**4. Light quality in supplemental lighting in vegetable growing in completely controlled environment without daylight**

The suitable light quality in the greenhouses actually refers to the wavelengths (colors) that are efficient in inducing photosynthesis in plants and other growing processes. The light wavelengths are expressed in nanometers (nm). The visible spectrum wavelengths range from about 390 to 760 nm, which is only a small portion of the sunlight (radiation) electromagnetic spectrum. The visible light consists of: violet (380–430 nm), blue (430–500 nm), green (500–570 nm), yellow (570–590 nm), orange (590–630 nm), and red light (630–760 nm). The visible light range mostly corresponds to the Photosynthetically Active Radiation (PAR) from about 400 to 700 nm. The stated wavelengths have the right amount of energy for the biochemical processes, while their ratio in the available light is of crucial importance for determining the quality of light. About half of the sunlight energy participates in the photosynthetic processes. The rest of the energy comes from the sunlight short wavelength spectrum (UV—ultraviolet radiation) and sunlight long wavelength spectrum (IR—infrared radiation).

Blue section of the spectrum, also known as cool light, induces these wavelengths that encourage vegetative and leaf growth through strong root growth and intense photosynthesis.

Red section of the spectrum induces stem growth, tuber and bulb formation, flowering, and fruit production, and chlorophyll production.

Far-red light may cause plants to stretch (elongate) and may trigger flowering in some long-day plants. The plants are exposed more to the far-red than to the red light, which may become a problem with the greenhouse vegetable crop production due to possible shading (for whatever reason) or due to the reduced plants vegetative space.

Green and yellow sections of the spectrum that reach the plants are reflected, thus giving them their green color. Most of the absorbed sunlight wavelength belongs to the blue and red range of the spectrum. However, the recent studies have shown that plants do also absorb some green and yellow light, using it in the process of photosynthesis [4]. Generally, a light source that provides light in the entire visible range will better meet the needs of the plant.

For the time being, in the greenhouse vegetable crops growing practice, the high-pressure sodium (HPS) lamps are used, but also the LED lamps are gaining (**Figure 1**) an increasing significance in the plastic and glass greenhouses and in special chambers vegetable production. Also, in The Netherlands, the latest studies at the Wageningen and Maastricht universities research centers have their guidelines for greenhouse lighting with little or no natural daylight for special feature vegetable crops growing—increased vitamin C content, reduced nitrates content, increased sugar content, and higher yield.

With red, white, and far red light, it is possible to prepare ideal light recipe for particular vegetable species and improve process of photosynthesis and production of assimilates which empower plants. The most important is how plants response on various recipes. So, plants become more resistant toward unfavorable conditions for its growth and toward diseases. In case of adding combination of red, blue, and far red light to combination of red, white, and far red light, it is possible to reach more

**309**

plants species [4].

**Figure 1.**

**installation**

supplemental lighting.

*Urban Horticulture and Its Modernization by Using LED Lightning in Indoors Vegetable…*

than 20 various recipes of plants lightning. Then, in combination with CO2, temperature, various substrates, and humidity, it is possible to obtain ideal light recipes for optimal plant growth. Such kind of experiments could be expensive, but with

According to Goldammer [5] besides optimal light recipe for the particular crops, it is necessary to understand process of plant growth in order to apply it in the practice, and to do optimizing all the other parameters like climate, irrigation, nutrition, software, sensors, seeds, substrates. Actually, all parameters in indoor plant environment are gathering via sensors and special software in computer where it is possible to control and manage them. The right interaction between all mentioned parameters and growing crops give the best results in indoor completely controlled environment in vegetable crop production. Vegetable crops are kept out of bugs and pests, taste optimized, could be produced all year around in natural way, with less waste in fresh food production, generally. On that way, food is clean,

The most suitable for urban horticulture are usage of NFT systems, combined NFT system, and rockwool cubes, and LEDs above the crops, or LEDs could be used between plants rows grown on rockwool substrates. Which type of crops growing and type of LEDs which would be applied depend on morphology of

Generally, nowadays, trend in horticulture is vegetable production under the LED lightning because of numerous advantages in comparison with other types of

**5. Supplemental carbon dioxide in vegetable production in completely controlled environment and in the greenhouses with LED lightning** 

Carbon dioxide (CO2) gas is the essential component for the process of photosynthesis, and the plants uptake it through their stomata on the leaves.

good plan and expertise (know-how) costs could be lower.

*LED lightning in between rows of cucumber plants with daylight in modern glasshouse.*

healthy, and nutritious, and production is efficient.

*DOI: http://dx.doi.org/10.5772/intechopen.90723*

*Urban Horticulture and Its Modernization by Using LED Lightning in Indoors Vegetable… DOI: http://dx.doi.org/10.5772/intechopen.90723*

**Figure 1.** *LED lightning in between rows of cucumber plants with daylight in modern glasshouse.*

than 20 various recipes of plants lightning. Then, in combination with CO2, temperature, various substrates, and humidity, it is possible to obtain ideal light recipes for optimal plant growth. Such kind of experiments could be expensive, but with good plan and expertise (know-how) costs could be lower.

According to Goldammer [5] besides optimal light recipe for the particular crops, it is necessary to understand process of plant growth in order to apply it in the practice, and to do optimizing all the other parameters like climate, irrigation, nutrition, software, sensors, seeds, substrates. Actually, all parameters in indoor plant environment are gathering via sensors and special software in computer where it is possible to control and manage them. The right interaction between all mentioned parameters and growing crops give the best results in indoor completely controlled environment in vegetable crop production. Vegetable crops are kept out of bugs and pests, taste optimized, could be produced all year around in natural way, with less waste in fresh food production, generally. On that way, food is clean, healthy, and nutritious, and production is efficient.

The most suitable for urban horticulture are usage of NFT systems, combined NFT system, and rockwool cubes, and LEDs above the crops, or LEDs could be used between plants rows grown on rockwool substrates. Which type of crops growing and type of LEDs which would be applied depend on morphology of plants species [4].

Generally, nowadays, trend in horticulture is vegetable production under the LED lightning because of numerous advantages in comparison with other types of supplemental lighting.
