JP-7854667-B2 - Method for inducing flower buds in hydroponic strawberry cultivation

Inventors

• 竹葉 剛

Assignees

• 株式会社エコタイプ次世代植物工場
• 株式会社いちご研究室

Dates

Publication Date

20260507

Application Date

20241007

Claims (3)

1. The first step in cultivating strawberries is to use tap water until the cotyledons unfurl from the seeds, After the cotyledons have unfolded, a second step is to supply the strawberry seedlings with germination-stage nutrient solution while replenishing air, and then switch to supplying the strawberry seedlings with growth-stage nutrient solution. Next, a third step is to switch from the growth nutrient solution to tap water and supply the tap water to the strawberry seedlings while irradiating the strawberry seedlings with blue light having a peak wavelength in the 400-500 nm wavelength range for 2 to 4 days. Subsequently, the fourth step is to switch to a nutrient solution for growth and supply it to the strawberry seedlings, A method for inducing flower buds in hydroponic strawberry cultivation, characterized by comprising the following features.
2. The method for inducing flower buds in strawberry hydroponics according to claim 1, characterized in that, in the third step, near-ultraviolet light having a peak wavelength in the wavelength range of 300 to 400 nm is irradiated onto the strawberry seedlings along with the blue light.
3. The method for inducing flower buds in strawberry hydroponics according to claim 1 or 2, characterized in that, in the second step, the nutrient solution for germination has lower electrical conductivity than the nutrient solution for growth.

Description

This invention relates to a method for inducing flower bud formation in hydroponic cultivation of strawberries. Conventionally, plant cultivation has incorporated techniques that use artificial light to regulate (control or promote) plant growth. For example, Patent Document 1 describes a plant cultivation method in which growing plants are irradiated with artificial light consisting of blue light having a specific output wavelength and a specific photosynthetic photon flux density. This method is described as promoting flower bud formation in plants. Japanese Patent Publication No. 2001-258389 This table shows the effect of oxidative stress treatment on strawberry flower bud induction based on the number of days applied according to the first embodiment (results of Test 1).This table shows the effect of different nutrient solutions and light sources on inducing flower buds in strawberries during oxidative stress treatment according to the first embodiment (results of Test 2).This table shows the effect of different light intensities on inducing flower buds in strawberries during oxidative stress treatment according to the first embodiment (results of Test 3).This table shows the effect of oxidative stress treatment with near-ultraviolet light on strawberry flower bud induction (results of Test 4) according to the second embodiment.This table shows the effect of different nutrient solutions and light sources on inducing flower buds in strawberries during oxidative stress treatment with near-ultraviolet light according to the second embodiment (results of Test 5).This table shows the effect of different light intensities on inducing strawberry flower buds due to oxidative stress treatment with near-ultraviolet light according to the second embodiment (results of Test 6).This table shows the effect of oxidative stress treatment on Phalaenopsis orchids on flower bud induction (results of Test 7) based on the number of days of treatment according to the third embodiment.This table shows the effect of different nutrient solutions and light sources on inducing flower buds in Phalaenopsis orchids during oxidative stress treatment according to the third embodiment (results of Test 8).This table shows the effect of different light intensities on inducing flower bud formation in Phalaenopsis orchids during oxidative stress treatment according to the third embodiment (results of Test 9). The present invention relates to a plant cultivation method in which growing plants are irradiated with specific blue light and supplied with a nitrogen-free nutrient solution. When cultivated in this manner, blue light receptors within the plant receive the blue light, generating reactive oxygen species and inducing oxidative stress. This shifts the plant's growth from vegetative to reproductive growth, effectively stimulating the formation of substances that induce flower bud formation in the plant's leaves, thereby significantly promoting flower bud formation. Oxidative stress (hereinafter referred to as oxidative stress) is a condition that generates reactive oxygen species in living organisms. Conditions that induce oxidative stress include, for example, strong light, water stress (drought), carbon dioxide ( CO₂ ) deficiency, and low temperatures. There are two blue light receptors in plants: cryptochrome and phototropin. These absorb blue light and near-ultraviolet light, and are involved in promoting, controlling, and regulating flower bud formation in plants. Cryptochrome and phototropin absorb blue light in the 400-500 nm wavelength range and near-ultraviolet light in the 300-400 nm wavelength range. The peak wavelengths of light absorbed by cryptochrome and phototropin are 350 nm and 450 nm, respectively. Cryptochrome, in particular, plays a role in controlling flower bud formation. Substances that induce flower bud formation in plant leaves include, for example, the flowering hormone florigen. This invention relates to a cultivation method that effectively promotes flower bud formation by applying oxidative stress to growing plants. This method shifts the plant's growth from vegetative growth (where the plant grows larger for individual maintenance) to reproductive growth (where flower bud formation is promoted for species maintenance). This significantly accelerates flower bud formation in the plant. This invention describes the use of blue light of a specific wavelength in the cultivation method of the present invention. The light source used (blue light) must have an output wavelength peak that falls within the blue region of 400-500 nm. In the case of a light source with multiple output peaks or an irregular and broad spectral output pattern, it is acceptable if at least 50% of the output energy falls within the 400-500 nm wavelength range. From the viewpoint of effective flower bud induction, the spectral width of the peak wavelength in blue light is preferably 100 nm or less in half width at half maximum. In addition