials by absorption of UV radiation while permitting photosynthesis to occur with blue light in the absence of attendant heat generating and dehydrating radi-ations caused by green, yellow and infra-red light. The objective is made possible according to the preferred embodiment of the invention by interposing separately, continuously, or discontinuously, a com-bination of filters made of solid material between the sun and the growing plants which block out radiation in those wave lengths which are either physiologically harmful or which retard growth, but do not inhibit those wavelengths which are necessary for photosynthesis, metabolism, differentiation and development.
Method and apparatus for encouraging maximal plant growth which method and apparatus comprise a light filter which prevents the natural decay of plant growth stimulating materials by absorption of UV radiation while permitting photosynthesis to occur with blue light in the absence of attendant heat generating and dehydrating radi-ations caused by green, yellow and infra-red light. The objective is made possible according to the preferred embodiment of the invention by interposing separately, continuously, or discontinuously, a com-bination of filters made of solid material between the sun and the growing plants which block out radiation in those wave lengths which are either physiologically harmful or which retard growth, but do not inhibit those wavelengths which are necessary for photosynthesis, metabolism, differentiation and development.
Description
3 & ~
~$T~OD AND APPARATUS FOR ~SB I~
PLANT GRO~T~ PROMOTIO~ A~D FLOWER D~V~LOPNB~T
.
Field of the Invention The curren~ invention relate~ to green plant growth promoting apparatu~ for use in maximizing the production of food crop ~nd flowering plants. It involves the provi~ion of ~everal ~pecially con~tituted thermopla~tic screen~ which offer ~ingley or in combi-nation ~hade from the auxin-destroying W radiation, the growth retarding photoJynthesi -unu~able green and infra-red light o~ tha sun, but the same time, will optimize the photo~ynthesi~ rate of the~
plant and encourage rapid growth. In addition, by c~reful ~election of the ~creen wavalength combination~, growth control and flowering may be managed~by those ~killed in the art of horticultureO
Background of the Invention Numerou attempts have been made to control the growth anviron ment of crop plants ~o as to improve yield and control tha timing o~
.
flowering. The~e include providing shelter from wind and heavy rain, as for example by errection of a "greenhou~e"r or by ~applying various chemicals which control growth by simulating the effects of the natural plant hormones. Inevitably there i~ a trade off, in :
~:
:: ~: ` :
~ . ~
1 ~0~
~ the ca~e of the greenhou~e, ~corching become~ a problem due to light focu~ing and the overheating created by the "greenhouse effect" of trapping radiant energy, wherea~ in the case of ah~mLcal application there are attendent problems as~ociated with re~idue~ both in the food crop and in the ~oil.
In order to under~tand fully the ~ignificance of the current invention it is fir~t necessary to review the constitution of terre~trial sunlight and to reali~e how plant~ exploit this radia-tion.
Terre~trial ~unlight ha~ been con~idered to consi~t of short-wave ultraviolet light (W -B, 290-320 nm), long-wave ultra-violet light ~W -A, 320-400 nm), vi~ible light (400-700nm) and infra-red light (700-2500 nm). On a clear day at ~ea level, the di~tribution of solar radiation i3 about 1 - 2 ~ W, 42% yi~ible and 57% infra--red. It i~ now generally recognized that the W -B radiation i~
dangeroue to all living cell~ leading to variou~ genotoxlc di~order~
by mutation and will cau~e, at high enough expo~ure level~, plant and animal cell death. W -A on the other hand i~ apparently harm-lea~ to animal ti~uee at natural radiation level~, but green plants have utilized the hormone-destroying effect of W -A light to control or regulate their growth, while protecting themselve~ a~ be~t they can from the dangerous UV-B rays with the pigment chlorophyll. It ha~ been known ~ince Darwin'~ time that plants produce a grow~h atimulating sub~tance (hormone or auxin) near their growth tips which diffu~e~ downward~ promoting further growth and that if completely ~haded, plant~ will grow, for a limited period, at about thrse time~ their illuminated rate (e.g. "forcing" of hyacynthe ox rhubarb ~hoot ~ and that the bending of plants towards light i~
cau~ed by the protection of the auxin from light denaturation on the dark~ide of plants grown on say a window ~ill. The ~pecLfic wave-lengths of light which denature auxins lie in the W-range, 290 - 340 nm and the photoly~is of such auxins can occur even at quite meager l~ght intensitie~. Prevention of photolyeis would render the plants continuou~ly ~en~itive to their own growth ~timulation.
In a similar manner, the induction of flower formation and develop-ment ha~ been determined to ~e influenced by the presence and the . ~,-- ~
,, , .:. . -: .
- ~ .
:' .
-` - 1 30~
- intensity of natural red light and conaequently flowering may be encouraged or delayed by manipulating the filtered environment ao as to provide or absorb thoae wavelength6 re~pon~ible. It i~ the purpo~e of thi3 invention to provide auch an environment or environ-ment3.
Summary of the Invention Briefly described, the pre~ent invention provide~ method and apparatua for encouraging maximal plant growth which method and apparatu~ comprise a light filter which preventa the natural decay of plant growth ~timulating material~ by ab~orption of W radiation while permitting photo0ynthesi~ to occur with blue light in the abaence of attendant heat generating and dehydrating radiations cauaed by green, yellow and infra-red light. Ths objective is made posaible according to the preferred embodiment of the invention by interpoaing a combination of filters made of ~olid material between the sun and the growing plant~ which block out radiation in thoae wavelength~ which are either physiologically harmful or which retard growth, but do not inhibit tho~e wavelengths which are nece~sary for photosynthesis, metaboli~m, differentiation and developmsnt.
The apparatus of the preferred embodiment of the present inven-tion comprise~ at leaat three filter~ employed either together, ~eparately, continuoualy, or diacontinuoualy, a~ a canopy ahove growing plant~.
It i~ recorded in the prior art that plants may be protected from aolar radiation by the provi~ion of a ~ingle filter which will ~imultaneou~ly and selectively abaorb UV and other radiations to protect plant~ from phy~iologlcally dangerous radiation (e.g~
wa~elengths of 300 - 330 nm, in Mutzha~, U.S. Patent 4,200,360);
however, the present invention allows the nur~aryman to vary the wavelength range and intenaity continuoualy, and during the growth of hi~ crop. The advantage here i~ that variou~ ~tage~ of plant development ~uch a~ flowering or fruiting may be modified and managed as well a~ the rate of the planta growth.
1 309~6.j - Other objects, features and advantages of the present inven-tion will become apparent upon reading and understanding this spec;f;cation in conjunction w;th the drawings.
Brief Description of the Drawings Fig. 1 is a graph representat;ng the selective absorption of wavelengths of sunlight, in accordance with a preferred embodiment of the present invention.
Fig. 2 is a cross-sectional, side view of an apparatus in accordance with the present invention, depicting a preferred embod-iment thereof.
Detailed Description of the Pre-ferred Embodiment Attention is now d;rected to more specif;c details' of pre-ferred embodiments of the method and apparatus of the present invent;on, with reference in greater detail to the drawings. In accordance with the present invention, a filter assembly 10 displays selective and variable radiation absorption features. In the preferred embodiment, the filter assembly 10 comprises three screens 12, 14, 16 (or three sets of screens 12, 14, 16).
The outer screen 12 of the three screens provides a mechanism by which the plants may be protected from harmful UV radiation. The outer screen 12 ls constituted so as to exclude from the grow~ng pl'ants, by absorption, that port.ion of UV-light known to cause DNA-~amage and denaturation of the naturally occuring plant growth promoters and auxins, but at the same t~me to transmit as ~uch whit light and i'nfra-red as practical. The wavelengths to be absorbed ~y this outer filter screen 12 lie, therefore, in the range 290 - 340 nm.
~See Fig. 1.) A suitable material for the outer screen 12 is any thermo-plastic material or acrylic resin in the form of either a thin film or - woven or laminated material but exhibiting the property of being transparent to solar energy wavelengths above 340 nm which are those associated with heat and photosynthesis. Suitable materials for the outer screen 12 when in film form are resins~of polyv;nyl chloride, : :
, -t ~ a6 polyolefins such as polyethylene and polypropylene, or acrylic resins such as polymethylmethacrylate. Copolymers such as polyeth-ylene/vinyl acetate and butadiene/styrene would also su~fice. Such resins may also include plasticisers such as phthallate esters. The outer screen 12 includes UV absorbers of various chemical types at such concentration to prov;de both longevity to the material and selective absorption of UV below 340 nm. It is preferrable that the outer screen 12 shall not have significant absorption, i.e. greater than 20~, of the natural wavelengths of light above 340 nm. In preferred embodiments of the present invention, the UV absorbers constitute between 0.01 and 0.5% by weight of the screen material. An example of a suitable UV absorber is (2-Chloroethyl) phosphate or acetophenone at a concentration of 0.1 w/w. Another example of d suitable absorber is 2[2 hydroxy - 5 menthylphenyl] ben~otriazole at a concentration of 0.05% w/w.
A preferred material for the outer screen is polyethylene Filn of thickness between 100 and 300 microns, for example 200 microns, and this may be a single film or a laminate form with a reinforcin~ nylon or polyester net to give greater physical strength. The resin should also he light stable and non-volatile at the reiatively h~yh temperatures used in blow forming, extrusion or callendering of lay-flat film. (i.e. about 150 C). It is also essentlal according to the invention that the outer film be not polished, and, preferrably, it should be finished as a matte or taffeta surface to provide a llght diffusion~effect. The growth of plants is enhanced by diffused rather than direct light.
The second screen 14, which is, preferrably, arranged be~ween the outer screen 12 and tt!e grow~ng plants, provides, in the preferred embodiment, protection from the unnecessary heating effect of light within the spectral wave1ength ranges 510 - 61Q nm and 8Q0 - 2500 nm.
(See Fig. 1.). In the preferred embodimen~, the second screen 14 is comprised of a~set of two screening fllms. These two films making up the second set-of screens are ideally identical to each other although not necessarily so. The ~obJective of this set is to provide the plants~ at the dlscretion of the nurseryman, with an optional single . : :
.
: .
, .
;
1 ~ ~' 9 ~
- or double degree of shade from heat (800 - 2500 nm~ and intense green - and yellow light tS10 - 610 nm) but permitting maximum photo-synthesis, synthesis of chlorophyll and photomorphogenesis,-to occur.
These screens should absorb maximally within the wavelength range 510 - 610nm and conseque~tly appear purple or violet Tn colour. Suitable materials for these screens are as described for the outer screen lZ
but there is no necessity to include UV absorbers and a suitable thickness is between 100 - 300 microns. However, included in these screens according to the present invention and to achieve the objective of absorbing light in the range 510 - 610 nm, a pigment SUC~l as CI pigment Violet 37 (carbazole dioxazine) must be included in the formulation of the said screens at a concentration of, for example, 0.05% w/w. This same pigment accomplishes the desired absorption of infra-red radiation of wavelengths between 800 nm and 2500 nm.
Preferrably, the pigment or dye used is heat and light stable. Care must be taken however when selecting d suitable pigment that little, if any, absorption occurs in the photosynthesis-essential ranges of 340 ~ 510 nm ~blue) and ~10 - 710 nm (red~. A combinatlon of -the previously described, UV absorbing, outer screen 12 and this second screen 14 (or set of screens 14~ absorbing green, yellow and infra-red light, provide the plants with selected solar protection. Experience has shown growth rates to be enhanced by up to three times the unprotected rate. This combination of screens has been sho~lln to encourage growth and development, especially of young plants.
In order to delay the flowering and ~ruiting of mature plants~
it -s necessary to provide, according to the invention, a third screen 16, comprising a set of at least one additional or alternative filter which will absorb those wavelengths of light known to be e~fective in lnducing flowering, i.e. red liyht in the range 610 - 710 nm.
Provision of this third screen filter 16, either in combination with the outer screen 12 and the second set oF screens 14 previously described, or in combination wlth just the outer screen 12, will permit synchronisation of plant growth and flowering. When flowering is required, the nurseryman has simply to remove this third screen filter 16 which absorbs light in the range 510 - 710 nm and replace it , .. . . . .
~ ~ ?
': -~ .
. .
- by the second screen 14 which transmits red light in the range 610 -710 nm. This third screen 16, in the preferred ~mbodiment, also absorbs infra-red radiation ~00 - 2500 nm). The objective of the third screen filter 16 is achieved by constructing a filter material as that previously described for the second set 14 but including in the formulation a pigment which will absorb substantially only red, green and yellow light in the range 510 - 710 nm, bu-t which will transmit light in the blue region of the spec~rum, i.e. between 340 and 500 nm. (See Fig. 1.) Such a filter will appear blue and a suitable pigment would be, for example, CI pigment blue 60 (Cromo-ptha, Blue A3R, Indanthone blue~. This same pigment accomplishes desired absorption of infra-red radiation of wavelengths in the range 8no nm and 2500 nm. Preferrably, the pigment or dye utilized is heat and light stable.
It is seen that the filter assembly 10 of the present invention functions as a growth regulator and promoter and that each of the three screens 12, 14, 16 individually contributes to the ideal photosynthetic and development needs of green plants. Because any one green plant does not use the same wavelengths of solar radiation at different times during its growth and development, the present invention provides a means whereby the nurseryman can choose which filtered light environment he thinks fit for his crop. This choice of environment is accomplished, in accoraance with the preferre~ enl~
bodirnent, by selectively interposing one or more of the filter screens I2, 14, 16 between the growing plants and sun.
Furthermore, in addition to its functions as a growtll reg-ulator and promoter, the present invention provides environmental control by eliminating those wave-lengths of light which cause overheating, dehydration and wilting. These energy-rich wave-lengths of light do their damage without contributing to the photosynthetic capacity of the plant, and, therefore, are of little benefit to the plant during the gro~th period in the natural environment. Elimi-nation of these rays permit unhindered growth during dayl~ght hours.
In order to capitalize on such growth stimulation, the plants su ~ 35 stimulated need~to operate their photosynthesis machinery to maximum ..... , .. -. - - ~ .
J `;f ~ ) 6 . . .
.: - .
.. ..
; 8 - advantage. Maximal photosynthesis is governed by several l;mit;ng factors including temperature (range 68 - 86 F), carbon dioxide concentra-tion (natural limit 0.03%, but ideally 10 - 15%), water content (plants must remain turgid~ and light intensity (ideally about 33X full sunlight intensity~. With respect to the current invention, in addition to protecting the plant from mutation and auxin photalysis, the apparatus is capable of controlling photo-synthetic rate by preventing overheating and, therefore, excess water loss, and providing the plant with only those wavelengths of light usable in photosynthesis, i.e. red and blue light, thus preventing the 3rowth and photosynthesis retardation effect o~ hi~h light intensity known as solarization. The apparatus brings maximum advantage to crops grown in hot, arid, high light intensity regions, e.g. Mediterranean and tropical climates, but considerable advantage should be accrued in temperate zones.
Whereas, 100% absorption of radiation within the stated wavelengths is an ideal embodiment of the present invention, the invention is practiced whenever there is absorption of radiation, in any amounts, of any wavelengths within the stated ranges of wave-lengths. Preferred embodiments of the present invention absorb biclogically signif;cant amounts of radiation of substantially all wavelengths within the stated ranges of wavelengths. One example of a filter assembly 10, in accordance with the present invention, i~cludes an outer screen 12 contain;ng an agent or agents which a~sorbs at least ~0~ of the UV radiation within the stated ran~es of wavelengths, 290 - 340 nm; and the second and third sets of screens 14, 16 contain agents which absorbs at least 50% of the respective green/yellow, red and infra-red radiation within the stated ranges of wavelengths (510 - 6~0 nm and ~00 - 2500 nm) and (610 - 710 nm and 80¢
- 2500 nm), respectively.
A filter assembly 10 in the form of a greenhouse 20 o~
conventional construction exemplifies a form in which the growth promotors may be supported and varied (See Figure 2). In such a greenllouse structure 20, the outer screen 12 o~ the filter assembly 10 fnrms the semi-permanent weather structure ~i.e. roof and sides) of .~.. ~, .. ~ .
.... .. . ' ~ :' :', . :
~, : ., .
.: .
' . ~
1 ~ ~J ~ G
the greenhouse. The second screen 14 and third screen 16 are mounted on rollers 22, 23 inside the greenhouse, between the outer screen 12 and the growing plants 30. Hoisting ropes 25, 26 are connected to the ends of the second screen 14 and third screen 16 and extended over pulleys 27, 28 at the peak 29 of the greenhouse 20. Thus, the second screen 14 and third screen 16 func-tion as blinds or curtains which the nurser~nan selectively interposes, alternately or together, between the outer screen 12 and the plants 30 by unrolling and rolling th screens 14, 16 using the ropes 25, 26 and rollers 22, 23. ~lowever, the scope of the present invention is not to be limited to the physical structure of a canopy or greenhouse.
In an alternate embodiment of the present invention, the filter assembly 10 comprises only two screens or sets of screens which are employed either together, separately, continuously or discon-tinuously between the radiation source and th~ plants. In such an embodiment, one' screen (i.e. the stationary screen~ possesses the absorption qualities of both outer screen 12 and second screen 14 as descrlbed above, and the other screen 16 (i.e. the retractable screen) absorbs, at least, radiation of wavelen~ths 610 - 710 nm.
Whereas, the present invention has been described in detail with- particular reference to preferred embod~ments thereof, it is understood that modifications and var;ations may be effected within the spirit and scope of the invention, as described before and as defined in the appended claims.
' '.
:
.
., , - , , . , . . , ~ - . .. .
~$T~OD AND APPARATUS FOR ~SB I~
PLANT GRO~T~ PROMOTIO~ A~D FLOWER D~V~LOPNB~T
.
Field of the Invention The curren~ invention relate~ to green plant growth promoting apparatu~ for use in maximizing the production of food crop ~nd flowering plants. It involves the provi~ion of ~everal ~pecially con~tituted thermopla~tic screen~ which offer ~ingley or in combi-nation ~hade from the auxin-destroying W radiation, the growth retarding photoJynthesi -unu~able green and infra-red light o~ tha sun, but the same time, will optimize the photo~ynthesi~ rate of the~
plant and encourage rapid growth. In addition, by c~reful ~election of the ~creen wavalength combination~, growth control and flowering may be managed~by those ~killed in the art of horticultureO
Background of the Invention Numerou attempts have been made to control the growth anviron ment of crop plants ~o as to improve yield and control tha timing o~
.
flowering. The~e include providing shelter from wind and heavy rain, as for example by errection of a "greenhou~e"r or by ~applying various chemicals which control growth by simulating the effects of the natural plant hormones. Inevitably there i~ a trade off, in :
~:
:: ~: ` :
~ . ~
1 ~0~
~ the ca~e of the greenhou~e, ~corching become~ a problem due to light focu~ing and the overheating created by the "greenhouse effect" of trapping radiant energy, wherea~ in the case of ah~mLcal application there are attendent problems as~ociated with re~idue~ both in the food crop and in the ~oil.
In order to under~tand fully the ~ignificance of the current invention it is fir~t necessary to review the constitution of terre~trial sunlight and to reali~e how plant~ exploit this radia-tion.
Terre~trial ~unlight ha~ been con~idered to consi~t of short-wave ultraviolet light (W -B, 290-320 nm), long-wave ultra-violet light ~W -A, 320-400 nm), vi~ible light (400-700nm) and infra-red light (700-2500 nm). On a clear day at ~ea level, the di~tribution of solar radiation i3 about 1 - 2 ~ W, 42% yi~ible and 57% infra--red. It i~ now generally recognized that the W -B radiation i~
dangeroue to all living cell~ leading to variou~ genotoxlc di~order~
by mutation and will cau~e, at high enough expo~ure level~, plant and animal cell death. W -A on the other hand i~ apparently harm-lea~ to animal ti~uee at natural radiation level~, but green plants have utilized the hormone-destroying effect of W -A light to control or regulate their growth, while protecting themselve~ a~ be~t they can from the dangerous UV-B rays with the pigment chlorophyll. It ha~ been known ~ince Darwin'~ time that plants produce a grow~h atimulating sub~tance (hormone or auxin) near their growth tips which diffu~e~ downward~ promoting further growth and that if completely ~haded, plant~ will grow, for a limited period, at about thrse time~ their illuminated rate (e.g. "forcing" of hyacynthe ox rhubarb ~hoot ~ and that the bending of plants towards light i~
cau~ed by the protection of the auxin from light denaturation on the dark~ide of plants grown on say a window ~ill. The ~pecLfic wave-lengths of light which denature auxins lie in the W-range, 290 - 340 nm and the photoly~is of such auxins can occur even at quite meager l~ght intensitie~. Prevention of photolyeis would render the plants continuou~ly ~en~itive to their own growth ~timulation.
In a similar manner, the induction of flower formation and develop-ment ha~ been determined to ~e influenced by the presence and the . ~,-- ~
,, , .:. . -: .
- ~ .
:' .
-` - 1 30~
- intensity of natural red light and conaequently flowering may be encouraged or delayed by manipulating the filtered environment ao as to provide or absorb thoae wavelength6 re~pon~ible. It i~ the purpo~e of thi3 invention to provide auch an environment or environ-ment3.
Summary of the Invention Briefly described, the pre~ent invention provide~ method and apparatua for encouraging maximal plant growth which method and apparatu~ comprise a light filter which preventa the natural decay of plant growth ~timulating material~ by ab~orption of W radiation while permitting photo0ynthesi~ to occur with blue light in the abaence of attendant heat generating and dehydrating radiations cauaed by green, yellow and infra-red light. Ths objective is made posaible according to the preferred embodiment of the invention by interpoaing a combination of filters made of ~olid material between the sun and the growing plant~ which block out radiation in thoae wavelength~ which are either physiologically harmful or which retard growth, but do not inhibit tho~e wavelengths which are nece~sary for photosynthesis, metaboli~m, differentiation and developmsnt.
The apparatus of the preferred embodiment of the present inven-tion comprise~ at leaat three filter~ employed either together, ~eparately, continuoualy, or diacontinuoualy, a~ a canopy ahove growing plant~.
It i~ recorded in the prior art that plants may be protected from aolar radiation by the provi~ion of a ~ingle filter which will ~imultaneou~ly and selectively abaorb UV and other radiations to protect plant~ from phy~iologlcally dangerous radiation (e.g~
wa~elengths of 300 - 330 nm, in Mutzha~, U.S. Patent 4,200,360);
however, the present invention allows the nur~aryman to vary the wavelength range and intenaity continuoualy, and during the growth of hi~ crop. The advantage here i~ that variou~ ~tage~ of plant development ~uch a~ flowering or fruiting may be modified and managed as well a~ the rate of the planta growth.
1 309~6.j - Other objects, features and advantages of the present inven-tion will become apparent upon reading and understanding this spec;f;cation in conjunction w;th the drawings.
Brief Description of the Drawings Fig. 1 is a graph representat;ng the selective absorption of wavelengths of sunlight, in accordance with a preferred embodiment of the present invention.
Fig. 2 is a cross-sectional, side view of an apparatus in accordance with the present invention, depicting a preferred embod-iment thereof.
Detailed Description of the Pre-ferred Embodiment Attention is now d;rected to more specif;c details' of pre-ferred embodiments of the method and apparatus of the present invent;on, with reference in greater detail to the drawings. In accordance with the present invention, a filter assembly 10 displays selective and variable radiation absorption features. In the preferred embodiment, the filter assembly 10 comprises three screens 12, 14, 16 (or three sets of screens 12, 14, 16).
The outer screen 12 of the three screens provides a mechanism by which the plants may be protected from harmful UV radiation. The outer screen 12 ls constituted so as to exclude from the grow~ng pl'ants, by absorption, that port.ion of UV-light known to cause DNA-~amage and denaturation of the naturally occuring plant growth promoters and auxins, but at the same t~me to transmit as ~uch whit light and i'nfra-red as practical. The wavelengths to be absorbed ~y this outer filter screen 12 lie, therefore, in the range 290 - 340 nm.
~See Fig. 1.) A suitable material for the outer screen 12 is any thermo-plastic material or acrylic resin in the form of either a thin film or - woven or laminated material but exhibiting the property of being transparent to solar energy wavelengths above 340 nm which are those associated with heat and photosynthesis. Suitable materials for the outer screen 12 when in film form are resins~of polyv;nyl chloride, : :
, -t ~ a6 polyolefins such as polyethylene and polypropylene, or acrylic resins such as polymethylmethacrylate. Copolymers such as polyeth-ylene/vinyl acetate and butadiene/styrene would also su~fice. Such resins may also include plasticisers such as phthallate esters. The outer screen 12 includes UV absorbers of various chemical types at such concentration to prov;de both longevity to the material and selective absorption of UV below 340 nm. It is preferrable that the outer screen 12 shall not have significant absorption, i.e. greater than 20~, of the natural wavelengths of light above 340 nm. In preferred embodiments of the present invention, the UV absorbers constitute between 0.01 and 0.5% by weight of the screen material. An example of a suitable UV absorber is (2-Chloroethyl) phosphate or acetophenone at a concentration of 0.1 w/w. Another example of d suitable absorber is 2[2 hydroxy - 5 menthylphenyl] ben~otriazole at a concentration of 0.05% w/w.
A preferred material for the outer screen is polyethylene Filn of thickness between 100 and 300 microns, for example 200 microns, and this may be a single film or a laminate form with a reinforcin~ nylon or polyester net to give greater physical strength. The resin should also he light stable and non-volatile at the reiatively h~yh temperatures used in blow forming, extrusion or callendering of lay-flat film. (i.e. about 150 C). It is also essentlal according to the invention that the outer film be not polished, and, preferrably, it should be finished as a matte or taffeta surface to provide a llght diffusion~effect. The growth of plants is enhanced by diffused rather than direct light.
The second screen 14, which is, preferrably, arranged be~ween the outer screen 12 and tt!e grow~ng plants, provides, in the preferred embodiment, protection from the unnecessary heating effect of light within the spectral wave1ength ranges 510 - 61Q nm and 8Q0 - 2500 nm.
(See Fig. 1.). In the preferred embodimen~, the second screen 14 is comprised of a~set of two screening fllms. These two films making up the second set-of screens are ideally identical to each other although not necessarily so. The ~obJective of this set is to provide the plants~ at the dlscretion of the nurseryman, with an optional single . : :
.
: .
, .
;
1 ~ ~' 9 ~
- or double degree of shade from heat (800 - 2500 nm~ and intense green - and yellow light tS10 - 610 nm) but permitting maximum photo-synthesis, synthesis of chlorophyll and photomorphogenesis,-to occur.
These screens should absorb maximally within the wavelength range 510 - 610nm and conseque~tly appear purple or violet Tn colour. Suitable materials for these screens are as described for the outer screen lZ
but there is no necessity to include UV absorbers and a suitable thickness is between 100 - 300 microns. However, included in these screens according to the present invention and to achieve the objective of absorbing light in the range 510 - 610 nm, a pigment SUC~l as CI pigment Violet 37 (carbazole dioxazine) must be included in the formulation of the said screens at a concentration of, for example, 0.05% w/w. This same pigment accomplishes the desired absorption of infra-red radiation of wavelengths between 800 nm and 2500 nm.
Preferrably, the pigment or dye used is heat and light stable. Care must be taken however when selecting d suitable pigment that little, if any, absorption occurs in the photosynthesis-essential ranges of 340 ~ 510 nm ~blue) and ~10 - 710 nm (red~. A combinatlon of -the previously described, UV absorbing, outer screen 12 and this second screen 14 (or set of screens 14~ absorbing green, yellow and infra-red light, provide the plants with selected solar protection. Experience has shown growth rates to be enhanced by up to three times the unprotected rate. This combination of screens has been sho~lln to encourage growth and development, especially of young plants.
In order to delay the flowering and ~ruiting of mature plants~
it -s necessary to provide, according to the invention, a third screen 16, comprising a set of at least one additional or alternative filter which will absorb those wavelengths of light known to be e~fective in lnducing flowering, i.e. red liyht in the range 610 - 710 nm.
Provision of this third screen filter 16, either in combination with the outer screen 12 and the second set oF screens 14 previously described, or in combination wlth just the outer screen 12, will permit synchronisation of plant growth and flowering. When flowering is required, the nurseryman has simply to remove this third screen filter 16 which absorbs light in the range 510 - 710 nm and replace it , .. . . . .
~ ~ ?
': -~ .
. .
- by the second screen 14 which transmits red light in the range 610 -710 nm. This third screen 16, in the preferred ~mbodiment, also absorbs infra-red radiation ~00 - 2500 nm). The objective of the third screen filter 16 is achieved by constructing a filter material as that previously described for the second set 14 but including in the formulation a pigment which will absorb substantially only red, green and yellow light in the range 510 - 710 nm, bu-t which will transmit light in the blue region of the spec~rum, i.e. between 340 and 500 nm. (See Fig. 1.) Such a filter will appear blue and a suitable pigment would be, for example, CI pigment blue 60 (Cromo-ptha, Blue A3R, Indanthone blue~. This same pigment accomplishes desired absorption of infra-red radiation of wavelengths in the range 8no nm and 2500 nm. Preferrably, the pigment or dye utilized is heat and light stable.
It is seen that the filter assembly 10 of the present invention functions as a growth regulator and promoter and that each of the three screens 12, 14, 16 individually contributes to the ideal photosynthetic and development needs of green plants. Because any one green plant does not use the same wavelengths of solar radiation at different times during its growth and development, the present invention provides a means whereby the nurseryman can choose which filtered light environment he thinks fit for his crop. This choice of environment is accomplished, in accoraance with the preferre~ enl~
bodirnent, by selectively interposing one or more of the filter screens I2, 14, 16 between the growing plants and sun.
Furthermore, in addition to its functions as a growtll reg-ulator and promoter, the present invention provides environmental control by eliminating those wave-lengths of light which cause overheating, dehydration and wilting. These energy-rich wave-lengths of light do their damage without contributing to the photosynthetic capacity of the plant, and, therefore, are of little benefit to the plant during the gro~th period in the natural environment. Elimi-nation of these rays permit unhindered growth during dayl~ght hours.
In order to capitalize on such growth stimulation, the plants su ~ 35 stimulated need~to operate their photosynthesis machinery to maximum ..... , .. -. - - ~ .
J `;f ~ ) 6 . . .
.: - .
.. ..
; 8 - advantage. Maximal photosynthesis is governed by several l;mit;ng factors including temperature (range 68 - 86 F), carbon dioxide concentra-tion (natural limit 0.03%, but ideally 10 - 15%), water content (plants must remain turgid~ and light intensity (ideally about 33X full sunlight intensity~. With respect to the current invention, in addition to protecting the plant from mutation and auxin photalysis, the apparatus is capable of controlling photo-synthetic rate by preventing overheating and, therefore, excess water loss, and providing the plant with only those wavelengths of light usable in photosynthesis, i.e. red and blue light, thus preventing the 3rowth and photosynthesis retardation effect o~ hi~h light intensity known as solarization. The apparatus brings maximum advantage to crops grown in hot, arid, high light intensity regions, e.g. Mediterranean and tropical climates, but considerable advantage should be accrued in temperate zones.
Whereas, 100% absorption of radiation within the stated wavelengths is an ideal embodiment of the present invention, the invention is practiced whenever there is absorption of radiation, in any amounts, of any wavelengths within the stated ranges of wave-lengths. Preferred embodiments of the present invention absorb biclogically signif;cant amounts of radiation of substantially all wavelengths within the stated ranges of wavelengths. One example of a filter assembly 10, in accordance with the present invention, i~cludes an outer screen 12 contain;ng an agent or agents which a~sorbs at least ~0~ of the UV radiation within the stated ran~es of wavelengths, 290 - 340 nm; and the second and third sets of screens 14, 16 contain agents which absorbs at least 50% of the respective green/yellow, red and infra-red radiation within the stated ranges of wavelengths (510 - 6~0 nm and ~00 - 2500 nm) and (610 - 710 nm and 80¢
- 2500 nm), respectively.
A filter assembly 10 in the form of a greenhouse 20 o~
conventional construction exemplifies a form in which the growth promotors may be supported and varied (See Figure 2). In such a greenllouse structure 20, the outer screen 12 o~ the filter assembly 10 fnrms the semi-permanent weather structure ~i.e. roof and sides) of .~.. ~, .. ~ .
.... .. . ' ~ :' :', . :
~, : ., .
.: .
' . ~
1 ~ ~J ~ G
the greenhouse. The second screen 14 and third screen 16 are mounted on rollers 22, 23 inside the greenhouse, between the outer screen 12 and the growing plants 30. Hoisting ropes 25, 26 are connected to the ends of the second screen 14 and third screen 16 and extended over pulleys 27, 28 at the peak 29 of the greenhouse 20. Thus, the second screen 14 and third screen 16 func-tion as blinds or curtains which the nurser~nan selectively interposes, alternately or together, between the outer screen 12 and the plants 30 by unrolling and rolling th screens 14, 16 using the ropes 25, 26 and rollers 22, 23. ~lowever, the scope of the present invention is not to be limited to the physical structure of a canopy or greenhouse.
In an alternate embodiment of the present invention, the filter assembly 10 comprises only two screens or sets of screens which are employed either together, separately, continuously or discon-tinuously between the radiation source and th~ plants. In such an embodiment, one' screen (i.e. the stationary screen~ possesses the absorption qualities of both outer screen 12 and second screen 14 as descrlbed above, and the other screen 16 (i.e. the retractable screen) absorbs, at least, radiation of wavelen~ths 610 - 710 nm.
Whereas, the present invention has been described in detail with- particular reference to preferred embod~ments thereof, it is understood that modifications and var;ations may be effected within the spirit and scope of the invention, as described before and as defined in the appended claims.
' '.
:
.
., , - , , . , . . , ~ - . .. .
Claims (27)
1. A sunscreening article for the growth promotion of green plants, comprising a plurality of individual plastic screen materials, a first of said screen materials comprising first agent means for absorbing at least 80% of the naturally occur-ing auxin inactivating W radiation of wavelengths in the range 290 - 340 nm, and a second of said screen materials comprising second agent means for preventing transmittal through said second of said screen materials of at least 50% of the non--photosynthetically useful and growth retarding green/yellow and infra-red light of wavelengths in the ranges 510 and 610 nm and 800 and 2500 nm, respectively.
2. An article according to Claim 1, wherein said screens are con-structed of flexible sheet or film, 100 - 300 microns in thick-ness.
3. An article according to Claim 2, wherein the material is a thermoplastic material.
4. An article according to Claim 3, wherein the plastic material is a resin chosen from the group of polyvinyl chloride, polyo-lefin, polyester and an acrylic resin.
5. An article according to Claim 1, wherein said first agent means forms between 0.01 and 0.5% by weight of the said first of said sheet materials.
6. An article according to Claim 2, wherein said first agent means forms between 0.01 and 0.5% by weight of the said first of said sheet materials.
7. An article according to Claim 3, wherein said first agent means forms between 0.01 and 0.5% by weight of the said first of said sheet materials.
8. An article according to Claim 4, wherein said first agent means forms between 0.01 and 0.5% by weight of the said first of said sheet materials.
9. An article according to Claim 19 wherein said second agent means comprises a heat and light stable dye or pigment.
10. An article according to Claim 1, wherein said plurality of screen materials comprises a third screen material comprising third agent means for preventing transmittal of at least 50%
of the available solar radiation within the range 610 - 710 nm.
of the available solar radiation within the range 610 - 710 nm.
11. An article according to Claim 10, wherein said third agent means forms less than 1% by weight of said third screen material.
12. An article according to Claim 10, wherein the third agent means comprises a heat and light stable dye or pigment.
13. An article according to Claim 11, wherein the third agent means comprises a heat and light stable dye or pigment.
14. An article according to Claim 10, wherein each screen of said plurality of screens can be used in isolation or in combination to create a desirable plant growth or plant development environment.
15. A sunscreening apparatus for growth promotion of green plants, comprising:
first screen means for absorbing at least some UV
radiations of at least some wavelengths in the range of 290 to 340 nm, said first screen means acting upon radiation between the source of radiation and the subject green plants;
a second screen means for absorbing at least some radiation of at least some wavelengths in the range of 510 to 610 nm and at least some radiation of wavelengths in the range of 710 to 2500 nm; and control means for selectively imposing the radiation absorbing action of said second screen means upon radiations between the source of radiation and the subject green plants.
first screen means for absorbing at least some UV
radiations of at least some wavelengths in the range of 290 to 340 nm, said first screen means acting upon radiation between the source of radiation and the subject green plants;
a second screen means for absorbing at least some radiation of at least some wavelengths in the range of 510 to 610 nm and at least some radiation of wavelengths in the range of 710 to 2500 nm; and control means for selectively imposing the radiation absorbing action of said second screen means upon radiations between the source of radiation and the subject green plants.
16. Apparatus of Claim 15, wherein said first screen means comprises a sheet of material displaying said absorption qualities and a frame member supporting said sheet of material in an orientation between the sun and the subject plants; and wherein said second screen means comprises a sheet material displaying said absorption qualities; and wherein said control means comprises a roller and rope assembly to which said sheet material of said second screen means is mounted, said roller and rope assembly and said mounted sheet material functioning as a curtain assembly whereby the sheet material is alter-nately pulled from the roller to a blocking position between the sun and the subject green plants and rolled back onto the roller out of the blocking position.
17. Apparatus of Claim 15, further comprising:
a third screen means for absorbing at least some radi-ation of at least some wavelengths in the range of 610 to 710 nm; and second control means for selectively imposing the radia-tion absorbing action of said third screen means between the source of radiation and the subject green plants.
a third screen means for absorbing at least some radi-ation of at least some wavelengths in the range of 610 to 710 nm; and second control means for selectively imposing the radia-tion absorbing action of said third screen means between the source of radiation and the subject green plants.
18. A sunscreening apparatus for growth promotion of green plants, comprising:
first screen means for absorbing at least some W
radiations of at least some wavelengths in the range of 290 to 340 nm, said first screen means acting upon radiation between the source of radiation and the subject green plants;
second screen means for absorbing at least some radiation of at least some wavelengths in the range of 610 to 710 nm; and control means for selectively imposing the radiation absorbing action of said second screen means upon radiations between the source of radiation and the subject green plants.
first screen means for absorbing at least some W
radiations of at least some wavelengths in the range of 290 to 340 nm, said first screen means acting upon radiation between the source of radiation and the subject green plants;
second screen means for absorbing at least some radiation of at least some wavelengths in the range of 610 to 710 nm; and control means for selectively imposing the radiation absorbing action of said second screen means upon radiations between the source of radiation and the subject green plants.
19. Apparatus of Claim 18, further comprising:
a third screen means for absorbing at least some radiation of at least some wavelengths in the range of 510 to 610 nm and at least some radiation of at least some wavelengths in the range of 800 to 2500 nm; and second control means for selectively imposing the radiation absorbing action of said third screen means between the source of radiation and the subject green plants.
a third screen means for absorbing at least some radiation of at least some wavelengths in the range of 510 to 610 nm and at least some radiation of at least some wavelengths in the range of 800 to 2500 nm; and second control means for selectively imposing the radiation absorbing action of said third screen means between the source of radiation and the subject green plants.
20. A sunscreening apparatus for growth promotion of green plants, comprising:
first screen means for absorbing at least some W
radiations of at least some wavelengths in the range of 290 to 340 nm, said first screen means acting upon radiation between the source of radiation and the subject green plants;
second screen means for absorbing at least some radiations of at least some wavelengths in the range of 610 to 710 nm;
at least one screen means for absorbing at least some radiation of at least some wavelengths in the range of 510 to 610 nm and at least some radiation of at least some wavelengths in the range of 800 to 2500 nm, said one screen means being said first screen means or said second screen means or a third screen means; and control means for selectively imposing the radiation absorbing action of said second screen means upon radiations between the source of radiation and the subject green plants.
first screen means for absorbing at least some W
radiations of at least some wavelengths in the range of 290 to 340 nm, said first screen means acting upon radiation between the source of radiation and the subject green plants;
second screen means for absorbing at least some radiations of at least some wavelengths in the range of 610 to 710 nm;
at least one screen means for absorbing at least some radiation of at least some wavelengths in the range of 510 to 610 nm and at least some radiation of at least some wavelengths in the range of 800 to 2500 nm, said one screen means being said first screen means or said second screen means or a third screen means; and control means for selectively imposing the radiation absorbing action of said second screen means upon radiations between the source of radiation and the subject green plants.
21. Apparatus of Claim 20, wherein said one screen means comprises a third screen means; and wherein said apparatus further comprises second control means for selectively imposing the radiation absorbing action of said third screen means between the source of radiation and the subject green plants.
22. Method of promoting growth of green plants, said method comprising the steps of:
continually preventing exposure of the green plants to at least some W radiation of at least some wavelengths in the range of 290 - 340 nm; and selectively preventing exposure of the green plants to at least some radiation of at least some wave lengths in the range of 510 - 710 nm and in the range of 800-2500 nm.
continually preventing exposure of the green plants to at least some W radiation of at least some wavelengths in the range of 290 - 340 nm; and selectively preventing exposure of the green plants to at least some radiation of at least some wave lengths in the range of 510 - 710 nm and in the range of 800-2500 nm.
23. Method of Claim 22, further comprising the step of selectively preventing exposure of the green plants to at least some radiation of at least some wavelengths in the range of 610-710 nm.
24. method of promoting growth of green plants, said method comprising the steps of:
continually preventing exposure of the green plants to at least some W radiation of at least some wavelengths in the range of 290-340 nm; and selectively preventing exposure of the green plants to at least some radiation of at least some wave-lengths in the range of 600-710 nm.
continually preventing exposure of the green plants to at least some W radiation of at least some wavelengths in the range of 290-340 nm; and selectively preventing exposure of the green plants to at least some radiation of at least some wave-lengths in the range of 600-710 nm.
25. Method of Claim 24, further comprising the step of selectively preventing exposure of the green plants to at least some radiation of wavelengths in the range of 510-710 nm.
26. Method of Claim 24, further comprising the step of continually preventing exposure of the green plants to at least some radiation of at least some wavelengths in the range of 510-710 nm.
27. A sunscreening apparatus for growth promotion of green plants, comprising a plurality of independent screens, each of said screens comprising means for absorb ing radiation in a wavelength range different from the wavelength ranges absorbed by each of the other said screens, and means for moving said screens of said plural-ity of screens relative to one another, wherein each screen is used selectively, either alone or in combination with another screen, to affect specific wavelength radiation levels in the growing environment, through manipulation of said screens.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US060,749 | 1979-07-25 | ||
| US6074987A | 1987-06-10 | 1987-06-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1309866C true CA1309866C (en) | 1992-11-10 |
Family
ID=22031512
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000549288A Expired - Lifetime CA1309866C (en) | 1987-06-10 | 1987-10-14 | Apparatus for use in plant growth promotion and flower development |
Country Status (2)
| Country | Link |
|---|---|
| AU (3) | AU639202B2 (en) |
| CA (1) | CA1309866C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2062791A1 (en) * | 1989-06-22 | 1990-12-23 | Lawrence J. Crowley | Solar blind for a greenhouse |
| WO1990015523A1 (en) * | 1989-06-22 | 1990-12-27 | Lawrence John Crowley | Solar blind for a greenhouse |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL52412A (en) * | 1977-06-29 | 1980-07-31 | Yeda Res & Dev | Polyethylene sheeting for covering tunnel shaped structures used in agriculture |
| DE3223445A1 (en) * | 1982-06-23 | 1983-12-29 | Maximilian Friedrich Prof. Dr.-Ing. 8000 München Mutzhas | RADIATION PROTECTION FILTER FOR PLANTS |
| SE8403986L (en) * | 1984-08-06 | 1986-02-07 | Svensson Ludvig Int | VEXTHUSGARDIN |
-
1987
- 1987-10-06 AU AU79405/87A patent/AU639202B2/en not_active Ceased
- 1987-10-14 CA CA000549288A patent/CA1309866C/en not_active Expired - Lifetime
-
1993
- 1993-10-22 AU AU50220/93A patent/AU5022093A/en not_active Abandoned
-
1996
- 1996-08-07 AU AU61957/96A patent/AU6195796A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| AU5022093A (en) | 1993-12-23 |
| AU6195796A (en) | 1996-10-10 |
| AU639202B2 (en) | 1993-07-22 |
| AU7940587A (en) | 1988-12-15 |
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