SPECTRUM FOR PROMOTING GROWTH OF CANNABIS PLANTS

Abstract

A spectrum for promoting growth of cannabis plants. The spectrum comprises adding an irradiation of red light with peak wavelength at 655-690 nm into an indoor growing environment of cannabis to improve the levels of THC and CBD, the cannabinoid substances in cannabis. A ratio of photon number of the red light to the photon number of the entire light source is in a range from 40% to 70%. While maintaining the light intensity and other growth conditions, the yields and levels of THC and CBD, the cannabinoid substances in cannabis, can be increased by up to 32.48%.

Claims

1. A spectrum for promoting growth of cannabis plants, comprising: adding an irradiation of red light into an indoor growing environment of cannabis to improve accumulation of levels and yields of tetrahydrocannabinol (THC) and cannabidiol (CBD) in the cannabis; wherein the red light has a peak wavelength at 655-690 nm.

2. The spectrum of claim 1, the step of adding the irradiation of red light having the peak wavelength at 655-690 nm into an indoor growing environment of cannabis comprises a combined irradiation with other wavelength bands or an independent irradiation.

3. The spectrum of claim 2, wherein the in the combined irradiation with other wavelength bands, a ratio of the photon number of the red light to the photon number of the entire light source is 40-70%.

4. The spectrum of claim 3, wherein the ratio of the photon number of the red light to the photon number of the entire light source is 52-65%.

5. The spectrum of claim 2, wherein the light source used in the indoor growing environment of cannabis is a LED light source.

6. The spectrum of claim 4, wherein the LED light source is composed of 11.11-22.22% blue light, 40-70% red light, and 18.89-37.78% green light.

7. The spectrum of claim 4, wherein the blue light has a peak wavelength at 440-460 nm, the red light has a peak wavelength at 660-685 nm, and the green light has a peak wavelength at 505-526 nm.

8. The spectrum of claim 7, wherein the peak wavelength of the red light lies at 680 nm.

9. The spectrum of claim 6, wherein a ratio of the photon number of the blue light to the photon number of the red light is 1:4.

10. The spectrum of claim 3, wherein the LED light source is realized directly by a LED chip or by using the LED chip to excite a phosphor material.

11. The spectrum of claim 3, wherein an initial light intensity is 80 μmol/m.sup.2 s, a maximum light intensity is 1000 μmol/m.sup.2 s, and a photoperiod is 10-16 h/d.

12. The spectrum of claim 1, wherein the light source used in the indoor growing environment of cannabis is a LED light source.

13. The spectrum of claim 5, wherein a ratio of the red light in the LED light source is 52-65%.

14. The spectrum of claim 6, wherein a ratio of the red light in the LED light source is 52-65%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a spectral distribution diagram from a LED light source which is realized directly by a LED chip according to the present disclosure.

[0022] FIG. 2 is a spectral distribution diagram from a LED light source which is realized by using the LED chip to excite a phosphor material according to the present disclosure.

[0023] FIG. 3 is a spectral distribution diagram of red-light waveband from a LED light source which is realized by using the LED chip.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The present disclosure will be further described in detail below with reference to the drawings and specific embodiments, in order to better understand the objective, the technical solution and the advantage of the present disclosure. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the disclosure.

[0025] In the early stage of treatment to cannabis seedling, top branches of strong cannabis mother plant are selected as stem cuttings for plant cutting, or cannabis seeds are selected for sowing. The seedling stage is about 2 weeks. The cannabis seedlings with good rooting conditions are transplanted into the substrate or rock wool for the vegetative growth phase (the vegetative growth stage is about 4 weeks). Each rock wool block has 1 plant, and a density for the transplanted cannabis seedlings is 9 plants/m.sup.2. The plant is topped when the plant is about 20 cm high for triggering the growth of side branches. After the vegetative growth stage is finished, the plant is moved to the flower promotion stage for flower promotion treatment. The planting density of the plant in the flower promotion stage is 4-6 plants/m.sup.2. A distinguishment to the male and female flowers is required. The male flowers will be removed, and the female plants will be cultivated. The cultivation environment is set to have a day and night temperature at 24-26° C./21-22° C., humidity at 60-70%, CO.sub.2 concentration at 10000 ppm. Throughout the growth process, the LED light source directly realized by the LED chip is an artificial light source. The spectrum distribution diagram directly realized by the LED chip is shown in FIG. 1. The LED light source as shown provides a light environment for the growth of cannabis. An initial light intensity is set to 80-100 μmol/m.sup.2 s. As the plant height increases, the light intensity may reach 500-1000 μmol/m.sup.2 s in the late stage, and the photoperiod is 10-16 h/d. After 7-9 weeks of growth at the flowering stage, the accumulation of levels and yields of THC and CBD, the cannabinoid substances in plants, would be promoted.

Embodiment 1

[0026] Top branches of strong cannabis mother plant are selected as stem cuttings for plant cutting. After the plant cutting is finished (the plant cutting stage is about 2 weeks), the cannabis seedlings with good rooting conditions are transplanted into the rock wool or the substrate for the vegetative growth phase (the vegetative growth stage is about 4 weeks). Each rock wool block has 1 plant, and a density for the transplanted cannabis seedlings is 9 plants/m.sup.2. The plant is topped when the plant is about 20 cm high for triggering the growth of side branches. After the vegetative growth stage is finished, the plant is moved to the flower promotion stage for flower promotion treatment. The planting density of the plant in the flower promotion stage is 4 plants/m.sup.2. A distinguishment to the male and female flowers is required. The male flowers are removed, and the female plants is cultivated as before. The cultivation environment is set to have a day and night temperature at 24-26° C./21-22° C., humidity at 60-70%, CO.sub.2 concentration at 10000 ppm. Throughout the growth process, the LED light source is used to provide a light environment for the growth of the plant. An initial light intensity is set to 100 μmol/m.sup.2 s. As the plant height increases, the light intensity reaches 550 μmol/m.sup.2 s in the late stage, and the photoperiod is 12 h/d. Four control examples 1-4 are provided by using the blue LED light source having peak wavelength at 450 nm, the red LED light source having peak wavelength at 630 nm, the red LED light source having peak wavelength at 710 nm, and the red LED light source having peak wavelength at 730 nm, respectively. Six experimental examples 1-6 are provided by using the red LED light source having peak wavelength at 655 nm, 660 nm, 670 nm, 680 nm, 685 nm, 690 nm, respectively. When harvesting, the levels of CBD and THC in the cannabis plants are determined, and the dry weight of the inflorescence is collected at the same time to calculate the yields of CBD and THC per plant. The experimental results are shown in Table 1.

TABLE-US-00001 TABLE 1 Peak CBD THC Inflorescence CBD THC Ind. WL/ level level DW yield yield Irradiation nm (%) (%) g/plant g/plant g/plant Cont. Ex. 1 450 5.27 4.58 58.27 2.91 3.07 Cont. Ex. 2 630 5.42 4.60 83.14 4.51 3.82 Cont. Ex. 3 710 4.74 3.89 31.15 1.48 1.21 Cont. Ex. 4 730 4.52 3.57 24.84 1.12 0.89 Exptl. Ex. 1 655 5.69 4.80 83.09 4.74 3.98 Exptl. Ex. 2 660 5.77 4.87 82.45 4.76 4.02 Exptl. Ex. 3 670 6.05 5.04 83.02 5.02 4.18 Exptl. Ex. 4 680 6.14 5.24 83.78 5.14 4.39 Exptl. Ex. 5 685 6.06 5.11 84.67 5.13 4.33 Exptl. Ex. 6 690 5.80 4.86 79.57 4.62 3.87

[0027] The results suggest that, compared with control examples 1-4, the red light source in experimental examples 1-6 may greatly improve the levels of THC and CBD in the cannabis. Besides, compared with control example 1, the red light having peak wavelength at 680 nm is the most effective one which improves the levels of THC and CBD up to 16.51%. At the same time, the red light sources in experimental examples 1-6 are also good for the accumulation of inflorescence weight in the cannabis, and improving the yields of CBD and THC per plant.

Embodiment 2

[0028] Top branches of strong cannabis mother plant are selected as stem cuttings for plant cutting. After the plant cutting is finished (the plant cutting stage is about 2 weeks), the cannabis seedlings with good rooting conditions are transplanted into the rock wool or the substrate for the vegetative growth phase (the vegetative growth stage is about 4 weeks). Each rock wool block has 1 plant, and a density for the transplanted cannabis seedlings is 9 plants/m.sup.2. The plant is topped when the plant is about 20 cm high for triggering the growth of side branches. After the vegetative growth stage is finished, the plant is moved to the flower promotion stage for flower promotion treatment. The planting density of the plant in the flower promotion stage is 4 plants/m.sup.2. A distinguishment to the male and female flowers is required. The male flowers are removed, and the female plants is cultivated as before. The cultivation environment is set to have a day and night temperature at 24-26° C./21-22° C., humidity at 60-70%, CO.sub.2 concentration at 10000 ppm. Throughout the growth process, the LED light source is used to provide a light environment for the growth of the plant. An initial light intensity is set to 100 μmol/m.sup.2 s. As the plant height increases, the light intensity reaches 750 μmol/m.sup.2 s in the late stage, and the photoperiod is 12 h/d. Spectrum of combined light source are used in four control examples (Cont. Ex. 5-8 as shown in Table 2) and five experimental examples (Exptl. Ex. 7-11 as shown in Table 2). The peak wavelength of blue lights in the spectrum in both control examples and experimental examples lie at 450 nm, while the green light at 526 nm and the red light at 660 nm. A ratio of the green light to the blue light is fixed at 1.7. Different ratios of red light are provided in control examples 5-8 and experimental examples 7-11. When harvesting, the levels of THC and CBD in the cannabis are determined, and the dry weight of the inflorescence is collected at the same time to calculate the yields of THC and CBD per single plant. The experimental results are shown in Table 2.

TABLE-US-00002 TABLE 2 Spectral composition and Peak characteristics X1, X2, X3, Ratio of Ratio of Ratio of 400-499 500-599 600-780 nm nm nm photons photons photons to to to Biological indicators 380-780 380-780 380-780 Inflores- nm light nm light nm light CBD THC cence CBD THC source source source level level DW yield yield SN (%) (%) (%) (%) (%) g/plant g/plant g/plant Cont. 31.48 53.52 15 9.42 3.19 120.37 11.34 3.84 Ex. 5 Cont. 25.92 44.08 30 9.65 3.30 124.49 12.01 4.11 Ex. 6 Cont. 7.41 12.59 80 9.56 3.26 123.58 11.81 4.03 Ex. 7 Cont. 3.70 6.30 90 9.03 3.08 118.35 10.69 3.65 Ex. 8 Exptl. 22.22 37.78 40 10.89 3.61 138.26 15.06 4.99 Ex. 7 Exptl. 17.78 30.22 52 11.21 3.74 139.12 15.60 5.20 Ex. 8 Exptl. 15.56 26.44 58 11.41 3.82 143.25 16.34 5.47 Ex. 9 Exptl. 12.95 22.05 65 11.23 3.72 145.69 16.36 5.42 Ex. 10 Exptl. 11.11 18.89 70 10.72 3.56 140.21 15.03 4.99 Ex. 11

[0029] The results suggest that, compared with control examples 5-8, the experimental examples 7-11, which regulates the ratio of red light to the light source in a range of 40-70%, may greatly increase the levels of THC and CBD in the cannabis. Compared with control example 5, the levels of CBD and THC in experimental example 9 have been increased by 21.13% and 19.75%, respectively. At the same time, it is beneficial to improve the accumulation of inflorescence weight of cannabis and increase the yields of CBD and THC per plant by adding into the combination of blue light and green light with different ratios of red light.

Embodiment 3

[0030] Top branches of strong cannabis mother plant are selected as stem cuttings for plant cutting. After the plant cutting is finished (the plant cutting stage is about 2 weeks), the cannabis seedlings with good rooting conditions are transplanted into the rock wool or the substrate for the vegetative growth phase (the vegetative growth stage is about 4 weeks). Each rock wool block has 1 plant, and a density for the transplanted cannabis seedlings is 9 plants/m.sup.2. The plant is topped when the plant is about 20 cm high for triggering the growth of side branches. After the vegetative growth stage is finished, the plant is moved to the flower promotion stage for flower promotion treatment. The planting density of the plant in the flower promotion stage is 4 plants/m.sup.2. A distinguishment to the male and female flowers is required. The male flowers are removed, and the female plants is cultivated as before. The cultivation environment is set to have a day and night temperature at 24-26° C./21-22° C., humidity at 60-70%, CO.sub.2 concentration at 10000 ppm. Throughout the growth process, the LED light source is used to provide a light environment for the growth of the plant. An initial light intensity is set to 100 μmol/m.sup.2 s. As the plant height increases, the light intensity reaches 800 μmol/m.sup.2 s in the late stage, and the photoperiod is 12 h/d. A light source composed of 15% blue light, 25% green light and 60% red light is provided as the experimental light source. The blue light has a peak wavelength at 450 nm, the green light has a peak wavelength at 520 nm. On this basis, same ratio of red lights having different peak wavelengths are introduced to form control examples 9-11 and experimental examples 12-17 (as shown in Table 3). Additionally, the ratio of photon numbers between the red light (600-780 nm) and the blue light (400-499 nm) is 4:1. When harvesting, the levels of CBD and THC in the cannabis are determined, and the dry weight of the inflorescence is collected at the same time to calculate the yields of CBD and THC per plant. The experimental results are shown in Table 3.

TABLE-US-00003 TABLE 3 Spectral composition and Peak characteristics X1, X2, X3, Ratio of Ratio of Ratio of 400-499 500-599 600-780 nm nm nm photons photons photons to to to Biological indicators 380-780 380-780 380-780 Inflores- nm light nm light nm light Red CBD THC cence CBD THC source source source peak level level DW yield yield SN (%) (%) (%) WL (%) (%) g/plant g/plant g/plant Cont. 15 25 60 630 10.65 3.65 136.49 14.54 4.98 Ex. 9 Cont. 15 25 60 710 9.12 3.15 119.46 10.89 3.76 Ex. 10 Cont. 15 25 60 730 8.56 3.04 112.58 9.64 3.42 Ex. 11 Cont. 15 25 60 655 10.93 3.76 137.56 15.04 5.17 Ex. 12 Exptl. 15 25 60 660 11.01 3.80 136.25 15.00 5.18 Ex. 13 Exptl. 15 25 60 670 11.15 3.83 138.65 15.46 5.31 Ex. 14 Exptl. 15 25 60 680 11.34 3.91 139.24 15.79 5.44 Ex. 15 Exptl. 15 25 60 685 11.28 3.84 138.62 15.64 5.32 Ex. 16 Exptl. 15 25 60 690 10.98 3.78 139.57 15.32 5.28 Ex. 17

[0031] The results suggest that the obtained CBD and THC levels will be verified when the wavelength of red light is changed in the combined irradiation of red-blue-green light. Compared with control examples 9-11, the light sources in experimental examples 12-17 will improve, in a certain, the levels of THC and CBD in cannabis. Compared with control example 11, the light source in experimental example 15 improves the levels of CBD and THC up to 32.48% and 28.62%, respectively. At the same time, the addition of different ratios of red light will be beneficial to improve the accumulation of inflorescence weight of cannabis and increase the yields of CBD and THC per plant.

[0032] In summary, plants experience different light qualities through photoreceptors such as phytochromes and cryptochromes. The light absorbed by plants is concentrated in the visible part of the wavelength range of 380 to 780 nm. Red light accounts for about 85% of the absorbed physiological radiation light energy, and blue light accounts for about 12%. Therefore, the red light and blue light are essential light qualities for plant growth. The red light is mainly used to generate assimilate and accumulate biomass, and the blue light is a necessary condition for chlorophyll synthesis and chloroplast formation. The blue light affects the morphology of plants by controlling the stomata shape. At the same time, the blue light can also promote the accumulation of secondary metabolites in plants. Green light has always been a controversial light quality. Some scholars believe that it will inhibit the growth of plants, cause the plants to be short and reduce the yield of leafy vegetables. In the present disclosure, under the proof of the above-mentioned embodiments, it is beneficial for promoting accumulation of levels and yields of CBD and THC, the cannabinoid substances in cannabis, by adding an irradiation of red light with peak wavelength at 655-590 nm into the indoor growing environment of cannabis and maintaining the ratio of photon number of the red light (600-780 nm) to the photon number of the entire light source (380-780 nm) in a range of 40-70%. Therefore, different plants may have different optimal spectral formula during growth. The special spectral formula for cannabis as provided may enable the cannabis to accumulate and synthesize more THC and CBD, secondary metabolites in the cannabis, during the industrial cultivation.

[0033] It should be noted that the aforementioned embodiments are merely preferred embodiments of the present disclosure, and those embodiments are not to be deemed as limiting the scope of the invention. The scope of the disclosure should be limited by the by the scope of the claims. It will be apparent to those skilled in the art that other modifications and changes may be made without departing from the spirit and scope of the disclosure.